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  • Brassica napus
  • Phosphorus
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  • 1995-1999  (3.039)
  • 1960-1964
  • 1955-1959  (807)
  • 1950-1954  (286)
  • 1930-1934  (175)
Jahr
Schlagwörter
  • 1
    Digitale Medien
    Digitale Medien
    Mycorrhizal infection and ageing affect element localization in short roots of Norway spruce [Picea abies (L.) Karst.] (1995)
    Springer
    Mycorrhiza 5 (1995), S. 417-422 
    Details
    ISSN: 1432-1890
    Schlagwort(e): Key words Calcium ; Iron ; Lead ; Phosphorus ; Short roots ; X-ray microanalysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  Norway spruce [Picea abies (L.) Karst.] seedlings, nonmycorrhizal of mycorrhizal with Laccaria laccata or Paxillus involutus were grown in a quartz sand-nutrient solution system for 6 months and then treated with 5 μM Pb for 4 days. Element contents of cortex cell wall of young, medium and old short roots were determined by X-ray microanalysis of longitudinal thin sections. The Pb content was influenced neither by age nor by the distance from the root tip (up to 1.7 mm) but was significantly lower in the P. involutus mycorrhizae than in the L. laccata mycorrhizae or in nonmycorrhizal short roots. In the P. involutus mycorrhizae, the P content of the cortex cell walls was twice as high in young mycorrhizae than in old mycorrhizae. In the nonmycorrhizal short roots and the L. laccata mycorrhizae, P content was influenced neither by age nor by distance from the root tip. The Ca and Fe contents of the cortex cell walls increased with age in the nonmycorrhizal short roots and the mycorrhizae. It is concluded that the element content of the cortex cell walls of short roots is strongly influenced by age, while the distance from the root tip seems to be of minor importance.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213442
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  • 2
    Digitale Medien
    Digitale Medien
    Effect of onion (Allium cepa) root exudates on the hyphal growth of Gigaspora margarita (1995)
    Springer
    Mycorrhiza 6 (1995), S. 57-59 
    Details
    ISSN: 1432-1890
    Schlagwort(e): Key words Arbuscular mycorrhizae ; Gigaspora margarita ; Allium cepa ; Phosphorus ; Root exudate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  The effect of root exudates from onions differing in P status on spore germination and hyphal growth of arbuscular mycorrhizal fungi was investigated. Onion (Allium cepa) was grown in solution culture at different phosphorus concentrations (0, 0.1, 1.0, 8.0 and 24.0 mg P l–1) and root exudates were collected. When spores of the arbuscular mycorrhizal fungus, Gigaspora margarita were incubated with these root exudates, spore germination was only slightly affected but hyphal growth was greatly affected, particularly with exudates from P-deficient plants. This suggests that the P nutrition of host plants influences the composition of root exudates and thereby the hyphal growth of arbuscular mycorrhizal fungi.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s005720050106
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  • 3
    Digitale Medien
    Digitale Medien
    Effects of vesicular-arbuscular mycorrhiza on Tagetes erecta and Zinnia elegans (1995)
    Springer
    Mycorrhiza 6 (1995), S. 61-64 
    Details
    ISSN: 1432-1890
    Schlagwort(e): Key words Glomus etunicatum ; Flowering ; VAM ; Phosphorus ; Potassium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  Seeds of Tagetes erecta and Zinnia elegans were planted in soil inoculated with the vesicular-arbuscular mycorrhizal fungus Glomus etunicatum. This procedure produced positive effects on both Tagetes and Zinnia compared with the control: faster flowering and an increased number of flowers. Shoot height, shoot and root dry weights and percentage infected root length were also measured. The reactions of these plants to mycorrhizal infection were shown to be independent of changes in the phosphorus, potassium and sodium contents of the plants.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s005720050107
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  • 4
    Digitale Medien
    Digitale Medien
    Mycorrhizal infection and ageing affect element localization in short roots of Norway spruce [Picea abies (L) Karst.] (1995)
    Springer
    Mycorrhiza 5 (1995), S. 417-422 
    Details
    ISSN: 1432-1890
    Schlagwort(e): Calcium ; Iron ; Lead ; Phosphorus ; Short roots ; X-ray microanalysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Norway spruce [Picea abies (L.) Karst.] seedlings, nonmycorrhizal of mycorrhizal with Laccaria laccata or Paxillus involutus were grown in a quartz sand-nutrient solution system for 6 months and then treated with 5 μM Pb for 4 days. Element contents of cortex cell wall of young, medium and old short roots were determined by X-ray microanalysis of longitudinal thin sections. The Pb content was influenced neither by age nor by the distance from the root tip (up to 1.7 mm) but was significantly lower in the P. involutus mycorrhizae than in the L. laccata mycorrhizae or in nonmycorrhizal short roots. In the P. involutus mycorrhizae, the P content of the cortex cell walls was twice as high in young mycorrhizae than in old mycorrhizae. In the nonmycorrhizal short roots and the L. laccata mycorrhizae, P content was influenced neither by age nor by distance from the root tip. The Ca and Fe contents of the cortex cell walls increased with age in the nonmycorrhizal short roots and the mycorrhizae. It is concluded that the element content of the cortex cell walls of short roots is strongly influenced by age, while the distance from the root tip seems to be of minor importance.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213442
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  • 5
    Digitale Medien
    Digitale Medien
    Impact of vesicular arbuscular mycorrhizal fungi andRhizobium on the growth and P, N and Fe uptake by faba-bean (1995)
    Springer
    Nutrient cycling in agroecosystems 43 (1995), S. 43-48 
    Details
    ISSN: 1573-0867
    Schlagwort(e): Phosphorus ; nitrogen ; iron ; VAM ; Rhizobium ; faba-bean
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The effect of rhizobial inoculation, vesicular arbuscular mycorrhizal (VAM) fungi on the growth, P, N and Fe uptake by faba-bean plants (Vicia faba L.V. Giza 2) grown in virgin sandy soil, treated with super or rock-P were studied under green-house conditions. The earthern pots received a half of the recommended rate of P either as single super phosphate or rock-P in the rate of 20 mg P/kg soil, and calcium ammonium nitrate was added in the rate of 10 mg N/kg soil. Iron was applied in two levels 0 and 5 mg Fe/kg soil, in the form of iron sulphate (FeSO4·7H2O). Dry matter yield, as well as P, N and Fe-uptake were determined. Nodule numbers and their dry weights, spore numbers and mycorrhizal root infection were determined. Results indicated that, fungal infection and rhizobial inoculation either alone or in combination increased dry matter yield as compared to uninoculated plants, whereas the percentages increase in dry matter were 34, 26 and 57% in case of super-P application, while they were 56, 47 and 89% in case of rock-P when inoculated withRhizobium, VAM and dual inoculation respectively. Also P, N and Fe uptake were significantly increased due to inoculation, and dual inoculation resulted the highest effect. Generally, inoculation withRhizobium and/or mycorrhizae can remove the deficient effect of P and Fe on N2-fixation and plant growth in the soil of low nutrients content.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00747681
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  • 6
    Digitale Medien
    Digitale Medien
    DNA sequences of the two homoeologous SLR1 genes of Brassica napus cv Westar (1995)
    Springer
    Sexual plant reproduction 8 (1995), S. 254-255 
    Details
    ISSN: 1432-2145
    Schlagwort(e): Brassica napus ; SLR1 genes ; Pollination ; Stigma-specific
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00228946
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  • 7
    Digitale Medien
    Digitale Medien
    Synthesis and phosphorylation of pollen proteins during the pollen-stigma interaction in self-compatible Brassica napus L. and self-incompatible Brassica oleracea L. (1995)
    Springer
    Sexual plant reproduction 8 (1995), S. 345-353 
    Details
    ISSN: 1432-2145
    Schlagwort(e): Brassica napus ; Brassica oleracea ; Pollen-stigma interaction ; Pollen protein synthesis ; Pollen protein phosphorylation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A technique is described which permits the in vivo study of protein synthesis and phosphorylation in the pollen of Brassica spp. during the early stages of the pollen-stigma interaction. In Brassica napus and B. oleracea, compatible pollination is followed by a dramatic activation of protein synthesis in the pollen involving the synthesis of approximately 40 proteins. After incompatible pollinations in B. oleracea, virtually no newly synthesised polypeptides were detected in the pollen except for a small group of high molecular weight proteins which were not normally synthesised during compatible pollinations. Both compatible and incompatible pollinations were followed by the appearance of newly phosphorylated proteins in the pollen; these fell into four distinct groups. In B. oleracea, the number of phosphorylated proteins and the degree of phosphorylation of individual proteins within the four groups differed between compatible and incompatible pollinations. One group of phosphorylated proteins appeared to correspond with the small group of high molecular weight polypeptides which were synthesised in pollen after incompatible pollinations. These findings are discussed in the perspective of cell signalling during the pollen-stigma interaction in Brassica and also in terms of their possible implication in sporophytic self-incompatibility.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00243202
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  • 8
    Digitale Medien
    Digitale Medien
    Ab initio molecular dynamics — Applications to the molecular and solid state physics of phosphorus (1995)
    Springer
    Theoretical chemistry accounts 91 (1995), S. 237-248 
    Details
    ISSN: 1432-2234
    Schlagwort(e): Ab initio molecular dynamics ; Phosphorus ; Clusters ; Liquid phoshorus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Summary We review combined molecular dynamics (MD) and density functional (DF) simulations and their applicability in chemistry and physics. This method (also termedab initio MD, “first principles” MD or “Car-Parrinello” method) exhibits characteristic strengths and weaknesses, and we demonstrate both in a set of typical example applications from molecular physics (phosphorus clusters) and solid state physics/chemistry (liquid phosphorus). Dynamical, finite temperature, simulations deriving interatomic forces from state-of-the-art density functional calculations represent a substantial advance over both (i) traditional pointwise total energy and electronic band structure calculations and (ii) classical MD simulations with empirical or semi-empirical forces, and have already yielded qualitatively new insights in several fields.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01114990
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  • 9
    Digitale Medien
    Digitale Medien
    Antennal perception of oilseed rape,Brassica napus (Brassicaceae), volatiles by the cabbage seed weevilCeutorhynchus assimilis (Coleoptera, Curculionidae) (1995)
    Springer
    Journal of chemical ecology 21 (1995), S. 1649-1664 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Ceutorhynchus assimilis ; cabbage seed weevil ; Coleoptera ; Curculionidae ; Brassica napus ; oilseed rape ; volatiles ; isothiocyanates ; EAG ; SCR ; GC-EAG ; GC-SCR
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The response of theCeutorhynchus assimilis antenna to volatiles in air entrainment-derived extracts of oilseed rape,Brassica napus, was studied using coupled gas chromatography (GC)-electroantennography (EAG) and coupled GC-single cell recording (SCR). By means of these techniques and coupled gas chromatography-mass spectrometry (GC-MS), 25 active compounds were identified, including isoprenoids and compounds derived from fatty acids and amino acids. Some of the latter, the isothiocyanates and goitrin, and probably indole and benzyl cyanide, are catabolites of glucosinolates. The electrophysiological activity of the identified compounds was confirmed by EAG using a physiologically discriminating dose, and by SCR studies. The importance of the combined use of the EAG and SCR techniques was demonstrated, since specific olfactory cells were located for five compounds that did not elicit significant EAG responses. The majority of the olfactory cells from which single cell recordings were obtained showed very high specificity, and in numerous recordings there were consistent pairings of specific cell types.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02033667
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  • 10
    Digitale Medien
    Digitale Medien
    Combined effects of nitrogen and elevated CO2 on soils from controlled environment studies (1995)
    Springer
    Water, air & soil pollution 85 (1995), S. 1551-1556 
    Details
    ISSN: 1573-2932
    Schlagwort(e): Nitrogen ; Carbon dioxide ; Phosphorus ; Calcium ; Potassium ; Magnesium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Energietechnik
    Notizen: Abstract This paper describes the effects of elevated CO2 and N fertilization on soils planted with ponderosa pine (Pinus ponderosa) seedlings in short-term greenhouse studies. The high degree of homogeneity in the soils used allowed sensitive evaluation of soil changes in response to treatments. Elevated CO2 had no detectable effect upon soil N availability, but both CO2 and N fertilization caused significant changes in soil available (NH4F/HCl-extractable) P. Some of these changes could be accounted for by plant uptake, some were apparently due to differences in P immobilization (biotic or abiotic). N fertilization caused reductions in exchangeable K, Ca and Mg which could not be accounted for by plant uptake and were probably due to increased leaching. None of the reductions in soil available nutrients observed were of sufficient magnitude to cause nutrient deficiencies over the approximate 1-year duration of these studies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00477201
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  • 11
    Digitale Medien
    Digitale Medien
    HeteroTOCSY-based experiments for measuring heteronuclear relaxation in nucleic acids and proteins (1995)
    Springer
    Journal of biomolecular NMR 6 (1995), S. 180-188 
    Details
    ISSN: 1573-5001
    Schlagwort(e): DNA ; Phosphorus ; Cadmium ; Heteronuclear ; Relaxation ; Hetero TOCSY ; Cytosine arabinoside ; LAC9
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Summary While both 31P and 113Cd are present at locations of interest in many different macromolecular systems, heteronuclear-detected relaxation measurements on these nuclei have been restrained by limitations in either resolution or signal-to-noise ratio. We have developed hetero TOCSY-based methods to overcome both of these problems. Two-dimensional versions of these experiments were utilized to measure 31P T1 and T2 values in DNA oligonucleotides; the additional resolution offered by a second dimension allowed determination of these values for most of the 31P resonances in a DNA dodecamer. The results from the experiments indicated that there was little significant variation in T1 values for the different phosphates in the DNA dodecamer; however, the T2 values showed a clear pattern, with lower values in the interior of the sequence than at the ends of the helix. Furthermore, a significant correlation between 31P chemical shifts and T2 values was observed. One-dimensional, frequency-selective versions of these experiments were also developed for use on systems containing a smaller number of heteronuclear spins. These methods were applied to investigate the heteronuclear relaxation properties of 113Cd in 113Cd2LAC9(61), a Cys6Zn2 DNA-binding domain. Data from the experiments confirm biochemical evidence that more significant differences occur in the metal-protein interactions between the two metal-binding sites than has been previously identified for proteins containing this motif.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00211782
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  • 12
    Digitale Medien
    Digitale Medien
    A cDNA clone encoding an IgE-binding protein from Brassica anther has significant sequence similarity to Ca2+-binding proteins (1995)
    Springer
    Plant molecular biology 29 (1995), S. 1157-1165 
    Details
    ISSN: 1573-5028
    Schlagwort(e): Anther ; Brassica napus ; Brassica rapa ; Ca2+-binding protein ; cDNA cloning ; pollen allergen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Thirteen cDNA clones encoding IgE-binding proteins were isolated from expression libraries of anthers of Brassica rapa L. and B. napus L. using serum IgE from a patient who was specifically allergic to Brassica pollen. These clones were divided into two groups, I and II, based on the sequence similarity. All the group I cDNAs predicted the same protein of 79 amino acids, while the group II predicted a protein of 83 amino acids with microheterogeneity. Both of the deduced amino acid sequences contained two regions with sequence similarity to Ca2+-binding sites of Ca2+-binding proteins such as calmodulin. However flanking sequences were distinct from that of calmodulin or other Ca2+-binding proteins. RNA-gel blot analysis showed the genes of group I and II were preferentially expressed in anthers at the later developmental stage and in mature pollen. The recombinant proteins produced in Escherichia coli was recognized in immunoblot analysis by the IgE of a Brassica pollen allergic patient, but not by the IgE of a non-allergic patient. The cDNA clones reported here, therefore, represent pollen allergens of Brassica species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00020459
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  • 13
    Digitale Medien
    Digitale Medien
    Characterization of a low-temperature-induced cDNA from winter Brassica napus encoding the 70 kDa subunit of tonoplast ATPase (1995)
    Springer
    Plant molecular biology 28 (1995), S. 943-948 
    Details
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; cold acclimation ; cold-regulated genes ; tonoplast ATPase ; abscisic acid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A cDNA clone, pBN59, was isolated by differential screening of a cDNA library of winter Brassica napus during cold acclimation. Nucleotide sequence of BN59 was found to be homologous to that encoding the 70 kDa subunit of the vacuolar H+-ATPase in plants. Transcripts hybridizing to BN59 accumulated during exposure to low temperatures and to the exogenous application of abscisic acid (ABA). Western blot analyses also indicated an increase in the 70 kDa subunit during cold acclimation. The accumulation of an endomembrane H+-ATPase is consistent with the observation of osmotic adjustment, increases in endogenous ABA and the proliferation of endomembranes during cold acclimation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00042078
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  • 14
    Digitale Medien
    Digitale Medien
    Molecular cloning and expression of a turgor-responsive gene in Brassica napus (1995)
    Springer
    Plant molecular biology 27 (1995), S. 541-551 
    Details
    ISSN: 1573-5028
    Schlagwort(e): abscisic acid ; Brassica napus ; cold ; drought ; salinity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract During droughting plants activate a number of genes involved in adaptation to water stress. We have isolated one such gene, btg-26, from Brassica napus. Expression of btg-26 is induced in leaf tissue within 72 h of withholding water. At 81% relative water content (RWC), when the plant is just beginning to show signs of wilting, expression is already increased six-fold over levels found in leaf tissue from fully hydrated plants. btg-26 expression reaches a maximum eleven-fold induction at 63% RWC, then transcript levels decrease as RWC continues to drop. btg-26 is also activated in plants exposed to high salinity, low temperature, heat shock and the plant hormone abscisic acid. Analysis of the deduced amino acid sequence revealed similarity to the dehydrogenase family of enzymes. These results suggest that btg-26 encodes a protein whose function may be required early during general osmotic stress in some unknown adaptive metabolic pathway.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00019320
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  • 15
    Digitale Medien
    Digitale Medien
    Classification and expression of a family of cyclin gene homologues in Brassica napus (1995)
    Springer
    Plant molecular biology 27 (1995), S. 263-275 
    Details
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; cell division cycle ; cyclin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In order to investigate the role of cell division in plant development, we isolated several plant genes which encode homologues of animal and yeast cell cycle regulators known as cyclins. Through the use of degenerate primers and the polymerase chain reaction (PCR) we isolated a Brassica sequence which showed homology to the ‘cyclin box’ functional domain found within cyclin proteins. Southern blot analysis indicated that Brassica napus has a large number of genes containing cyclin box-related sequences. This was further supported by the isolation of cyclin box sequences from six different genomic clones. In addition, we have isolated two different cyclin cDNA clones, BnCYC1 and BnCYC2, from a Brassica napus shoot apical cDNA library. Both of the cDNA clones contain a ‘destruction box’ regulatory domain similar to animal mitotic cyclins. Northern blot analysis using BnCYC2 shows mRNA levels which correlate well with the level of cell division in various tissues. Messenger RNA abundance was highest in 1–3 mm leaves, root tips and shoot apices. The mRNA detected using BnCYC1 was restricted to young leaves and the shoot apex, suggesting divergent, organ-specific roles for cyclin family members. The results demonstrate that the plant cyclin gene family is more extensive than previously demonstrated and consists of genes expressed in all dividing tissues as well as a subset of developmentally specific members.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00020182
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  • 16
    Digitale Medien
    Digitale Medien
    Characterization of a new myrosinase in Brassica napus (1995)
    Springer
    Plant molecular biology 27 (1995), S. 863-874 
    Details
    ISSN: 1573-5028
    Schlagwort(e): Brassica napus ; glucosinolates ; myrosinase ; thioglucoside glucohydrolase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A full-length cDNA clone defining the new myrosinase gene family MC in Brassica napus was isolated and sequenced. Southern hybridization showed that the MC family probably consists of 3 or 4 genes in B. napus. MC genes are expressed in the developing seed, but not in the vegetative tissues investigated. In situ hybridizations to developing seeds showed that the MC genes are expressed in the myrosin cells of the embryo axis and the cotyledons. Complexes with myrosinase and myrosinase-binding protein (MBP) were purified and characterized. Sequencing of peptides from myrosinases occurring in the complexes showed that the 70 kDa myrosinase is encoded by the MC genes, whereas the 65 kDa myrosinase is encoded by the MB genes. This is in contrast to the 75 kDa myrosinase which occurs in free form and is encoded by the MA genes. Deglycosylations of the myrosinase complexes and the free myrosinase showed that the molecular sizes of the myrosinases could be reduced significantly by this treatment, and that the size differences between the different myrosinases are mainly due to differences in glycosylation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00037015
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  • 17
    Digitale Medien
    Digitale Medien
    Improvement in the quality of seed storage protein by transformation of Brassica napus with an antisense gene for cruciferin (1995)
    Springer
    Theoretical and applied genetics 91 (1995), S. 627-631 
    Details
    ISSN: 1432-2242
    Schlagwort(e): Brassica napus ; Cruciferin ; Antisense ; Seed storage protein ; Amino-acid composition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The levels of certain essential amino acids, in particular cysteine, lysine and methionine, in the seed storage protein of a commercial spring variety of rape, Brassica napus, have been increased by the introduction of an antisense gene for cruciferin, which is the most abundant storage protein in rapeseed. The antisense construct contained part of the cruA gene in an inverted orientation, and the gene was driven by the 5′ flanking region of the gene for napin such that antisense RNA was expressed in a seed-specific manner. The construct was introduced by Agrobacterium-mediated gene transfer. In self-pollinated seeds (T1 seeds) of transgenic plants there was a reduction in the levels of the α1β1 and α2/3β2/3 subunits of cruciferin, whereas the level of the α4β4 subunit was unchanged. The total protein and lipid contents of transgenic seeds did not differ significantly from that of normal seeds. Seeds with reduced amounts of cruciferin accumulated higher amounts of napin than non-transformed seeds, but the level of oleosin was unaffected. Amino-acid analysis of the seed storage protein revealed that T1 seeds with reduced amounts of cruciferin contained higher relative levels of three essential amino acids, namely, lysine, methionine and cysteine, with increases of 10%, 8% and 32% over the respective levels in non-transgenic seeds (B. napus cv Westar).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00223289
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  • 18
    Digitale Medien
    Digitale Medien
    RFLP mapping of quantitative trait loci controlling seed aliphatic-glucosinolate content in oilseed rape (Brassica napus L) (1995)
    Springer
    Theoretical and applied genetics 91 (1995), S. 802-808 
    Details
    ISSN: 1432-2242
    Schlagwort(e): Aliphatic glucosinolates ; Brassica napus ; Restriction fragment length polymorphism (RFLP) ; Genomic mapping
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We report the RFLP mapping of quantitative trait loci (QTLs) which regulate the total seed aliphaticglucosinolate content in Brassica napus L. A population of 99 F1-derived doubled-haploid (DH) recombinant lines from a cross between the cultivars Stellar (low-glucosinolate) and Major (high-glucosinolate) was used for singlemarker analysis and the interval mapping of QTLs associated with total seed glucosinolates. Two major loci, GSL-1 and GSL-2, with the largest influence on total seed aliphatic-glucosinolates, were mapped onto LG 20 and LG 1, respectively. Three loci with smaller effects, GSL-3, GSL-4 and GSL-5, were tentatively mapped to LG 18, LG 4 and LG 13, respectively. The QTLs acted in an additive manner and accounted for 71 % of the variation in total seed glucosinolates, with GSL-1 and GSL-2 accounting for 33% and 17%, respectively. The recombinant population had aliphatic-glucosinolate levels of between 6 and 160 μmoles per g-1 dry wt of seed. Transgressive segregation for high seed glucosinolate content was apparent in 25 individuals. These phenotypes possessed Stellar alleles at GSL-3 and Major alleles at the four other GSL loci demonstrating that low-glucosinolate genotypes (i.e. Stellar) may possess alleles for high glucosinolates which are only expressed in particular genetic backgrounds. Gsl-elong and Gsl-alk, loci which regulate the ratio of individual aliphatic glucosinolates, were also mapped. Gsl-elong-1 and Gsl-elong-2, which control elongation of the α-amino-acid precursors, mapped to LG 18 and LG 20 and were coincident with GSL loci which regulate total seed aliphatic glucosinolates. A third tentative QTL, which regulates side-chain elongation, was tentatively mapped to LG 12. Gsl-alk, which regulates H3CS-removal and side-chain de-saturation, mapped to LG 20.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220963
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  • 19
    Digitale Medien
    Digitale Medien
    Mapping loci controlling vernalization requirement and flowering time in Brassica napus (1995)
    Springer
    Theoretical and applied genetics 90 (1995), S. 727-732 
    Details
    ISSN: 1432-2242
    Schlagwort(e): Brassica napus ; Restriction fragment length polymorphism ; Vernalization ; Days-to-flowering ; Linkage map
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Rapeseed cultivars (Brassica napus L.) can be classified into annual and biennial groups according to their requirement for vernalization in order to induce flowering. The genetic control of these phenotypic differences is not well understood, but this information could be valuable for the design of breeding approaches to accelerate rapeseed improvement. In order to map loci controlling this variation, a doubled haploid population, derived from a cross between annual and biennial cultivars, was evaluated for vernalization requirement and days-to-flowering in a replicated field experiment using three treatments: no vernalization, 4 weeks of vernalization and 8 weeks of vernalization. A linkage map of 132 RFLP loci was used to locate loci controlling these traits. Marker segregation in one region of linkage group 9 was strongly associated with the annual/biennial growth habit in the unvernalized treatment and with days-to-flowering in all three treatments. Two other regions with smaller effects on days-to-flowering were also identified.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00222140
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  • 20
    Digitale Medien
    Digitale Medien
    Molecular tagging of the dwarf BREIZH (Bzh) gene in Brassica napus (1995)
    Springer
    Theoretical and applied genetics 91 (1995), S. 756-761 
    Details
    ISSN: 1432-2242
    Schlagwort(e): Brassica napus ; Dwarfing gene ; Bulked segregant analysis ; Near-isogenic lines ; Genetic mapping ; RAPD markers ; RFLP markers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We mapped the dwarf Bzh gene in B. napus with RAPD and RFLP markers. Research of the linked markers proceeded in two ways: a random approach through the construction of a detailed genetic map and targeting of the dwarf gene using both near-isogenic lines (NILs) and the bulked segregant analysis (BSA) method. The BSA approach was the most efficient in finding DNA markers linked to Bzh, whereas the efficiency of the NILs approach was limited by a too great similarity of the genetic background between the dwarf donor parent and the recurrent lines. Eight RAPD markers were identified as linked to Bzh, the closest being at 0.8±0.7 cM. The random genetic mapping approach added markers and extended the linkage group containing Bzh. This work represents the first step towards a better understanding of the dwarf mutation, the development of marker-assisted selection, and the cloning of the underlying gene responsible for dwarfing.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220955
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  • 21
    Digitale Medien
    Digitale Medien
    Synthesis of high erucic acid rapeseed (Brassica napus L.) somatic hybrids with improved agronomic characters (1995)
    Springer
    Theoretical and applied genetics 91 (1995), S. 1129-1136 
    Details
    ISSN: 1432-2242
    Schlagwort(e): Brassica napus ; somatic hybrids ; protoplast fusion ; Erucic acid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Novel Brassica napus somatic hybrids have been created through protoplast fusion of B. oleracea var. botrytis and B. rapa var. oleifera genotypes selected for high erucic acid (22:1) content in the seed oil. Fifty amphidiploids (aacc) and one putative hexaploid (aacccc) hybrid were recovered in one fusion experiment. Conversely, only one amphidiploid and numerous regenerates with higher DNA contents were produced in a similar fusion using a different B. rapa partner. Hybridity was confirmed by morphology, isozyme expression, flow cytometry, and DNA hybridization. Analysis of organellar DNA revealed a distinct bias toward the inheritance of chloroplasts from the B. rapa (aa) genome. All amphidiploids set self-pollinated seed. A erucic acid content as high as 57.4% was found in the seed oil of one regenerated plant. Fatty acid composition was stable in the R1 generation and was coupled with increased female fertility. Other novel agronomic characters in the hybrids recovered include large seed size, lodging resistance, and non-shattering seed pods.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00223931
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  • 22
    Digitale Medien
    Digitale Medien
    Study of microspore-culture responsiveness in oilseed rape (Brassica napus L.) by comparative mapping of a F2 population and two microspore-derived populations (1995)
    Springer
    Theoretical and applied genetics 91 (1995), S. 841-847 
    Details
    ISSN: 1432-2242
    Schlagwort(e): Microspore culture ; Responsiveness genes ; Comparative mapping ; Doubled haploid populations ; Brassica napus ; Segregation distortion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract RFLP segregation analyses were performed on a F2 population and two F1 microspore-derived populations from the same cross between a microspore culture-responsive parent (‘Topas’) and a non-responsive parent (‘Westar’). A total of 145 loci were detected with 87 cDNA clones. Eighty-two markers were common across all three populations. A total of 66 markers was assembled into 18 linkage groups and 16 markers remained unlinked. Segregation distortions were significant for 29% of the markers in the F2 population and 23% and 31% in microspore-derived populations M3 and M5, respectively. An equivalent number of markers showed biased segregation towards each parental allele in the F2 population while more markers showed a significant deviation from the expected Mendelian ratio towards the responsive parent in both microspore-derived populations. Different subsets of markers showed segregation distortions in the three populations indicating that the selective pressures leading to microsporederived plants are different from those acting during selfing of the F1. Linkage groups 1 and 18 were identified as putative chromosomal regions associated with microspore-culture responsiveness.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00223890
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  • 23
    Digitale Medien
    Digitale Medien
    RFLP mapping of resistance to the blackleg disease [causal agent, Leptosphaeria maculans (Desm.) Ces. et de Not.] in canola (Brassica napus L.) (1995)
    Springer
    Theoretical and applied genetics 91 (1995), S. 1190-1194 
    Details
    ISSN: 1432-2242
    Schlagwort(e): Brassica napus ; DNA mapping ; Leptosphaeria maculans ; Quantitative trait loci ; Restriction fragment length polymorphism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We report the tagging of genes involved in blackleg resistance, present in the French cultivar Crésor of B. napus, with RFLP markers. A total of 218 cDNA probes were tested on the parental cultivars Crésor (resistant) and Westar (susceptible), and 141 polymorphic markers were used in a segregating population composed of 98 doubled-haploid lines (DH). A genetic map from this cross was constructed with 175 RFLP markers and allowed us to scan for specific chromosomal associations between response to blackleg infection and RFLP markers. Canola residues infested with virulent strains of Leptosphaeria maculans were used as inoculum and a suspension of pycnidiospores from cultures of L. maculans, including the highly virulent isolate Leroy, was sprayed to increase disease pressure. QTL mapping suggested that a single chromosomal region was responsible for resistance in each of the four environments tested. This QTL accounted for a high proportion of the variation of blackleg reaction in each of the assays. A second QTL, responsible for a small proportion of the variation of blackleg reaction, was present in one of four year-site assays. A Mendelian approach, using blackleg disease ratings for classifying DH lines as resistant or susceptible, also allowed us to map resistance in the region of the highly significant LOD scores observed in each environment by interval mapping. Results strongly support the presence of a single major gene, named LmFr 1 controlling adult plant resistance to blackleg in spring oil-seed rape cultivar Crésor. Several RFLP markers were found associated with LmFr 1.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220928
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  • 24
    Digitale Medien
    Digitale Medien
    Analysis of self-incompatibility interactions in 30 resynthesized Brassica napus lines. I. Fluorescence microscopic studies (1995)
    Springer
    Theoretical and applied genetics 90 (1995), S. 665-670 
    Details
    ISSN: 1432-2242
    Schlagwort(e): Brassica napus ; Self-incompatibility S-allele ; Interspecific hybridization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Thirty Brassica napus lines have been developed through interspecific hybridization of B. oleracea and B. campestris lines with defined S-allele constitutions. These lines, which represent 29 different S-allele combinations, were tested in a diallel of test-pollinations to determine the activity of the introgressed S-alleles and intergenomic dominance relationships. Some consistent trends were observed: B. oleracea S-alleles high in the dominance series (e.g. S8, S14, S29) were always active in the resynthesized B. napus lines, whereas recessive S-alleles (S2, S15) lost their activity in some test combinations. The B. campestris S-alleles were active in most cases, although 2 alleles were partially inactivated by the recessive B. oleracea allele S15.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00222131
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  • 25
    Digitale Medien
    Digitale Medien
    Comparison of rapeseed cultivars and resynthesized lines based on allozyme and RFLP markers (1995)
    Springer
    Theoretical and applied genetics 91 (1995), S. 62-67 
    Details
    ISSN: 1432-2242
    Schlagwort(e): Brassica napus ; Resynthesized rapeseed ; Genetic distance ; Isozymes ; Allozymes ; RFLP
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract It has frequently been suggested to use the resynthesis of rapeseed (Brassica napus) from B. campestris and B. oleracea to broaden its genetic base. The objective of the present study is twofold: (1) to compare the genetic variation within resynthesized rapeseed with a world-wide collection of oilseed rape cultivars, and (2) to compare genetic distances estimated from RFLP markers with distances estimated from a relatively small number of allozyme markers. We investigated 17 resynthesized lines and 24 rapeseed cultivars. Genetic distances were estimated either based on the electrophoresis of seven allozymes, with a total of 38 different bands, or based on RFLP data of 51 probe/enzyme combinations, with a total of 355 different bands. The results of allozyme and RFLP analyses agreed reasonably well. Genetic distances, estimated from two independent sets of RFLP data with 25 and 26 probe/enzyme combinations respectively, were highly correlated; hence about 50 RFLP markers are sufficient to characterize rapeseed material with a large genetic diversity. The cultivars were clustered into three groups: (1) spring rapeseed of European and Northern American origin, (2) winter rapeseed of European and Northern American origin, and (3) rapeseed of Asian origin. Several of the resynthesized rapeseed lines were similar to European winter rapeseed cultivars, whereas others had quite unique patterns. It is concluded, that resynthesized rapeseed is a valuable source for broadening the genetic variation in present breeding material of Brassica napus. However, different lines differ widely in their suitability for this purpose.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220859
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  • 26
    Digitale Medien
    Digitale Medien
    Mapping the genome of rapeseed (Brassica napus L.). II. Localization of genes controlling erucic acid synthesis and seed oil content (1995)
    Springer
    Theoretical and applied genetics 91 (1995), S. 972-977 
    Details
    ISSN: 1432-2242
    Schlagwort(e): Brassica napus ; RFLP ; Erucic acid genes ; Oil content ; QTL mapping
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A F1 microspore-derived DH population, previously used for the development of a rapeseed RFLP map, was analysed for the distribution of erucic acid and seed oil content. A clear three-class segregation for erucic acid content could be observed and the two erucic acid genes of rapeseed were mapped to two different linkage groups on the RFLP map. Although the parents of the segregating DH population showed no significant difference in seed oil content, in the DH population a transgressive segregation in oil content was observed. The segregation closely followed a normal distribution, characteristic of a quantitative trait. Using the program MAPMAKER/QTL, three QTLs for seed oil content could be mapped on three different linkage groups. The additive effects of these QTLs explain about 51% of the phenotypic variation observed for this trait in the DH population. Two of the QTLs for oil content showed a close association in location to the two erucic acid genes, indicating a direct effect of the erucic acid genes on oil content.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00223908
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  • 27
    Digitale Medien
    Digitale Medien
    Cell cycle dependent distribution of phosphorylated proteins in microspores and pollen ofBrassica napus L., detected by the monoclonal antibody MPM-2 (1995)
    Springer
    Protoplasma 187 (1995), S. 117-126 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Androgenesis ; Brassica napus ; Microspore culture ; Pollen embryogenesis ; Protein phosphorylation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The monoclonal antibody MPM-2, which interacts with a mitosis-specific phosphorylated epitope, has been used to study phosphorylation of proteins in microspores and pollen ofBrassica napus. One- (1-D) and two-dimensional (2-D) immunoblots revealed that MPM-2 recognized a family of phosphorylated proteins in freshly isolated microspores and pollen. The same set of phosphorylated proteins was found after 8 h of culture at embryogenie (32 °C) and non-embryogenic (18 °C) conditions. Two major spots were observed on 2-D immunoblots, one of which (Mr≈75 kDa, pI≈5.1) co-localized with the 70 kDa heat shock protein. Immunolabelling of sectioned microspores and pollen showed that MPM-2 reactive epitopes were predominantly observed in the nucleoplasm from G1 until G2-phase, and in the cytoplasm during mitosis. This may be due to a cell cycle related translocation of phosphoproteins from the nucleus to the cytoplasm, or alternate phosphorylation and dephosphorylation in nucleus and cytoplasm. Detectability of epitopes on sections depended on the embedding procedure. Cryo processing revealed epitope reactivity in all stages of the cell cycle whereas polyethylene glycol embedded material showed no labelling in the cytoplasm during mitosis. Processing might reduce the antigenicity of cytoplasmic MPM-2 detectable proteins, probably due to dephosphorylation. The MPM-2 detectable epitope was observed in all cells investigated, irrespective of culture conditions, and its intracellular distribution depended on the cell cycle stage and was not related to the developmental fate of the microspores and pollen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01280239
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  • 28
    Digitale Medien
    Digitale Medien
    Cellular changes during heat shock induction and embryo development of cultured microspores ofBrassica napus cv. Topas (1995)
    Springer
    Protoplasma 185 (1995), S. 106-112 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Brassica napus ; Embryogenesis ; Heat shock ; Induction ; Microspore embryogenesis ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Brassica napus cv. Topas microspores, isolated and cultured near the time of the first pollen mitosis and subjected to a heat treatment of 24 h, can be induced to develop into haploid embryos. This is a study of microspore structure during induction and embryo determination. Early during the 32.5 °C incubation period the nucleus moved away from the edge of the cell, and granules, 30 to 60 nm in diameter, appeared in the mitochondria and as a cluster in the cytoplasm. Cells divided symmetrically and at the end of the heat treatment, acquired the features of induced bicellular structures described previously. The features persisted as the cells divided randomly within the exine for 4–7 days following heat induction. Multicellular structures released from the exine underwent periclinal divisions resulting in protoderm differentiation of the globular embryo, thus determining embryo development. The cytoplasm of early heart-stage embryos contains abundant polyribosomes. Non-embryogenic development was indicated by large accumulations of starch and/or lipid and thickened cell walls or an unorganized pattern of cell division following release of the multicellular structures from the exine. Embryogenesis is discussed in terms of induction, embryo determination and development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01272758
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  • 29
    Digitale Medien
    Digitale Medien
    Short-term accumulation of organic matter and nutrient contents in two dry sand ecosystems (1995)
    Springer
    Plant ecology 120 (1995), S. 161-171 
    Details
    ISSN: 1573-5052
    Schlagwort(e): Biomass ; Heathland ; Inland dunes ; Nitrogen ; Organic matter ; Phosphorus ; Production
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Inland dunes in northwestern Europe support a number of dry vegetation types. These ecosystems are poor in nutrients and it has been suggested that accumulation of nutrients triggers succession in such systems. We studied the accumulation of organic matter and N and P over a 30 months period in two adjacent ecosystems, the Spergulo-Corynephoretum and the Genisto-Callunetum. Amounts of plant matter and soil organic matter significantly accumulated during the sampling period in the Genisto-Callunetum but not in the Spergulo-Corynephoretum. While nutrient concentrations of live and dead phytomass in the Spergulo-Corynephoretum were significantly higher than in the Genisto-Callunetum, total nutrient contents in the systems showed the opposite pattern. N and P concentrations in litter were relatively high compared with the other fractions of plant matter and the amount of N significantly increased in both ecosystems during the sampling period. Soil moisture contents showed a seasonal pattern. It was highest in the top soil layer and higher in the Genisto-Callunetum than in the Spergulo-Corynephoretum. The estimated annual increase of total N in these two ecosystems was consistent with rates of atmospheric N deposition (wet fall + dry fall) measured in comparable Dutch sites.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00034345
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  • 30
    Digitale Medien
    Digitale Medien
    Isolation of homozygous transgenicBrassica napus lines carrying a seed-specific chimeric 2S albumin gene and determination of linkage relationships (1995)
    Springer
    Molecular breeding 1 (1995), S. 143-153 
    Details
    ISSN: 1572-9788
    Schlagwort(e): 2S Albumin ; Brassica napus ; chimeric seed storage protein gene ; co-transformation ; T-DNA insertion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract UsingAgrobacterium tumefaciens-mediated gene transfer, 14 T0Brassica napus plants carrying one of three chimeric 2S albumin seed protein genes were obtained after co-transformation with theneo gene. Plants were made homozygous using either cell haploid culture or, for single-copy plants, traditional crossing methods. Sixty-five percent of kanamycin-resistant plants contained at least one copy of the seed protein gene, and multiple copies were usually at a single locus. In the majority of cases, at least one copy of theneo gene was linked to an introduced 2S albumin gene, demonstrating that co-transformation is not a reliable way to obtain lines without the marker gene linked to the gene of interest. In 3 T0 plants sequences derived from beyond the left border of the vector were integrated in the plant genome, in two cases partially rearranged, confirming that T-DNA insertion is not always precise. Procedures for efficiently determining this are described. This work highlights the extra steps needed to prepare transgenic lines for field studies and potential further breeding.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01249699
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  • 31
    Digitale Medien
    Digitale Medien
    Replacement of fish meal in salmonid diets by soya meal reduces phosphorus excretion (1995)
    Springer
    Aquaculture international 3 (1995), S. 265-268 
    Details
    ISSN: 1573-143X
    Schlagwort(e): Atlantic salmon (Salmo salar) ; Effluent ; Feed composition ; Phosphorus ; Protein sources
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00118109
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  • 32
    Digitale Medien
    Digitale Medien
    Variability in phytic acid content and protein digestibility of grain legumes (1995)
    Springer
    Plant foods for human nutrition 47 (1995), S. 163-172 
    Details
    ISSN: 1573-9104
    Schlagwort(e): Grain legumes ; Phytic acid ; Phosphorus ; Protein ; Protein digestibility ; Seed size
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Several genotypes, number given within parenthesis, of chickpea, pigeonpea, urd bean, mung bean and soybean, differing in seed characteristics were analyzed for phytic acid, in vitro protein digestibility (IVPD), protein, total phosphorus, and seed size. Phytic acid contents and IVPD values differed significantly among and within these species. Phytic acid content (mg/g) was the highest in soybean (36.4) followed by urd bean (13.7), pigeonpea (12.7), mung bean (12.0) chickpea (9.6). On an average, phytic acid constituted 78.2 percent of the total phosphorus content and this percentage figure was the highest in soybean and the lowest in mung bean. In vitro protein digestibility (IVPD) of pigeonpea and chickpea genotypes varied from 60.4 to 74.4 percent and 65.3 to 79.4 percent, respectively. The IVPD values of genotypes of mung bean, urd bean and soybean ranged from 67.2 to 72.2 percent, 55.7 to 63.3 percent and 62.7 to 71.6 percent, respectively. There was a significant negative correlation between phytic acid and IVPD of these genotypes. Phytic acid was significantly and positively correlated with protein but the magnitude of correlation was very low in chickpea and pigeonpea. Results indicate that the genotypes of pulses with low phytic acid content could be identified and used in breeding program to improve their nutritive value and utilization.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01089266
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  • 33
    Digitale Medien
    Digitale Medien
    The K/Na and Ca/Na ratios and rapeseed yield, under soil salinity or sodicity (1995)
    Springer
    Plant and soil 175 (1995), S. 251-255 
    Details
    ISSN: 1573-5036
    Schlagwort(e): Brassica napus ; Ca/Na ratio ; K/Na ratio ; rapeseed yield ; salinity ; sodicity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Rapeseed (Brassica napus) is a crop relatively tolerant to salt and sodium. Our objective was to study the interactions between Na, K and Ca and their relationship with its yield under the isolated effects of soil salinity or sodicity. Two experiments were carried out using pots filled with the Ah horizon of a Typic Natraquoll. There were three salinity levels (2.3 dS m-1; 6.0 dS m-1 and 10.0 dS m-1) and three sodicity levels, expressed as sodium adsorption ratios (SAR: 12; 27 and 44). The soil was kept near field capacity. As soil salinity increased, the K/Na and Ca/Na ratios in the tissues decreased markedly but yields and aerial biomass production were not affected. As soil SAR value increased, the K/Na and Ca/Na ratios in plants and K-Na and Ca-Na selectivities decreased. Plants could not maintain their Ca concentration in soil with a high SAR. The grain yield and biomass production diminished significantly in the highest SAR treatment. Our results are consistent with those showing detrimental osmotic effects of salts in Brassica napus. Conversely, under sodicity, the K/Na and Ca/Na ratios in plant tissues decreased considerably, in accordance with grain and biomass production. These results show that the effects of sodicity are different from those of salinity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00011361
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  • 34
    Digitale Medien
    Digitale Medien
    Nitrogen incorporation and remobilization in different shoot components of field-grown winter oilseed rape (Brassica napus L.) as affected by rate of nitrogen application and irrigation (1995)
    Springer
    Plant and soil 177 (1995), S. 255-264 
    Details
    ISSN: 1573-5036
    Schlagwort(e): Brassica napus ; canola ; nitrogen nutrition ; irrigation ; 15N isotope ; oilseed rape
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The seasonal course of nitrogen uptake, incorporation and remobilization in different shoot components of winter oilseed rape (Brassica napus L.) was studied under field conditions including three rates of 15N labelled nitrogen application (0, 100 or 200 kg N ha-1) and two irrigation treatments (rainfed or watered at a deficit of 20 mm). The total amount of irrigation water applied was 260 mm, split over 13 occasions in a 7-week-period ranging from 1 week before onset of flowering until 4 weeks after flowering. Nitrogen application and irrigation increased plant growth and nitrogen accumulation. Irrespective of N and irrigation treatment more than 50% of total shoot N was present in the stem when flowering started. At the end of flowering, pod walls were the main N store containing about 30–40% of shoot N. The quantities of N remobilized from stems and pod walls amounted in all treatments to about 70% of the N present in these organs at mid-flowering. At harvest, stem and pod walls each contained about 10% of total shoot N, the remaining 80% being incorporated into seeds. The main component contributing to the response of seed N accumulation to nitrogen application and irrigation was pods in axillary racemes. Up to 20 kg N ha-1, corresponding to about 10% of final shoot N content, was lost from the plants by leaf drop. Irrigation increased the recovery at harvest of applied N from 30% to about 50%, while the level of N application did not affect the N recovery. 15N labelled (fertilizer derived) nitrogen constituted a greater proportion of the N content in old leaves than in young leaves and increased with age in the former, but not in the latter. Relative to soil N, fertilizer derived N also contributed more to the N content of vegetative than to that of reproductive shoot components. Small net changes in shoot N content after flowering reflected a balance between N import and export, leading to continuous dilution of 15N labelled N with unlabelled N.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00010132
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  • 35
    Digitale Medien
    Digitale Medien
    Studies of cotyledon protoplast cultures from B napus, B. campestris and B. oleracea. II: Callus formation and plant regeneration (1995)
    Springer
    Plant cell, tissue and organ culture 40 (1995), S. 73-84 
    Details
    ISSN: 1573-5044
    Schlagwort(e): Brassica napus ; B. campestris ; B. oleracea ; cotyledon protoplasts ; callus formation and growth ; plant regeneration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Cotyledons from twelve cultivars of Brassica; B. napus (Westar, Eureka, Global, Pivot and Narc 82); B. campestris: (Arlo, Sonja, Bunyip and Wonk Bok) and B. oleracea (Phenomenal Early, Sugar Loaf and Earliball) were used for protoplast isolation and culture in a comparative study of cell colony and callus formation, and plant regeneration. The formation of cell colonies and callus from protoplast cultures were significantly influenced by the light conditions of seed germination. All twelve cultivars showed callus formation from protoplast cultures derived from cotyledons of seedlings grown in dark for 3 days followed by 1 day dim light (dark/dim light-grown). Callus was obtained in all five liquid media used: modified K8P(1), modified K8P(2), modified MS, modified B and modified NN. In contrast, only six cultivars exhibited callus formation from the protoplasts isolated from cotyledons of seedlings germinated under light conditions for 7 days (light-grown) and in only three media: modified K8P(1), modified MS, modified B. Callus, derived from protoplast cultures isolated from dark/dim light-grown cotyledons and grown on K3 or MS series solid media for about 1 month, could develop shoots when further transferred onto MS series regeneration media. All five cultivars of B. napus, three of the four cultivars of B. campestris (Arlo, Sonja and Bunyip) and one of the three cultivars of B. oleracea (Sugar Loaf) exhibited shoot regeneration from protoplast cultures within 2–3 months after protoplast isolation. The frequency of shoot regeneration ranged among 1–22.5%. A high degree of reproducibility was observed in cultivars Westar, Eureka, Global, Arlo, Bunyip and Sugar Loaf. In contrast, among the six cultivars that formed callus in protoplast culture derived from light-grown cotyledons, only three cultivars from B. napus (Westar, Eureka, Global) exhibited shoot regeneration 5.5 months after protoplast isolation. Regenerated shoots from cultivars Westar, Eureka and Bunyip and Sugar Loaf, which derived from protoplasts of dark/dim light germinated seedling and were induced to root on rooting media, survived in soil and grew to produce silique and set seeds.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00041121
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  • 36
    Digitale Medien
    Digitale Medien
    Gene dispersal from genetically modified oil seed rape in the field (1995)
    Springer
    Euphytica 81 (1995), S. 283-289 
    Details
    ISSN: 1573-5060
    Schlagwort(e): Key words ; Brassica napus ; field trial ; gene dispersal ; genetic modification ; pollination ; oil seed rape
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary A field trial was carried out with oil seed rape plants that had been genetically modified to contain genes coding for marker characters (β-glucuronidase, kanamycin resistance and asulam resistance). The aim of the experiment was to examine a method of studying gene dispersal in an agricultural environment. The central area of the field plot comprised 150 genetically modified plants and 450 plants not expressing the marker genes. These were surrounded by additional non-expressing plants. The plants were allowed to freely cross pollinate and a sample of the resultant progeny from non-expressing plants were screened for expression of the marker characters and for the presence of the introduced genes (by PCR). Limited gene dispersal was detected and the frequency of modified seedlings amongst the progeny of a plant appeared to have been strongly influenced by the genotype of the immediately adjacent plants.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00025619
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  • 37
    Digitale Medien
    Digitale Medien
    Hybridization of radish (Raphanus sativus L.) and oilseed rape (Brassica napus L.) through a flower-culture method (1995)
    Springer
    Euphytica 83 (1995), S. 159-168 
    Details
    ISSN: 1573-5060
    Schlagwort(e): Brassica napus ; flower-culture method ; intergeneric cross ; oilseed rape ; radish ; Raphanus sativus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Hybridization between radish and oilseed rape has been cumbersome, requiring elaborate embryo rescue techniques. With a modified flower culture method, we have achieved successful hybridization between radish and (transgenic) oilseed rape without the laborious and technically demandingin vitro ovule or embryo rescue techniques. The hybrid nature of the intergeneric hybrids was demonstrated using morphological traits, and DNA analyses. The described method will facilitate the generation ofRaphanobrassica hybrids useful for biosafety studies of the potential for transgenes to spread in weedyCruciferae as well as for breeding programs aimed at introducing useful radish genes, e.g. nematode resistance genes, into oilseed rape.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01678044
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  • 38
    Digitale Medien
    Digitale Medien
    Assessment of microinjection for introducing DNA into uninuclear microspores of rapeseed (1995)
    Springer
    Plant cell, tissue and organ culture 40 (1995), S. 97-100 
    Details
    ISSN: 1573-5044
    Schlagwort(e): Brassica napus ; β-glucuronidase ; polymerase chain reaction ; transformation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Approximately 2,000 embryogenic uninuclear microspores of rapeseed (Brassica napus) cv. Topas were intranuclearly injected with a chimaeric β-glucuronidase (Escherichia coli Uid A) gene. Stable integration had not occurred among 55 plants that were regenerated. Coinjection of the dye Lucifer Yellow and detection of injected DNA by the polymerase chain reaction revealed high frequencies of transfer. However, the amount of DNA injected was less than 20 copies, which may have been insufficient for stable transformation of microspores.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00041124
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  • 39
    Digitale Medien
    Digitale Medien
    High frequency somatic embryogenesis and plantlet regeneration from hypocotyl protoplast cultures of Brassica napus (1995)
    Springer
    Plant cell, tissue and organ culture 42 (1995), S. 113-115 
    Details
    ISSN: 1573-5044
    Schlagwort(e): Hypocotyl protoplast ; Brassica napus ; somatic embryogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A simple protocol has been developed for high frequency protoplast regeneration via somatic embryogenesis in B. napus. Protoplasts isolated from hypocotyl tissue of 8–12 day old seedlings of Brassica napus ISN706 (AACC) when cultured in KM(A) medium resulted in divisions with a, frequency ranging from 30–35%. Regeneration of plantlets was possible by both organogenesis and embryogenesis. Nearly 80% of the call transferred on to MS medium supplemented with 5.0 mg l-1 2iP, 0.1 mg l-1 NAA, 0.001 mg l-1 GA3, 0.5 g l-1 PVP and 0.5 g l-1 MES displayed somatic embryogenesis. The somatic embryos developed into normal plantlets, and also displayed secondary, repetitive embryogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00037689
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  • 40
    Digitale Medien
    Digitale Medien
    High level expression in Escherichia coli, purification and properties of chloroplast fructose-1,6-bisphosphatase from rapeseed (Brassica napus) leaves (1995)
    Springer
    Photosynthesis research 46 (1995), S. 313-322 
    Details
    ISSN: 1573-5079
    Schlagwort(e): Brassica napus ; chloroplast ; fructose-1,6-bisphosphatase ; rapeseed ; recombinant enzyme ; reductive activation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In chloroplasts, the light-modulated fructose-1,6-bisphosphatase catalyzes the formation of fructose 6-bisphosphate for the photosynthetic assimilation of CO2 and the biosynthesis of starch. We report here the construction of a plasmid for the production of chloroplast fructose-1,6-bisphosphatase in a bacterial system and the subsequent purification to homogeneity of the genetically engineered enzyme. To this end, a DNA sequence that coded for chloroplast fructose-1,6-bisphosphatase of rapeseed (Brassica napus) leaves was successively amplified by PCR, ligated into the Ndel/EcoRI restriction site of the expression vector pET22b, and introduced into Escherichia coli cells. When gene expression was induced by isopropyl-β-d-thiogalactopyranoside, supernatants of cell lysates were extremely active in the hydrolysis of fructose 1,6-bisphosphate. Partitioning bacterial soluble proteins by ammonium sulfate followed by anion exchange chromatography yielded 10 mg of homogeneous enzyme per 1 of culture. Congruent with a preparation devoid of contaminating proteins, the Edman degradation evinced an unique N-terminal amino acid sequence [A-V-A-A-D-A-T-A-E-T-K-P-]. Gel filtration experiments and sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the (recombinant) rapeseed chloroplast fructose-1,6-bisphosphatases was a tetramer [160 kDa] comprised of four identical subunits. Like other chloroplast fructose-1,6-bisphosphatases, the recombinant enzyme was inactive at 1 mM fructose 1,6-bisphosphate and 1 mM Mg2+ but became fully active after an incubation in the presence of either 10 mM dithiothreitol or 1 mM dithiothreitol and chloroplast thioredoxin. However, at variance with counterparts isolated from higher plant leaves, the low activity observed in absence of reductants was not greatly enhanced by high concentrations of fructose 1,6-bisphosphate (3 mM) and Mg2+ (10 mM). In the catalytic process, all chloroplast fructose-1,6-bisphosphatases had identical features; viz., the requirement of Mg2+ as cofactor and the inhibition by Ca2+. Thus, the procedure described here should prove useful for the structural and kinetic analysis of rapeseed chloroplast fructose-1,6-bisphosphatase in view that this enzyme was not isolated from leaves.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00020446
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  • 41
    Digitale Medien
    Digitale Medien
    Molecular cloning, expression and evaluation of phosphohydrolases for phytate-degrading activity (1995)
    Springer
    Journal of industrial microbiology and biotechnology 14 (1995), S. 396-402 
    Details
    ISSN: 1476-5535
    Schlagwort(e): Acid phosphatase ; Phytase ; Aspergillus ; Saccharomyces cerevisiae ; Phosphorus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Summary Four acid phosphatase (phosphomonoesterase E.C.3.1.3.2) genes, werecloned by polymerase chain reaction (PCR). These were pho3, pho5 and pho11 fromSaccharomyces cerevisiae and the gene for a phosphate-respressible acid phosphatase fromAspergillus niger. The individual genes were subcloned into anA. oryzae expression vector downstream from a starch-inducible α-amylase promoter and the resulting expression constructs were transformed into a mutant strain ofA. oryzae, AO7. Southern hybridization analysis confirmed that the acid phosphatase genes had been integrated into the host genome with estimates of integrated copy numbers ranging from 2 to 20 for individual transformants. Northern hybridization analysis of total RNA from individual transformants revealed the presence of a single transcript of the expected size of 1.8 kb. Production of recombinant protein was induced by the addition of 30 g L−1 of soluble starch in the fermentationmedia. Active acid phosphatases, not present in control cultures, were detected in the supernatant fractions of transformant cultures by acid phosphatase activity staining of non-denaturing polyacrylamide gels. The ability of the recombinant acid phosphatases to hydrolyze phytate was assessed by referenced phytase (myoinositol hexakisphosphate phosphohydrolase E.C. 3.1.3.8) activity assay procedures. A two- to six-fold increase in phytase activity was measured in transformants compared to control, untransformedA. oryzae. Sufficient quantities ofA. niger and pho5 recombinant acid phosphatases were generated from large-scale fermentations to assess the efficacy of these enzymes as phytate-degrading enzymes when included in poultry diets. Data indicated an increase in available phosphorus of 1 g kg−1 obtained with yeast acid phosphatase andA. niger acid phosphatase representing 40% utilization of unavailable dietary P compared to 48% utilization for commercial phytase.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01569957
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  • 42
    Digitale Medien
    Digitale Medien
    Structure-activity relationships of cyclopentane analogs of jasmonic acid for induced responses of canola seedlings,Brassica napus L (1995)
    Springer
    Journal of chemical ecology 21 (1995), S. 1735-1743 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Jasmonate ; Brassica napus ; canola ; toughness ; glucosinolate ; structure-activity ; analogue ; defense
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Jasmonic acid (JA) has potent activity in enhancing cotyledon toughness and stimulating the biosynthesis of 3-indolymethyl glucosinolate in seedlings of canola,Brassica napus L. Structure-activity relationships among cyclopentane analogs of JA revealed that maximum activity in both systems was achieved when an acetyl side chain (or a methylated acetyl side chain) occurred at the C-1 ring position, ann-pentenyl side chain at the C-2 ring position, and a keto group at the C-3 ring position. Although coronatine and coronafacic acid both possess a cyclopentane ring with a keto group at the C-3 position, only coronatine was active inB. napus seedlings. Coronatine, a chlorosis-inducing toxin essential to the infectivity of pathovars ofPseudomonas syringae, acted as a complete molecular mimic of JA and had the same stimulatory effect on specific indole glucosinolates inBrassica species, thereby casting doubt on the hypothesis that indole glucosinolates serve in bacterial pathogen defense. Similarities and differences for structural requirements for activity among several diverse physiological systems affected by jasmonates likely reflect species-, tissue-, and developmental-specific differences.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02033673
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  • 43
    Digitale Medien
    Digitale Medien
    Modification of cell development in vitro: The effect of colchicine on anther and isolated microspore culture in Brassica napus (1995)
    Springer
    Plant cell, tissue and organ culture 40 (1995), S. 255-270 
    Details
    ISSN: 1573-5044
    Schlagwort(e): anther/microspore culture ; Brassica napus ; colchicine ; embryogenesis ; microtubules ; pollen mitosis I
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In an attempt to discover the biological basis of microspore derived embryogenesis, the effect of the antimicrotubule agent colchicine on anther and free microspore embryogenesis was investigated. The microtubule inhibitor colchicine promoted embryogenesis from cultured anthers, both with regard to the number of anthers responding and the number of embryos being produced per anther. A similar promotional response was also observed with cultured microspores. Although the parameters for cultured anthers and free microspores differed, administration of the drug for a short period immediately prior to pollen mitosis I seems to exert the maximum promotional effect. Of the five cultivars of Brassica napus studied, all responded to colchicine treatment. However, the drug did release more embryogenic potential in poor-responding varieties (i.e. Lirawell and Optima) than in the highest responding variety (Topas). Colchicine also resulted in increased embryogenic response in microspores cultured at lower temperatures. These results are considered in terms of models proposed to explain the switch in microspore development from a gametophytic to a sporophytic pathway. The use ofcolchicine as agent to promote embryogenesis in previously recalcitrant species other than Brassica is also discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00048132
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  • 44
    Digitale Medien
    Digitale Medien
    Compatibility of poly(ethylene 2,6-naphthalate) and poly(butylene 2,6-naphthalate) blends (1995)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1807-1810 
    Details
    ISSN: 0032-3888
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Blends prepared from poly(ethylene 2,6-naphthalate) (PEN) and poly(butylene 2,6-naphthalate) (PBN) show only partial miscibility judged from their glass transition temperatures. Two distinct mechanical behaviors are observed: brittle for the blends 〈 20 wt% of PBN, while ductile 〉 20 wt% of PBN. The experimental modulus and strength values of the blends are within the predicted values according to Kleiner and Paul models, respectively. This means that PEN/PBN blends are somewhat compatible based on their tensile properties. Especially for 20 wt% of PBN blend, the high modulus and strength are observed. The viscosity of the blend is high, which may imply a somewhat entangled morphology in the amorphous state.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pen.760352210
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  • 45
    Digitale Medien
    Digitale Medien
    Masthead (1995)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995) 
    Details
    ISSN: 0032-3888
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pen.760352301
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  • 46
    Digitale Medien
    Digitale Medien
    Effects of mixing porcedures on properties of compatibilized polypropylene/nylon 6 blends (1995)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1821-1833 
    Details
    ISSN: 0032-3888
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: The paper consides the effects of compatibilization with maleic anhydride grafted polypropylene (PP-g-MAH) on the propertie of immiscible blends of polypropylene (PP) and nylon 6 (N6). We prepared the blends by three different mixing processes; single-step blending, two-step blending with reactive premixing, and two-step blending with nonreactive premixing, to determine the effective mixiing process for fine morphological structure thermal stability, and mechanical properties. Dynamic melt reheological properties were measured to examine the modification of elastic properties by the compatibilizer. In addtion, thermal analysis was also carried out to detect the change in crystallization and thereby to probe the degree of compatibilizaton. The results show that compatibilized blends prepared by teh single-step process exhibit improved phase morphology, thermal stability, and mechanical properties for dried conditions, compared with other blend types. Finally, the water absorption test indicates that the added compatibilizer yields enhanced water resistance in spite of the strong intrinsic hydrophilicity of N6. In particular, two-step blending with reactive premixing is most effective in improving water resistance and reducing degradation of mechanical properties after moisture absorption.
    Zusätzliches Material: 14 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pen.760352302
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  • 47
    Digitale Medien
    Digitale Medien
    A hybrid numerical technique to model 3-D flow fields in resin transfer molding processes (1995)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1834-1851 
    Details
    ISSN: 0032-3888
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: A hybrid two-/three-dimensional solution technique is presentedto model 3-D flow fields in resin transfer moeling using Darcy's low. The 3-D flow field is only solved for regions where all three velocity components are significant, thus largely reducing the number of unknowns. Elsewhere, the commonly used 2-D approximation for flow in thin gaps between plates is employe.d The method is applied to regions where the flow splits, such as T-joints. Because of the uncertainties associated with an accurate determination of the permeability in these regions, a simplified decompled procedure is procesed, which reduces the computational complexity. In this procedure, the flow front is advanced using the 2-D formulation. The 2-D formulation also provides the boundary conditions for the subsequent computation of the 3-D flow field without feedback of flow field information to the 2-d model. The governing equations are solved using boundary fitted coordinate systems (BFCS) together with the finite difference method (FDM). Numerical as well as algebraic grid generation and domain decomposition are employe dto generate grids that always concide with the continuously deforming and enlarging flow domain. Results that include the trackingof numerical tracer particles to visualize the three-dimensionality of the flow field are presented for isothermal flow of a Newtonian fluid through a T-joint. This detailed flow field description is expected to form the basis for a rather accurate simulation of quantitities that largely depend on the fluid particle pathlines, such as the degree of cure. The method is also extendable to shear-thinning fluids as well as to 3-D flow in the vicinity of the flow front.
    Zusätzliches Material: 22 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pen.760352303
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  • 48
    Digitale Medien
    Digitale Medien
    Theory of competition between breakup and coalescence of droplets in flowing polymer blends (1995)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1872-1877 
    Details
    ISSN: 0032-3888
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: The Smoluchowski equation for the breakup and coalescence of dispersed droplets has been solved for flowing polymer blends. A scaling form for the distribution of droplet sized derived and published for a system of clusters with fragmentation and coagualation was used in our dervation. Equations are developed here for the average droplet size and for the characteristic time of transition to steady state flow of blends with a high content of the dispersed phase. Expressions reasonably describing the average size of droplets for all concentrations were obtained by a theory modification. Measured dependences of droplet size on the blend composition can be matched only if simultaneous collisions of three and more droplets are considered. The results of the theory indicate that the mechanism of droplet breakup (formation of pieces with the same or different volumes) has only a small effect on their average size in concentrated systems. The dependence of droplet size on the shear rate in flow is determined by properties of the blend components, and is generally nonmonotonic.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pen.760352306
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  • 49
    Digitale Medien
    Digitale Medien
    Performance of reprocessed multilayer LDPE/nylon-6 film (1995)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1878-1883 
    Details
    ISSN: 0032-3888
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Multilayer LDPE/nylon-6 films with an overall content of 71 wt% LDPE, 24 wt% nylon-6, and 5 wt% PE-based tie-layer adhesive were reprocessed under both minimal and extensive mixing conditions. Thermal and mechanical properties, oxygen and water vapor permeability, and morphology of the reprocessed samples were determined. The modulus and yield stress of the reprocessed films fell between those of the pure homopolymers, whereas percent elongation at break and energy-to-break for all reprocessed films were less than those of the homopolymers. In minimally reprocessed film, layering of LDPE (low-density polyethylene) and nylon-6 was retained, whereas in extensively mixed samples, nylon-6 domains were spherical and ranged from 0.2 to 7 μm. Minimally reprocessed film exhibited good O2 and H2O vapor barrier properties, whereas extensively-mixed samples had poor barrier properties. Properties of well-mixed blends prepared both with and without adhesive showed that 5 wt% adhesive did not compatibilize the LDPE and nylon-6 components.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pen.760352307
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  • 50
    Digitale Medien
    Digitale Medien
    Assessment of residual stresses during cure and cooling of epoxy resins (1995)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1895-1898 
    Details
    ISSN: 0032-3888
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: A new stress monitoring technique, a stress-tracking device, is described here. It has been used to study some important properties of epoxy resin. Residual stresses, including a curing shrinkage stress and a cooling shrinkage stress, were measured automatically and continuously during curing and cooling. Simultaneously, information such as an apparent gelation time and glass transition temperature were obtained directly during the experiment. These epoxy resin properties were related to the extent of cure. Varying cure temperature produced changes of cure behavior, which resulted in different residual stresses.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pen.760352309
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  • 51
    Digitale Medien
    Digitale Medien
    Study of reaction injection molding of polyurethane microcellular foam (1995)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1899-1906 
    Details
    ISSN: 0032-3888
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Processing of microcellular foam was investigated for the feasibility of production of tough and lightweight polyurethanes. To increase the nucleation rate in a gas-supersaturated resin, ultrasonic excitation was applied to the mixture of polyol(polyether-based polyol) and isocyanate(diphenyl methane diisocyanate). A microcellular structure was produced by two sequential steps, i.e., supersaturationof the polyol resin with nitrogen gas at elevated pressure and ultrasonic bubble nucleation right after the impingement mixing of two components of the polyurethane system. Theoretical analyses based on nucleation theories were employed to predict the rate of nucleation in the gas-supersaturated polyurethane. The rate of nucleatio in the resin was predicted by classical nucleation and cluster theories. In the experimental investigation, ultrasonic excitation was applied to increase the nucleation rate in the resin that had been saturated by nitrogen at a saturation pressure 〈 2.0 MPa.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pen.760352310
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  • 52
    Digitale Medien
    Digitale Medien
    Modeling the mechanical properties in polypropylene/polyamide-6 blends with core shell morphology (1995)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1917-1922 
    Details
    ISSN: 0032-3888
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Polypropylene/Polyamide-6 (PP.PA) blends containing maleic anhydride grafted elastomers were prepared by reactive blending. Three different types of core shell morphologies were obtained and characterized by transmission electron microscopy (TEM). The midulus of these elastomer midified PP/PA (70/30) blends with core shell type morphology is compared to predictions derived from the Kerner model. The multiphase morphology of these blends could be modeled by sequential application of the Kerner equation to two-phase subinclusions. Using morphological data ontained by TEM, good agreement between experimental and calculated values was ontained. The results are used to tailor PP/Pa-6 blends combining stiffness and toughness.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pen.760352402
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  • 53
    Digitale Medien
    Digitale Medien
    Creep analysis of thermiplastics using stress relaxation data (1995)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1931-1937 
    Details
    ISSN: 0032-3888
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: One of the major factors limiting the use of thermoplastics in engineeing applications is the inadequacy of existing design data. Much of the data do not span appropriate ranges of stress, strain, time, or temperature. This study addresses the need to develop an accelerated method for generating long-time design data to support the innovative use of engineering thermoplastics. In particular, stress relaxation tests (SRT) were performed on polycarbonate (PC) and midified poly(phenylene oxide)(PPO), and used to generate time-dependent design data through the short-time measurement of the material's current state without dependence on elastic modulus. The test results and analyses reported here indicate the SRT method to be an efficeint means of generating accurate and repeatable creep and secant modulus data which may be directly used in design. Therefore, SRT shows great potential both as a design parameter development tool, and as a quality control instrumetn for assessing batch-to-batch variability.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pen.760352404
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  • 54
    Digitale Medien
    Digitale Medien
    Morphology and evolutionary implications of the annual cycle of secretion and sperm storage in spermathecae of the salamander Ambystoma opacum (Amphibia: Ambystomatidae) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 35-46 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Females of the marbled salamander, Ambystoma opacum, store sperm in exocrine glands called spermathecae in the roof of the cloaca. Eggs are fertilized by sperm released from the spermathecae during oviposition. Some sperm remain in the spermathecae following oviposition, but these sperm degenerate within a month and none persists more than 6 mo after oviposition. Thus, sperm storage between successive breeding seasons does not occur. Apical secretory vaculoes are abundant during the fall mating season and contain a substance that is alcian blue+ at pH 2.5. Production of secretory vacuoles decreases markedly after oviposition, and the glands are inactive by the summer months. Ambystoma opacum is a terrestrial breeder, and some mating occurs prior to arrival at pond basins where oviposition occurs. Mating prior to arrival at the ovipository site may prolong the breeding season, leading to fitness implications for both males and females. Females have opportunities for more matings, and the possibilities for sperm competition in the spermathecae are enhanced. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230106
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  • 55
    Digitale Medien
    Digitale Medien
    Annual changes in fine structure of inner epithelial lining of the ovary of a marine sculpin, Alcichthys alcicornis (Teleostei: Scorpaeniformes), with internal gametic association (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 85-97 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Alcichthys alciocornis has a viscous ovarian fluid in the ovarian cavity, which plays an important role in its unique mode of reproduction called internal gametic association (i.e., internal insemination and sperm-egg association but a delay in the physiological fertilization until spawning). Seasonal changes in fine structure of the inner epithelial lining and capillary endothelium of the ovary revealed that ovarian fluid originated as a result of the secretory activity of the tissues. The ovarian cavity of A. alcicornis is lined with an ovigerous lamella epithelium and an ovarian wall epithelium. During the spawning period, both epithelia actively secreted proteinaceous substances which seemed to constitute the ovarian fluid. The substances appear to be synthesized in the rough-surfaced endoplasmic reticulum from the material which was transported from the blood capillary, taken into the epithelial cells by endocytosis, accumulated in secretory vesicles via Golgi apparatus in the cells, and finally released into the ovarian cavity by exocytosis. Microapocrine secretion was also observed to occur in both epithelia. Secretory activity of both epithelia by exocytosis and microapocrine secretion showed distinct seasonal changes. Active exocytosis and microapocrine secretion were observed during the spawning period (April-May). These activities slightly declined during the degeneration period (May-June) and were lost during the early recovery period (July). During the mid to late recovery period (October-March), there was some exocytosis but no microapocrine secretion. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230108
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  • 56
    Digitale Medien
    Digitale Medien
    Surface morphology of hamster (Mesocricetus auratus) decidual cells in vitro (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 167-174 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Cell surface morphology of hamster decidual cells isolated from day 8 implantation swellings was studied, using both phase-contrast and scanning electron microscopy. Two kinds of cells, fibroblastic and epithelioid, were identified in cultures examined by phase-contrast microscopy. Fibroblastic cells were spindle-shaped, having pointed or blunt terminals on one end and bifid or webbed projections at the other end. Epithelioid cells, on the other hand, were flat and discoid, having a distinctively ruffled plasma membrane. Further, the plasma membrane of epithelioid cells formed rope-like or flange-like processes. The significance of such adaptations is discussed. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230205
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  • 57
    Digitale Medien
    Digitale Medien
    Skeletal morphogenesis in the urodele skull: II. Effect of developmental stage in thyroid hormone-induced remodeling (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 149-166 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: This study investigates the effect of developmental stage on thyroid hormone (TH)-mediated remodeling in the skeletal tissues of hemidactyliine plethodontid urodeles. Rate of morphogenesis was quantified in 17 metamorphic tissues for three different size-age classes of Eurycea bislineata larvae immersed in a metamorphic dosage of T4. Extent of morphogenesis after a 3-week immersion was also quantified in these tissues plus four larval ones for the full size range of E. bislineata larvae and for less complete size ranges of E. wilderae, E. longicauda guttolineata, Gyrinophilus porphyriticus, and Pseudotriton ruber larvae. Although all tissues respond more slowly with decreasing size/age, two tissue-specific effects are evident in all species. Larval ossifications are less inducible than metamorphic ossifications, and progressive metamorphic events are more retarded and, in some cases, more prone to abnormal morphogenesis than regressive ones. The first effect agrees with the prediction that tissues that naturally remodel at metamorphosis are more responsive to a metamorphic dosage of TH than those that respond at a larval stage and lower TH. The second effect agrees with the prediction that progressive morphogenesis is more likely to be impaired at small size than regressive morphogenesis, although the frequent discrepancies between individuals of similar size implicate developmental age more than size in this effect. Collectively, these two effects provide only equivocal support for the hypothesis that direct development in plethodontids evolved via precocious TH activity. However, the unexpected transition from ceratobranchial replacement to ceratobranchial shortening in medium-sized larvae suggests that the former pathway requires a longer period of cell specification at low TH. Since ancestral plethodontids appear to have been distinguished by an exceptionally long larval period with exceptionally low TH activity, this developmental prerequisite may in turn be partly responsible for their singular evolution of ceratobranchial replacement. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230204
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  • 58
    Digitale Medien
    Digitale Medien
    Atomic force microscopy of the morphology of the matrix and mineral components of the otolith of Hyperoglyphe antarctica (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 203-214 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The sagittal otolith of Hyperoglyphe antarctica (Centrolophidae: Teleostei) has a prismatic structure in which the anti-sulcal growth axes of each prism consist of a series of nested cones each composed of a mineral layer followed by an organic matrix layer. Broken sections show the mineral layers to be composed of stacks of crystals. Otolith matrix that has been decalcified and air-dried, or critical-pont-dried, retains a periodic structure of repeating high and low matrix density. At high magnifications, both broken whole crystal surfaces and decalcified matrix surfaces have a granular structure. Chloroxbleached whole otoliths also show a granular crystalline structure. At higher magnifications, the air-dried matrix showed a parallel fiber structure with similar dimensions to keratin fibers. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230208
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  • 59
    Digitale Medien
    Digitale Medien
    Cellular ultrastructure and catecholamine histofluorescence of the heart of the Australian lungfish, Neoceratodus forsteri (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 191-201 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Ultrastructural descriptions of the dipnoan heart are lacking. Many ultrastructural features of the heart of the Australian lungfish, Neoceratodus forsteri, resemble those of other lower vertebrates. The epicardial cells appear to be adapated for the exchange of material with the pericardial fluid. The most prominent features of the endocardial cells are numerous moderately electron-dense vesicles found within the cytoplasm. These organelles might have an endocrine function. The myocardiocytes are typically small. The banding pattern of the sarcomere is shared with most fish. The intercalated disc has a convoluted path and consists of desmosomes and fascia adherens. Caveolae are a prominent feature of the sarcoplasm. The sarcoplasmic reticulum is sparse, and T-tubules are lacking. Atrial myocardial dense bodies occur in vast numbers throughout the atrium and are occasionally seen in the ventricle. These vesicles are chromaffin-positive but fail to show catecholamine fluorescence. They are likely to contain peptides related to ANP. Subendothelial cells exhibiting catecholamine-specific fluorescence are scattered throughout the atrium. Ultrastructurally these cells contain many chromaffin-positive granules. Chromaffin cells represent another cell type with a probable endocrine function within the heart of N. forsteri. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230207
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  • 60
    Digitale Medien
    Digitale Medien
    Masthead (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995) 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230301
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  • 61
    Digitale Medien
    Digitale Medien
    Morphology of complex lymphoepithelial organs of the anal canal (“anal tonsil”) in the bottlenose dolphin, Tursiops truncatus (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 263-268 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: A complex of lymphoepithelial organs, the “anal tonsils,” is a consistent structure in the anal canal of the bottlenose dolphin, Tursiops truncatus. This complex occurs as a circumferential cluster of discrete tonsil like aggregations of lymphoid tissues, together with epithelial ducts (“crypts”) and occasional mucus secretory units in the extreme lower portion of the intestinal tract. These structures are concentrated in the segment lined by stratified squamous epithelium and extend for a variable distance cephalad from the anal aperture. The tonsils appear to be most active, judged by the amount of lymphoid tissue present, in young animals. Depletion of lymphocytes and cystic enlargement of the crypts, probably representing functional as well as morphological involution, is a consistent feature of older animals. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230304
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  • 62
    Digitale Medien
    Digitale Medien
    Prenatal development of the integument in Delphinidae (Cetacea: Odontoceti) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 269-287 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The prenatal development of epidermis, dermis, and hypodermis was studied in embryos of different ago of two delphinid species (Stenella attenuata, Delphinus delphis), using light and transmission electron microscopical methods. The delphinid embryo is covered by a multilayered tissue formed by four different epidermal generations (periderm, stratum intermedium-I, str. intermedium-II, str. spinosum) produced by the str. basale. The first layer appears at about 40-50 mm of body length, the second type (s.i.-I) about 60-160 mm, and the third type (s.i.-II) is present at 160-500 mm. The first spinosal cells are produced at 225-260 mm body length; thenceforth, the epidermis increases continuously in thickness. Epidermal ridge formation begins about 400-mm body length. The development of the dermis is characterized by the early production of thin connective tissue fibers (40- 70-mm body length) and simultaneously the cutaneuous muscle matures in structure. Vascular development intensifies between embryos of 150-225 mm, and collagen production increases markedly in fetuses of 225-260-mm length. These events are paralledled by an increase in dermal thickness. The first elastic fibers can be recognized in the skin from the abdomen at about 600-mm body length. The development of the hypodermis is marked by very rapid and constantly progressing growth, beginning about 60-mm body length. The first typical fat cells appear in animals of 360-400 mm. Regional differences are obvious for all skin layers with regard to the flippers, where structural maturation proceeds more rapidly than in dorsal or abdominal regions. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230305
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  • 63
    Digitale Medien
    Digitale Medien
    Design of the predatory legs of water bugs (Hemiptera: Nepidae, Naucoridae, Notonectidae, Gerridae) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 289-302 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Functional comparative morphology of predatory legs in five species of water bugs (Ilyocoris cimicoides, Nepa cinerea, Ranatra linearis, Notonecta glauca, and Gerris lacustris) has been investigatd adn the following peculiarities of leg design were revealed.1Subcoxal articulation may be monoaxial (G. lacustris, N. glauca), or, in contrast to walking leg type, biaxial (N. cinerea, R. linearis, I. cimicoides); the first axis is oriented along the coxa (torsion axis), the second one is perpendicular to the first (non-torsion axis).2In contrast to walking leg type, which is characterized by cross suspension of the axis of coxal rotation in thoracal skeleton, this axis in G. lacustris is placed vertically. Non-torsion coxal axis in R. linearis is oriented strongly transversal. This axis directs the leg strike forward.3Legs in the majority of species are planar: Torsion axes of the coxa, femur, and tibia are placed in the same plane. Axes of rotation of consequent joints in I. cimicoides are reciprocally sloped. Therefore, the end of the leg outlines the spiral trajectory, when all angles of joints are opening (closing). This is an adaptation for clinging to the stems of water plants.4Passive adduction of the femur in the trochanter-femoral joint in N. glauca allows it to go around protuberances of the body wall, when the leg is sliding along them; recurrent femur movement during releasing from the obstacele is active due to the rt.fe muscle.5Only R. linearis has predatory legs, which permit the high-speed pursuit of potential prey; other species realize this function using the swimming legs, whereas the forelegs are used for the manipulation movements.6Muscle arrangement in the prothorax of different species reflects both leg construction and constructional constraints of body design. Powerful flexor muscles (co1, co2, co3, co5, fl.ti, et.ti in R. linearis; fl.ta, fl.ti in N. glauca; fl.ti in I. cimicoides) have long tendons and short muscle bundles, which originate on the leg wall. As a result, the powerful force is developed along the muscle tendon.7Some features of the predatory leg are common for the species studies: elongation of coxae, thickening of femora, and increase of the degree of junction of tibia and tarsus. The muscles, which move the distal segment of the leg, are reinforced and the sclerite of the fl.ti tendon is enlarged. The joint angle of the distal segment is increased to 120°. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 27 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230306
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  • 64
    Digitale Medien
    Digitale Medien
    Allometry and developmental integration of body growth in a piranha, Pygocentrus nattereri (Teleostei: Ostariophysi) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 341-355 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Piranhas, like many teleosts, change their diets on both ontogenetic and phylogenetic time scales. Prior studies have suggested that pervasive morphological changes in body form on a phylogenetic time scale may be related to changes in diet, but previous reports have found little shape change in piranhas on an ontogenetic time scale. We re-examine the post-transformational allometry of body form in one piranha, Pygocentrus nattereri (Kner), using the method of thin-plate splines decomposed by their partial warps. We find substantial evidence of allometry, primarily elongation of the mid-body relative to the more anterior and posterior regions, elongation of the postorbital and nape regions relative to the more anterior head and posterior body, and deepening of the head relative to the body. In addition to these pervasive changes throughout the body, there are some that are more localized, especially elongation of the postorbital region relative to eye diameter and snout, and an even more localized elongation of the snout relative to eye diameter. Initial dietary transitions are associated with changes in head and jaw proportions, but rates of shape change decelerate through growth, so that the final transition to a diet increasingly dominated by small whole fish appears associated with change largely in overall body size. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230309
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  • 65
    Digitale Medien
    Digitale Medien
    Ultrastructurally different muscle cell types in Eisenia foetida (Annelida, Oligochaeta) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995), S. 87-96 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Muscles in the body wall, intestinal wall, and contractile hemolymphatic vessels (pseudohearts) of an oligochaete anelid (Eisenia foetida) were studied by electron microscopy. The muscle cells in all locations, except for the outer layer of the pseudohearts, are variants of obliquely striated muscle cells. Cells comprising the circular layer of the body wall possess single, peripherally located myofibrils that occupy most of the cytoplasm and surround other cytoplasmic organelles. The nuclei of the cells lie peripherally to the myofibrils. The sarcomeres consist of thin and thick myofilaments that are arranged in parallel arrays. In one plane of view, the filaments appear to be oriented obliquely to Z bands. Thin myofilaments measure 5-6 nm in diameter. Thick myofilaments are fusiform in shape and their width decreases from their centers (40-45 nm) to their tips (23-25 nm). The thin/thick filament ratio in the A bands is 10. The Z bands consist of Z bars alternating with tubules of the sarcoplasmic reticulum. Subsarcolemmal electron-dense plaques are found frequently. The cells forming the longitudinal layer of the body wall musculature are smaller than the cells in the circular layer and their thick filaments are smaller (31-33 nm centrally and 21-23 nm at the tips). Subsarcolemmal plaques are less numerous. The cells forming the heart wall inner layer, the large hemolymphatic vessels, and the intestinal wall are characterized by their large thick myofilaments (50-52 nm centrally and 27-28 nm at the tips) and abundance of mitochondria. The cells forming the outer muscular layer of the pseudohearts are smooth muscle cells. These cells are richer in thick filaments than vertebrate smooth muscle cells. They differ from obliquely striated muscle cells by possessing irregularly distributed electron-dense bodies for filament anchorage rather than sarcomeres and Z bands and by displaying tubules of smooth endoplasmic reticulum among the bundles of myofilaments. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 21 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052240110
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  • 66
    Digitale Medien
    Digitale Medien
    Internal fertilization, testis and sperm morphology in glandulocaudinae fishes (Teleostei: Characidae: Glandulocaudinae) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995), S. 131-145 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: In this report, the gonads of 32 glandulocaudine species, representing 18 genera, are compared with 11 outgroup characiform species. Through the presence of spermatozoa within the ovarian cavity, internal fertilization of the female is confirmed for the 16 genera for which mature ovaries were available. No outgroup ovary studied contains spermatozoa. All mature glandulocaudine testes have a large portion of the posterior testis, which is devoid of developing germ cells and spermatocysts (aspermatogenic), devoted to sperm storage, with the degree of partitioning in that region varying greatly within the group. All outgroup species examined have spermatozoa with spherical nuclei. With the exception of the species of the genus Planaltina, which also have spherical nuclei, all glandulocaudines have elongated nuclei, which vary among the species from 3.6 μm to 31.6 μm in length. Distinct sperm packets (spermatozeugmata) are formed in five genera by two different methods. In the genera Xenurobrycon, Tyttocharax, and Scopaeocharax, all of the tribe Xenurobryconini, the spermatozeugmata are formed within the spermatocysts and released fully formed. In all genera of the tribe Glandulocaudini, which includes Glandulocauda and Mimagoniates, loose spermatozoa are released which cluster into spermatozeugmata within the posterior storage areas. These morphological specializations are discussed within a phylogenetic framework as adaptations for internal fertilization and are hypothesized to be independently derived. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052240203
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  • 67
    Digitale Medien
    Digitale Medien
    Presence of interdigitating cells in thymus of the sea bass, Dicentrarchus labrax L. (Teleost) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995), S. 199-203 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Interdigitating cells in the thymus of the sea bass, Dicentrarchus labrax, occur principally in the internal zone and in the border with the external zone. Ultrastructurally, the most characteristic cytological features of these cells are their low electron density, complicated labyrinthine membrane-membrane contacts, scantiness of cytoplasmic organelles, presence of Birbeck-like granules, juxtanuclear tubulo-vesicular complex, and phagocytic capacity. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052240208
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  • 68
    Digitale Medien
    Digitale Medien
    Morphological, histochemical, and ultrastructural characterization of the salivary glands and proboscises of three species of glossiphoniid leeches (Hirudinea: Rhynchobdellida) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 225 (1995), S. 1-18 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Morphological and ultrastructural features of the salivary glands and proboscises of Placobdella ornata, Placobdella parasitica, and Desserobdella picta were studied by light and electron microscopy. Chemical composition of the salivary cells was investigated using a variety of histochemical techniques. Placobdella ornata and P. parasitica have compact salivary glands with discrete pairs of anterior and posterior glands, while the salivary cells contain one mucous and three proteinaceous secretions. Salivary glands of D. Picta are diffusely arranged and contain two mucous and two proteinaceous secretions. A cobalt-lysine forward-filling technique revealed that individual salivary cells consist of a roughly spherical soma and an elongated ductule. The majority of the internal space in a salivary soma is densely packed with spherical secretory granules which displace the cytoplasm to the periphery of the cell. Bundles of individual ductules enter the base of the proboscis on opposite sides and extend anteriorly. The ductules, also packed with secretory granules, are surrounded by microtubules associated with agranular endoplasmic reticulum, and merge with deep invaginations of the proboscis cuticle. The secretory granules are released at the end of these invaginations or pores. Pores were found on the tip, along the body, and on the luminal wall of the proboscises in all three species. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 24 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052250102
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  • 69
    Digitale Medien
    Digitale Medien
    In vivo strain in the humerus of pigeons (Columba livia) during flight (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 225 (1995), S. 61-75 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Longitudinal and principal strain recordings were made in vivo at three sites (dorsal, anterior, and ventral) on the humeral midshaft of pigeons executing five modes of free flight: Take-off, level flight, landing, vertical ascent, and near-vertical descent. Strains were also recorded while the birds flew carrying weights that were 33%, 50%, or 100% of their body weight. The relative distribution of strain measured at the three surface midshaft sites and across the bone's cortex was found to be similar for all flight modes. Principal strains recorded in the dorsal and ventral humerus indicated considerable torsion produced by aerodynamic loading of the wing surface posterior to the bone. Measured torsional shear strains (maximum: 2,700-4,150 μ ε during level flight) were 1.5 times greater than longitudinal strains. In addition to torsion, the humerus is also subjected to significant dorsoventral bending owing to lift forces acting on the wing during the downstroke. Analysis of the cross-sectional distribution of longitudinal strains at the humeral midshaft cortex shows that the orientation of bending shifts in a regular manner during the downstroke, indicating that the wing generates progressively more thurst (vs. lift) later in the downstroke. This shift is less during take-off and vertical ascent when greater lift is required. Peak principal and longitudinal strains increased by an average of only 50% from landing to vertical ascending flight and take-off (e.g., dorsal humerus: -1,503 to -2,329 μ ε) and did not exceed -2,600 μ epsiv; at any site, even when the birds flew carrying twice their body weight. Strains recorded when birds flew at two times their body weight (100% BW load) were similar in magnitude to those recorded during vertical ascent and take-off and likely represent those developed during maximal performance. Strains developed within the midshaft were maximal in the anterodorsal and posteroventral cortices, not at the dorsal, ventral, and anterior sites at which strain was recorded. Consequently, maximum strains experienced by the bone are probably 20-25% greater than those recorded (ca. 3,200 μ ε), indicating a safety factor of about 3.5 for compressive strain failure. The much higher shear strains, however, indicate a lower safety factor (1.9), in which the bone's torsional strength is its most critical design feature. Finally, the magnitude and distribution of strains developed in the humerus of pigeons are generally similar to those recorded in the humerus of large fruit-eating bats during flight. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052250106
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  • 70
    Digitale Medien
    Digitale Medien
    Cephalometric correlates of echolocation in the chiroptera: II. Fetal development (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 225 (1995), S. 107-123 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Cephalometry was used to detect patterns of cranial growth in fetal bats that were stained differentially for bone and cartilage. Three developmental features distinguish embryos of taxa that echolocate nasally from embryos of taxa that echolocate orally: (1) the basicranium is retained ventral to the cervical axis, (2) the rostrum is retained below the basicranial axis, and (3) the lateral semicircular canals are rotated caudally. Together, the first two actions align the fetal nasal cavity with what will be the long axis of the adult body in flight. The third action aligns the lateral semicircular canals with the horizontal. In contrast, skulls of oral-emitting taxa are constructed such that the oral cavity is aligned with the long axis of the body in flight. The evolution of head posture and skull form in microchiropteran bats has been constrained by the demands of vocalization, i.e., ultrasonic echolocation. Accordingly, the ontogeny of the microchiropteran skull has been canalized along two distinct developmental paths - oral-emitting and nasal-emitting Baupläne. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052250109
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  • 71
    Digitale Medien
    Digitale Medien
    Masthead (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 225 (1995) 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052250301
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  • 72
    Digitale Medien
    Digitale Medien
    Effects of caffeine treatment on the fine structure, silica secretion, and shell morphology of the testate amoeba Assulina muscorum (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 225 (1995), S. 251-260 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Assulina muscorum secretes morphologically altered shells when cultured in a medium with 5 mM caffeine. The siliceous scales, normally distributed in a regular overlapping pattern, are disorganized, thicker and wider than normal, and occasionally have incompletely silicified surfaces that appear irregular in profile in transmission electron microscopic ultrathin sections. The shape of the silica deposition vesicles (SDVs) in the cytoplasm is altered and they are less regularly arranged. The swollen appearances of the SDVs, and of nearby Golgi tubules, give additional evidence that caffeine affects the fine structural morphology of membranous secretory organelles and can disrupt their normal depositional activity. In addition to the greater thickness and width of the siliceous scales in caffeine-treated cells, the length and width of the shell are larger compared to controls, but the aspect ratio (length / width) is smaller. The latter is attributed to a larger increase in width relative to the increase in length of the caffeine-reated cells. Since some of the scales are deposited with the long axis laterally on the shell surface, in addition to being greater in width, this raises the interesting question of whether the morphology of the SDVs and the siliceous products influences the size and morphogenesis of the shell. Further research is needed to clarify the interaction of the SDVs with the cytoplasmic cytoskeletal system during shell morphogenesis. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052250302
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  • 73
    Digitale Medien
    Digitale Medien
    Spinal cord central canal of the German shepherd dog: Morphological, histological, and ultrastructural considerations (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995), S. 205-212 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: This study deals with some macroscopical, microscopical, and ultrastructural aspects of the spinal cord central canal of the German shepherd dog. The caudal end of the spinal cord is constituted by the conus medullaris, which may extend to the first sacral vertebra, the terminal ventricle, and the filum terminale. The latter structure is considered as internum (second to third sacral vertebrae) or externum (fifth caudal vertebra), according to its relation to the dura mater. Occasionally, there is a second anchorage which is close to the level of the sixth caudal vertebra. The central canal is surrounded by a ciliated ependymal epithelium, which differs depending upon the levels. The most caudal part of the filum terminale bears a columnar ciliated ependymal epithelium surrounded by two layers of glia and pia mater, which separate the central canal from the subarachnoid space. Microfil injections show a communication between the cavity and the subarachnoid space, as the plastic is able to pass through the ependymal epithelium. At the level of the terminal ventricle there are real separations of the ependymal epithelium, which seem to connect the lumen of the spinal canal with the subarachnoid space. These structures probably constitute one of the drainage pathways of the cerebrospinal fluid. The diameter of the central canal is related to the age of the animal. However, even in very old animals the spinal cord central canal reaches the tip of the filum terminale and remains patent until death. At the ultrastructural level the ependymal cells present villi, located on cytoplasmic projections, cilia, dense mitochondria, and oval nuclei. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052240209
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  • 74
    Digitale Medien
    Digitale Medien
    Developing embryo and cyclic changes in the uterus of Peripatus (Macroperipatus) acacioi (Onychophora, Peripatidae) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995), S. 179-198 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Female reproductive tracts of the viviparous neo-tropical onychophoran Peripatus acacioi have been examined at different times throughout the year, and the altering relationship between the developing embryo and the uterus is described. Depending on her age and time of year, the female may have one or two generations of embryos within her uterus. The uterine wall consists of a thin outer epithelium and basal lamina, three layers of muscles, and a thick basal lamina beneath an inner epithelium lining the uterus lumen. These layers are consistent along the length of the uterus apart from the inner epithelial lining, which varies according to position in the uterus and the developmental stage of embryos contained in the uterus. Early embryos are positioned along the length of the uterus and therefore have space in which to grow. During cleavage and segment formation, each embryo is contained within a fluid-filled embryo cavity that increases in size as the embryo grows. Morulae and blastulae are separated by lengths of empty uterus in which the epithelial lining appears vacuolated. Until the process of segment formation is complete, the embryos are attached to a placenta by a stalk and remain in the same part of the upper region of the uterus. As these embryos grow, the lengths of vacuolated cell-lined uterus between them decrease. Each embryo cavity is surrounded by the epithelial sac, the maternal uterine epithelium, which becomes overlaid by a thin layer of cells, the embryo sac, which is believed to be of embryonic origin. The placenta is a syncytial modification of the epithelial sac located at the ovarian end of each embryo cavity covered by the embryo sac and is analogous to the mammalian noninvasive epitheliochorial placenta. Segment-forming embryos have their heads directed toward the ovary. As the embryo gets longer during segment formation, its posture changes from coiled to flexed. Once segment formation is complete, the embryo loses contact with its stalk, an embryonic cuticle forms, and the embryo turns around so that its head is directed toward the vagina. The embryo escapes from its embryo sac and moves to the lower part of the uterus. In the lower part of the uterus, the straightened fetuses are first unpigmented but subsequently become pigmented as the secondary papillae on the body surface form and an adult-type cuticle forms beneath the embryonic cuticle. While the embryos are contained within their embryo cavities, nutrients are supplied by the placenta. Throughout development the mouth is open and in the mature fetus the gut is lined by peritrophic membrane and material is present in the gut lumen. Trachea have been observed only in fetuses that were ready for birth. Insemination, cyclical changes in the uterine epithelium, and the nature of the cuticle shed at parturition are discussed. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 33 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052240207
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  • 75
    Digitale Medien
    Digitale Medien
    Mechanics of the avian propatagium: Flexion-extension mechanism of the avian wing (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 225 (1995), S. 91-105 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The supporting elements of the avian propatagium were examined in intact birds and as isolated components, using static force-length measurements, calculated models, and airflow observations. The propatagial surface supported between Lig. propatagiale (LP) and brachium-antebrachium is equally resistant to distortion over the range of wing extension used in flight. The lengths LP assumes in flight occur across a nearly linear, low-stiffness portion of the force-length curve of its extensible pars elastica. In an artificial airflow, intact wings automatically extend; their degree of extension is roughly correlated with the airflow velocity. Comparisons between geometric models of the wing and the passive force-length properties of LPs suggest that the stress along LP blances the drag forces acting to extend the elbow. The mechanical properties (stiffness) of the LP vary and appear to be tuned for flight-type characteristics, e.g., changes in wing extension during flight and drag. Lig. limitants cubiti and LP combine to limit elbow extension at its maximum, a safety device in flight preventing hyperextension of the elbow and reduction of the propatagium's cambered flight surface. Calculations using muscle and ligament lengths suggest that M. deltoideus, pars propatagialis, via its insertions onto both the propatagial ligaments, controls and coordinates propatagial deployment, leading edge tenseness, and elbow/wing extension across the range of wing extensions used in flight. The propatagial ligaments and M. deltoideus, pars propatagialis, along with skeleto-ligamentous elbow/carpus apparatus, are integral components of the wing's extension control mechanism. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052250108
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  • 76
    Digitale Medien
    Digitale Medien
    Comparative embryology of teleostean fishes. I. Development and staging of the american shad, Alosa sapidissima (Wilson, 1811) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 225 (1995), S. 125-167 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: A new approach to devising embryological staging systems allows improved phylogenetic comparisons of developmental patterns. As in traditional approaches, morphological features provide the defining criteria for stages, but unlike traditional normal tables, each stage is defined by no more than one or two morphological criteria that are fundamental developmental features of all teleosts. Additional developmental features that occur concurrently with the defining criteria of a stage are treated as variables potentially uncoupled from the defining criteria for that stage. This system is well suited to detect phylogenetic heterochrony and promises to increase our understanding of conserved vs. labile features in teleostean embryology. In this study, I explain the defining criteria for American shad and then make comparisons with other clupeoids. The development of American shad includes 35 stages extending from fertilization to metamorphosis. Comparisons with other clupeoids indicate that the developmental pattern of shad is representative of the early ontogeny of many clupeoids during the embryonic and yolk sac periods and may be conservative for the group. However, several concurrent features, particularly hatching, formation of neuromasts, and opercular development, vary in developmental timing among clupeoids. Comparisons indicate that shad embryos delay the development of these concurrent features relative to other clupeoids. Modifications of the developmental pattern for different species of clupeoids are heterochronic but their phylogenetic and adaptive significance is unknown. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 22 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052250202
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  • 77
    Digitale Medien
    Digitale Medien
    Fiber-type composition of hindlimb muscles in the turtle, Pseudemys (Trachemys) scripta elegans (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 225 (1995), S. 193-211 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: A description is provided of the fiber-type composition of several hindlimb muscles of the adult turtle, Pseudemys (Trachemys) scripta elegans. In addition, cross-section areas of each fiber type and an estimation of the relative (weighted) cross-section area (wCSA) occupied by the different fiber types are also provided. Seven muscles were selected for study, based on their suitability for future neurophysiological analysis as components of the segmental motor system, and on their homologies with muscles in other vertebrates. The test muscles were iliofibularis (ILF), ambiens (AMB), external gastrocnemius (EG), extensor digitorum communis (EDC), flexor digitorum longus (FDL), tibialis anterior (TA), and peroneus anterior (PA). Serial sections of these muscles were stained for myosin adenosine triphosphatase (ATPase), NADH-diaphorase, and alpha-glycerophosphate dehydrogenase (α-GPDH), thereby enabling fiber-type classification on the basis of indirect markers for contraction speed and oxidative (aerobic) vs. glycolytic (anaerobic) metabolism. All muscles contained three fiber types: Slow oxidative (SO; possibly including some non-twitch tonic fibers); fast oxidative glycolytic (FOG); and fast glycolytic (Fg). There were at least 30% FOG and 50% FOG + Fg fibers in the seven muscles, the extreme distributions being the predominantly glycolytic ILF vs. the predominantly oxidative FDL muscle (ILF - 15.5% SO, 35.2% FOG, 49.3% Fg vs. FDL - 49.1% SO, 41.1% FOG, 9.8% Fg). As in other species, the test muscles exhibited varying degrees of regional concentration (compartmentalization) of the different fiber types. This feature was most striking in ILF. Pronounced compartmentalization was also observed in AMB, EG, PA, TA, and EDC, whereas the distribution of fiber types in the highly oxidative FDL was homogeneous. In five of the seven muscles, fiber size was ranked with Fg 〉 FOF 〉 SO. In terms of wCSA, which provides a coarse-grain measure of the different fiber types' potential contribution to whole muscle peak force, all muscles exhibited a higher Fg and lower SO contribution to cross-section area than suggested by their corresponding fiber-type composition. The largest relative increases in wCSA vs. fiber-type composition were in the ILF and AMB muscles. We conclude that the turtle hindlimb provides some interesting possibilities for testing for a division of labor among different muscles during different movements (e.g., sustained vs. ballistic), and for study of the behavior of the different fiber (and motor unit) types under normal and perturbed conditions. The relationships between the present results and previous findings on homologous muscles of the mammalian (cat, rat) and reptilian (lizard) hindlimb are discussed. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052250205
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  • 78
    Digitale Medien
    Digitale Medien
    Occurrence of ampulla in the ductus deferens of the Indian garden lizard Calotes versicolor daudin (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 225 (1995), S. 261-268 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: During the breeding season, the terminal end of the ductus deferens of Calotes versicolor appears swollen and is comparable to the ampulla of the mammalian ductus deferens. Its anatomy was studied from paraffin sections. It differentiates along its length into five zones. The first has thick smooth muscle and pesudostratified epithelium; the second has luminal trabeculae with an epithelium showing evidence of secretory activity; the third has the epithelial mucosa abutting against the smooth muscle in the form of pocketlike indentations; the fourth has crypts between epithelial folds; and the fifth zone is a sphincter. The anatomy of this ampullary region is indicative of secretory as well as spermatophagous roles. It undergoes seasonal change and appears to be androgen-dependent. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052250303
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  • 79
    Digitale Medien
    Digitale Medien
    Perinatal changes in avian muscle: Implications from ultrastructure for the development of endothermy (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 225 (1995), S. 357-367 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Endothermic heat production and the capacity to shiver develop soon after hatching in birds, permitting chicks to regulate their body temperature. Physiological studies have not clearly identified the developmental events causing this change in function. Here, we use electron microscopy to examine the development of structures involved in muscle activation, contraction, and metabolism coincident with the development of shivering thermogenesis. A stereological study was used to compare the ultrastructure of chicken iliofibularis before endothermic heat production was present (24 h before hatching) and 120 h later, when the iliofibularis had substantial capacity for shivering. Profound increases were found in the t-tubule system and terminal cisternae, mitochondrial cristae, and lipids. The number of triadic profiles increased 3.8-fold (7.6 ± 1.31/100 μm2 to 28.5 ± 2.90/100 μm2 fiber area). The surface area of cristae per mitochondrial volume doubled (12.0 ± 1.50 pm2/pm3 to 25.7 ± 1.84 μm2/μm3). Lipid droplets were rare in the iliofibularis of embryos about to hatch, but accounted for 4.4% of the muscle fiber volume in day 4 birds. We suggest that these ultrastructural changes more fully activate the iliofibularis, allow it to produce more heat both from calcium pumping and from contraction, and increase its endurance, thus permitting the muscle to be effective in thermogenesis. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052250307
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  • 80
    Digitale Medien
    Digitale Medien
    Masthead (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 226 (1995) 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052260101
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  • 81
    Digitale Medien
    Digitale Medien
    Sensory receptors on the adult labial and maxillary palpi and galea of Cicindela sexguttata (Coleoptera: Cicindelidae) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 226 (1995), S. 25-31 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Five types of sensilla are situated on the apical area of the labial and maxillary palpi and galea of Cicidela sexguttata. Large, conical, and peg-like sensilla are in rows on the central region of each palpus. These sensilla have a hollow cuticular peg, with an apical pore and multi-innervation. This central region of palpal sensilla is surrounded by campaniform sensilla that are disc-shaped and small conical peg sensilla. A similar type of conical sensillum as the found in the palpal central region is situated around the periphery of the palpal apex and apex of the galea. This conical peg sensillum is located in a shallow depression and is structurally similar to the other peg sensilla, but it has a mechanoreceptor neuron attached to the cuticular base of the sensillum. A long, single, trichoid sensillum is situated in the center of the galea and is hollow, thick-walled, porous, and multi-innervated. The apices of the palpi and galea have a large number of dermal gland openings that actively secrete a substance during the feeding process of the tiger beetle. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 15 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052260103
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  • 82
    Digitale Medien
    Digitale Medien
    Seasonal variation in ovarian histology of the viviparous lizard Sceloporus torquatus torquatus (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 226 (1995), S. 103-119 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Changes in ovarian histology during the reproductive cycle of the viviparous lizard Sceloporus torquatus torquatus are described. In general, the variation in follicular histology observed during the seasonal cycle is similar to that of other lizards. Sceloporus t. torquatus exhibits a cycle in which small, previtellogenic follicles exist in the ovary from December to August. Vitellogenesis occurs between September and November, followed by ovulation from late November to early December. Parturition occurs the following spring. After ovulation, the remaining follicular cells form the corpus luteum and luteolysis did not occur until April-May. Follicular atresia is commonly observed in previtellogenic follicles with polymorphic granulosa, but occurs less frequently in follicles during late vitellogenesis. There are two germinal beds in each ovary. The yolk nucleus is evident in young oocytes as is a vacuolated ooplasma prior to vitellogenesis. Extensive polymorphism is observed in yolk platelets. Mast cells and secretory cells are observed in the thecal layer of the follicular wall as are melanocytes in the ovarian stroma. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052260107
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  • 83
    Digitale Medien
    Digitale Medien
    Cytological aspects of vascular invasion by the trophoblast of Calomys callosus in hepatic tissues (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 226 (1995), S. 159-171 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Ectoplacental cones isolated from embryos on the seventh day of pregnancy wer transplanted beneath the hepatic capsule of recipeint adult animals to document the morphological patterns of vascular invasion by the trophoblast in the absence of the maternal environment and the influence of its peculiar vasculature. Females, and females and males of Calomys collosus, a cricetid rodent, were used, respectively, as embryo donors and recipient animals. Three to 5 days later, the grafted regions were excised and processed for light and electron microscopy. Invasion of the liver parenchyma by the trophoblast progressed along the vascular beds, associated with gradual phagocytosis of hepatic cells, greatly favoring the morphological characterization of invasive steps exhibited by the trophoblast to access the different kinds of vessels, to trespass the various vascular components and the different levels of the surrounding hepatic parenchyma. It is possible that either in utero during the establishment of embryomaternal circulation in early pregnancy or ex utero under experimental conditions, the trophblast exhibits similar vascular invasion behavior. In view of this, our findings may contribute to a better understanding of trophoblast cell migration to the maternal blood supply as well as the role of the trophoblast in the establishment of the placental circulation during pregnancy. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 17 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052260205
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  • 84
    Digitale Medien
    Digitale Medien
    A commentary on the segmental motor system of the turtle: Implications for the study of its cellular mechanisms and interactions (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 225 (1995), S. 213-227 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: A commentary is provided on the segmental motor system of the turtle Pseudemys (Trachemys) scripta elegans with an emphasis on neuronal, neuromuscular, and muscular mechanisms that control the development of force under normal, fatiguing, and pathophysiological conditions. For the central neuronal component of the segmental motor system, it has recently been shown that intracellular analysis of the firing properties of motoneurons and interneurons can be undertaken for relatively long periods of time in in vitro slices of the lumbosacral spinal cord of the adult turtle. In other less reduced in vitro preparations, analyses are available on complex motor behaviors generated by the isolated spinal cord. These behaviors of spinal neuronal networks are analogous in key aspects to those generated by the isolated in vivo cord, and by the cord in intact preparations. These results suggest that the neuronal components of the segmental motor system can now be studied from the cellular/molecular level of analysis in in vitro slice preparations to the systems level in conscious, freely moving animals. The in vitro approach can also be used for the analysis of cellular mechanisms in suprasegmental brain structures, which contribute to the control of voluntary movement. For the peripheral neuromuscular component of the segmental motor system, information is now available on muscle fiber types and selected aspects of sensory innervation, and it is feasible to study the mechanical and biochemical properties of motor units. As such, the turtle presents a valuable model for exploring interrelations between the neuronal and mechanical components of the segmental motor system of the generalized tetrapod. A prominent feature of these recent developments is the extent to which they have been deriven by findings that have emphasized an evolutionary conservation of motor-control mechanisms extending from ion channels, at the cellular level, to the control of multijointed movements at the systems level of analysis. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052250206
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  • 85
    Digitale Medien
    Digitale Medien
    Diversification of brain morphology in antarctic notothenioid fishes: Basic descriptions and ecological considerations (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 47-83 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The Notothenioidei, a perciform suborder of 120 species, dominates the ichthyofauna of the Southern Ocean around Antarctica. Unlike most teleost groups, notothenioids have undergone a corresponding ecological and phyletic diversification and therefore provide an excellent opportunity to study the divergence of the nervous system in an unusual environment. Our goal is to evaluate notothenioid brain variation in light of this diversification. To provide a baseline morphology, we examine the gross morphology and histology of the brain of Trematomus bernacchii, a generalized member of the family Nototheniidae. We then examine the variation in brain gross anatomy (32 species) and histology (10 species) of other notothenioids. Our sample represents about 27% of the species in this group and includes species from each of the six families, as well as species representing diverse ecologies. For comparison we reference the well-studied brains of two species of temperate perciformes (Perca flavescens and Lepomis humilis). Our results show that, in general, notothenioid brains are more similar to the brains of temperate perciforms than to the unusual brains of cave-dwelling and deep-sea fishes. Interspecific variation in gross brain morphology is comparable to that in Old World cyprinids and is illustrated for 17 species. Variation is especially noteworthy in the ecologically and geographically diverse family Nototheniidae. Measurements indicate that sensory regions (olfactory bulbs, eminentia granularis, and crista cerebellaris) exhibit the most pronounced variation in relative surface area. Association areas, including the corpus cerebelli and the telencephalon, exhibit moderate variation in size, shape, and lobation patterns. Regulatory areas of the brain, including the saccus vasculosus and the subependyma of the third ventricle, are also variable. These regions are best developed in species living in the subfreezing water close to the continent. In some species the expanded ependymal lining forms ventricular sacs, not previously described in any other vertebrate. Three species, including two nototheniids (Eleginops maclovinus and Pleuragramma antarcticum) and the only artedidraconid in our sample, have distinctive brains. The unique brain morphology of Pleuragramma is probably related to a sensory (lateral line) specialization for feeding. Within the Nototheniidae, a phyletic effect on cerebellar morphology is evident in the Coriiceps group and in the Pleuragramminae. Neither phyletic position nor ecological factors (water temperature, position in the water column, dietary habits) alone fully expalin the pattern of notothenioid brain diversification. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230107
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  • 86
    Digitale Medien
    Digitale Medien
    Announcement (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. I 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230202
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  • 87
    Digitale Medien
    Digitale Medien
    Skeletal morphogenesis in the urodele skull: I. Postembryonic development in the hemidactyliini (Amphibia: Plethodontidae) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 125-148 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The metamorphic species Eurycea bislineata is presented as a standard for evaluating the relationship between cranial ontogeny and life history in hemidactyliine plethodontid urodeles. Past and present descriptions are combined into a comprehensive summary of postembryonic skull development for this species, and the sequence, sizes of onset, and morphogenetic pathways are documented for all major remodelling events. Developmental series are also compared intraspecifically, between two populations of E. bislineata that differ in metamorphic size, and interspecifically, with species having different larval periods (Hemidactylium scutatum, Gyrinophilus porphyriticus, Pseudotriton ruber, E. wilderae, E. longicauda guttolineata) and with epigean (E. tynerensis, E. nana, and E. neotenes) and subterranean perennibranchiates (Haideotriton wallacei and Typhlomolge rathbuni). Cranial ontogeny is largely conserved in these hemidactyliines despite their disparate life histories. Outside the dichotomy of metamorphic and perennibranchiate development, variation is limited to interspecific differences involving the nasolacrimal duct, the repeated loss of the scleral cartilage, and minor dissociation of several metamorphic and postmetamorphic remodelling events. Some, but not all, of this variation is consistent with evolutionary differences in metamorphic size and age. The comparison of metamorphic and perennibranchiate hemidactyliines reveals a unique cranial ontogeny for urodeles, characterized by the abrupt and synchronous timing of almost all postembryonic remodelling, including the nasal skeleton, and the complete absence of these events in perennibranchiate forms. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230203
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  • 88
    Digitale Medien
    Digitale Medien
    Cytological and morphological ontogenesis and involution of the thymus in cichlid fishes (Cichlidae, Teleostei) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 175-190 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The ontogenesis and involution of thymus in cichlid fishes was studied with the aim of comparing development in the bottom-spawning species Tilapia zillii and T. tholloni, and in the mouth-brooding species Oreochromis auratus, O. niloticus, O. mossambicus, and Sarotherodon galilaeus. For comparison, data are also given on bottom-spawning Cichlasoma spp. from America and mouth-brooding Pseudotropheus auratus and Aulonocara nyassae from Africa. Developmental changes were followed histologically by means of light and electron microscopy of sections, beginning with embryos 24 h after fertilization, up to 14-year-old specimens of O. auratus. In all these fish, the anlagen of the thymus glands begins from the third and fourth gill pouches, and their development shows a high correlation with the pace of general organogenesis, which differs greatly in the bottom-spawning and mouth-brooding cichlids. In juveniles of bottom-spawners of 20-40 mm total length and in mouth-brooders of 40-60 mm total length, three cell types are present in the thymus: thymocytes, with large, dense nuclei; epitheliocytes, with long cell extensions containing bundles of tonofibrils; and reticulocytes, with short, granulated cell extensions. Hassall's corpuscles start to develop in larvae of T. zillii at 20-35 mm total length, and in specimens of 40 mm and more total length the corpuscles are typical, formed by inner and outer rings of epitheliocytes. At 30-45 mm total length, cell debris starts to accumulate in the interior of the corpuscles as an early sign of regression. As involution continues, macrophages accummulate within and around the Hassall's corpuscles. The epitheliocyte rings are eventually completely broken down. Isles of thymocytes persist in tilapias from the age of 1-14 years, but most of the thymus volume is occupied by blood lacunae and pigmented macrophage aggregations. The morphology is similar in the mouth-brooding species Pseudotropheus beginning at 1.5 years of age. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230206
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  • 89
    Digitale Medien
    Digitale Medien
    Ultrastructure of the ventral sucker of Schistosoma mansoni cercaria (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 215-223 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The ventral sucker of Schistosoma mansoni cercaria is a cupshaped structure that is attached to the ventral surface of the organism by a homogeneous connective tissue that surrounds the acetabular glands. The sucker consists of an extensive complex of circular and longitudinal muscles. The longitudinal muscles extend outwoard in a radial pattern to form the cup of the organ. Intermingled with the muscles are nerve bundles and subtegumental cells (cytons). Dendritic nerve fibers connect to sensory papillae which are found on the surface tegument. Two types of sensory papillae are present: a commonly found unsheathed uniciliated papilla, and a previously unidentified tegumental encapsulated structure. Tegument with spines covers the ventral sucker, although the tegumental encapsulated sensory papilla lacks spines. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230209
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  • 90
    Digitale Medien
    Digitale Medien
    Announcement (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. I 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230302
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  • 91
    Digitale Medien
    Digitale Medien
    Anatomy of neurons crossing the tritocerebral commissures of the cockroach Periplaneta americana (Blattaria) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 225-242 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The neuronal connections of the tritocerebral commissures of Periplaneta americana were studied in the brain-suboesophageal ganglion complex and the stomatogastric nervous system by means of heavy metal iontophoresis through cut nerve ends followed by silver intensification. The tritocerebral commissure 1 (Tc1) contains mainly the processes of the subpharyngeal nerve (Spn) whose neurons are located in both tritocerebral lobes and in the frontal ganglion. Some neurons of the frontal ganglion project through the Tc1 to the contralateral tritocerebrum. A few fibers in this commissure were observed projecting to the protocerebrum and the suboesophageal ganglion. There are tritocerebral neurons which pass through the Tc1 or the tritocerebral commissure 2 (Tc2) and extend on into the stomatogastric nervous system. One axon of a descending gaint neuron appears in the Tc2. This neuron lies in the tritocerebrum and connects the brain to the contralateral side of the ventral nerve cord. In addition, sensory fibers of the labral nerve (Ln) traverse both commissures to the opposite tritocerebrum. The anatomical and physiological relevance of the identified neuronal pathways is discussed. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230210
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  • 92
    Digitale Medien
    Digitale Medien
    Skeletal morphogenesis in the urodele skull: III. Effect of hormone dosage in TH-induced remodeling (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 243-261 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: This study examines the dosage dependency of thyroid hormone (TH)-mediated remodelling in the cranial skeleton of the hemidactyliine plethodontid urodele, Eurycea bislineata. One set of experiments quantifies morphogenetic responses in 21 tissues for four size-age classes of larvae immersed in four different T4 concentrations. A second set varies both the period and concentration of T4 treatment to evaluate the effect of different TH profiles on adult tissue shape. The tissues surveyed in this study exhibit a 100-fold range in TH sensitivity. Those in regressive morphogenesis have tissue-specific sensitivities which correlate with the timing of their remodelling in natural development: bone resorption is more sentitive than cartilage resorption and is initiated earlier in metamorphosis. In contrast, the TH sensitivities of tissues in progressive morphogenesis vary within each tissue type and even within some tissues, and they do not correlate with timing in natural development. Some explanation for this discrepancy is offered by the constant spatial and temporal relationships between nasal cartilage and dermal bone, which suggest that some TH-mediated ossification may additionally require induction by cartilage. Also, the failure of nasolacrimal duct morphogenesis at all but the lowest dosage correlates with the inductdion of integumentary changes that may preclude duct formation. Variable T4 treatments produce no effect upon the adult skull, other than loss of the nasolacrimal duct and/or foramen. These results have two developmental implicatons. First, the dosage dependencies of the nasolacrimal duct, ossification sequences, and cranial remodelling patterns all support a TH profile with exceptionally low levels at larval stages and at least a 100-fold increase at metamorphosis. Second, a small change in the rate of TH activity has the potential to effect a large-scale rearranggement and restructuring of TH-dependent remodelling. The lack of such transformations in metamorphic plethodontids suggests that TH activity is highly conserved in this group. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230303
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  • 93
    Digitale Medien
    Digitale Medien
    Masthead (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995) 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052240101
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  • 94
    Digitale Medien
    Digitale Medien
    Cephalic morphology of the honey possum, Tarsipes rostratus (Marsupialia: Tarsipedidae); an obligate nectarivore (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 303-323 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The sharply tapering skull of the honey possum is delicately constructed and has only a few, minute teeth; its mandible is reduced to a thin, flexible rod. The mandibular fossa has been diplaced caudally to the caudomedial corner of the squamosal. Head skeletons of the feathertail glider and western pygmy-possum, omnivores that are closely related to the honey possum, bear greater resemblance to the distantly related carnivorous fat-tailed dunnart than to the honey possum.Selected muscles associated with the jaws, hyoid, and tongue of these four mouse-sized (9-22 g) marsupials are described for the first time. The honey possum is characterized by a greatly reduced temporalis that is almost completely hidden by the eye. Its digastric consists of a single belly that inserts onto the caudal margin of the mylohyoid. The lateral pterygoid is relatively long as it extends caudally to insert onto the elongated mandible. The stylohyoid originates high up on the caudal surface of the tympanic bulla; it curves around the caudal and ventral surfaces of the bulla to reach the basihyoid. The insertion of the genioglossus is restricted to the caudal quarter of the tongue. Homologous muscles of the feathertail glider and western pygmy-possum are more similar to those of the fat-tailed dunnart. In addition to the very different musculoskeletal system, the honey possum has an unusual tongue that tapers to a fine point. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230307
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  • 95
    Digitale Medien
    Digitale Medien
    Development of the interphotoreceptor matrix in Xenopus laevis (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 223 (1995), S. 325-339 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Xenopus laevis interphotoreceptor matrix (IPM) contains a relatively aqueous insoluble wheat germ agglutinin (WGA)-binding component containing unidentifiied sialoglycoconjugates (Wood et al [1984] J. Comp. Neurol. 228:299-307). The appearance of WGA-binding macromolecules in the IPM was assessed during late embryonic stages (32-45) and in retinal rudiment cultures, using lectin cyutochemistry and Western blotting techniques. Metabolic labeling of the neural retina versus retinal pigment epithelium (RPE)-choroid of juvenile Xenopus with 35S-MET was also evaluated in vivo and in vitro. Lectin cytochemistry of eyes from developmental stages 32-42 demonstrated distinct WGA-ferritin-binding sites on the developing outer segment membranes and in the IPM compartment. At stages 44-46 extensive WGA-binding domains were present as an extracellular network with other randomly scattered domains near the retinal pigment epithelium. Retinal rudiments from stage 32-33 were isolated and allowed to differentiate in hanging drop culture (Hollyfield and Witkowsky [1974] J. Exp. Zool. 189:357-377) with or without an iinvesting pigment epithelium. Cultures developing with RPE exhibited an elaborate IPM with an anastomosing meshwork of WGA-ferritin binding sites. In the absence of RPE only limited amoutns of binding restricted to the immediate vicinity of the developing photoreceptor outer segement membranes was observed. When Western blots were probed with WGA-HRP, stage 32-45 retinas demonstrated a major WGA-binding band of 126 kD. Similar amounts of WGA-binding macromolecules were synthesized in preparations cultured in the presence or absence of the investing RPE. During development the major WGA-binding component is a 126-kD protein. Equivalent synthesis of this protein in the presence and absence of RPE suggests that the PE is not required for synthesis of this 126-kD component. These results suggest that the retina is the primary site of synthesis of the WGA-binding components of the Xenopus IPM, whereas the PE plays a principal role in their assembly and organization. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052230308
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  • 96
    Digitale Medien
    Digitale Medien
    Structure of ovaries in ensign scale insects, the most primitive representatives of Coccomorpha (Insecta, Hemiptera) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995), S. 23-29 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The ovaries of Orthezia urticae and Newsteadia floccosa are paired and composed of numerous short ovarioles. Each ovariole consists of an anterior trophic chamber and a posterior vitellarium that contains one developing oocyte. The trophic chamber contains large nurse cells (trophocytes) and arrested oocytes. The total number of germ cells per ovariole (i.e., cluster) is variable, but it is always higher than 32 and less than 64. This suggests that five successive mitotic cycles of a cystoblast plus additional divisions of individual cells are responsible for the generation of the cluster. Cells of the trophic chamber maintain contact with the oocyte via a relatively broad nutritive cord. The trophic chamber and oocyte are surrounded by somatic cells that constitute the inner epithelial sheath around the former and the follicular epithelium around the latter. Anagenesis of hemipteran ovarioles is discussed in relation to the findings presented. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052240104
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  • 97
    Digitale Medien
    Digitale Medien
    Biomechanical adaptation of ulnar cross-sectional morphology in brachiating primates (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995), S. 111-123 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The forelimbs of hylobatids (gibbons and siamang) are distinctive among tetrapods in that they are loaded in overall tension during normal locomotion. While hylobatid ulnae must also encounter bending stresses in the course of their full range of locomotor behavior, their loading regime differs from that of quadrupedal anthropoids in that these bending stresses are distributed evenly along the bone, are not exerted in a preferred plane, and are probably of generally lower magnitude. This study examines the degree to which hylobatid ulnae are adapted to this suspensory loading regime. We obtained cross-sections of ulnae at various increments along the length of the bone using CAT scans. The sample comprises 476 cross-sections representing the ulnae of 25 individuals from five species of comparable body size. We show that in gibbons and siamang, the patterning of ulnar cross-sectional area and resistance to bending in the dorsoventral plane along the ulnar diaphysis differ from that of similarly sized quadrupedal anthropoids in the manner predicted by a suspensory loading regime. We also find the same pattern for the ulnae of Ateles, whose loading regime may be fairly similar to that of hylobatids. However, we find that the cross-sectional shape of the ulnar diaphysis in hylobatids and Ateles does not differ from that of quadrupedal monkeys in the manner predicted by a suspensory loading regime. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052240112
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  • 98
    Digitale Medien
    Digitale Medien
    Formation and regression of the corpus luteum of the American alligator (Alligator mississippiensis) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995), S. 97-110 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Luteal morphology of the American alligator is unique when compared to other reptiles but is similar to that of its phylogenetic relatives, the birds. The theca is extensively hypertrophied, but the granulosa never fills the cavity formed following the ovulation of the ovum. The formation of the corpus luteum (CL) is correlated with elevated plasma progesterone concentrations, which decline dramatically after oviposition with the onset of luteolysis. Unlike those of most other reptiles, the central luteal cell mass is composed of two cell types; one presumably is derived from the granulosa, whereas the other is from the theca interna. Both cell types are present throughout gravidity but only one cell type is seen during mid to late luteolysis. A significant decline in luteal volume occurs following oviposition and continues throughout the post-oviposition period. The fastest decline in luteal volume occurs in the month immediately after oviposition; this rate then slows. Luteolysis appears to continue for a year or more following oviposition, as distinct structures of luteal origin can still be identified in animals 9 months after oviposition. The size of persistent CL can be used to determine whether a given female oviposited during the previous nesting season. Females with CL having volumes greater than 0.2 cm2 or CL diameters greater than 0.4 cm were active the previous season. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052240111
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  • 99
    Digitale Medien
    Digitale Medien
    Myological Peculiarities in Rhinoderma darwinii (Anura: Rhinodermatidae) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995), S. 125-129 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The myology of Rhinoderma darwinii is re-analyzed. Fourteen muscles (m. deltoides scapularis, m. coracoradialis, m. coracobrachialis brevis, m. omohyoideus, m. cucularis, m. interhyoideus, m. levator mandibular posterior externus, m. levator mandibular posterior articularis, m. levator posterior longus, m. geniohyoideus lateralis, m. geniohyoideus medialis, m. intermaxillaris, m. iliofibularis and m. iliofemoralis) are unique with respect to either structure or points of origin and/or insertion. An apical supplementary element of the m. intermandibularis is reported for the first time in the species, and another muscle, associated with the skin of the thigh, is described for the first time among anurans. Myological characters may be useful characters for future systematic and phylogenetic analysis of the Rhinodermatidae, one of the less diversified and enigmatic groups of neotropical frogs. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052240202
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  • 100
    Digitale Medien
    Digitale Medien
    Incubation temperature and gonadal sex affect growth and physiology in the leopard gecko (Eublepharis macularius), a lizard with temperature-dependent sex determination (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995), S. 159-170 
    Details
    ISSN: 0362-2525
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Temperature-dependent sex determination (TSD), in which the temperature at which an egg incubates determines the sex of the individual, occurs in egg-laying reptiles of three separate orders. Previous studies have shown that the embryonic environment can have effects lasting beyond the period of sex determination. We investigated the relative roles of incubation temperature, exogenous estradiol, and gonadal sex (testis vs. ovary) in the differentiation of adult morphological and physiological traits of the leopard gecko, Eublepharis macularius. The results indicate that incubation temperature, steroid hormones, and gonads interact in the development of morphological and physiological characters with incubation temperature resulting in the greatest differences in adult phenotype. Incubation temperature did not affect reproductive success directly, but may influence offspring survival in natural situations through effects on adult female body size. Postnatal hormones seem to be more influential in the formation of adult phenotypes than prenatal hormones. These results demonstrate that TSD species can be used to investigate the effects of the physical environment on development in individuals without a predetermined genetic sex and thus provide further insight into the roles of gonadal sex and the embryonic environment in sexual differentiation. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jmor.1052240205
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