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  • Electronic Resource  (50)
  • 2000-2004
  • 1985-1989  (50)
  • 1985  (50)
  • Genetics
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 277 (1985), S. 151-152 
    ISSN: 1432-069X
    Keywords: Genetics ; Hair dysplasia ; Protein polyacrylamide gel electrophoresis ; Uncombable hair syndrome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European archives of psychiatry and clinical neuroscience 234 (1985), S. 325-334 
    ISSN: 1433-8491
    Keywords: Calcification of basal ganglia, bilateral non-arteriosclerotic ; Fahr's syndrome ; Neuropsychiatric sequelae in Fahr's syndrome ; Parathormone dysfunctions ; Calcium-phosphorus metabolism ; Genetics ; Stammganglienverkalkung, bilateral symmetrische ; Fahrsches Syndrom ; neuropsychiatrische Veränderungen beim Fahr-Syndrom ; Parathormonhaushalt ; Calcium-Phosphor-Stoffwechsel ; Genetik
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Wir berichten über eine Untersuchung zur bilateral symmetrischen Stammganglienverkalkung (Fahrsches Syndrom). Aus einer Sippe von insgesamt 45 Probanden konnten 31 untersucht werden, 7 davon boten einen CT-positiven Befund. Bei zumindest einem weiteren Probanden (verstorben) ergibt sich aus der Anamnese der dringende Verdacht auf ein Fahrsches Syndrom. Die breit gef ächerte, aus technischen Gründen jedoch ambulante Untersuchung, sollte verschiedene Differentialdiagnosen der bilateral symmetrischen Stammganglienverkalkung abklären bzw. ausschließen. Es wurde der Versuch unternommen, die Ätiologie unserer Fälle auf Nebenschilddrüsendysfunktion oder Parathormonresistenz einzuengen. Zusätzliche Untersuchungen, wie z. B. Kupfer-, Eisen- oder Magnesiumbestimmungen stehen in Zusammenhang mit Befunden über die Zusammensetzung der “Hirnsteine”. Weiters maßen wir in unserer Untersuchung psychiatrischen, testpsychologischen, neurologischen und elektroencephalographischen Untersuchungen große Bedeutung bei. Sie sollten, zum Teil mit Falldarstellungen, ausführliche neuropsychiatrische Befunde vermitteln, da in bisherigen Arbeiten zum Fahrschen Syndrom diesen Gesichtspunkten häufig untergeordnete Bedeutung beigemessen wurde. 19 der 31 Probanden zeigten gleichzeitig neurologische, psychopathologische, testpsychologische und im EEG nachweisbare Abweichungen vom Normbefund. Zusätzlich fiel die Häufung psychopathologischer Auffälligkeiten nach Art affektiver Erkrankungen im Rahmen eines bestehenden hirnorganischen Psychosyndroms auf. Als direkte Ursache der neuropsychiatrischen Veränderungen nehmen wir morphologische Veränderungen im Bereich der Stammganglien, möglicherweise hervorgerufen durch Calcium- und Phosphorstoffwechselstörungen, an. Trotz des CT als einer Untersuchungstechnik, die einer wesentlich früheren Erfassung des Fahrschen Syndroms entgegenkommt, nehmen wir an, daß morphologische Veränderungen sich klinisch zu einem Zeitpunkt manifestieren können, zu welchem sie noch unterhalb der CT-Nachweisgrenze liegen. Die von uns erhobenen Stoffwechselbefunde, die denkbaren genetischen Aspekte and neuro-psychiatrischen Ergebnisse werden mit den aus der Literatur bekannten Befunden diskutiert.
    Notes: Summary We present a familial study (45 members), in which 31 members have been examined. Seven were afflicted with bilateral symmetrical calcification of the basal ganglia (Fahr's syndrome), as verified by CT scans. The case history and biochemical results for one additional proband, who had died, strongly indicate that this patient also had Fahr's syndrome. The wide range of examinations used in our study were aimed at excluding differential diagnoses of bilateral symmetrical calcification of the basal ganglia, other than when the origin was suspected to be in the parathyroid. The examinations had to be undertaken on an outpatient basis. Some of the variables, such as Fe, Cu, and Mg in the plasma, are connected with results that have been published on the composition of the apatite deposits. Psychiatric, psychological, neurological, and EEG examinations are emphasized. Together with the case reports they are meant to illustrate the neuropsychiatric aspects of this syndrome, the composite view of which has often been previously neglected. Nineteen of 31 probands showed neurological, psychopathological, psychological, and encephalographical deviations. We also noted a high incidence of organic brain syndromes that are phenomenologically similar to affective disorders. We believe these deviations to be directly related to morphological alterations of the basal ganglia, possibly due to errors in phosphorous and calcium metabolism. Although the CT scan has greatly facilitated the diagnosis of intracerebral calcifications, we assume that basal ganglia alterations under the CT-density threshold may also be of clinical importance. Our metabolic results, genetic issues, and neuropsychiatric findings are discussed.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 71 (1985), S. 39-43 
    ISSN: 1432-2242
    Keywords: Peas ; Genetics ; Foliage ; Heterozygosity ; Heterosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Eight near-isogenic lines of pea representing all the homozygous combinations of three genes af, st and tl, which modify leaf shape and size, were crossed in all possible ways excepting reciprocals. An analysis of the resulting 36 families has shown that homozygous mutant alleles at the tl locus acting with homozygous mutant alleles at the af and st loci increase both seed weight and plant haulm weight. The mutant alleles at the af and st loci seem, when homozygous, to have little effect by themselves upon seed weight but they do increase or decrease haulm weight, respectively. There is clear evidence of heterotic effects resulting from heterozygosity at each one of the three loci which modify seed weight, haulm weight and basal branching. The implications of such heterotic effects in pea breeding programmes are discussed.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 71 (1985), S. 461-466 
    ISSN: 1432-2242
    Keywords: Hordeum vulgare ; β-glucan ; Doubled haploids ; Genetics ; Correlated characters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Random inbred lines produced by doubled haploidy (DH) and single seed descent (SSD) have been used to investigate the genetics of β-glucan (gum) content in barley (Hordeum vulgare). Genetical analyses indicated that gum content is controlled by a simple additive genetic system. Significant negative genetic correlations were observed between β-glucan content, thousand grain weight and height in the DH samples. These correlations were much reduced in the SSD samples and would suggest linkage of the genes controlling these characters. The presence of repulsion linkages could be exploited in a barley breeding programme by producing F1 derived DH to generate recombinants with high thousand grain weight and low β-glucan content. Genetical parameters estimated from DH and F3 samples have successfully been used to predict the number of inbred lines transgressing the parental range for β-glucan content and bivariate combinations involving β-glucan.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1573-5133
    Keywords: Adaptation ; Dam ; Enzymes ; Electrophoresis ; Evolution ; Genetics ; Physiology ; Regulated streams ; Thermal maximum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Critical thermal maxima (CTM) and genetic variation were compared for red shiners, Notropis lutrensis, from regulated and unregulated sites on the Brazos River in northcentral Texas. Tailwater fish acclimated to 25°C had significantly lower CTM's than those from a site upstream from the dam and unregulated downstream sites. Significantly different intrasite variances were observed, with two- and four-fold larger CTM variances in fish from within 1 km and 30 km of the dam. Genetic variation was determined from electrophoretic comparisons at 21 structural gene loci. Mean heterozygosity was greatest at regulated sites. Tests for locus heterogeneity at five variable loci indicated that regulated and unregulated populations are not homogeneous. Fish under regulation were genetically more similar to each other than they were to those not affected by regulation. The proportions of the gene variance attributable to habitat alteration were partitioned, and fully one-third of the gene variation was attributed to stream regulation. Patterns of variation in thermal tolerance and metabolic enzymes in the red shiner correlated closely with temperature regimes associated with hypolimnion release from the dam. These adaptive responses have occurred in less than 40 years.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 89 (1985), S. 199-226 
    ISSN: 1573-5036
    Keywords: Ecology ; Genetics ; Physiology ; Salt tolerance ; Tomato species
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary An interdisciplinary approach to breeding for stress tolerance in plants has gained considerable recognition in the past few years. Accordingly, this article presents a synthesis of the genetic, physiological, and ecological aspects of salt tolerance in plants. An understanding of these aspects and the interrelationships between them is essential for an efficient breeding program. A significant part of the presentation concentrates on the basic problems associated with the genetics of tolerance to stresses and of quantitative characters in general, since many of the unsolved problems relevant to the genetics of salt tolerance are still general. Significant progress in the breeding of quantitative as well as qualitative traits in multicellular organisms depends on an understanding of the genetic and epigenetic dimensions of gene action. The discussion therefore includes an overview of (1) the limited existing knowledge on the genetic control of salt tolerance and (2) the physiological mechanisms and molecular targets central to the control of salt resistance as expressed by the amount and stability of yield. An additional subject emphasized here concerns the main strategies of adaptation of wild species to their natural habitats. An understanding of them is essential to (1) enable distinction between traits that can increase agricultural yield and traits that are favorable only for survival under natural conditions (such a distinction is essential, especially when wild species are used as a gene source), and (2) predict the best combinations of characters for efficient agricultural production in stressful environments.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 39-58 
    ISSN: 0192-253X
    Keywords: Drosophila melanogaster ; trisomy 3L ; dosage compensation ; heat shock ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Production of trisomic-3L Drosophila melanogaster has allowed further investigation of compensated levels of gene expression in autosomal trisomies. We find that four enzyme loci on this arm produce diploid levels of gene product in trisomic-3L larvae. For one of these genes, we show that all three alleles are expressed at similar levels. Two genes on 3L display dose-dependent levels of gene product, and their location, relative to the four compensating loci, indicates that these two classes of genes are not regionally separated. In trisomic-2R larvae, the level of enzyme produced from on 2R-linked gene was dose dependent. In contrast, measurements of five loci on the X chromosome in metafemales (X trisomies) suggest that most genes are compensated in these individuals. Heat-shock gene expression in trisomic-3L salivary glands was qualitatively similar to diploids. The quantities of the small hsps (from the 67B cluster on 3L) suggest that these four genes respond independently to the trisomic condition; two produce compensated levels of protein, whereas the other two produce dose-dependent levels of protein. The amount of hsp 83 produced in trisomies was similar to diploids (compensated). However, quantification of hsp 83 RNA showed that a dose-dependent level of transcript was produced. This implies that hsp 83 compensation is controlled post-transcriptionally.
    Additional Material: 4 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 93-100 
    ISSN: 0192-253X
    Keywords: heat shock ; phenocopy ; forked ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Heat shock uncovers the recessive forked phenotype when heterozygotes between f36a and wild-type are heated during sensitive periods in pupal development. We call the phenocopy of a mutant in such a heterozygote a heterocopy. The heterocopy in f36a/+ is virtually identical to the mutant phenotype; however, bristles on different parts of the body are affected during different sensitive periods. We discuss the hypothesis that the heat shock acts by affecting expression of the wild-type gene product corresponding to the mutant gene. The sensitive period for heterocopy induction in a specific tissue is proposed to correspond to the normal time of gene expression for the forked gene product in a particular tissue.
    Additional Material: 7 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 151-151 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 11
    ISSN: 0192-253X
    Keywords: Dictyostelium discoideum ; revertants of stmF mutants ; cGMP metabolism ; cGMP-specific phosphodiesterase ; suppressor mutations ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: stmF mutants of Dictyostelium discoideum produce long, banded aggregation streams on growth plates and exhibit altered cGMP metabolism. To learn more about the role of cGMP in chemotaxis and the nature of the defect in these mutants, 15 nonstreaming (Stm+) revertants of two stmF mutants were isolated and characterized. Fourteen of the revertants continued to show the elevated cAMP-induced cGMP response and very low cGMP-specific phosphodiesterase (cGPD) activity characteristic of their stmF parents. Parasexual genetic analysis revealed that many of these Stm+ revertants carried phenotypic suppressors unlinked to stmF. One Stm+ revertant, strain HC344, exhibited a low, prolonged cGMP response and relatively high cGPD activity throughout development. To determine whether the elevated cGPD activity in this revertant resulted from increased enzyme production or enhanced enzyme activity, cGPDs were partially purified from the wild-type strain, the stmF parent and revertant HC344, and properties of the enzymes were compared. cGPDs from the stmF mutant and the revertant showed similar differences from the wild-type enzyme in kinetic properties, thermal stability, and sensitivity to certain inhibitors. These results suggest that stmF is the structural gene of the cGPD. In addition, the unusual cGMP response in revertant HC344 appeared to be due to increased production of an altered cGPD.
    Additional Material: 5 Ill.
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  • 12
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 213-238 
    ISSN: 0192-253X
    Keywords: ciliate pattern formation ; expression of mutations ; Tetrahymena thermophila mutations ; reversals of symmetry ; spatial organization of cell surface ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The initial changes of cell-surface organization that occurred as the recessive janAl (janus) mutation of Tetrahymena thermophila first became expressed were elucidated in a special mating scheme in which old macronuclei homozygous for janA+ were synchronously replaced by new macronuclei homozygous for janAl. During this period of onset of expression, the number, regularity, and asymmetry of the ciliary rows remained unchanged. New normal (primary) oral apparatuses (OAs) continued to be formed posterior to old OAs, as in normal cells. At about four fissions after conjugation, abnormal (secondary) OAs with a partial reversal of asymmetry began to appear nearly opposite to the primary OAs, close to but not at the eventual circumferential position of janAl secondary OAs. The array of contractile vacuole pores (CVPs), normally located adjacent to two ciliary rows centered near 22% of the cell circumference to the righ of the primary oral meridian, underwent a two-step transformation: first, the number of adjacent ciliary rows bearing CVPs increased to 3, 4, and sometimes 5, then “skipped” rows appeared within this broadened CVP-arc to split the single set of CVPs into two separated subsets. The CVP transformations occurred gradually and progressively. They began prior to the expression of secondary OAs but accelerated as secondary OAs appeared. As the CVP are became broader, its midpoint shifted somewhat to the right, away from the primary oral meridian, but ended up close to halfway between the primary and secondary oral meridians. The data provide a better fit to an intercalation model than to an alternative double gradient model, suggesting that the janAl mutation alters the large-scale organization of positional values by preventing the expression of a subset of these values and thus provoking reverse-intercalation of the remainder.
    Additional Material: 16 Ill.
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  • 13
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 293-293 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 14
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 297-297 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 15
    ISSN: 0192-253X
    Keywords: Drosophila ; temperature effects ; heat-shock ; cell-lethal mutation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Pulses of various durations at temperatures between 29 and 38°C were applied to developing larvae of Drosophila melanogaster carrying the temperature-sensitive cell-lethal mutation 1 (1)ts726. The results show that it is not possible to reduce the time required for the induction of abnormalities in the mutant by treating larvae with heat pulses at temperatures higher than 29°C. Instead, treatment with high temperature leads to fewer abnormalities than 29°C treatments. Furthermore with high temperature treatments, the mutation has less effect on viability than is seen at 29°C. It is suggested that 1 (1)ts726 leads to abnormalities and death by a temperature-induced imbalance between different physiological or development events, rather than by interfering with the ability of the cell or the organism to withstand high temperature in general.
    Additional Material: 5 Ill.
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  • 16
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 59-74 
    ISSN: 0192-253X
    Keywords: Dictyostelium discoideum ; cell cohesion ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Three stage-specific cohesive systems operate in D. discoideum: VEG, elaborated by vegetative cells: AR, by aggregation competent cells; and PAR, by post aggregation stage cells. Previous study of a mutant strain JC-5 had shown the stability of its PAR system (but not the AR) to be temperature sensitive. However, the phenotypic expression of this mutation termed Coh A is complicated by the presence in that strain of a preexisting mutant gene Rde A, which accelerates developmental events generally and alters the pattern of morphogenesis. Genetic evidence presented here indicates that the two mutations have been separated by parasexual recombination yielding a Coh A, Rde A+ segregant class of which strain JC-36 is a prototype.At the permissive temperature, JC-36 follows a morphogenetic sequence like that of the wild type in respect to timing, morphogenetic pattern, and spore appearance. At the restrictive temperature, it forms normal aggregates at the usual time but exhibits two morphogenetic aberrancies during post aggregative development. First, fruit construction is arrested at a stage approximating the 16 hr “Bottle” stage of the wild type, though more squat and blunt tipped, and then the aggregate regresses. Cytodifferentiation into spores and stalk cells is also blocked. Second, a shift of slugs migrating normally at the permissive temperature to the restrictive causes the latter to disintegrate progressively as they leave clumps of cells behind them within the flattened sheath.JC-36 cells developing at the restrictive temperature also exhibited a decrease in EDTA resistant cohesivity attributable on two grounds to the sensitivity of the PAR system. In addition, the disappearance of the AR system completed in the wild type by the Mexicanhat (18-19 hr) stage is indefinitely arrested at an intermediate level in JC-36.
    Additional Material: 6 Ill.
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  • 17
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 113-132 
    ISSN: 0192-253X
    Keywords: eliminated DNA ; facultatively persistent sequences ; macronuclear development ; Tetrahymena thermophila ; phenotypic assortment ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: During conjugation in the ciliated protozoan, Tetrahymena thermophila, a somatic MAC-ronucleus develops from the germinal MICronucleus. Ten to 20 percent of the MIC genome is eliminated during this process. Three repetitive families have been identified which have different levels of repetition in the MIC and are eliminated to different degrees in the MAC. Some members of two of these families persist in the MAC. In this study, we have looked at these persistent sequences in the MAC of cell lines from a variety of sources including several inbed strains, two sets of caryonides, caryonidal subclones, and vegetatively aged cell clones. The results suggest that the sequences that remain in the MAC have a genetic predisposition to persist. However, epigenetic variations occur as the MAC develops so that only some of the persistent sequences are actually observed in a particular MAC. Polymorphisms may be generated if alternative processing of a single MIC segment occurs. These polymorphisms can later be resolved by phenotypic assortment during vegetative growth. These facultatively persistent sequences appear to differ from sequences previously described in this organism.
    Additional Material: 6 Ill.
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  • 18
    ISSN: 0192-253X
    Keywords: ecdysteroid ; prothoracic gland ; temperature sensitive ; Drosophila ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The dominant temperature-sensitive mutation L(3)3DTS (DTS-3) in Drosophila melanogaster causes lethality of heterozygotes during the third larval instar at the restrictive temperature (29°C). Temperature-shift experiments revealed two distinct temperature-sensitive periods, with lethal phases during the third larval instar (which may persist for 4 weeks) and during the late pupal stage. At 29°C mutant imaginal discs are unable to evert in situ, but did evert normally if cultured in the presence of exogenous ecdysterone or when implanted into wild-type larval hosts. The only morphologically abnormal tissue present in the lethal larvae is the ring gland, the prothoracic gland being greatly hypertrophied in third instar DTS-3 larvae. Injection of a single wild-type ring gland rescued these mutant larvae, indicating that the mutant gland is functionally, as well as morphologically, abnormal. Finally, the mutant larvae were shown to have less than 10% of the wild-type ecdysteroid levels. These results are all consistent with a proposed lesion in ecdysteroid hormone production in DTS-3 larvae. A comparison with the phenotypes of other “ecdysone-less” mutants is presented.
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  • 19
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 1-25 
    ISSN: 0192-253X
    Keywords: developmental mutants ; axolotl ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The Mexican axolotl (Ambystoma mexicanum) has enjoyed wide use in experimental embryology for over 100 yr. Its usefulness has been extended into the area of developmental genetics largely due to the contributions of R. Briggs and R. R. Humphrey at Indiana University. To date over 30 mutants have been described, almost all of which affect development. Some of these have been discovered in inbred strains while others have been uncovered in recent Mexican imports. These mutants can be subdivided into several major classes. Maternal effect mutations lead to deficiencies in informational, structural, or metabolic components of the egg essential to early development prior to the time at which the embryo's own genome becomes active. In contrast, the developmental lethals affect later stages in embryogenesis when both morphogenetic and biochemical events are determined exclusively by the genotype of the embryo. Most lead to death at about feeding stage. Some, the cell lethals, are believed to suffer from fundamental metabolic defects affecting all parts of the embryo. Others affect the development of specific organs or tissues. The developmental nonlethals also affect specific systems, but ones that are not essential to survival. Some affect the development and survival of pigment cells and these, along with isozyme variants, are useful as markers in developmental experiments.A number of the mutants have been studied in detail, but others scarcely at all. The purpose of this review is to bring them to the attention of all developmental biologists in the hope that their potential will be even more widely recognized.
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  • 20
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
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  • 21
    ISSN: 0192-253X
    Keywords: Tripsacum dactyloides ; Zea mays ; tripsacoid maize ; abnormal development ; ribosomal DNA ; restriction site change ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Some of the derivatives of a cross of maize (Zea mays L.) × Tripsacum dactyloides (L) L (2n = 72) have abnormal development leading to strange and striking morphologies. The Tripsacum chromosomes in these “tripsacoid” maize plants (with Tripsacum-like characteristics) were eliminated and the maize chromosomes were recovered through repeated backcrossing to maize. As an initial attempt to analyze the DNA alterations in tripsacoid maize, we have detected a few restriction site changes in the ribosomal DNA repeat of these plants (Hpa II, Bal I, Sst I, Mbo II, and Sph I) and a new Sph I site was mapped to the spacer region between the 26S and 17S genes. Several possible mechanisms for the generation of a new restriction site are discussed, and we propose that the transient presence of Tripsacum genome during the backcrossing in some way induced a rapid amplification and fixation of new restriction sites in a relatively short period of time.
    Additional Material: 6 Ill.
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  • 22
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 133-150 
    ISSN: 0192-253X
    Keywords: vitellogenesis ; Drosophila melanogaster ; egg shell ; oogenesis ; vitellogenin ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Ovarian follicle cells of wild type Drosophila melanogaster simultaneously secrete yolk polypeptides (YP1, YP2 and YP3) and vitelline membrane proteins. In order to understand the relationship between these two secretory activities, we have investigated the ultrastructure of a female sterile mutation that alters YP1 secretion and vitelline membrane deposition. Homozygous fs(1)1163 females lay eggs that collapse and contain reduced quantities of YP1. Secretory granules in follicle cells contain an electron-translucent component that is assembled into the developing vitelline membrane in both mutant and wild-type ovaries, and an electron-dense component that disperses after secretion in wild-type ovaries. Mutant ovaries differ from wild-type by (1) having larger secretory granules (2) forming clumps of the dense secretory component within the developing vitelline membrane (3) accumulating more tubules in the cortical ooplasm of vitellogenic oocytes, and (4) possessing altered yolk spheres. Mutant ovaries implanted into wild-type hosts showed no improvement in the secretory granules and slight improvement in the vitelline membrane clumps but amelioration of the oocyte phenotypes. Since genetic evidence suggests that the fs(1)1163 mutation resides in or near the Yp1 gene and biochemical data show that the mutation alters YP1 structure, we conclude that the ultrastructural phenotypes are due to a structurally abnormal YP1 in the mutant. The alteration in vitelline membrane structure caused by the dense clumps could account for collapsed eggs and, hence, the female sterility of the mutant.
    Additional Material: 23 Ill.
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  • 23
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 24
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 247-255 
    ISSN: 0192-253X
    Keywords: Drosophila ; triploid intersexes ; sex differentiation ; dosage compensation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Triploid intersexes homozygous for a mutant (msl-2) known to impede the hyperactivation of the X chromosome in diploid males differentiate into adults, sexually indistinguishable from their heterozygous sibs. A shift toward female sexual differentiation mediated by manipulating the rearing temperature is accompanied by an apparent increase in the level of an X-linked gene product. This unexpected result is rationalized in terms of differential lethality of individuals at the two extremities of the distribution of X-activity levels in intersexes raised at a particular temperature. No evidence of a mosaicism comparable to the sexual mosaicism exhibited could be found with respect to an X-linked gene product in triploid intersexes.
    Additional Material: 2 Ill.
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  • 25
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 281-291 
    ISSN: 0192-253X
    Keywords: DNA insertion ; reversion ; variegation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A spontaneous white mutation recovered in Drosophila mauritiana is unstable and reverts to normal eye color at a frequency greater than 4 per 1,000 ×-chromosomes. Germ line reversion occurs at a high rate in D. mauritiana males and in interspecific hybrid females, while the rate is depressed in D. mauritiana females. These events are not restricted to the germ line, as cases of variegated patterns of eye pigmentation, indicating somatic reversion, are recovered at a frequency comparable to that of the male germ line reversion rate. Germ line reversion events are genetically stable, while the somatic variegation patterns are not heritable. The patterns of eye pigment variegation produced suggests that reversion events are occurring throughout development. Whole genome DNA digests blotted and probed with the cloned D. melanogaster white gene indicate that this unstable white mutation in D. mauritiana is associated with an insertion of DNA that is lost upon reversion to wild type, indicating that this DNA insert is in fact a transposable element.
    Additional Material: 2 Ill.
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  • 26
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 1 (1985), S. 15-24 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 1 Ill.
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  • 27
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 1 (1985), S. 25-38 
    ISSN: 0749-503X
    Keywords: Cyclic AMP ; phosphoprotein phosphatase ; protein kinase ; suppressor ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The ppd1 mutant of yeast, Saccharomyces cerevisiae, was isolated as a suppressor of the cyr2 mutation which caused alteration of the catalytic subunit of cAMP-dependent protein kinase. Three peaks of phosphoprotein phosphatase activity (peak I, II and III) were identified by DEAE-Sephacel chromatography of crude extracts of the wild-type strain. The ppd1 mutant was deficient in peak III phosphoprotein phosphatase activity. The peak III enzyme efficiently utilized the phosphorylated forms of NAD-dependent glutamate dehydrogenase and trehalase as substrate. The ppd1 mutation did not suppress the cyr1, CYR3 or ras1 ras2 mutations. The ppd1 locus was located on chromosome II and had identical characteristcs with glc1. The ppd1 mutation suppressed the G1 arrest caused by nutritional limitation, but maintained sensitivity to mating pheromone. In diploids homozygous for the ppd1 mutation, no premeiotic DNA replication and commitment to intragenic recombination occurred and no spores were formed, suggesting that the accumulation of phosphorylated proteins in the absence of one of the phosphoprotein phosphatases is required for mitosis but not for the initiation of meiosis.
    Additional Material: 3 Ill.
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  • 28
    ISSN: 0749-503X
    Keywords: Heat shock ; translational control ; heterologous gene expression ; Saccharomyces ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Plasmid pPW229, containing the 2·25 kilobase transcribed sequence for the 70 000 Dalton heat shock protein of Drosophila,1 was integrated into plasmid CV13 and used to transform Saccharomyces cerevisiae. Upon a heat shock, at 41°C for 20 min, a new 70 000 Dalton protein appeared in the transformants. This protein was not detected in transformants grown at 23°C, nor in transfromants carrying the hybrid plasmid from which the structural gene for the 70 000 Dalton protein had been deleted. RNA was isolated from transromants grown at 23°C and from transformants heat shocked at 41°C. RNA complementary to the Drosophila heat shock gene was present in the transformants, grown either at 23°C or heat shocked. No complementary RNA was detected in yeast cells transformed with the hybrid plasmid from which the structural gene had been deleted. The Drosophila heat shock gene in yeast appears to be transcribed constitutively but translated only under heat shock conditions.
    Additional Material: 4 Ill.
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  • 29
    ISSN: 0749-503X
    Keywords: Killer ; virus-like particles ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: L-A-E double-stranded RNA (dsRNA), when introduced into cells carrying L-A-H and M2 dsRNAs, does not eliminate the L-A-H dsRNA, but (i) L-A-E does lower the copy number of L-A-H dramatically and (ii) L-A-E eliminates M2 dsRNA from the cell. That these two effects of L-A-E are related is shown by the fact that mutants of a strain carrying L-A-H and M2 selected for their resistance to exclusion of M2 by L-A-E [effect (ii)] have an altered L-A-H whose copy number is not lowered by L-A-E [effect (i)]. Although the L-A in K1 strains (L-A-HN in all cases examined) differs significantly both genetically and physically from the L-A in the K2 strain studied (L-A-H), the L-A-HN from the K1 strains can maintain M2 dsRNA, and the L-A-H from the K2 strains can maintain M1 dsRNA.
    Additional Material: 2 Ill.
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  • 30
    ISSN: 0749-503X
    Keywords: Apomictic sporulation ; meiosis restoration ; nucleo-mitochondrion interaction ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In an apomitic strain of Saccharomyces cerevisiae (ATCC 4117-H2) which undergoes a single nuclear division during sporulation and consequently forms asci containing two uninucleate diploid spores, a study was undertaken to investigate the effects of cultivation in three presporulation media (YPA; YNB; SMM) on nuclear division and ascoporogenesis in sporulation medium. Comparison of effects of presporulation culture in these media on the number of spores formed per ascus showed that a marked induction (30 ± 4·3 per cent) of three- and four-spored asci could occur in sporulation medium following cultivation in a defined YNB medium supplemented with a 1 per cent solution of vitamins and containing decreased ammonium sulphate and increased glucose levels. Experiments in which the concentrations of glucose and of ammonium sulphate were varied simultaneously indicated that the initial presporulation carbon to nitrogen source ratio is an important factor in determining tetrad formation in sporulation medium. Nuclear staining demonstrated two classes of asci: binucleate (one- and two-spored) and tetranucleate (three- and four-spored). Genetic evidence and data concerning effects of inclusion in sporulation medium of a meiotic inhibitor (glucose) indicated spores in tetrads were haploid rather than diploid. This ability to condition a significant number of cells for meiotic rather than apomictic differentiation made possible investigation of effects of mitochondrial inhibitors on both developmental processes simultaneously. It was found possible to selectively inhibit meiotic development by inclusion in sporulation medium of appropriate concentrations of specific inhibitors. Moreover, the data suggest meiotic sporulation is more strictly dependent than apomictic sporulation on mitochondrial function.
    Additional Material: 4 Ill.
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  • 31
    Electronic Resource
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 1 (1985), S. 82-82 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 32
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 1 (1985) 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 33
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 34
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 1 (1985), S. 67-77 
    ISSN: 0749-503X
    Keywords: Galactose metabolism ; regulation ; genefusion ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We present the nucleotide sequence of a 1599-base pair (bp) DNA fragment containing the entire GAL7 gene that encodes galactose-1-phosphate uridyltransferase of Saccharomyces cerevisiae. The deduced peptide was composed of 364 amino acid residues. The expected molecular weight was 42 005 daltons, which agreed with the observed value for the purified enzyme.1 The 3′-end of the GAL7 transcript mapped at a position 82 bp downstream from the UAA termination codon by the S1 nuclease protection experiment. We constructed a GAL7′-lac′Z fusion on various types of yeast plasmid vectors. The fused gene on any type of vector was induced by galactose and repressed by glucose as for the GAL7 gene on the chromosome. The response of GAL7′-lac′Z fusion to gal4Δ and gal80Δ regulatory mutations was also similar to the response of the chromosomal GAL7 gene. By using various deletions in the 5′-flanking region of the gene fusion, we delimited the sequence essential for galactose controlled expression with a 180 bp-fragment of DNA lying 92 bp upstream of the transcription initiation site.
    Additional Material: 4 Ill.
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  • 35
    Electronic Resource
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 1 (1985), S. 139-157 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 1 Ill.
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  • 36
    Electronic Resource
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 1 (1985), S. 83-138 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 10 Ill.
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  • 37
    Electronic Resource
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    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 1 (1985), S. 177-177 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 38
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 1 (1985), S. 173-175 
    ISSN: 0749-503X
    Keywords: Phosphofructokinase ; glycolysis ; alternative pathway(s) ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 1 Ill.
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  • 39
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 1 (1985), S. 159-171 
    ISSN: 0749-503X
    Keywords: PET18 ; temperature sensitive growth ; killer ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The basis of pleiotropy shown by the pet18 mutants of Saccharomyces cerevisiae (rho-0, KIL-0 and temperature sensitive growth) was examined by cloning the fragment which complements the defect in growth at 37°C of the pet18 mutants. the cloned DNA could complement the defect in the maintenance of the killer plasmid but did not give the cell the ability to maintain mitochondrial DNA. Sequence analysis of the cloned DNA revealed the presence of four open reading frames, at least two of which are necessary for the complementation activity. By using the cloned DNA as a probe, we found that two independent pet18 mutants have a deletion covering the entire sequence contained in the probe. From these results we predict that the traits of the pet18 mutants that concern temperature sensitivity and killer of the pet18 mutants are controlled by a separate gene(s) from that which participates in the maintenance of mitochondrial DNA.
    Additional Material: 7 Ill.
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  • 40
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 1 (1985) 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 41
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 1 (1985), S. 1-14 
    ISSN: 0749-503X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Additional Material: 5 Tab.
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  • 42
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 295-296 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 43
    Electronic Resource
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 75-75 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 44
    Electronic Resource
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 77-92 
    ISSN: 0192-253X
    Keywords: Drosophila ; muscle mutant ; larval muscle ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The phenotypic analysis of a new spontaneous recessive lethal mutation of Drosophila melanogaster is described. The lethal(2)thin mutation maps at 85.6 on chromosome 2 and produces a characteristic long, thin puparium due to an inability to shorten the larval form prior to pupariation. Histological examination of larval muscles and behavioural studies support the hypothesis that the mutation affects the striated structure of the larval muscles in late larval stages. Lethality largely occurs due to an inability to perform the movements necessary for pupation, although there is evidence for larval and possibly embryonic lethal phases.
    Additional Material: 8 Ill.
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  • 45
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985) 
    ISSN: 0192-253X
    Keywords: Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 46
    Electronic Resource
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 199-212 
    ISSN: 0192-253X
    Keywords: ultrastructure ; cell death ; Drosophila melanogaster ; imaginal disk ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The temperature-sensitive mutant l(3)c43hs1 is lethal at the restrictive temperature late in the last larval instar and has wing disks that show excessive growth when larvae are reared at 25°C. Such mutant disks give rise to defective wings showing duplications and deficiencies. Abnormal folding patterns are localized to the region between the wing pouch and the area where adepithelial cells are found; the disks retain an epithelial morphology. Apoptotic cell death is distributed throughout the wing disks without any obvious concentration of dead cells in a specific area. Cell death is seen as early as 12 hr after a shift to the restrictive temperature. Temperature shift experiments also show that cell death precedes the onset of overgrowth, but since the spatial distribution of death is not localized to the regions of abnormal folds, it is unlikely that cell death and overgrowth are causally related.
    Additional Material: 8 Ill.
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  • 47
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 239-246 
    ISSN: 0192-253X
    Keywords: Drosophila melanogaster ; germ line ; somatic line ; pole cell transplantation ; mosaics ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The Drosophila melanogaster mutant fs(1)1304 is an ovary autonomous female sterile mutant that causes abnormal morphology of the egg. Vitellogenesis proceeds at an abnormally slow rate in homozygous females. We have used pole cell transplantation to construct germ line mosaics in order to determine whether the 1304 defect depends upon the genotype of the germ line cells (oocyte or nurse cells) or the somatic line (follicle cells). We have found that the germ line is the primary target tissue where the mutant gene is expressed.
    Additional Material: 5 Tab.
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  • 48
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 269-280 
    ISSN: 0192-253X
    Keywords: UV ; DNA repair ; photoreactivation ; algae ; dark repair ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The response of Volvox to ultraviolet irradiation was analyzed. Young individuals isolated from a synchronous culture were exposed to UV light (120 J/m2) and subjected to variable lenght periods of dark following irradiation. The major effect of the UV treatment was the inability of the gonidia present in the colonies at the time of irradiation to continue and complete the developmental program. Individuals show a heightened sensitivity to UV for a limited period immediately following inversion and are insensitive at other stages of development. The cytotoxic effect of UV during this interval is completely reversed by the immediate exposure to white light and is increased with longer periods of dark treatment prior to exposure to white light. The temporal profile of the sensitivity defines a smooth curve in which the maximal sensitivity occurs three hours after inversion. The response to higher doses of UV (up to 500 J/m2) is a nonlinear increase in cytotoxicity and is disproportionanately greater in those individuals just prior to the period of maximal sensitivity than those later in development. The results suggest that Volvox has at least two pathways for the repair of UV damage and that one of these, the principal dark repair pathway, is temporarily deficient in the gonidia of young individuals.
    Additional Material: 4 Ill.
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  • 49
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 179-197 
    ISSN: 0192-253X
    Keywords: embryonic development ; phenocopies ; heat shock ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Heat shock of pre-adult Drosophila disrupts development and causes phenotypic abnormalities. Type of abnormality depends on developmental stage at time of shock. Defects probably result from disruption of stage specific processes by the heat shock response (which includes reduction of normal mRNA and protein production). This study uses heat shock to study stage specific processes in early development. Short, intense shocks (2-3 min, 42-43°C) are administered to carefully staged embryos within the first 5 h of development. Stage specific defects occur following shock at syncitial blastoderm or later. Abnormal segmentation follows shock at syncitial or cellular blastoderm. Segmentation is also disrupted by shocks 1 h after the onset of gastrulation, but not by shocks at the onset of gastrulation. Segmentation defects include phenocopies of pair rule mutants, which lack parts of alternate segments. Defective shortening of the germ band is common following shock at the onset of gastrulation. Germ band shortening normally occurs several hours after the time of shock; thus heat shock specifically affects control of a later developmental process. Development does not simply cease at the time of the distrupted process; rather a specific step in the developmental sequence is omitted or altered. Stage specific defects do not occur following pre-blastoderm shock. Pre-blastoderm eggs have few or no normal processes controlled by transcription, and poor ability to induce the heat shock response. This suggests that stage specific defects require disruption of transcription controlled processes. Pre-blastoderm eggs survive a 3-min shock less well than older eggs. The ability of older eggs to induce the heat shock response probably enhances survival. The mutant hairy was also investigated. Extreme alleles show a striking pair rule phenotype, while a weak allele does not. Heat shock of animals heterozygous or homozygous for the weak allele at blastoderm specifically increases the frequency of the extreme hairy phenotype. Thus heat shock may disrupt the same developmental process as is altered by the mutation.
    Additional Material: 5 Ill.
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  • 50
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    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 6 (1985), S. 257-268 
    ISSN: 0192-253X
    Keywords: Drosophila hydei ; cell death ; imaginal discs ; wing reduction ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Cell death and its effect on wing size have been described in some wing mutants of Drosophila hydei. Dead cells in the imaginal discs were localized by Nile-bule and acridine-orange staining. Various Notch (N) alleles, the mutation Costal-nick (Cnk) and the compound N/Cnk show characteristic patterns of cell death in the imaginal wing disc. Some but not all of the structural features of the adult wing can be related to the site of cell death during larval stages. In NAx types, extensive cell death is followed by regenerative growth, invalidating a simple relation between size of the disk and size of the wing. In Nts/Cnk cell death and wing morphology depend on the breeding temperature. From temperature experiments we conclude that cell death starts between day 4 and 5 after egg laying and can be induced by a shift to the restrictive temperature during the critical phase. Patterns of wing incisions and cell death in Nts/Cnk genotypes seem not to be delimited by any of the known compartment boundaries.
    Additional Material: 6 Ill.
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