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  • 101
    Electronic Resource
    Electronic Resource
    Coffee biotechnology and its application in genetic transformation (1997)
    Springer
    Euphytica 96 (1997), S. 167-172 
    Details
    ISSN: 1573-5060
    Keywords: Coffea spp. ; coffee ; genetic ; in vitro ; regeneration ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The most important advances obtained on in vitro coffee regeneration systems and in coffee genetic transformation, drawing perspectives and scopes to further studies in these fields are presented and discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1002969429010
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  • 102
    Electronic Resource
    Electronic Resource
    Comparison of the activities of CaMV 35S and FMV 34S promoter derivatives in Catharanthus roseus cells transiently and stably transformed by particle bombardment (1997)
    Springer
    Plant molecular biology 33 (1997), S. 943-946 
    Details
    ISSN: 1573-5028
    Keywords: CaMV 35S promoter ; Catharanthus roseus ; FMV 34S promoter ; particle bombardment ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Activities of several CaMV 35S and FMV 34S promoter derivatives fused to the gusA reporter gene were compared in suspension-cultured Catharanthus roseus cells that were transiently and stably transformed using particle bombardment. Our data demonstrate that the 35S and a deletion derivative of the 34S promoter combined with particle bombardment form useful tools for genetic engineering of C. roseus cells. Our results disagree on several points with activities of 35S and 34S promoter derivatives reported for tobacco, indicating that absolute and relative promoter activities can differ between plant species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005763605355
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  • 103
    Electronic Resource
    Electronic Resource
    EFFECTS OF HUMIC ACID ON TRANSPORT AND TRANSFORMATION OF MERCURY IN SOIL-PLANT SYSTEMS (1997)
    Springer
    Water, air & soil pollution 95 (1997), S. 35-43 
    Details
    ISSN: 1573-2932
    Keywords: humic acid ; mercury ; transport ; transformation ; soil-plant system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The influence of humic acid (HA) on the transport and transformation of mercury (Hg) in soil was studied. No available Hg could be detected (〈2.5 μg kg-1) in alluvial soil when the content of HA-carbon (HA-C) was higher than 0.2 g kg-1 although a large amount of Hg (8 μg kg-1) was applied to the soil. The available Hg decreased with the increase of HA in purple soil (r=0.735). There are significant correlations between HA concentration and organic Hg in the tested soils (r=0.974 for the purple soil and r=0.979 for the alluvial soil). The increase of HA results in decrease of Hg absorbed by plant from the soil. A loss of Hg from soil caused by microbes was observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026468724284
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  • 104
    Electronic Resource
    Electronic Resource
    the effect of phosphate on the transformation of ferrihydrite into crystalline products in alkaline media (1997)
    Springer
    Water, air & soil pollution 97 (1997), S. 397-412 
    Details
    ISSN: 1573-2932
    Keywords: desorption ; ferrihydrite ; modelling ; phosphate ; TEM ; transformation ; wastewater
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The presence of phosphate retards the transformation of ferrihydrite into crystalline products. Increasing phosphate from 0 to 1 mole % results in an order of magnitude decrease in the rate of transformation of ferrihydrite at pH 12. Levels of phosphate of ∼1 mol % suppress the formation of goethite (α-FeO(OH)) and result in the formation of a product consisting of η-Fe2O3. Higher levels of phosphate result in the ferrihydrite remaining amorphous, even after several hundred hours. Phosphate prevents formation of goethite by hindering the dissolution of ferrihydrite rather than by interfering with nucleation and growth of goethite in solution. The transformation rate of pure ferrihydrite is also strongly inhibited in the presence of dissolved phosphate. This is due to surface complexation. The transformation rate was measured at temperatures of 60 °C and 70 °C. The rate of transformation was found to be described by either (i) a solid-state reaction equation for powdered compacts or (ii) a zero-order reaction controlled by desorption. The transformation of the ferrihydrite matrix was accompanied by the loss of the phosphate trace component. X-ray diffraction indicates that no solid solution involving phosphate substitution into η-Fe2O3 is formed. Transmission electron microphotographs of the original precipitates containing phosphate confirm the presence of the phosphate and demonstrate its involvement in linking together extremely small particles of ferrihydrite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026416426611
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  • 105
    Electronic Resource
    Electronic Resource
    The effect of phosphate on the transformation of ferrihydrite into crystalline products in alkaline media (1997)
    Springer
    Water, air & soil pollution 97 (1997), S. 397-412 
    Details
    ISSN: 1573-2932
    Keywords: desorption ; ferrihydrite ; modelling ; phosphate ; TEM ; transformation ; wastewater
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The presence of phosphate retards the transformation of ferrihydrite into crystalline products. Increasing phosphate from 0 to 1 mole % results in an order of magnitude decrease in the rate of transformation of ferrihydrite at pH 12. Levels of phosphate of ∼1 mol % suppress the formation of goethite (α-FeO(OH)) and result in the formation of a product consisting ofη-Fe2O3. Higher levels of phosphate result in the ferrihydrite remaining amorphous, even after several hundred hours. Phosphate prevents formation of goethite by hindering the dissolution of ferrihydrite rather than by interfering with nucleation and growth of goethite in solution. The transformation rate of pure ferrihydrite is also strongly inhibited in the presence of dissolved phosphate. This is due to surface complexation. The transformation rate was measured at temperatures of 60 °C and 70 °C. The rate of transformation was found to be described by either (i) a solid-state reaction equation for powdered compacts or (ii) a zero-order reaction controlled by desorption. The transformation of the ferrihydrite matrix was accompanied by the loss of the phosphate trace component. X-ray diffraction indicates that no solid solution involving phosphate substitution intoη-Fe2O3 is formed. Transmission electron microphotographs of the original precipitates containing phosphate confirm the presence of the phosphate and demonstrate its involvement in linking together extremely small particles of ferrihydrite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02407475
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  • 106
    Electronic Resource
    Electronic Resource
    Effects of humic acid on transport and transformation of mercury in soil-plant systems (1997)
    Springer
    Water, air & soil pollution 95 (1997), S. 35-43 
    Details
    ISSN: 1573-2932
    Keywords: humic acid ; mercury ; transport ; transformation ; soil-plant system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The influence of humic acid (HA) on the transport and transformation of mercury (Hg) in soil was studied. No available Hg could be detected (〈2.5 μg kg−1) in alluvial soil when the content of HA-carbon (HA-C) was higher than 0.2 g kg−1 although a large amount of Hg (8 μg kg−1) was applied to the soil. The available Hg decreased with the increase of HA in purple soil (r=0.735). There are significant correlations between HA concentration and organic Hg in the tested soils (r=0.974 for the purple soil and r=0.979 for the alluvial soil). The increase of HA results in decrease of Hg absorbed by plant from the soil. A loss of Hg from soil caused by microbes was observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02406154
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  • 107
    Electronic Resource
    Electronic Resource
    Plasmid-assisted morpholine degradation by Pseudomonas fluorescens CAS 102 (1997)
    Springer
    World journal of microbiology and biotechnology 14 (1997), S. 7-10 
    Details
    ISSN: 1573-0972
    Keywords: Biodegradation ; morpholine ; plasmid ; Pseudomonas fluorescens ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A fast-growing Pseudomonas fluorescens CAS102, isolated by enrichment technique from polluted soil, effectively utilized morpholine as the energy source. The strain was able to grow in high concentrations of morpholine but accumulation of ammonia inhibited its growth and complete mineralization. The molar conversion ratio of morpholine to ammonia was 1:0.82. The organism harboured a single, multiple antibiotic- and heavy metal-resistance 140kb plasmid which was resistant to curing. Transformation studies showed that the morpholine degradative phenotype was expressed only in Pseudomonas putida and not in Escherichia coli. Growth studies on different degradative intermediates of morpholine suggested that plasmid-encoded genes were involved in the heterocyclic ring cleavage and the remaining reactions were mediated by chromosomal genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008855912907
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  • 108
    Electronic Resource
    Electronic Resource
    BET Sample Pretreatment of Synthetic Ferrihydrite and its Influence on the Determination of Surface Area and Porosity (1997)
    Springer
    Journal of porous materials 4 (1997), S. 165-169 
    Details
    ISSN: 1573-4854
    Keywords: ferrihydrite ; hematite ; BET ; porosity ; catalyst ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Ferrihydrite is a poorly-ordered iron oxyhydroxide which possesses a high specific surface area (〉200 m2/g). This makes it an important constituent for surface related processes in nature and catalysis. This study focuses on the precautions that have to be taken in the sample preparation prior to BET measurements in order to avoid essential structural transformations. The experiments showed that temperatures between 90 and 120°C are necessary to remove surface contaminations and simultaneously prevent structural transformation of the ferrihydrite during the outgassing procedure. Furthermore, care has to be taken to keep the humidity low in the immediate proximity of the sample, due to the strong impact of this parameter on the structural stability of ferrihydrite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009610800182
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  • 109
    Electronic Resource
    Electronic Resource
    Enhanced resistance to two stem borers in an aromatic rice containing a synthetic cryIA(b) gene (1997)
    Springer
    Molecular breeding 3 (1997), S. 401-414 
    Details
    ISSN: 1572-9788
    Keywords: Bacillus thuringiensis ; Chilo suppressalis ; biolistic ; rice ; Scirpophaga incertulas ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Rice cultivars of isozyme group V include high-quality, aromatic rices that are difficult to improve by traditional methods because of the loss of quality characters upon sexual hybridization. Their low-tillering plant type predisposes them to economic loss from attack by stem borers, a group of insects to which they are susceptible. We report here the enhancement of stem borer resistance in cv. Tarom Molaii through transformation by microprojectile bombardment. Embryogenic calli derived from mature seeds were bombarded with gold particles coated with plasmid pCIB4421, carrying a synthetic truncated toxin gene based on the cryIA(b) gene from Bacillus thuringiensis, and plasmid pHygII, carrying the hygromycin phosphotransferase (hpt) selectable marker gene. Inclusion of 50 mg/l hygromycin B in culture media from bombardment through to rooting of plantlets eliminated escapes. The procedure generated three independent hpt transformants of which two also contained the cryIA(b) gene. One such line (No. 827) produced truncated (67 kDa) CryIA(b) protein equivalent to about 0.1% of total soluble protein. The cryIA(b) gene was controlled by the promoter of the maize C4 PEP carboxylase gene and was expressed in leaf blades but was not expressed to a detectable level in dehulled mature grain. Line 827 contained about 3 copies of the cryIA(b) gene which segregated as a single dominant Mendelian locus in the second (T1) and third (T2) generations and co-segregated with enhanced resistance to first-instar larvae of striped stem borer (Chilo suppressalis) and yellow stem borer (Scirpophaga incertulas). T2 line 827-6 homozygous for the cryIA(b) gene showed no dead hearts or whiteheads after infestation with stem borers, whereas T2 line 827-25 lacking the gene averaged 7 dead hearts per plant and 2.25 whiteheads per plant. These results establish that transformation of high-quality rices of group V is a feasible alternative to sexual hybridization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009695324100
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  • 110
    Electronic Resource
    Electronic Resource
    Genetic transformation of Populus genotypes with different chimaeric gene constructs: transformation efficiency and molecular analysis (1997)
    Springer
    Transgenic research 6 (1997), S. 111-121 
    Details
    ISSN: 1573-9368
    Keywords: Ac ; Agrobacterium ; aspen ; Populus ; transformation ; transposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Aspen (Populus tremula) and hybrid aspen (P. tremula × P. tremuloides) were transformed with different gene constructs using two types of promoter. The aim was to determine the influence of the reporter gene rolC, controlled by promoters of viral or plant origin, on genetic and morphologic expression of different transgenic aspen clones. An improved transformation method using leaf discs was developed, by which putative transgenic plantlets were regenerated at high efficiencies (up to 34%) on kanamycin-containing medium. Transgenic aspen carrying the rolC gene from Agrobacterium rhizogenes under control of the cauliflower-35S-promoter are reduced in size with smaller leaves, whereas aspen transgenic for the same rolC gene, but under control of the light inducible rbcS promoter from potato, are only slightly reduced in size compared to untransformed controls. However, all clones carrying 35S-rolC and rbcS-rolC genes revealed light-green colouration of leaves when compared to untransformed aspen. Owing to this special feature, constructs were used in which expression of the rolC gene was inhibited by insertion of a transposable element, Ac, from maize. Transgenic aspen transformed with the 35S-Ac-rolC and rbcS-Ac-rolC genes were morphologically similar to untransformed aspen, but out of 54 independently regenerated 35S-Ac-rolC transgenic aspen clones, 30 clones showed light-green/dark green variegated leaves. In contrast, out of 19 independently transformed rbcS-Ac-rolC aspen clones, only two clones revealed light-green/dark green variegated leaves. The role of bacterial strains in transformation, and molecular genetics of transgenic aspen plants (including the function of the transposable element, Ac, in the aspen genome) are discussed
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018421620040
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  • 111
    Electronic Resource
    Electronic Resource
    Transient expression of anthocyanin genes in barley epidermal cells: potential for use in evaluation of disease response genes (1997)
    Springer
    Transgenic research 6 (1997), S. 233-244 
    Details
    ISSN: 1573-9368
    Keywords: transformation ; Erysiphe graminis ; powderymildew ; coleoptile
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A transient assay is described that should allow evaluation of the role of host genes in disease response by enhancing or disrupting expression of those genes in specific cells and looking for effects on disease development. The assay also has the potential for assessing utility of host and non-host genes in enhancing resistance to disease in transgenic plants. Particle bombardment with a helium discharge particle gun was utilized to transiently express genes in epidermal cells of coleoptiles of barley (Hordeum vulgare). An anthocyanin reporter gene construct provided a means of identifying those cells that were transiently expressing introduced DNA. Optimal transient expression rates were achieved two days following bombardment with 1800 psi helium pressure, 1.0 μm diameter gold particles, and coleoptile pre- and post-treatment in 0.30--0.35 m mannitol/sorbitol. Under optimal conditions, at least 35 cells expressed anthocyanin per bombardment. Transiently expressing cells were inoculated with the fungal pathogen, Erysiphe graminis f. sp. hordei, and fungal development observed. Neither the bombardment procedures, the presence of nearby dead cells, nor accumulation of anthocyanin within living cells affected fungal development in living cells. Therefore, incorporation of disease-related genes onto the same plasmid as the reporter genes will allow evaluation of the role of those genes in disease development or suppression. Since particle bombardment is possible with a great range of different plant tissues, the described methodology should exhibit wide applicability for evaluating genes in diverse plant-pathogen interactions, as well as genes involved in many other biological processes
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018498309562
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  • 112
    Electronic Resource
    Electronic Resource
    Matrix attachment regions (MARs) enhance transformation frequency and transgene expression in poplar (1997)
    Springer
    Transgenic research 6 (1997), S. 415-420 
    Details
    ISSN: 1573-9368
    Keywords: GUS ; matrix attachment regions ; Populus ; transformation ; transgene expression ; Agrobacterium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We tested the value of a matrix attachment region (MAR) fragment derived from a tobacco gene for increasing the frequency of Agrobacterium-mediated transformation. A binary vector that carried a GUS reporter gene containing an intron and an nptII gene was modified to contain flanking MAR elements within the T-DNA borders. Vectors containing or lacking MARs were then used to transform tobacco, a readily transformabl e poplar clone (Populus tremula × P. alba), and a recalcitrant poplar clone (Populus trichocarpa × P. deltoides). MARs increased GUS gene expression approximately 10-fold in the two hybrid poplar clones and twofold in tobacco one month after cocultivation with Agrobacterium; MARs also increased the frequency of kanamycin-resistant poplar shoots recovered
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018439518649
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  • 113
    Electronic Resource
    Electronic Resource
    Transformation of a grain legume (Lupinus angustifolius L.) via Agrobacterium tumefaciens-mediated gene transfer to shoot apices (1997)
    Springer
    Molecular breeding 3 (1997), S. 341-349 
    Details
    ISSN: 1572-9788
    Keywords: Agrobacterium tumefaciens ; bar gene ; grain legume ; Lupinus angustifolius ; phosphinothricin ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Transgenic plants of Lupinus angustifolius L. (cvs. Unicrop and Merrit) were routinely generated using Agrobacterium-mediated gene transfer to shoot apices. The bar gene for resistance to phosphinothricin (PPT, the active ingredient of the herbicide Basta) was used as the selectable marker. After co-cultivation, the shoot apex explants were transferred onto a PPT-free regeneration medium and their tops were thoroughly wetted with PPT solution (2 mg/ml). The multiple axillary shoots developing from the shoot apices were excised onto a medium containing 20 mg/l PPT. The surviving shoots were transferred every second week onto fresh medium containing 20 mg/l PPT. At each transfer, the number of surviving shoots decreased, until it stabilized. Indeed, some of these chimeric shoots surviving the PPT selection, eventually produced new green healthier axillary shoots which could be transferred to soil. This whole process took from 5 to 9 months after co-cultivation. Average transformation frequencies of 2.8% for cv. Unicrop and of 0.4% for the commercial cultivar Merrit were achieved. Molecular analysis of T0, T1, and T2 generations demonstrated stable integration of the foreign gene into the plant genome and expression of the integrated gene. Transformed plants of the T1 and T2 generations were resistant in glasshouse trials where the herbicide Basta (0.1 mg/ml) was sprayed onto whole plants. These results demonstrate that Agrobacterium-mediated gene transfer to preorganised meristematic tissue combined with axillary regeneration can form the basis of a routine transformation system for legume crop species which are difficult to regenerate from other explants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009642620907
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  • 114
    Electronic Resource
    Electronic Resource
    Agrobacterium tumefaciens-mediated transformation of Brassica napus winter cultivars (1997)
    Springer
    Transgenic research 6 (1997), S. 279-288 
    Details
    ISSN: 1573-9368
    Keywords: Agrobacterium tumefaciens ; Brassica napus ; wintercultivar ; transformation ; GUS ; hygromycin ; kanamycin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An efficient protocol for Agrobacterium tumefaciens-mediated transformation of six commercial Brassica napus winter cultivars is described. Two B. napus spring cultivars were analysed for comparison. Five strains of A. tumefaciens with different combinations of nopaline and octopine chromosomal backgrounds and virulence plasmids were used for cocultivation. Selection of putative regenerated transgenic plants was performed on kanamycin- or hygromycin-containing media. The scores of transgenic plants were calculated on the basis of GUS (β-glucuronidase) activity, detected by the histochemical X-Gluc test. Target tissue derived from the cut surface of cotyledon petioles resulted in successful transformation with all the winter cultivars tested. Target tissue from hypocotyl segments resulted in a successful transformation with only one winter cultivar. The transformation rates for B. napus winter cultivars in this study were higher than in previous reports. Southern blot analysis revealed that integration of marker genes occurred in single and in multiple copies and at multiple loci in the genome. The transgenic plants all grew normally and developed fertile flowers after a vernalization period. After self-pollination, Southern blot analysis of selected GUS active F1 plants revealed that introduced marker genes were stably inherited to the next generation. These data demonstrate that morphologically normal, fertile transgenic plants of B. napus winter cultivars can be achieved with both nopaline- and octopine-derived A. tumefaciens strains. This protocol should have a broad application in improvement of Brassica napus winter cultivars by introduction of foreign genes
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018458628218
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  • 115
    Electronic Resource
    Electronic Resource
    SAAT: sonication-assisted Agrobacterium-mediated transformation (1997)
    Springer
    Transgenic research 6 (1997), S. 329-336 
    Details
    ISSN: 1573-9368
    Keywords: Agrobacterium ; SAAT ; sonication ; transformation ; wounding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Plant transformation via Agrobacterium can be limited by both host specificity and the inability of Agrobacterium to reach the proper cells in the target tissue. Described here is a new and efficient Agrobacterium-based transformation technology that overcomes these barriers and enhances DNA transfer in such diverse plant groups as dicots, monocots, and gymnosperms. This new technology, called sonication-assisted Agrobacterium-mediated transformation (SAAT), involves subjecting the plant tissue to brief periods of ultrasound in the presence of Agrobacterium. Scanning electron and light microscopy reveal that SAAT treatment produces small and uniform fissures and channels throughout the tissue allowing the Agrobacterium easy access to internal plant tissues. Unlike other transformation methods, this system has the potential to transform meristematic tissue buried under several cell layers. SAAT increases transient transformation efficiency in several different plant tissues including leaf tissue, immature cotyledons, somatic and zygotic embryos, roots, stems, shoot apices, embryogenic suspension cells and whole seedlings. A 100- to 1400-fold increase in transient β- glucuronid ase expression has been demonstrated in various tissues of soybean, Ohio buckeye, cowpea, white spruce, wheat and maize. Stable transformation of both soybean and Ohio buckeye has been obtained using SAAT of embryogenic suspension culture tissues. For soybean, SAAT treatment was necessary to obtain stable transformation with this tissue
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018470930944
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  • 116
    Electronic Resource
    Electronic Resource
    The Anopheles albimanus white gene: molecular characterization of the gene and a spontaneous white gene mutation (1997)
    Springer
    Genetica 101 (1997), S. 87-96 
    Details
    ISSN: 1573-6857
    Keywords: Anopheles albimanus ; malaria vector ; transformation ; white gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have cloned and characterized the white gene of Anopheles albimanus. Comparison of the deduced amino acid sequence of this white gene with its homologs from six species of Diptera show that the An. albimanus gene is most similar to the white gene of An. gambiae (92% identity). A spontaneous white-eyed mutant An. albimanus was caused by an approximately 10 kb insertion into a CT dinucleotide repeat region of intron 2 of the white locus. The flanks of this insertion are long (at least 400 bp), nearly perfect inverted terminal repeat sequences. This cloned white gene should be useful as a marker for germ line transformation of An. albimanus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018376525897
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  • 117
    Electronic Resource
    Electronic Resource
    Transformation of rice mediated by Agrobacterium tumefaciens (1997)
    Springer
    Plant molecular biology 35 (1997), S. 205-218 
    Details
    ISSN: 1573-5028
    Keywords: Agrobacterium tumefaciens ; rice ; transformation ; monocotyledons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Agrobacterium tumefaciens has been routinely utilized in gene transfer to dicotyledonous plants, but monocotyledonous plants including important cereals were thought to be recalcitrant to this technology as they were outside the host range of crown gall. Various challenges to infect monocotyledons including rice with Agrobacterium had been made in many laboratories, but the results were not conclusive until recently. Efficient transformation protocols mediated by Agrobacterium were reported for rice in 1994 and 1996. A key point in the protocols was the fact that tissues consisting of actively dividing, embryonic cells, such as immature embryos and calli induced from scutella, were co-cultivated with Agrobacterium in the presence of acetosyringonc, which is a potent inducer of the virulence genes. It is now clear that Agrobacterium is capable of transferring DNA to monocotyledons if tissues containing ‘competent’ cells are infected. The studies of transformation of rice suggested that numerous factors including genotype of plants, types and ages of tissues inoculated, kind of vectors, strains of Agrobacterium, selection marker genes and selective agents, and various conditions of tissue culture, are of critical importance. Advantages of the Agrobacterium-mediated transformation in rice, like on dicotyledons, include the transfer of pieces of DNA with defined ends with minimal rearrangements, the transfer of relatively large segments of DNA, the integration of small numbers of copies of genes into plant chromosomes, and high quality and fertility of transgenic plants. Delivery of foreign DNA to rice plants via A. tumefaciens is a routine technique in a growing number of laboratories. This technique will allow the genetic improvement of diverse varieties of rice, as well as studies of many aspects of the molecular biology of rice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005847615493
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  • 118
    Electronic Resource
    Electronic Resource
    Molecular cloning and expression analysis of dihydroflavonol 4-reductase gene in flower organs of Forsythia × intermedia (1997)
    Springer
    Plant molecular biology 35 (1997), S. 303-311 
    Details
    ISSN: 1573-5028
    Keywords: competitive PCR ; flavonoid pathway ; Forsythia ; gene expression ; transformation ; woody ornamentals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The expression, during flower development, of the gene encoding the anthocyanin pathway key enzyme dihydroflavonol 4-reductase (DFR) was investigated in floral organs of Forsythia × intermedia cv. ‘Spring Glory’. Full-length DFR and partial chalcone synthase (CHS) cDNAs, the gene of interest and a flavonoid pathway control gene respectively, were obtained from petal RNA by reverse transcription PCR. Whereas for CHS northern blot analysis enabled the study of its expression pattern, competitive PCR assays were necessary to quantify DFR mRNA levels in wild-type plants and in petals of 2 transgenic clones containing a CaMV 35S promoter-driven DFR gene of Antirrhinum majus. Results indicated a peak of CHS and DFR transcript levels in petals at the very early stages of anthesis, and different expression patterns in anthers and sepals. In comparison to wild-type plants, transformants showed a more intense anthocyanin pigmentation of some vegetative organs, and a dramatic increase in DFR transcript concentration and enzymatic activity in petals. However, petals of transformed plants did not accumulate any anthocyanins. These results indicate that other genes and/or regulatory factors should be considered responsible for the lack of anthocyanin production in Forsythia petals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005881032409
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    Production of ROL gene transformed plants of Rosa hybrida L. and characterization of their rooting ability (1997)
    Springer
    Molecular breeding 3 (1997), S. 39-47 
    Details
    ISSN: 1572-9788
    Keywords: adventitious root formation ; Agrobacterium tumefaciens ; A. rhizogenes ; rootstock ; rose ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Transgenic plants of the rootstock Rosa hybrida L. cv. Moneyway were produced via a two-step procedure. First, kanamycin-resistant roots were generated on stem slices from micropropagated shoots, which were cocultivated with Agrobacterium tumefaciens containing the neomycin phosphotransferase II (NPTII) gene for conferring kanamycin resistance, together with individual ROL genes from A. rhizogenes. Root formation was quite efficient and up to two kanamycin-resistant roots per stem slice were produced. In the second step, these roots were used to regenerate transgenic plants via somatic embryogenesis. Although regeneration lasted up to 12 months, production of several transformants was successfully accomplished. Untransformed escapes were not found, indicating that the initial selection on kanamycin resistance was reliable. The presence of a combination of ROLA, B and C genes enhanced adventitious root formation on micropropagated shoots and explants of stems and leaves. It appears that the auxin sensitivity was increased to such a degree that cells were able to respond even to endogenous auxins present in shoots and leaves. Rooting experiments in greenhouse demonstrated that adventitious root formation on cuttings was improved threefold upon introduction of these ROL genes. It is concluded that a method was developed for the production of ROL gene transformed roses with improved rooting characteristics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009617704014
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  • 120
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    The sensitivity of transgenic spruce (Picea glauca (Moench) Voss) cotyledonary somatic embryos and somatic seedlings to kanamycin selection (1997)
    Springer
    Transgenic research 6 (1997), S. 123-131 
    Details
    ISSN: 1573-9368
    Keywords: β-GUS ; embryogenesis reinduction ; kanamycin ; NPTII ; Piceaglauca ; selection ; somatic embryos ; somaticseedlings ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transformed white spruce cultures containing immature Stage I somatic embryos, were developed after particle bombardment of somatic embryos with pBI 426, carrying an expression cassette with a gus::nptII fusion gene. These Stage I cultures did not show tolerance to kanamycin concentrations above 3 to 5 mg l−1, although assays for GUS and NPTII showed that functional enzymes were present in the transgenic tissue. Embryonic liquid suspension cultures were initiated from this transformed tissue. After treatment on agar-solidified maturation medium with 48 μm (±)-ABA high numbers of Stage III (cotyledonary) somatic embryos were produced. When subjected to an embryogenesis re-induction process with 2,4-D and BA, these Stage III embryos produced a new generation of Stage I embryogenic tissues which could tolerate 5--10 mg l−1 kanamycin. Stage III somatic embryos could alternatively be placed onto germination medium for the development of somatic seedlings. When germinated in the presence of 20 mg l−1 kanamycin, 77% of inoculants were resistant. The stability of integration of the gus::nptII fusion gene in the genome of white spruce Stage III somatic embryos and somatic seedlings was confirmed through Southern blot analysis
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018473604111
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  • 121
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    Engineered resistance to tomato spotted wilt virus in transgenic peanut expressing the viral nucleocapsid gene (1997)
    Springer
    Transgenic research 6 (1997), S. 297-305 
    Details
    ISSN: 1573-9368
    Keywords: peanut ; engineered virusresistance ; tomato spotted wiltvirus ; transformation ; nucleocapsid ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The nucleocapsid gene of tomato spotted wilt virus Hawaiian L isolate in a sense orientation, and the GUS and NPTII marker genes, were introduced into peanut (Arachis hypogaea cv. New Mexico Valencia A) using Agrobacterium-mediated transformation. Modifications to a previously defined transformation protocol reduced the time required for production of transformed peanut plants. Transgenes were stably integrated into the peanut genome and transmitted to progeny. RNA expression and production of nucleocapsid protein in transgenic peanut were observed. Progeny of transgenic peanut plants expressing the nucleocapsid gene showed a 10- to 15-day delay in symptom development after mechanical inoculations with the donor isolate of tomato spotted wilt virus. All transgenic plants were protected from systemic tomato spotted wilt virus infection. Inoculated non-transformed control plants and plants transformed with a gene cassette not containing the nucleocapsid gene became systemically infected and displayed typical tomato spotted wilt virus symptoms. These results demonstrate that protection against tomato spotted wilt virus can be achieved in transgenic peanut plants by expression of the sense RNA of the tomato spotted wilt virus nucleocapsid gene
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018462729127
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  • 122
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    Transgenic cotton resistant to herbicide bialaphos (1997)
    Springer
    Transgenic research 6 (1997), S. 385-392 
    Details
    ISSN: 1573-9368
    Keywords: transgenic cotton ; bialaphos ; particle bombardment ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Resistance to bialaphos, a non-selective herbicide, was intro duced into cotton through genetic engineering. A gene encoding phosphinothric in acetyltransferase (bar) from Streptomyces hygroscopicus was inserted into elite varieties of cotton through particle bombardment. Based on the marker gene, β-glucuronidase (gus) expression, a total of 18 Pima (Gossypium barbadense), 45 DP50 (G. hirsutum L.), 20 Coker 312 (G. hirsutum) and 2 El Dorado (G. hirsutum) transgenic plants were recovered. Integration of the bar gene into cotton genomic DNA was confirmed by Southern blot analysis and gene expression was confirmed by northern blot and enzyme assays. Herbicide (Basta®) tolerance up to 15 000 ppm was demonstrated in greenhouse trials. The newly introduced herbicide tolerance trait is inherited in a Mendelian fashion in the progenies of germline transformants. This study demonstrates the potential for particle bombardment to introduce commerically important genes directly into elite varieties of cotton. This mode of gene transfer can expedite the introduction of transgenic cotton products into world markets
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018483300902
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  • 123
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    The Use of Sonication for the Efficient Delivery of Plasmid DNA into Cells (1997)
    Springer
    Pharmaceutical research 14 (1997), S. 750-756 
    Details
    ISSN: 1573-904X
    Keywords: DNA delivery ; cells ; sonication ; cavitation ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Purpose. Ultrasonic methods have considerable potential for the introduction of macromolecules into cells. In this paper we demonstrate that, under controlled conditions, application of 20kHz ultrasound to a suspension of yeast cells facilitates the delivery of plasmid DNA into these cells. Methods. Aliquots of growing yeast cells (Saccharomyces cerevisae, strain AH22) were suspended in buffer and exposed to 20kHz ultrasound from a laboratory (probe-type) sonicator in the presence of microgram quantities of plasmid DNA. Efficiency of DNA delivery was scored as the number of cells transformed. Results. Cell transformation was optimal at 30 seconds sonication using an output of 2.0 watts and resulted in a 20 fold enhancement over control values. At extended sonication times, fewer cells showed evidence of transformation because of reduced cell viability. The increased DNA uptake and the decreased cell viability were both attributable to acoustic cavitation events during sonication. The extent of acoustic cavitation was measured and it was found that there was an increase in cavitation events with increased sonication time. Cell viability was shown to be directly related to the number of cavitation events. The effects of sonication on plasmid DNA were investigated and indicated that the structural integrity of plasmid DNA was unaffected by the sonication conditions employed. Conclusions. Under controlled conditions, ultrasound is an effective means of delivering plasmid DNA into cells. The subsequent expression of DNA molecules in cells depends upon a balance between transient cell damage and cell death.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1012198321879
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  • 124
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    Optimization of biolistic method for transient gene expression and production of agronomically useful transgenic Basmati rice plants (1996)
    Springer
    Plant cell reports 15 (1996), S. 963-968 
    Details
    ISSN: 1432-203X
    Keywords: Basmati rice ; Group 1 Indica ; biolistics ; transformation ; protease inhibitor gene ; late embryogenesis-abundant protein gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have developed a reproducible biolistic procedure for the efficient transformation of embryogenic suspension cells of an improved aromatic Indica rice variety, Pusa Basmati 1. The β-glucuronidase gene was used to assay transient transformation; other plasmids carrying either a potato protease inhibitor 2 (Pin2) gene, or a late embryogenesis-abundant protein (LEA3) gene from barley, were used for the optimization of biolistic process and transgenic plant production. After optimization of the procedure, over 600 transient transformants and at least five fertile plants showing integrative transformation were obtained per bombarded filter. At least 30% of the plants were derived from independent transformation events. The new improved procedure involves the use of a reporter gene or other useful genes driven by the strong rice actin 1 gene (Act1) promoter, osmotic pre-conditioning of cells for 24 h on medium supplemented with 0.25 M mannitol prior to bombardment, use of gold particles for DNA delivery, and use of plant regeneration medium with high (1.0%) agarose concentration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231597
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  • 125
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    Regeneration of fertile transgenic indica (group 1) rice plants following microprojectile transformation of embryogenic suspension culture cells (1996)
    Springer
    Plant cell reports 15 (1996), S. 465-469 
    Details
    ISSN: 1432-203X
    Keywords: Indica rice ; cell suspension ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Regenerable embryogenic suspensions of elite Indica (group 1) rice varieties IR24, IR64, IR72 and an advanced Indica rice breeding line IR57311-95-2-3 were established within 6–8 weeks from 3–4 week old calli derived from mature seeds. Transgenic rice plants were obtained by introducing a plasmid carrying genes encoding hygromycin phosphotransferase (hph, conferring resistance to hygromycin B) and ß-glucuronidase (uidA), both driven by the CaMV 35S promoter, via particle bombardment of embryogenic suspensions. The effect of osmotic conditioning on transformation was evaluated. Regenerated plants were resistant to hygromycin B and expressed the uidA (GUS) gene. The growth of mother plants (R0) was normal and seeds were produced. Southern blot analysis of R0 and R1 plants showed that hygromycin resistant plants contained intact hph genes that were inherited in a Mendelian fashion. A protocol for a simple, efficient, repeatable, genotype- and environment-independent Indica rice transformation system is described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00232975
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  • 126
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    Accelerated production of transgenic wheat (Triticum aestivum L.) plants (1996)
    Springer
    Plant cell reports 16 (1996), S. 12-17 
    Details
    ISSN: 1432-203X
    Keywords: Triticum aestivum L. ; wheat ; transformation ; biolistics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have developed a method for the accelerated production of fertile transgenic wheat (Triticum aestivum L.) that yields rooted plants ready for transfer to soil in 8–9 weeks (56–66 days) after the initiation of cultures. This was made possible by improvements in the procedures used for culture, bombardment, and selection. Cultured immature embryos were given a 4–6 h pre-and 16 h post-bombardment osmotic treatment. The most consistent and satisfactory results were obtained with 30 μg of gold particles/bombardment. No clear correlation was found between the frequencies of transient expression and stable transformation. The highest rates of regeneration and transformation were obtained when callus formation after bombardment was limited to two weeks in the dark, with or without selection, followed by selection during regeneration under light. Selection with bialaphos, and not phosphinothricin, yielded more vigorously growing transformed plantlets. The elongation of dark green plantlets in the presence of 4–5 mg/l bialaphos was found to be reliable for identifying transformed plants. Eighty independent transgenic wheat lines were produced in this study. Under optimum conditions, 32 transformed wheat plants were obtained from 2100 immature embryos in 56–66 days, making it possible to obtain R3 homozygous plants in less than a year.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01275440
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    Thermomechanical properties of smart composites (1996)
    Springer
    Acta mechanica solida Sinica 9 (1996), S. 357-363 
    Details
    ISSN: 0894-9166
    Keywords: smart composites ; shape memory effect ; transformation ; constitutive relations ; toughening ; thermomechanics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The smart composite materials reinforced by SMA show a high performance and special deformation behavior. The thermomechanical constitutive formulas of the composites are derived by means of Eshelby's equivalent inclusion method and Mori-Tanaka's mean field concept. The interaction between the inclusion and crack and toughening mechanism are considered and the energy release rate of a crack in the smart composite is calculated. This work shows that there are the multiple mechanisms contributing to the toughening of the smart composite materials reinforced by SMA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02206458
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  • 128
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    A pair of stream functions for three-dimensional vortex flows (1996)
    Springer
    Zeitschrift für angewandte Mathematik und Physik 47 (1996), S. 821-836 
    Details
    ISSN: 1420-9039
    Keywords: Stream functions ; vector potential ; transformation ; vortex flows
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract Introducing a vector potential, that is based on a pair of stream functions, and a velocity potential, antisymmetric equations for the stream functions are derived with the help of a variational principle. It is found that the equations are in a suitable form to investigate flows with helical symmetry, and, for example, to connect upstream axisymmetric flows with downstream helical flows. The special case of a transition from an upstream solid-body vortex to a downstream helical flow is investigated in detail. Furthermore, the stream-function equations are particularly useful to investigate general small-amplitude inertia waves on vortex flows. Time-dependent helical flows that are time-independent in a suitably rotating frame of reference can also be discussed with the proposed method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00920036
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  • 129
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    Electrotransformation ofClostridium thermosaccharolyticum (1996)
    Springer
    Journal of industrial microbiology and biotechnology 16 (1996), S. 342-347 
    Details
    ISSN: 1476-5535
    Keywords: transformation ; electroporation ; Clostridium thermosaccharolyticum ; thermophile
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Transformation of the thermophileClostridium thermosaccharolyticum ATCC 31960 was achieved using plasmid pCTC1 and electroporation. Evidence supporting transformation was provided by Southern blots, detection of the plasmid in 10 out of 10 erythromycin-resistant clones, retransformation ofE. coli andC. thermosaccharolyticum with plasmid DNA isolated fromC. thermosaccharolyticum, and a proportional relationship between the number of transformants and the amount of DNA added. Transformation efficiencies were very low for plasmid DNA prepared fromE. coli (0.6 transformants mg−1 DNA), although somewhat higher for plasmid DNA prepared fromC. thermosaccharolyticum (52 transformants mg−1 DNA). Transformation-dependent erythromycin resistance indicates that an adenosine methylase gene originating fromEnterococcus faecalis, a mesophile, is expressed inC. thermosaccharolyticum. The plasmid pCTC1 appears to be replicated independently of the chromosome, as indicated by visualization of recovered plasmid on gels, and retransformation using recovered plasmid. pCTC1 is maintained inC. thermosaccharolyticum at both 45 and 60°C. Restriction analysis showed little or no rearrangement occurred upon passage through the thermophile.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01570112
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    Characterization of human papillomavirus type 57b: Transforming activity and comparative sequence analysis as probes for biological determinants associated with high-risk oncogenic viruses (1996)
    Springer
    Virus genes 12 (1996), S. 165-178 
    Details
    ISSN: 1572-994X
    Keywords: HPV57 ; viral genome ; sequence ; transformation ; oncogenicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The association of human papillomavirus type 57 (HPV-57) with premalignant and malignant tumors of the nasal cavity was previously reported (Wu et al., Lancet341, 522, 1993). We determined the complete nucleotide sequence of HPV-57b (GenBank 37537), which was molecularly cloned from a benign fungiform papilloma, and compared it with other HPV types and HPV-57a, which was cloned from an inverted papilloma of the maxillary sinus by de Villiers et al. (Virology171, 248. 1989). Comparative and phylogenetic analysis of amino acid sequences of the HPV-57b oncogenes E5, E6, and E7 were performed with HPV-6, 11, 16, and 18. Phylogenetic trees using the Jotun-Hein algorithm indicated a closer relationship of HPV-57b E5 and E7 with corresponding genes of HPV-18. Signature pattern analysis of these two oncogenes was also in agreement with a closer relatedness to HPV-16 and 18 oncogenes, which are associated with a high risk for malignant progression. Compared with 7861 bp of HPV-57a, HPV-57b had 7868 bp as well as differences in the restriction enzyme sites and the open reading frames, including at least five additional ones. To investigate the oncogenic potential of HPV-57b, NIH 3T3 and REF52 cells were cotransfected with two plasmids: pKP54.HPV-57b, which contains the HPV-57b genome, and pMT.neo. 1, which confers resistance to G418. After selection in culture medium containing G418, 58% of the G418r NIH 3T3 colonies and 47% of the G418r REF52 colonies exhibited morphological transformation. These results indicate that the transcriptional regulatory elements and the oncoproteins of HPV-57b are active in vitro to induce cellular transformation, as are other high-risk HPV types.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00572955
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  • 131
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    Interactions between the regulatory regions of twoAdh alleles (1996)
    Springer
    Genetica 97 (1996), S. 1-14 
    Details
    ISSN: 1573-6857
    Keywords: alcohol dehydrogenase ; Drosophila ; enhancer ; regulation ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A region (NS1) that acts like an enhancer is located approximately 300 bp upstream of the larval cap site in theAdh gene ofD. melanogaster. When this sequence is deleted (ΔNS1), the gene fails to express ADH protein. Gene expression can be restored by placing a secondAdh gene with an intact enhancer elsewhere on the same plasmid. In these circumstances, both genes are expressed equally regardless of their orientation on the plasmid. In this report we further characterize the interactions that occur when a single enhancer activates expression from a proximal and distant promoter. We have made the following observations: (1) While the two genes are expressed equivalently, their expression relative to a plasmid carrying two intact genes is reduced by a factor of 2 to 6 depending on the orientation of the two genes. (2) The single enhancer drives expression of both genes on any given plasmid molecule. (3) The enhancer does not interact with theAdh gene from which the NS7 region (which spans the larval TATA box) is removed. (4) Expression of the ΔNS1 gene can be restored by an intact gene when both are inserted together into theDrosophila genome via P element-mediated transformation. (5) Increasing the separation between the two genes on a plasmid by up to 15 kbp does not prevent the restoration of expression of the ΔNS1 gene. We propose a model that explains how a single enhancer can stimulate equal expression from two genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00132575
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    Quetzal: a transposon of the Tc1 family in the mosquito Anopheles albimanus (1996)
    Springer
    Genetica 98 (1996), S. 141-147 
    Details
    ISSN: 1573-6857
    Keywords: culicidae ; gene vector ; transformation ; transposable element ; transposase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A member of the Tc1 family of transposable elements has been identified in the Central and South American mosquito Anopheles albimanus. The full-length Quetzal element is 1680 base pairs (bp) in length, possesses 236 bp inverted terminal repeats (ITRs), and has a single open reading frame (ORF) with the potential of encoding a 341-amino-acid (aa) protein that is similar to the transposases of other members of the Tc1 family, particularly elements described from three different Drosophila species. The approximately 10–12 copies per genome of Quetzal are found in the euchromatin of all three chromosomes of A. albimanus. One full-length clone, Que27, appears capable of encoding a complete transposase and may represent a functional copy of this element.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00121362
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  • 133
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    Skull evolution in the rhinocerotidae (Mammalia, Perissodactyla): Cartesian transformations and functional interpretations (1996)
    Springer
    Journal of mammalian evolution 3 (1996), S. 261-279 
    Details
    ISSN: 1573-7055
    Keywords: Cartesian ; transformation ; splines ; rhinoceros ; skull ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cartesian transformation, applied as a landmark morphometric method, is used to investigate some of the evolutionary shape changes leading to the skulls of the modern rhinoceroses. The early Oligocene genusSubhyracodon serves as the primitive shape from which the extant genera (Dicerorhinus, Rhinocerso, Diceros, andCeratotherium) have been transformed. Coordinate data for 21 landmarks, defined in lateral view, are analyzed by the computer program Thinplate Splines. Each of the four transformations are interpreted separately as shape change fromSubhyracodon. Computed results forRhinoceros are also compared with previous results obtained by visual interpretation (the classic method). Among the extant genera,Ceratotherium andRhinoceros have the most derived shapes and are opposites with respect to orientation of the occiput and relative size of the mandible angle. The significance of these foci of change is discussed in terms of the functions of the masseter and posterior temporalis muscles. In head positions associated with feeding on short vs. tall grasses, the two skull shapes are consistent with a role for these muscles in support of a large mandible against gravity. This common factor may help to explain both shapes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01458183
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  • 134
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    Techniques for genetic engineering in mycobacteria (1996)
    Springer
    Antonie van Leeuwenhoek 69 (1996), S. 243-256 
    Details
    ISSN: 1572-9699
    Keywords: Mycobacterium ; transformation ; plasmid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The study of mycobacterial genetics has experienced quick technical developments in the past ten years, despite a relatively slow start, caused by difficulties in accessing these recalcitrant species. The study of mycobacterial pathogenesis is important in the development of new ways of treating tuberculosis and leprosy, now that the emergence of antibiotic-resistant strains has reduced the effectiveness of current therapies. The tuberculosis vaccine strain M. bovis BCG might be used as a vector for multivalent vaccination. Also, non-pathogenic mycobacterial strains have many possible biotechnological applications. After giving a historical overview of methods and techniques, we will discuss recent developments in the search for alternative host strains and DNA transfer systems. Special attention will be given to the development of vectors and techniques for stabilizing foreign DNA in mycobacteria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00399613
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  • 135
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    DNA in soil: adsorption, genetic transformation, molecular evolution and genetic microchip (1996)
    Springer
    Antonie van Leeuwenhoek 70 (1996), S. 1-10 
    Details
    ISSN: 1572-9699
    Keywords: adsorption ; clay ; DNA ; environment ; evolution ; genetic microchip ; interactions ; microorganisms ; nucleases ; soil ; stability ; transformation ; genetic microchip
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This review examines interactions between DNA and soil with an emphasis on the persistence and stability of DNA in soil. The role of DNA in genetic transformation in soil microorganisms will also be discussed. In addition, a postulated mechanism for stabilization and elongation/asserbly of primitive genetic material and the role of soil particles, salt concentrations, temperature cycling and crystal formation is examined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00393564
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  • 136
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    The effects of exogenous auxin and rol genes on root formation in Rosa hybrida L. ‘Moneyway’ (1996)
    Springer
    Plant growth regulation 19 (1996), S. 123-131 
    Details
    ISSN: 1573-5087
    Keywords: adventitious root formation ; Agrobacterium tumefaciens ; Agrobacterium rhizogenes ; auxin ; GUS ; Ri roots ; rose ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effect of indole-3-butyric acid (IBA) on the formation of non-transformed and rol gene transformed roots on stem slices of in vitro cultured shoots of Rosa hybrida L. ‘Moneyway’ was examined. Formation of adventitious roots on this rootstock was dependent on the IBA dose; it was not affected by the presence of other root primordia on the same explant. Application of 0.32 to 1 μM IBA during 5 days, followed by transfer to medium without hormones resulted in maximum root formation (90%) after three weeks. The formation of such untransformed roots was completely inhibited by transfer to medium with 5 mg 1−1 kanamycin two days after excision. Ri roots were formed upon inoculation with A. rhizogenes LBA9402 harbouring two plasmids: pRi1855, comprising the rol genes and the binary plasmid p 35Sgusintron with the nptII gene for kanamycin resistance and the CaMV 35Sgusintron gene. The formation of these Ri roots on kanamycin-containing medium was independent of the presence of IBA. Stem slices inoculated with a disarmed A. tumefaciens GV3101, harbouring only the nptII gene, formed callus and subsequently roots in the presence of kanamycin exclusively on medium with high IBA concentrations (10 or 100 μM). Root formation at 100 μM IBA was considerably improved by transformation with the rolB gene under the influence of the strong CaMV 35S promoter. In addition, low IBA (0.1 and 1 μM) stimulated the formation of roots only on stem slices transformed with A. tumefaciens harbouring the rolA+rolB+rolC genes; the rooting response at 10 μM IBA was much improved. It was concluded that the 35SrolB gene and especially a combination of rolA, B and C genes promote the rooting response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00024578
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    Chimaeric CP47 mutants of the cyanobacterium Synechocystis sp. PCC 6803 carrying spinach sequences: Construction and function (1996)
    Springer
    Photosynthesis research 48 (1996), S. 147-162 
    Details
    ISSN: 1573-5079
    Keywords: gene replacement ; Photosystem II ; photosynthesis ; thylakoid membranes ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chimaeric mutants of the cyanobacterium Synechocystis sp. PCC 6803 have been generated carrying part or all of the spinach psbB gene, encoding CP47 (one of the chlorophyll-binding core antenna proteins in Photosystem II). The mutant in which the entire psbB gene had been replaced by the homologous gene from spinach was an obligate photoheterotroph and lacked Photosystem II complexes in its thylakoid membranes. However, this strain could be transformed with plasmids carrying selected regions of Synechocystis psbB to give rise to photoautotrophs with a chimaeric spinach/cyanobacterial CP47 protein. This process involved heterologous recombination in the cyanobacterium between psbB sequences from spinach and Synechocystis 6803; which was found to be reasonably effective in Synechocystis. Also other approaches were used that can produce a broad spectrum of chimaeric mutants in a single experiment. Functional characterization of the chimaeric photoautotrophic mutants indicated that if a decrease in the photoautotrophic growth rates was observed, this was correlated with a decrease in the number of Photosystem II reaction centers (on a chlorophyll basis) in the thylakoid membrane and with a decrease in oxygen evolution rates. Remaining Photosystem II reaction centers in these chimaeric mutants appeared to function rather normally, but thermoluminescence and chlorophyll a fluorescence measurements provided evidence for a destabilization of QB −. This illustrates the sensitivity of the functional properties of the PS II reaction center to mild perturbations in a neighboring protein.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00041005
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  • 138
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    Deviating T-DNA transfer fromAgrobacterium tumefaciens to plants (1996)
    Springer
    Plant molecular biology 31 (1996), S. 677-681 
    Details
    ISSN: 1573-5028
    Keywords: Agrobacterium tumefaciens ; Arabidopsis thaliana ; T-DNA transfer ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We analyzed 29 T-DNA inserts in transgenicArabidopsis thaliana plants for the junction of the right border sequences and the flanking plant DNA. DNA sequencing showed that in most lines the right border sequences transferred had been preserved during integration, corroborating literature data. Surprisingly, in four independent transgenic lines a complete right border repeat was present followed by binary vector sequences. Cloning of two of these T-DNA inserts by plasmid rescue showed that in these lines the transferred DNA consisted of the complete binary vector sequences in addition to the T-region. On the basis of the structure of the transferred DNA we propose that in these lines T-DNA transfer started at the left-border repeat, continued through the vector part, passed the right border repeat, and ended only after reaching again this left-border repeat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00042239
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  • 139
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    Engineering of the aspartate family biosynthetic pathway in barley (Hordeum vulgare L.) by transformation with heterologous genes encoding feed-back-insensitive aspartate kinase and dihydrodipicolinate synthase (1996)
    Springer
    Plant molecular biology 32 (1996), S. 611-620 
    Details
    ISSN: 1573-5028
    Keywords: aspartate kinase ; dihydrodipicolinate synthase ; Hordeum vulgare L. ; lysine overproduction ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In prokaryotes and plants the synthesis of the essential amino acids lysine and threonine is predominantly regulated by feed-back inhibition of aspartate kinase (AK) and dihydrodipicolinate synthase (DHPS). In order to modify the flux through the aspartate family pathway in barley and enhance the accumulation of the corresponding amino acids, we have generated transgenic barley plants that constitutively express mutant Escherichia coli genes encoding lysine feed-back insensitive forms of AK and DHPS. As a result, leaves of primary transformants (T0) exhibited a 14-fold increase of free lysine and an 8-fold increase in free methionine. In mature seeds of the DHPS transgenics, there was a 2-fold increase in free lysine, arginine and asparagine and a 50% reduction in free proline, while no changes were observed in the seeds of the two AK transgenic lines analysed. When compared to that of control seeds, no differences were observed in the composition of total amino acids. The introduced genes were inherited in the T1 generation where enzymic activities revealed a 2.3-fold increase of AK activity and a 4.0–9.5-fold increase for DHPS. T1 seeds of DHPS transformants showed the same changes in free amino acids as observed in T0 seeds. It is concluded that the aspartate family pathway may be genetically engineered by the introduction of genes coding for feed-back-insensitive enzymes, preferentially giving elevated levels of lysine and methionine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020202
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  • 140
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    Hormone independent root organ cultures of rye (Secale cereale) (1996)
    Springer
    Plant cell, tissue and organ culture 46 (1996), S. 109-115 
    Details
    ISSN: 1573-5044
    Keywords: cereals ; plant hormones ; hairy roots ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This work describes the growth of rye root organ cultures which were capable of being repeatedly subcultured in hormone-free medium. They showed morphological characteristics, growth rate, inability to produce shoots, and response to auxins and cytokinins similar to those of the Agrobacterium rhizogenes (Ri plasmid) transformed hairy root cultures of tobacco and red beet which were used for comparison. The root cultures of rye were initiated from callus produced on a medium containing the growth regulators (plant hormones) 2,4-d and kinetin, then transferred to hormone-free medium. However not all rye explants gave rise to callus that would differentiate into stable hairy root cultures and rye seedling root explants did not grow if placed directly on a hormone-free medium. Rice and wheat produced callus and roots on a medium containing hormones but root organ cultures could not be maintained on a hormone-free medium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00034843
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  • 141
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    Coat protein-mediated protection to cucumber mosaic virus infections in cultivated tomato (1996)
    Springer
    Euphytica 88 (1996), S. 139-149 
    Details
    ISSN: 1573-5060
    Keywords: coat protein ; cucumber mosaic virus ; Lycopersicon ; tomato ; transformation ; virus resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Cucumber mosaic virus (CMV) infections rank among the most devastating diseases in the commercial culture of tomato (Lycopersicon esculentum Mill.), for which suitable sources of natural resistance are not available. The concept of pathogen-derived resistance, however, offers an alternate approach to combat plant viral diseases by transformation of crops with nucleotide sequences derived from the viral genome. This report demonstrates the successful application of such a pathogen-derived resistance gene comprising the CMV coat protein (CP) gene, to generate protection to CMV infections in cultivated tomato. Transformation of an inbred tomato line with the CMV CP gene isolated from a subgroup I strain, engendered high levels of protection to various CMV strains, including a virulent strain causing lethal necrosis and a typical subgroup II strain. Moreover, when challenged by natural infection through aphid vectors in open field, levels of protection were largely maintained in hemizygous hybrids. In all, these results demonstrate that synthetic resistance genes based on the CMV CP gene make excellent sources of broad spectrum resistance to CMV infections for introgression into tomato breeding programs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00032445
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  • 142
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    Expression of the Volvox gene encoding nitrate reductase: Mutation-dependent activation of cryptic splice sites and intron-enhanced gene expression from a cDNA (1996)
    Springer
    Plant molecular biology 31 (1996), S. 1-12 
    Details
    ISSN: 1573-5028
    Keywords: cryptic splice sites ; intron-enhancement ; gene expression ; nitA cDNA ; Volvox ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Use of the nitrate reductase encoding gene (nitA) as selection marker has facilitated the successful nuclear transformation of Volvox carteri. The Volvox nitA gene contains 10 introns. A stable nitA mutation in the Volvox recipient strain 153–81 resides in a G-to-A transition of the first nucleotide in the 5′ splice site of nitA intron 2. This mutation resulted in at least three non-functional splice variants, namely: (1) intron 2 was not spliced at all; (2) a cryptic 5′ splice site 60 nt upstream or (3) a cryptic 5′ splice site 16 nt downstream of the mutation were activated and used for splicing. When we used nitA cDNA (pVcNR13) for transformation of V. carteri 153–81, a low efficiency of about 5×10-5 transformants per reproductive cell was observed. Re-integration of either intron 1 (pVcNR15) or introns 9 and 10 (pVcNR16) in the transforming cDNA increased transformation rates to 5×10-4. In parallel, pVcNR15-transformed Volvox exhibited growth rates that were 100-fold increased over the pVcNR13-transformed alga. This intron-enhancement of nitA gene expression appears to be associated with post-transcriptional processing and ‘channelling’ of the message. These data suggest an important role of splicing for gene expression in V. carteri.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020601
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  • 143
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    The effect of cadmium on the transformation of ferrihydrite into crystalline products at pH 8 (1996)
    Springer
    Water, air & soil pollution 91 (1996), S. 307-325 
    Details
    ISSN: 1573-2932
    Keywords: ferrihydrite ; cadmium ; transformation ; crystallization ; wastewater solids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Ferrihydrite, prepared in the presence of 0 to 20 mole % Cd in the solution, was used to study the transformation of ferrihydrite into crystalline products. The result showed that the presence of Cd strongly retards the transformation of ferrihydrite into crystalline products, suppressing the formation of goethite and leading to a product which eventually consists entirely of hematite at pH 8 and at 70 °C. The fraction of hematite in the transformation products increased with increasing level of Cd in the system. When 9 mole % Cd was present, the transformation product consisted entirely of hematite. The chemical analysis and XRD data showed that Cd was incorporated into the lattice of iron oxides, Cd-hematite and Cd-goethite being formed. The mole % Cd which replaced iron in the iron oxides increased with increasing level of Cd in the system below 9 mole % Cd. Above this value, but below 20 mole % the mole % of Cd incorporated in the lattice of iron oxides was constant at about 2.9 mole %. The volume of the unit cell of Cd-goethite increased with increasing level of Cd in the system until the goethite production was entirely suppressed. The volume of the unit cell of Cd-hematite also increased with increasing level of Cd, below 9 mole % of Cd in the system. Above this value, it was constant. Scanning electron microscopic examination showed that the presence of Cd affected the morphology of hematite more than that of goethite. The goethite grew from ferrihydrite as acicular crystals independent of the amount of Cd in the system. The shape of hematite particles varied from irregular platelets with lower Cd level, to ellipsoids, with higher Cd level in the system, and it also suggested that Cd prevented the formation of goethite by hindering the dissolution of ferrihydrite rather than by interfering with nucleation and growth of goethite from solution. The rate of transformation was studied at pH 8, 50 °C and 70 °C. The transformations were first order reactions at both temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00666266
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  • 144
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    Jacobians for isoparametric finite elements (1996)
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 12 (1996), S. 755-766 
    Details
    ISSN: 1069-8299
    Keywords: finite elements ; isoparametric ; Jacobian ; transformation ; valid ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Isoparametric elements are only valid if the Jacobian determinant of the transformation between a given element and a master element does not change sign within or on the element boundary. Some algorithms are known which analyse Jacobians for various element types. Some necessary conditions are presented for determining the validity of an element.
    Additional Material: 5 Tab.
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  • 145
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    Normal rat intestinal cells IEC-18: characterization and transfection with immortalizing oncogenes (1996)
    Springer
    Cytotechnology 21 (1996), S. 11-19 
    Details
    ISSN: 1573-0778
    Keywords: intestinal cells ; oncogenes ; transformation ; tumorigenicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract IEC-18 cells, a cell line derived from the ileum of rat intestine, have the characteristics of normal cells since they have a contact inhibited cell growth, do not form colonies in soft agar and are not tumorigenic when injected in nude mice. IEC-18 cells were transfected with nuclear oncogenes, c-myc, v-myc and SV40 T antigen in order to obtain immortal cell lines. Independent clones were isolated and characterized for the growth properties. Expression of v-myc altered the morphology of the cells and shortened the doubling time. A slow growth together with a low cloning efficiency was associated with the expression of SV40 T antigen. No changes either in growth or in morphology were observed in c-myc-expressing IEC-18 cells. Expression of these nuclear oncogenes did not result in the neoplastic transformation of the IEC-18 cells, since none of the clones lost the anchorage dependence or were able to form tumors in vivo. The c-myc-containing IEC-18 cells were unable to secrete in the growth medium TGF α and exposure to TGF β inhibited the growth rate by 30%. All these observations are consistent with the conclusion that the expression of nuclear oncogenes does not lead to the neoplastic transformation of these cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00364833
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  • 146
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    Transformation ofBrassica oleracea L.: a critical review (1996)
    Springer
    Molecular breeding 2 (1996), S. 185-210 
    Details
    ISSN: 1572-9788
    Keywords: Brassica oleracea ; Agrobacterium ; transformation ; direct gene transfer ; regeneration ; virulence ; flowering ; rol genes ; transgene expression ; transgene inactivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Brassica oleracea is a highly polymorphic species encompassing a wide range of important vegetable and fodder crops. Gene transfer into cultivated forms of this species requires reproducible and efficient methods for genetic transformation and plant regeneration. In this review, we have collated the research experience on transformation ofB. oleracea to highlight the problems encountered. Most research effort has been directed at developingAgrobacterium-mediated transformation methods with relatively little emphasis to date on direct gene transfer techniques. Common procedures for the transformation ofB. oleracea have not emerged, due to the inherent variability between and amongst genotypes. Future progress would be facilitated by the use of genetically fixed material, such as double-haploid or inbred lines, to reduce variation of response within genotypes and would avoid the need for cultivar-specific transformation protocols if responsive lines amenable to crossing with cultivated forms could be identified. The principal difficulties relate to combining efficient plant regeneration with gene transfer. Methods that enhance bacterial virulence and increase the proportion of cells susceptible to transformation and competent for regeneration are discussed. Inefficient selection is a major cause of poor transformation frequencies inB. oleracea and has resulted in the regeneration of chimeric plants uponAgrobacterium tumefaciens-mediated transformation. Promising results have been obtained withAgrobacterium rhizogenes-mediated transformation but the impact of therol genes on flowering of primary transformants has not yet been fully assessed. Strategies to reduce the deleterious effects of therol genes on flowering are discussed. Few agronomically useful characters have been introduced, the majority of research having been confined to the introduction of marker and reporter genes; possible candidate genes are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00564197
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  • 147
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    Agrobacterium rhizogenes-mediated induction of adventitious rooting fromPinus contorta hypocotyls and the effect of 5-azacytidine on transgene activity (1996)
    Springer
    Transgenic research 5 (1996), S. 75-85 
    Details
    ISSN: 1573-9368
    Keywords: Agrobacterium rhizogenes ; lodgepole pine ; rooting ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Bipartite constructs ofAgrobacterium rhizogenes strain LBA 9402 or A4RSII induced transformed roots on the hypocotyls ofPinus contorta following inoculation, LBA 9402 being more effective. The developmental sequence of root formation and morphology following infection were studied. Furthermore, the pattern of gene expression was studied during rooting and in roots using theuidA reporter gene driven by the 35S promoter. Morphologically most of the roots were normal, whether or not they expressed the reporter gene, but extensive proliferation of lateral roots was observed in some roots with β-glucuronidase (GUS) activity. All roots originated from tissues inside the endodermis, often similar to auxin-induced rooting in hypocotyl cutting as described by Grönroos and von Arnold (1987). Where the origin of GUS-positive roots could be traced, they developed from callus forming inside the endodermis. GUS activity was often observed along the root inside the endodermis, at the base of the lateral roots and at the root apex, but not in a region behind the apex. Stable integration of the transgene was verified using Southern blot analysis. To investigate wherther transgene inactivation occurs in conifer plants, root segments and calluses initiated from them were treated with 5-azacytidine. Treatment with 5-azacytidine increased the frequency of GUS-positive roots from about 20% to 50%. The effect of 5-azacytidine on calluses, however, varied among callus lines. To investigate whether methylation was the cause of transgene inactivation, DNA from 5-azacytidine-treated and untreated calluses was digested using the two isoschizomeric restriction enzymes,Hpa Il andMsp 1, which differ in their sensitivity to methylation. There was no evidence for methylation and demethylation at the cleavage sites examined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01969425
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  • 148
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    Tissue transglutaminase in mesenchymal tumour cells (1996)
    Springer
    Apoptosis 1 (1996), S. 126-130 
    Details
    ISSN: 1573-675X
    Keywords: SV40 ; tissue transglutaminase ; transformation ; tumour marker
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract During our search for novel transformation-sensitive proteins whose synthesis is abolished in tumour cells we found a cDNA clone coding for tissue transglutaminase. This enzyme was identified, at the protein as well as the mRNA level, in normal human fibroblasts, but was completely missing in their matched SV40 transformed counterparts. Since tissue transglutaminase has been implicated in cell cycle regulation and apoptosis, we investigated the possibility of whether this enzyme might represent a negative marker for tumour cells. We found that its synthesis varied largely among 10 cell lines derived from spontaneous mesenchymal tumours. While cells from a rhabdomyosarcoma and a chondrosarcoma did not produce it at all, an extremely high expression was observed in cells from an osteosarcoma and a liposarcoma. Thus, tissue transglutaminase is not a tumour-related marker.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01321018
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  • 149
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    High-efficiency, microprojectile-mediated cotransformation of sugarcane, using visible or selectable markers (1996)
    Springer
    Molecular breeding 2 (1996), S. 239-249 
    Details
    ISSN: 1572-9788
    Keywords: anthocyanin ; antibiotic G418 ; luciferase ; phosphinothricin ; Saccharum ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Transient expression of the maize anthocyanin regulatory elements,R andC1, was used to optimise parameters for microprojectile-mediated delivery of DNA into sugarcane embryogenic callus. Osmotic treatment of target tissues and particle acceleration in a high-pressure helium pulse increased the frequency of transient expression to 5–8×103 cells per bombardment, with minimal tissue damage. An average of 0.34% of transiently expressing cells developed into stably transformed, anthocyanin-pigmented proembryoids which subsequently regenerated into plantlets. However, constitutive expression ofR andC1 proved deleterious, and no anthocyanin-pigmented plant survived beyond 3 cm in height. We also compared selective subculture of callus portions showing luciferase activity with antibiotic selection on medium containing G418 or phosphinothricin, upon bombardment of callus with constructs driving strong expression ofluc, aphA orbar genes. Selective subculture based on luciferase activity enabled recovery of 1.4±0.5 independent transgenic plants per bombardment, compared to 19.8±3.7 independent transgenic plants per bombardment from an optimised G418 selection regimen, and no transformed plants from phosphinothricin selection. Whenluc andaphA on separate plasmids were coprecipitated onto microprojectiles before bombardment, 67–79% of callus lines selected for G418 resistance also showed luciferase activity detectable under a low-light camera. Southern analysis confirmed a very high cotransformation frequency, with variable copy numbers of introduced genes. The high efficiencies of gene transfer, selection and cotransformation in the optimised system, coupled with the simple initiation and regeneration of embryogenic callus, provide an effective tool for practical genetic transformation of sugarcane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00564201
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  • 150
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    The moss,Physcomitrella patens, transformed with apoaequorin cDNA responds to cold shock, mechanical perturbation and pH with transient increases in cytoplasmic calcium (1996)
    Springer
    Transgenic research 5 (1996), S. 167-170 
    Details
    ISSN: 1573-9368
    Keywords: calcium ; moss ; aequorin ; mutant ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The gene for apoaequorin has been used previously to indicate cytosolic calcium changes in higher plants. Here we report the transformation of the mossPhyscomitrella patens with the cDNA for apoaequorin. Stable transformants were obtained in the wild type which reconstitute the calcium-sensitive luminescent protein aequorinin vivo after incubation in coelenterazine, and continue to grow normally. The wild type responds to cold-shock (0–10°C) with increases in cytosolic calcium. Mechanical perturbation, in the form of touch, also induces transient increases in cytosolic calcium. A smaller response to pH, distinct from the touch response and exhibiting different kinetics, can also be detected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01969705
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  • 151
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    Transgenic white clover. Studies with the auxin-responsive promoter, GH3, in root gravitropism and lateral root development (1996)
    Springer
    Transgenic research 5 (1996), S. 325-335 
    Details
    ISSN: 1573-9368
    Keywords: Trifolium repens ; transformation ; forage legume ; GUS promoter fusion ; tropic response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We report an improved method for white clover (Trifolium repens) transformation usingAgrobacterium tumefaciens. High efficiencies of transgenic plant production were achieved using cotyledons of imbibed mature seed. Transgenic plants were recovered routinely from over 50% of treated cotyledons. Thebar gene and phosphinothricin selection was shown to be a more effective selection system thannptII (kanamycin selection) oraadA (spectinomycin selection). White clover was transformed with the soybean auxin responsive promoter, GH3, fused to the GUS gene (β-glucuronidase) to study the involvement of auxin in root development. Analysis of 12 independent transgenic plants showed that the location and pattern of GUS expression was consistent but the levels of expression varied. The level of GH3:GUS expression in untreated plants was enhanced specifically by auxin-treatment but the pattern of expression was not altered. Expression of the GH3:GUS fusion was not enhanced by other phytohormones. A consistent GUS expression pattern was evident in untreated plants presumably in response to endogenous auxin or to differences in auxin sensitivity in various clover tissues. In untreated plants, the pattern of GH3:GUS expression was consistent with physiological responses which are regarded as being auxin-mediated. For the first time it is shown that localised spots of GH3:GUS activity occurred in root cortical tissue opposite the sites where lateral roots subsequently were initiated. Newly formed lateral roots grew towards and through these islands of GH3:GUS expression, implying the importance of auxin in controlling lateral root development. Similarly, it is demonstrated for the first time that gravistimulated roots developed a rapid (within 1 h) induction of GH3:GUS activity in tissues on the non-elongating side of the responding root and this induction occurred concurrently with root curvature. These transgenic plants could be useful tools in determining the physiological and biochemical changes that occur during auxin-mediated responses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01968942
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  • 152
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    Agrobacterium-mediated transformation of lombardy poplar (Populus nigra L. var.italica Koehne) using stem segments (1996)
    Springer
    Journal of forest research 1 (1996), S. 13-16 
    Details
    ISSN: 1610-7403
    Keywords: Agrobacterium tumefaciens ; lombardy polar ; Populus nigra L. var.italica Koehne ; shoot regeneration ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Genetically transformed lombardy poplar (Populus nigra L. var.italica Koehne) plants were regenerated by co-cultivation of stem segments withAgrobacterium tumefaciens strain LBA4404 that harbored a binary vector (pBI121) which included genes for β-glucuronidase (GUS) and neomycin phosphotransferase. Successful transformation was confirmed by the ability of stem segments to produce calli in the presence of kanamycin, histochemical and fluorometric assays of GUS activity in plant tissues, and Southern blot analysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02348333
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    Agrobacterium-mediated transformation of Javanica rice (1996)
    Springer
    Molecular breeding 2 (1996), S. 267-276 
    Details
    ISSN: 1572-9788
    Keywords: Agrobacterium ; Javanica rice ; regeneration ; rice ; TAIL-PCR ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Difficulties frequently encountered using direct DNA transfer methods for transformation of Javanica varieties of rice (Oryza sativa L.) have limited the application of biotechnology to these varieties. We now reportAgrobacterium-mediated transformation of Javanica cultivars Gulfmont and Jefferson that are, respectively, widely used or about to enter commercial cultivation in the southern USA. Vigorous, phenotypically normal, fertile plants expressing both the selectable marker and the gene of interest were obtained. Southern analysis showed that only one or two copies of the T-DNA insert were present. Sequence analysis of right border fragments of one line confirmed that insertion was into a coding region of rice nuclear DNA. This analysis also revealed the presence of relatively short regions of permuted T-DNA border sequences, similar to those found afterAgrobacterium-mediated transformation of dicots. Progeny analysis of lines bearing two copies showed co-segregation, indicating that they were located relatively closely on the same chromosome. The introduced genes were transmitted to the R1 and R2 generations in a Mendelian fashion, confirming the suitability of this approach for biotechnological improvement of elite rice cultivars.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00564204
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  • 154
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    Testing the unbiasedness hypothesis of foreign exchange rates and the analysis of transformations (1996)
    Springer
    Review of quantitative finance and accounting 6 (1996), S. 39-46 
    Details
    ISSN: 1573-7179
    Keywords: foreign exchange rate ; functional forms ; transformation ; forward rate ; spot rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract Recent researchers have utilized various functional forms for testing the hypothesis that the forward rate is an unbiased predictor of future spot rates in foreign exchange markets. We compare a large number of these functional forms for a similar time period and test their consistency with the data for five major currencies. Our results imply that certain functional form models may be inappropriate for some currencies. Researchers must, therefore, be cautious of misspecification due to erroneous functional forms when testing the unbiased forward rate hypothesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00290795
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  • 155
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    Enhanced expression of heregulin in c-erb B-2 and c-Ha-ras transformed mouse and human mammary epithelial cells (1996)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 60 (1996), S. 437-446 
    Details
    ISSN: 0730-2312
    Keywords: heregulin ; transformation ; erb B-2 ; c-Ha-ras ; mammary cells ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Heregulin β1 was found to stimulate the anchorage-dependent, serum-free growth of nontransformed human MCF-10A mammary epithelial cells. Unlike epidermal growth factor, transforming growth factor α, or amphiregulin, heregulin β1 was also able to induce the anchorage-independent growth of MCF-10A cells. In contrast, the anchorage-dependent, serum-free growth of c-Ha-ras or c-erb B-2 transformed MCF-10A cells was unaffected by heregulin β1, whereas heregulin β1 was able to stimulate the anchorage-independent growth of these cells. c-Ha-ras or c-erb B-2 (c-neu) transformed MCF-10A or mouse NOG-8 mammary epithelial cells express elevated levels of 2.5, 5.0, 6.5, 6.8, and 8.5 kb heregulin mRNA transcripts and/or synthesize cell-associated 25, 29, 50, and 115 kDa isoforms of heregulin. Since the MCF-10A cells and transformants also express c-erb B-3, these data suggest that endogenous heregulin might function as an autocrine growth factor for Ha-ras or erb B-2 transformed mammary epithelial cells. © 1996 Wiley-Liss, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.
    Additional Material: 3 Ill.
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  • 156
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    Production of fertile transgenic barley (Hordeum vulgare L.) plant using the hygromycin-resistance marker (1995)
    Springer
    Plant cell reports 14 (1995), S. 329-334 
    Details
    ISSN: 1432-203X
    Keywords: Barley ; Hordeum vulgare ; immature embryo ; particle bombardment ; particle gun ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fertile transgenic barley (Hordeum vulgare L.) plants were obtained by high velocity particle bombardment. The plasmid pBCl was used to deliver the selectable hph gene and reporter Gus gene into immature embryo. After the selection culture 18 hygromycin resistant plants were obtained. Samples for Southern hybridization and enzymatic Gus assay were obtained from 11 plants. Southern hybridization confirmed the presence of the hph gene in the 11 hygromycin resistant plants(T0). Enzymatic assay indicated that all the t0 plants that showed hph positive in Southern analysis possessed detectable amount of Gus activity. To date all the 11 t0 plants reached maturity and mature seeds were obtained Transmission of the hph gene to progeny(T1) of two independent t0 plants was confirmed by Southern hybridization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00232038
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  • 157
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    Transformation of peas (Pisum sativum L.) using immature cotyledons (1995)
    Springer
    Plant cell reports 15 (1995), S. 254-258 
    Details
    ISSN: 1432-203X
    Keywords: Pisum sativum ; transformation ; regeneration ; phosphinothricin ; Agrobacterium tumefaciens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A reliable Agrobacterium tumefaciens-mediated transformation method has been developed for peas (Pisum sativum) using immature cotyledons as the explant source. Transgenic plants were recovered from the four cultivars tested: Bolero, Trounce, Bohatyr and Huka. The method takes approximately 7 months from explant to seed-bearing primary regenerant. The binary vector used carried genes for kanamycin and phosphinothricin resistance. Transformed pea plants were selected on 10 mg/l phosphinothricin. The nptII and bar genes were shown to be stably inherited through the first sexual generation of transformed plants. Expression of the phosphinothricin-resistance gene in the transformed plants was demonstrated using the ‘Buster’ (=‘Basta’) leaf-paint test and the phosphinothricin acetyl transferase enzyme assay.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00193730
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  • 158
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    Transgenic plants of rutabaga (Brassica napobrassica) tolerant to pest insects (1995)
    Springer
    Plant cell reports 15 (1995), S. 97-101 
    Details
    ISSN: 1432-203X
    Keywords: Brassica napobrassica ; Agrobacterium tumefaciens ; cryIAgene ; transformation ; insect-tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cotyledons cut from axenic seedlings were immersed inAgrobacterium tumefaciens suspension which was treated with acetosyringone and nopaline at low pH overnight. The infected cotyledon explants were cultured on MSB medium (MS salts + B5 Vitamins) containing 6-BA 3mg/1 for 2–3 days, and transferred onto selective medium (MSB with kanamycin 50–100 mg/l). Kanamycin-resistant shoots were selected. More than 60 regenerated plants were obtained. About 60% of the plants showed high NPT II activity. Southern blot hybridization showed that some of the plants gave a positive signal with the insecticidal crystal protein gene (cry IA gene) probe, and exhibited tolerant to insects such asPieris rapae (cabbage caterpillar) in leaf feeding experiments. Kanamycin-resistance and insect-resistance were maintained in the progeny.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01690262
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  • 159
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    Glyphosate-tolerant CP4 and GOX genes as a selectable marker in wheat transformation (1995)
    Springer
    Plant cell reports 15 (1995), S. 159-163 
    Details
    ISSN: 1432-203X
    Keywords: Wheat ; transformation ; glyphosate ; CP4/GOX ; embryos
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The lack of alternative selectable markers in crop transformation has been a substantial barrier for commercial application of agricultural biotechnology. We have developed an efficient selection system for wheat transformation using glyphosate-tolerant CP4 and GOX genes as a selectable marker. Immature embryos of the wheat cultivar Bobwhite were bombarded with two separate plasmids harboring the CP4/GOX and GUS genes. After a 1 week delay, the bombarded embryos were transferred to a selection medium containing 2 mM glyphosate. Embryo-derived calli were subcultured onto the same selection medium every 3 weeks consecutively for 9–12 weeks, and were then regenerated and rooted on selection media with lower glyphosate concentrations. Transgenic plants tolerant to glyphosate were recovered. ELISA assay confirmed expression of the CP4 and GOX genes in R0 plants. Southern blot analysis demonstrated that the transgenes were integrated into the wheat genomes and transmitted to the following generation. The use of CP4 and GOX genes as a selectable marker provides an efficient, effective, and alternative transformation selection system for wheat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00193711
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  • 160
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    Continuous transformations of differential equations with delays (1995)
    Springer
    Georgian mathematical journal 2 (1995), S. 1-8 
    Details
    ISSN: 1572-9176
    Keywords: 34K05 ; 34K15 ; Differential equation ; delay argument ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract The aim of this paper is to find the class of continuous pointwise transformations (as general as possible) in the framework of which Kummer's transformationz(t)=g(t)y(h(t)) represents the most general pointwise transformation converting every linear homogeneous differential equation of thenth order into an equation of the same type. Further, some forms of these equations having certain subspaces of solutions are considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02257729
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    The role of amphiregulin in breast cancer (1995)
    Springer
    Breast cancer research and treatment 33 (1995), S. 103-114 
    Details
    ISSN: 1573-7217
    Keywords: amphiregulin ; breast tumors ; EGF receptor ; oncogenes ; steroid hormones ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Amphiregulin (AR) is an epidermal growth factor (EGF)-related peptide that operates exclusively through the EGF receptor and that can bind to heparin. AR also possesses nuclear localization sequences in the extended NH2-terminal region suggesting an additional intracellular site of action. AR mRNA and protein expression have been detected in primary human mammary epithelial cell strains, nontransformed human mammary epithelial cell lines, several human breast cancer cell lines, and primary human breast carcinomas. The frequency and levels of AR protein expression are generally higher in invasive breast carcinomas than in ductal carcinomasin situ or in normal, noninvolved mammary epithelium. In addition, AR can function as an autocrine and/or juxtacrine growth factor in human mammary epithelial cells that have been transformed by an activated c-Ha-ras proto-oncogene or by overexpression of c-erb B-2. AR expression is also enhanced by mammotrophic hormones such as estrogens and other growth factors such as EGF.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00682718
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  • 162
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    Crop improvement through tissue culture (1995)
    Springer
    World journal of microbiology and biotechnology 11 (1995), S. 409-415 
    Details
    ISSN: 1573-0972
    Keywords: Breeding ; embryo culture ; haploids ; micropropagation ; protoplasts ; synthetic seed ; transformation ; wide hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Plant tissue culture comprises a set of in vitro techniques, methods and strategies that are part of the group of technologies called plant biotechnology. Tissue culture has been exploited to create genetic variability from which crop plants can be improved, to improve the state of health of the planted material and to increase the number of desirable germplasms available to the plant breeder. Tissue-culture protocols are available for most crop species, although continued optimization is still required for many crops, especially cereals and woody plants. Tissueculture techniques, in combination with molecular techniques, have been successfully used to incorporate specific traits through gene transfer. In vitro techniques for the culture of protoplasts, anthers, microspores, ovules and embryos have been used to create new genetic variation in the breeding lines, often via haploid production. Cell culture has also produced somaclonal and gametoclonal variants with crop-improvement potential. The culture of single cells and meristems can be effectively used to eradicate pathogens from planting material and thereby dramatically improve the yield of established cultivars. Large-scale micropropagation laboratories are providing millions of plants for the commercial ornamental market and the agricultural, clonally-propagated crop market. With selected laboratory material typically taking one or two decades to reach the commercial market through plant breeding, this technology can be expected to have an ever increasing impact on crop improvement as we approach the new millenium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00364616
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  • 163
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    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
    Keywords: Brassica napus ; β-glucuronidase ; polymerase chain reaction ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00041124
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    Advances in alternative DNA delivery techniques (1995)
    Springer
    Plant cell, tissue and organ culture 40 (1995), S. 1-15 
    Details
    ISSN: 1573-5044
    Keywords: electrophoresis ; intact tissue electroporation ; microinjection ; silicon carbide fiber ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This review describes recent advances in alternative DNA-delivery techniques with particular emphasis on silicon carbide fibers, intact tissue electroporation, electrophoresis and microinjection. The advantages/disadvantages of each method along with a historical overview and theory of practice are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00041112
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    Steroidal glycoalkaloids in cell and shoot teratoma cultures ofSolanum dulcamara (1995)
    Springer
    Plant cell, tissue and organ culture 43 (1995), S. 191-197 
    Details
    ISSN: 1573-5044
    Keywords: Agrobacterium tumefaciens ; shoot culture ; Solanum dulcamara ; solasodine ; steroidal glycoalkaloid ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Bittersweet (Solanum dulcamara L., Solanaceae) is of interest as a source of steroidal alkaloids for the commercial production of hormones. Since glycoalkaloid production is positively correlated to differentiation, tumor and teratoma cultures of the soladulcidine chemotype were established by transformation withAgrobacterium tumefaciens. A newly developed HPLC-system, which allowed separation and sensitive quantitation of the glycoalkaloids soladulcidine-tetraoside, solamargine and solasonine, was used to analyse glycoalkaloid profiles in plants and cultures. Tumors and teratoma were charcterized by a shift in their alkaloid pattern from soladulcidine tetraoside to the solasodine glycosides solamargine and solasonine. Shoot teratoma showed a total glycoalkaloid content of 1% dw, which is about fivefold higher than in the source plant. A regenerated plant retained the altered alkaloid spectrum; the levels, however, equalled those of the source plant. From the alteration of alkaloid pattern in the transformed cultures suggestions can be made concerning the biosynthetic pathway. Completion of the biosynthesis of the aglycone is likely to be complete before glycosylation occurs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00052175
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    Expression of the Aspergillus niger glucose oxidase gene in Penicillium nalgiovense (1995)
    Springer
    World journal of microbiology and biotechnology 11 (1995), S. 322-325 
    Details
    ISSN: 1573-0972
    Keywords: Fungal starter culture ; gene expression ; glucose oxidase ; Penicillium nalgiovense ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The glucose oxidase gene (god) from Aspergillus niger was expressed in Penicillium nalgiovense under control of the latter's homologous transcription signals. The GOD protein was synthesized in an active form, leading to increased glucose oxidase activity. The expression vector was introduced into P. nalgiovense along with a selectable plasmid carrying the dominant amdS marker gene of A. nidulans.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00367109
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    There is no more important task than transforming education by design (1995)
    Springer
    Systemic practice and action research 8 (1995), S. 259-262 
    Details
    ISSN: 1573-9295
    Keywords: education ; societal transformation ; systems design ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Sociology
    Notes: Abstract For education we are already in the next century. Whatever we offer in our schools today will define the creative capacity, the competence, and the character of the generation which will shape the society of the 21st century. But many of us share a realization that today's schools are far from being able to do justice to the education of future generations. There is a growing awareness that our current design of education is out-of-sync with the new realities of the information/knowledge era. Those who are willing to face these new realities understand that: Rather thanextend education we shouldtranscend it; rather thanrevising it, we shouldre-vision it; and rather thenre-forming it, we shouldtrans-form it by design.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02250474
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  • 168
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    Variability in the response toPseudomonas solanacearum of transgenic lines of potato carrying a cecropin gene analogue (1995)
    Springer
    Potato research 38 (1995), S. 371-378 
    Details
    ISSN: 1871-4528
    Keywords: bacterial wilt ; resistance ; transformation ; Agrobacterium ; S. tuberosum L. ; transgenic plant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Transgenic potato plants of cv. Désirée carrying an antibacterial gene, coding for a cecropin lytic peptide analogue, were inoculated with a virulent strain ofPseudomonas solanacearum under controlled conditions. The disease index scored during three repeated infection trials indicated an increased variability in plant response among the transgenic lines which gave either a more susceptible or a more resistant response to the pathogen when compared with untransformed Désirée. Immunity toP. solanacearum was not observed, but it was possible to select a group of transgenic lines that showed resistance levels and disease development curves comparable to the field resistant cv. Cruza 148.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02357742
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    The role of disorder in phase transformations in PTFEPresented at ‘MakroAkron '94, 35th IUPAC Symposium on Macromolecules’, Akron, Ohio, 11-15 July 1994. (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Polymer International 37 (1995), S. 157-164 
    Details
    ISSN: 0959-8103
    Keywords: transformation ; X-ray ; modeling ; PTFE ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The transformation of PTFE from phase II to phase IV at 19°C and atmospheric pressure has been investigated using wide angle X-ray diffraction. Diffraction patterns were taken as a function of temperature. The integrated intensity of an equatorial peak present only in phase II was used to monitor the extent of the transformation. Peaks on the second and fifth layer lines were used to determine the effect of transformation and/or disorder. Integrated intensities on these three layer lines were shown to decrease differently with increasing temperature. The decrease in intensity on the second and fifth layer lines could be described in terms of a model comprising the initial integrated intensity, fraction transformed and the amount of rotational disorder present. Molecular modeling also was used to investigate the transformation. A commercially available force field was modified to represent the equilibrium solid state of PTFE. The modified force field was used to examine aspects of the transformation including the influence of neighboring molecules on the molecular conformation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pi.1995.210370302
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    CC series solution for bending of rectangular plates on elastic foundations (1995)
    Springer
    Applied mathematics and mechanics 16 (1995), S. 593-601 
    Details
    ISSN: 1573-2754
    Keywords: elastic foundation ; rectangular plate ; Stockes ; transformation ; analytical solution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Mathematics , Physics
    Notes: Abstract The analytical solution for the bending problem of the rectangular plates on an elastic foundation is investigated by using the Stockes' transformation of a double variables function. The numerical results for the rectangular plates with free edges on the elastic foundations under a concentrated force are given in the example.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02458727
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    Efficient transformation and regeneration of carnation cultivars usingAgrobacterium (1995)
    Springer
    Molecular breeding 1 (1995), S. 283-293 
    Details
    ISSN: 1572-9788
    Keywords: Agrobacterium ; carnation ; Dianthus caryophyllus ; regeneration ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We have developed an efficient method for transformation and regeneration of plants from carnation,Dianthus caryophyllus L. Whole leaves fromin vitro shoot cultures were mixed withAgrobacterium, cocultivated for 5 days and then plated on 2 µg/l chlorsulfuron (CS). Regenerated shoots and shoot clusters were divided into smaller sections and plated on 3 µg/l CS for selection to produce fully transformed shoots. Geneticin (G418) and kanamycin used were not as effective selective agents as CS. All regenerated shoots were vitrified. These were normalized, rooted and transferred to the greenhouse. 100% of regenerated plants were transformed based on rooting assay, GUS assay, PCR and Southern analysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02277428
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    Physical, chemical and physiological parameters for electroporation-mediated gene delivery into rice protoplasts (1995)
    Springer
    Transgenic research 4 (1995), S. 361-368 
    Details
    ISSN: 1573-9368
    Keywords: protoplast ; β-glucuronidase ; electroporation ; PEG ; transformation ; DNA integration pattern ; Oryza sativa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transformation of cereal protoplasts has been reported using several methods; however, the efficiencies of transformations are still very low. We have evaluated a number of parameters that influence electroporation-mediated DNA uptake and have also compared the efficiency of transient GUS activity and stable transformation obtained using an optimized electroporation method with that of the PEG method. The electroporation conditions tested were ionic composition of buffer, ionic strength, resistivity of buffer, type of anions, voltage, and capacitance. Protoplasts isolated from suspension cultures derived from immature embryos of rice (cvs Radon and IR-54) were used for this study. Stable transformation or transient GUS expression experiments were carried out using a plasmid construct containing the CaMV 35S promoter driving thebar gene and a rice actin promoter driving thegus A (uid A) gene (pAG35bar). Electroporation under optimized conditions resulted in about 13-fold higher GUS activities compared to the PEG method. Protoplast survival following optimized electroporation conditions was 55–60%, compared to 35–40% with the PEG treatment. Protoplasts isolated from a suspension culture at different ages gave substantially different levels of transient GUS expression following electroporation-mediated DNA uptake. In contrast, the age of the suspension culture did not influence PEG-mediated DNA uptake and transient GUS activities, which remained low throughout the culture period examined (21 months). Putatively transformed calluses were selected after three to four weeks on medium containing phosphinothricin as the selection agent. The transformation frequencies ranged from 6.2×10−5 to 5.4×10−4 with the electroporation method compared to 1.3×10−5 to 5.3×10−5 with the PEG method. Southern blot analysis of PPT-resistant calluses obtained by the electroporation-mediated transformation showed simple intergration patterns of integrated DNA in most of the transformants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01973754
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    Cell competence forAgrobacterium-mediated DNA transfer inPisum sativum L. (1995)
    Springer
    Transgenic research 4 (1995), S. 184-191 
    Details
    ISSN: 1573-9368
    Keywords: competence ; transient ; transformation ; Agrobacterium ; grain legume ; histochemical GUS-detection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Distribution and properties of pea (Pisum sativum L.) cells, competent forAgrobacterium-mediated transformation were analysed byin situ histochemical detection of GUS (β-glucuronidase) activity, 4 d after inoculation with engineeredAgrobacterium tumefaciens. The vector system consisted of the hypervirulent disarmed strain EHA101 and the binary plasmid pIBGUS, carrying an intron-containing, 35S-promotor drivengusA (oruidA) gene and two selectable marker genes. Cells competent for transformation were mainly restricted to the dedifferentiating cells neighbouring the vascular system of cotyledon and epicotyl explants. A standardized assay was developed, allowing determination and quantification of factors influencing number and distribution of competent cells. In etiolated seedlings, competence for transformation decreased with the distance of the epicotyl explant from the shoot apex and was specifically induced by the exogenous application of auxins. Transient expression ofgusA afterAgrobacterium-mediated DNA transfer was dramatically reduced upon application of cell-cycle and DNA replication inhibitors aphidicolin, colchicine and nalidixic acid. GUS expression after direct DNA transfer of double-stranded plasmid DNA (via PEG into protoplasts or via particle bombardment of epicotyl segments) was independent of cell-division/DNA replication. A GUS-positive mutant of EHA101 was constructed to allowin situ analysis of attaching bacteria within the plant tissue. Attachment and invasion was inhibited by well-developed cuticula but was restored after chloroform treatment of the tissue surface. Moreover, no correlation was found between distribution of attaching bacteria and the pattern of transformation-competent cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01968783
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    A conundrum in molecular toxicology: Molecular and biological changes during neoplastic transformation of human cells (1995)
    Springer
    Cell biology and toxicology 11 (1995), S. 329-345 
    Details
    ISSN: 1573-6822
    Keywords: adduct ; carcinogenesis ; DNA adduction ; human cell ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The process of multistage carcinogenesis lends itself to the concept that the effects of carcinogens are mediated through dose-related, multi-hit, linear changes. Multiplein vitro model systems have been developed that are designed to examine the cellular changes associated with the progression of cells through the different stages in the process; however, these systems may have inherent limitations due to the cell lines used for these studies, the manner of assessing the effects of the carcinogens, and the subsequent growth and differentiation of the exposed cells. Each of these variables results in increasing levels of uncertainty relative to the correlation of the events with the actual process of human tumor development. Therefore, the prediction of the ultimate effect of any carcinogen is difficult. Moreover, relationships between individual biological endpoints resulting from carcinogen treatment appear at best to be approximations. The presence of an activated carcinogen inside the cell can give rise to multiple outcomes, only some of which may be critical events. For example, site-specific modification of the 12th and 13th codons of H-ras is different than that in the adjacent 14th and 15th codons. It is interesting to speculate what effect these differences might have on a biological outcome, e.g., transformation to anchorage-independent growth. The use of different model systems to examine the effects of activated carcinogens also creates additional problems. Comparisons ofin vitro transformed cells with similar cells isolated from human tumors indicate that the culture environment appears to influence the expression of a particular phenotype, in that human tumor cells in culture express many of the same parameters as those found in cells transformed with carcinogensin vitro. If the process of transformation is linear, then less aggressive phenotypes should progress to a more aggressive transformed stage. However, in carcinogen-transformed human cells, the populations exhibit phenotypic diversity in that many of the transformed cells differentiate and fial to continue to divide in culture. Historically, we have assumed only a limited role for epigenetic modulation of molecular changes that occur during progression; however, our data suggest quite strongly that nonmalignant tumor populations can be converted to a more malignant phenotype without additional mutations taking place and, conversely, malignant populations can be downregulated to a nontumorigenic phenotype. Tumor cell plasticity is not only a fundamental characteristic of diverse types of human tumors, but also appears as an integral characteristic of carcinogen-transformed cellsin vitro.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01305905
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  • 175
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    Genetic engineering in marine cyanobacteria (1995)
    Springer
    Journal of applied phycology 7 (1995), S. 77-84 
    Details
    ISSN: 1573-5176
    Keywords: marine cyanobacteria ; Synechococcus gene transfer ; transformation ; conjugation ; electroporation ; particle gun
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Many species of microalgae producing useful materials have been isolated from marine environments. For their industrial application, widely applicable and stable gene expression is required. It is necessary to establish gene transfer methods as an essential first step in genetic manipulation. Although gene transfer techniques for cyanobacteria have been developed, only naturally transformable strains have been used. Here, we describe recent progress made in developing gene transfer methods for marine cyanobacteria. The following are covered: (1) transformation, (2) electroporation, (3) conjugation, (4) particle gun. A plasmid from the marine cyanobacterium, Synechococcus sp., whose copy number is dependent on salinity, was characterized. This plasmid is being used to develop a stable and controllable gene expression system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00003555
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  • 176
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    Activation of the C-fos promoter by increased internal pH (1995)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 57 (1995), S. 630-640 
    Details
    ISSN: 0730-2312
    Keywords: internal pH ; transformation ; c-fos ; AP-1 ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Changes in intracellular pH (pHin) take part in the mitogenic response. Their importance has been stressed by the finding that mouse fibroblasts expressing a yeast proton pumping ATPase (PMA1) exhibit a transformed phenotype and are tumorigenic. These cells do maintain a higher pHin, supporting the idea that elevated pHin may act as a proliferative trigger. Here we show that cells constitutively expressing PMA1 have higher levels of the AP-1 transcription factor. The use of stable transfectants and transient transfection assays show that PMA1 activity induces transactivation of the c-fos promoter. The activation of the promoter is mediated throughout the serum response element (SRE). The use of protein kinase C inhibitors suggests that AP-1 activation is achieved through a pathway independent of protein kinase C.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240570407
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  • 177
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    U2-SnRNP B″ protein gene is an early growth-inducible gene (1995)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 58 (1995), S. 490-498 
    Details
    ISSN: 0730-2312
    Keywords: serum-stimulation ; transformation ; chromatin structure mRNA ; RNA polymerase II ; μg-small nuclear RNP ; NIH-3T3 cells ; ras oncogene ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: In this work we isolated mouse U2-snRNP-specific b″ clones and analysed the expression of the mouse U2-snRNP-specific b″ and U1-snRNP-specific 70K genes in NIH-3T3 fibroblasts. Stimulation of growth-arrested NIH-3T3 cells with serum was found to evoke a rapid increase in the amount of cytoplasmic b″ and 70K mRNAs. These increases in mRNA did not require de novo protein synthesis. Moreover, the inhibition of protein synthesis by cycloheximide caused a superinduction in the amounts of the U1-snRNP-specific 70K transcripts. We also found that c-Ha-rasval12 oncogene-transformed NIH-3T3 cells have higher of the b″ and 70K mRNAs than the normal 3T3 cells. These data imply that the b″ and 70K are early growth response genes, and their enhanced expression might be of significance in the processing of pre-mRNAs into mature mRNAs.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240580412
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  • 178
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    Plasmid reorganization during integrative transformation in Hansenula polymorpha (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 11 (1995), S. 343-353 
    Details
    ISSN: 0749-503X
    Keywords: Yeast ; Hansenula polymorpha ; plasmid ; transformation ; ARS sequence ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: During studies of integrative transformation in Hansenula polymorpha, it was found that transformants with plasmids possessing the LEU2 gene of H. polymorpha were frequently unstable and lost plasmids while growing on non-selective medium. These transformants possessed reorganized plasmids capable of replication in H. polymorpha. Two such plasmids were isolated and characterized. It was shown that they contain additional DNA segments which were not present in the original plasmid used for transformation. Southern hybridization analysis carried out with labeled DNA probes derived from these segments showed that they consisted of H. polymorpha DNA. The hybridization patterns indicated that corresponding sequences were homologous to several chromosomal regions. These chromosomal DNA segments apparently carried H. polymorpha autonomous replicating sequences (HARS), since plasmids bearing them could transform H. polymorpha with high efficiency and were maintained in transformants in an autonomous state. Sequence analysis of one such captured chromosomal fragment revealed several eight- to ten-base AT-rich blocks similar to the presumed HARS sequence defined by Roggenkamp et al. (1986). Analogous reorganization was also observed with respect to integrative plasmids carrying the TRP3 and HIS3 genes of H. polymorpha and the ADE2 gene of Saccharomyces cerevisiae as selectable markers.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320110407
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  • 179
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    Studies on the transformation of intact yeast cells by the LiAc/SS-DNA/PEG procedure (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 11 (1995), S. 355-360 
    Details
    ISSN: 0749-503X
    Keywords: Saccharomyces cerevisiae genetics ; transformation ; cell wall permeability ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: An improved lithium acetate (LiAc)/single-stranded DNA (SS-DNA)/polyethylene glycol (PEG) protocol which yields 〉1 × 106 transformants/μg plasmid DNA and the original protocol described by Schiestl and Gietz (1989) were used to investigate aspects of the mechanism of LiAc/SS-DNA/PEG transformation. The highest transformation efficiency was observed when 1 × 108 cells were transformed with 100 ng plasmid DNA in the presence of 50 μg SS carrier DNA. The yield of transformants increased linearly up to 5 μg plasmid per transformation. A 20-min heat shock at 42°C was necessary for maximal yields. PEG was found to deposit both carrier DNA and plasmid DNA onto cells. SS carrier DNA bound more effectively to the cells and caused tighter binding of 32P-labelled plasmid DNA than did double-stranded (DS) carrier. The LiAc/SS-DNA/PEG transformation method did not result in cell fusion. DS carrier DNA competed with DS vector DNA in the transformation reaction. SS plasmid DNA transformed cells poorly in combination with both SS and DS carrier DNA. The LiAc/SS-DNA/PEG method was shown to be more effective than other treatments known to make cells transformable. A model for the mechanism of transformation by the LiAc/SS-DNA/PEG method is discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/yea.320110408
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  • 180
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    Agrobacterium-mediated transformation of white mustard (Sinapis alba L.) and regeneration of transgenic plants (1994)
    Springer
    Plant cell reports 13 (1994), S. 130-134 
    Details
    ISSN: 1432-203X
    Keywords: Sinapis alba L. ; Agrobacterium tumefaciens ; transformation ; regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A procedure for the regeneration of fertile transgenic white mustard (Sinapis alba L.) is presented. The protocol is based on infection of stem explants of 7–9 day old plants with an Agrobacterium tumefaciens strain harboring a disarmed binary vector with chimeric genes encoding neomycin phosphotransferase and β-glucuronidase. Shoots are regenerated from callus-forming explants within 3–4 weeks. Under selection, 10% of the explants with transgenic embryonic callus develop into fertile transgenic plants. Rooting shoots transferred to soil yield seeds within 14–16 weeks following transformation. Integration and expression of the T-DNA encoded marker genes was confirmed by histochemical β glucuronidase assays and Southern-DNA hybridization using primary transformants and S1-progeny. The analysis showed stable integration and Mendelian inheritance of trans-genes in transformed Sinapis lines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239878
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  • 181
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    Isolation and transformation of rice aleurone protoplasts (1994)
    Springer
    Plant cell reports 13 (1994), S. 394-396 
    Details
    ISSN: 1432-203X
    Keywords: Rice ; α-amylase ; protoplasts ; aleurone ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Protoplasts isolated from the aleurone have been used extensively in molecular studies focusing on hormone-mediated regulation of gene expression in barley seed. To extend the use of aleurone protoplasts to other species, we have determined the conditions necessary for the isolation of protoplasts from rice aleurone layers of germinated seed. Many of the common cell wall degrading enzymes used in making protoplasts were tested for their ability to release protoplasts from rice aleurone layers. Cellulysin was found to be the most effective. Transformation of these aleurone protoplasts was accomplished using polyethylene glycol and DNA constructs containing the firefly luciferase reporter gene under the control of two different promoters were tested. Luciferase expression was 24-fold greater when the reporter gene was under the control of the CaMV 35S promoter than when the promoter from the alcohol dehydrogenase 1 gene was used. With the isolation and transformation of aleurone protoplasts from rice, it is now possible to investigate molecular events occurring in this tissue during germination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234145
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  • 182
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    Hairy roots of Brassica napus: II. Glutamine synthetase overexpression alters ammonia assimilation and the response to phosphinothricin (1994)
    Springer
    Plant cell reports 14 (1994), S. 41-46 
    Details
    ISSN: 1432-203X
    Keywords: Agrobacterium rhizogenes ; Brassica napus ; glutamine synthetase ; phosphinothricin ; rape ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Hairy roots of Brassica napus (rape cv. Giant) have been produced that contain the cytosolic glutamine synthetase (GS) gene from Glycine max (soybean). Leaf explants were cocultivated with Agrobacterium rhizogenes strain A4T harbouring the binary vector pLN16. This vector was constructed by inserting a soybean cytosolic GS cDNA into the multiple cloning site of pGA643, placing it under the control of the CaMV promoter. In addition, the T-DNA region of pLN16 contained a NPTII gene for selection of transformed cells. Transgenic hairy roots grew prolifically on hormone-free media containing a selective level of kanamycin. Southern and northern analyses confirmed the presence of soybean GS DNA and transcripts, respectively. These transformed hairy roots also have a greater abundance of the GS polypeptide, approximately 3–6 fold greater GS activity and lower levels of endogenous ammonia. Hairy roots provide a useful system for studying responses to phosphinothricin (PPT). Hairy roots grown in media containing PPT had lower GS activity, greater ammonia accumulation and slower growth than controls. The presence of the soybean GS gene in the hairy roots reduced these PPT-induced effects and resulted in higher GS activity, lower ammonia levels and faster growth than in PPT-treated controls. Greater tolerance of PPT was also seen in shoots regenerated from the hairy roots displaying elevated levels of GS activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233296
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  • 183
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    Genetic ecology: A new interdisciplinary science, fundamental for evolution, biodiversity and biosafety evaluations (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 429-437 
    Details
    ISSN: 1420-9071
    Keywords: Genetics ; ecology ; DNA-transfer ; conjugation ; transformation ; transduction ; transposons ; dormant cells ; epilithon ; microbial colonisation ; symbiosis ; virus resistance ; biosafety ; release of genes ; insults to humanity ; evolution ; biodiversity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Genetic ecology is the extension of our modern knowledge in molecular genetics to studies of viability, gene expression and gene movements in natural environments like soils, aquifers and digestive tracts. In such milieux, the horizontal transfer of plasmid-borne genes between phylogenetically distant species has already been found to be much more frequent than had been expected from laboratory experience. For the study of exchanges involving chromosomally-located genes, more has to be learned about the behaviour of transposons in such environments. The results expected from studies in genetic ecology are relevant for considerations of evolution, biodiversity and biosafety. The role of this new field of research in restoring popular confidence in science and in its biotechnological applications is stressed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01920741
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  • 184
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    Stable expression of the GUS reporter gene in chrysanthemum depends on binary plasmid T-DNA (1994)
    Springer
    Plant cell reports 14 (1994), S. 59-64 
    Details
    ISSN: 1432-203X
    Keywords: Agrobacterium ; transformation ; T-DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three chrysanthemum (Dendranthema grandiflora) cultivars were cocultivated with 2 Agrobacterium tumefaciens strains in combination with 4 pBIN19 derived binary plasmids, all carrying the Nosnptll selection gene and 35Sgus(intron) reporter gene. All binary plasmids transferred DNA to chrysanthemum explants but only pMOG410 gave good stable expression of GUS. This plasmid differs from the other plasmids in 2 aspects: 1) It carries a restored nptll gene and 2) the selection gene is positioned at the left border side of the reporter gene. Cocultivation with AGLO(pMOG410) yielded up to 13 GUS positive shoots per 100 explants. The presence of the gus and nptll gene in recovered shoots was confirmed by PCR and Southern blot analysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233300
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  • 185
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    Plasmid mediated silver resistance in Acinetobacter baumannii (1994)
    Springer
    BioMetals 7 (1994), S. 49-56 
    Details
    ISSN: 1572-8773
    Keywords: Acinetobacter ; conjugation ; curing ; plasmid ; silver uptake ; silver resistance ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Acinetobacter baumannii BL88, an environmental isolate, was resistant to 13 metals and 10 antibiotics. Plumbagin cured resistance to silver, cadmium, antimony, streptomycin and ampicillin at varying frequencies. However, only silver resistance transferred (1 × 10−6 recepient−1) to Escherichia coli K12 during conjugation. Correspondingly there was transfer of a 54 kb plasmid (pUPI199) from A. baumannii BL88. The plasmid transformed E. coli DH5α cells at a frequency of 1 × 10−8 recepient−1. The growth rate of E. coli DH5; (pUPI199) was slower as compared with E. coli DH5α. Plasmid pUPI199 was 76 and 9.6% stable in the host A. baumannii BL88 in the presence and absence of selection pressure, respectively. A. baumannii BL88 was found to accumulate and retain silver whereas E. coli DH5α (pUPI199) effluxed 63% of the accumulated silver ions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00205194
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  • 186
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    Transmission of injected DNA sequences to multiple eggs of Metaseiulus occidentalis and Amblyseius finlandicus (Acari: Phytoseiidae) following maternal microinjection (1994)
    Springer
    Experimental and applied acarology 18 (1994), S. 319-330 
    Details
    ISSN: 1572-9702
    Keywords: Maternal microinjection ; transformation ; genetic improvement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The persistence of DNA injected into two species of adult female phytoseiids and its transmission to serial eggs deposited by them was assessed by the polymerase chain reaction (PCR). The effect of DNA concentration on persistence and transmission was examined in Metaseiulus occidentalis. M. occidentalis females were microinjected with plasmid DNA at three different concentrations (250, 500, 750 ng μL−1) and allowed to deposit one to five eggs before the females and their last eggs were analyzed. Plasmid DNA was found in 82% of the females assayed and in 70% of all the eggs analyzed (including the fifth eggs produced after microinjection). Transmission of DNA to multiple eggs was also examined in Amblyseius finlandicus. Females of this species are less traumatized by microinjection allowing analysis of transmission over a more extended number of eggs. Females were microinjected and allowed to deposit eggs until their death. DNA from every fifth egg was analyzed by the PCR. PCR products were amplified from 51% of the eggs and from all egg classes except the 30th egg. The persistence and presence of plasmid DNA in both eggs and females suggests that (1) maternal microinjection is a more efficient method for DNA delivery than traditional egg microinjection, (2) it may be possible to isolate transformants from fewer maternally-microinjected females than originally expected, and (3) maternal microinjection could be useful as a DNA delivery system in other phytoseiids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00116313
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  • 187
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    Canonical correlation and reduction of multiple time series (1994)
    Springer
    Annals of the Institute of Statistical Mathematics 46 (1994), S. 625-631 
    Details
    ISSN: 1572-9052
    Keywords: Rank of multiple time series ; transformation ; spectrum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract It is shown that a degenerate rankd-variate stationary time series can be reduced to a full rank time series of lower dimension via an orthogonal transformationT provided that ρ, the canonical correlation between past and future of the time series is strictly less than one. Procedures for estimation of rank of the multiple time series,T and testing ρ=1 are outlined, the latter is related to testing the unit root hypothesis in ARMA models.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00773471
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  • 188
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    Genetics and gibberellin production inGibberella fujikuroi (1994)
    Springer
    Antonie van Leeuwenhoek 65 (1994), S. 217-225 
    Details
    ISSN: 1572-9699
    Keywords: Gibberella fujikuroi ; gibberellins ; mutants ; regulation by nitrogen ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Gibberella fujikuroi (Fusarium moniliforme) is a complex group of plant pathogens. Some strains produce gibberellic acid and other gibberellins that promote growth and regulate various stages in plant development. The paper describes the research effort directed to development of genetic tools for this species. Furthermore the main features of the gibberellin biosynthetic pathway as established in Gibberella are described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00871950
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  • 189
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    Efficient plant regeneration through somatic embryogenesis from callus induced on mature rice embryos (Oryza sativa L.) (1994)
    Springer
    Plant cell, tissue and organ culture 36 (1994), S. 259-264 
    Details
    ISSN: 1573-5044
    Keywords: monocotyledons ; Oryza sativa L. ; plant regeneration ; rice ; somatic embryogenesis ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To obtain a reproducible efficient procedure for regeneration of rice plants through somatic embryogenesis from callus four published methods of callus induction and regeneration were compared. Callus was initiated from mature embryos of the Japonica cultivar Taipei 309 of rice (Oryza sativa L.). The number, mass and morphology of the callus formed on the scutellum were dependent on the medium used. A limited humidity and an optimal aeration of the culture vessels enhanced the frequency of embryogenesis and plant regeneration. A method described by Poonsapaya et al. (1989) was found to be the most efficient and was slightly modified. As a result 98% of the T309 embryos formed callus, of which 63% regenerated into plants. Each callus yielded an average of 6 plants. Plant morphology, fertility and seed set of the regenerants were found to be normal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00037729
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  • 190
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    Factors that effect leaf regeneration efficiency in apple, and effect of antibiotics in morphogenesis (1994)
    Springer
    Plant cell, tissue and organ culture 37 (1994), S. 257-269 
    Details
    ISSN: 1573-5044
    Keywords: adventitious shoots ; Malus x domestica Borkh. ; tissue culture ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Several factors that affect the frequency of organogenesis in apple leaf explants were examined for the scion cultivars ‘Empire’, ‘Freedom’, ‘Golden Delicious’, ‘Liberty’, ‘McIntosh’, and ‘Mutsu’ and for the rootstocks Malling 7A and Malling 26. The main factors affecting morphogenesis were BA concentration, basal medium, leaf explant origin and maturity, explant orientation, and photosynthetic photon flux. Depending on the genotype, optimal regeneration was obtained using either 22.2 or 31.1 μM BA and the N6 basal medium, with the exception of ‘Golden Delicious’ which regenerated better on MS medium. After 6 weeks, the average number of shoots per segment varied from 5 to 16, and the percentage of regeneration between 70 and 100%, depending on the genotype tested and the maturity of the explant. Regeneration capacity increased dramatically from the tip towards the base of the leaf, and was higher from the middle to the proximal end. Cefotaxime and carbenicillin, two antibiotics commonly used during transformation studies to eliminate Agrobacterium tumefaciens from plant tissue, were tested to determine their effect on morphogenesis. Cefotaxime at a dose of 250 mg 1-1 enhanced regeneration and shoot development, whereas carbenicillin at a dose of 500 mg l-1 induced abundant callus formation and inhibited regeneration. Kanamycin, a widely used selection agent for plant transformation, strongly inhibited regeneration even at very low doses. Schemes for selection and recovery of transgenic apple plants when kanamycin is used as the selection agent are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00042339
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  • 191
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    A robust protocol for site-directed mutagenesis of the D1 protein inChlamydomonas reinhardtii: A PCR-splicedpsbA gene in a plasmid conferring spectinomycin resistance was introduced into apsbA deletion strain (1994)
    Springer
    Photosynthesis research 42 (1994), S. 121-131 
    Details
    ISSN: 1573-5079
    Keywords: chloroplast ; Photosystem II ; psbA ; site-directed mutagenesis ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In this paper, we describe a protocol to obtain a site-directed mutants in thepsbA gene ofChlamydomonas reinhardtii, which overcomes several drawbacks of previous protocols, and makes it possible to generate a mutant within a month. Since the large size of the gene, and the presence of four large introns has made molecular genetics of thepsbA gene rather unwieldy, we have spliced all of the exons of thepsbA gene by PCR to facilitate genetic manipulation and sequencing of the gene. The resultant construct (plasmid pBA153, with several unique restriction sites introduced at exon boundaries) carried 1.2 and 1.8 kb intact sequences from the 5′- and 3′-flanking regions, respectively. The plasmid was used to transform a D1-deletion mutant and was found to complement the deletion and restore photosynthetic activity. In addition, a bacterialaadA gene conferring spectinomycin resistance (spe r) was inserted downstream of the intron-freepsbA gene, to give construct pBA155. This allowed selection of mutant strains deficient in photosynthesis by using spectinomycin resistance, and eliminated the possibility of selection for revertant strains which is a consequence of having to use photosynthetic activity as a selection pressure. Finally, pBA155 was used to construct pBA157, in which additional restriction sites were inserted to facilitate cassette mutagenesis for generation of mutations in spans thought to be involved in donor-side interactions. AllpsbA deletion strains transformed with intron-freepsbA-aadA constructs encoding the wild-type D1 sequence, and screened on spectinomycin plates for thespe r phenotype, were able to grow photosynthetically, and all showed identical kinetics for electron transfer from primary (QA) to secondary quinone (QB) in Photosystem II, as assayed by the decay of the high fluorescence yield on oxidation of the reduced primary acceptor (QA −).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02187123
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  • 192
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    Micropropagation of thirteen Malus cultivars and rootstocks, and effect of antibiotics on proliferation (1994)
    Springer
    Plant growth regulation 15 (1994), S. 55-67 
    Details
    ISSN: 1573-5087
    Keywords: apple (Malus × domestica Borkh.) ; selection ; tissue culture ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Several factors that affect in vitro establishment, proliferation, and rooting of thirteen Malus cultivars and rootstocks were studied. Apple shoot tips (1.5±0.5 cm in length) were established using ascorbic and citric acids as antioxidants. Four proliferation media containing 1.0 mg 1−1 BA and different concentrations of IBA and GA3 were tested. Proliferation rates varied depending on the genotype and medium used. The highest proliferation rate was obtained for a rootstock that produced 11.6±2.5 shoots (1.5±0.8 cm in length) per tube per month. Rooting was induced with IBA for all the genotypes tested. The optimal IBA concentration was cultivar dependent (between 0.1 and 1.0 mg 1−1 IBA), and lower concentrations were necessary to induce rooting in liquid rather than in solid medium. The effects on shoot-tip proliferation of cefotaxime, carbenicillin and kanamycin, three antibiotics commonly used for transformation studies, were also evaluated. Cefotaxime at 200 mg 1−1 stimulated shoot growth and development, but at 500 mg 1−1 caused abnormal shoot morphology. Carbenicillin at 500 mg 1−1, alone or in combination with cefotaxime at 200 mg 1−1, inhibited proliferation and caused excessive enlargement of the basal leaves, inducing callus formation and release of phenolic compounds in the medium. Kanamycin at 50 mg 1−1 was phytotoxic and caused shoot chlorosis and necrosis. Consideration of the toxicity of these antibiotics is critical when designing transformation schemes for selection and recovery of transgenic apple plants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00024677
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  • 193
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    Electronic Resource
    Production of fertile transgenic maize by electroporation of suspension culture cells (1994)
    Springer
    Plant molecular biology 24 (1994), S. 51-61 
    Details
    ISSN: 1573-5028
    Keywords: Zea mays L. ; transformation ; electroporation ; bar ; phosphinothricin acetyltransferase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fertile, transgenic maize plants were generated by electroporation of suspension culture cells that were treated with a pectin-degrading enzyme. Electroporation of cells from two different suspension cultures, one derived from A188 X B73 and one derived from a B73-related inbred, with a plasmid containing the bar gene, resulted in high-frequency recovery of stably transformed callus lines. Plants were regenerated from thirteen transformed callus lines and transmission of bar to progeny was demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00040573
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  • 194
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    Electronic Resource
    Stable transformation and long-term expression of the gusA reporter gene in callus lines of perennial ryegrass (Lolium perenne L.) (1994)
    Springer
    Plant molecular biology 24 (1994), S. 401-405 
    Details
    ISSN: 1573-5028
    Keywords: Lolium perenne L. ; transformation ; rice gene GOS2 ; long-term GUS expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Stable transformation of perennial ryegrass (Lolium perenne L.) was achieved by biolistic bombardment of a non embryogenic cell suspension culture, using the hpt and gusA gene. The transformation yielded on the average 5 callus lines per bombardment (1.4×106 cells). Stable integration of the genes into the plant genome was demonstrated by Southern analysis of DNA, isolated from hygromycin-resistant callus lines. The gusA reporter gene, which was regulated by the constitutive promoter of the rice gene GOS2, was expressed in both transient and stable transformation assays, indicating that this promoter is suitable for expression of a transferred gene in perennial ryegrass. Long-term GUS expression was observed in ca. 40% of the callus lines, whereas the other callus lines showed instability after 6 months and 1 year of culture.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00020178
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  • 195
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    Electronic Resource
    Molecular improvement of cereals (1994)
    Springer
    Plant molecular biology 25 (1994), S. 925-937 
    Details
    ISSN: 1573-5028
    Keywords: cereals ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00014667
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  • 196
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    Structure and function of selectable and non-selectable transgenes in maize after introduction by particle bombardment (1994)
    Springer
    Plant molecular biology 25 (1994), S. 951-961 
    Details
    ISSN: 1573-5028
    Keywords: Cell biology ; epigenetics ; maize ; transformation ; transgenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Zea mays transformants produced by particle bombardment of embryogenic suspension culture cells of the genotype A188 × B73 and selected on kanamycin or bialaphos were characterized with respect to transgene integration, expression, and inheritance. Selection on bialaphos, mediated by thebar orpat genes, was more efficient than selection on kanamycin, mediated by thenptII gene. Most transformants contained multicopy, single locus, transgene insertion events. A transgene expression cassette was more likely to be rearranged if expression of that gene was not selected for during callus growth. Not all plants regenerated from calli representing single transformation events expressed the transgenes, and a non-selectable gene (uidA) was expressed in fewer plants than was the selectable transgene. Mendelian inheritance of transgenes consistent with transgene insertion at a single locus was observed for approximately two thirds of the transformants assessed. Transgene expression was typically, but not always, predictable in progeny plants-transgene silencing, as well as poor transgene transmission to progeny, was observed in some plant lines in which the parent plants had expressed the transgene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00014669
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  • 197
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    Stably transformed cell lines from protoplasts of maize endosperm suspension cultures (1994)
    Springer
    Plant cell, tissue and organ culture 37 (1994), S. 39-46 
    Details
    ISSN: 1573-5044
    Keywords: endosperm cell culture ; maize ; protoplast ; transformation ; zeins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Protoplasts were isolated from Zea mays (L.) A69Y endosperm suspension cultures and transformed by polyethylene glycol mediated DNA uptake with chimaeric gene constructs containing β-glucuronidase (GUS) or neomycin phosphotransferase II (NPTII); GUS-expressing and Kanamycin-resistant cultures were recovered. The transformed cells showed integration of the introduced foreign genes into genomic DNA and maintained their ability to synthesize endosperm-specific reserve proteins (zeins). No deletion or rearrangement of zein genes were observed in transformed cultures. Stable transformation of cultured maize endosperm cells may therefore represent a new methodological approach for the study of the transcriptional regulation of endosperm-expressed genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00048115
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  • 198
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    Electronic Resource
    A simple technique for producing 13C or 14C-labelled fronds of Lemna gibba and their use in soil incubation investigations (1994)
    Springer
    Plant and soil 160 (1994), S. 185-191 
    Details
    ISSN: 1573-5036
    Keywords: carbon-labelling ; carbon dioxide production ; decomposition ; 14C-glucose ; Lemna ; soil organic matter ; sugars ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The duckweed Lemna gibba required light and a suitable energy source such as sucrose, glucose or fructose, for maximum growth in culture. The requirement for light was relatively unimportant and the plants grew well in a photon flux density of only 52 μmol m-2s-1 PAR. The uptake and incorporation of uniformly labelled 14C-glucose into fronds was related only to the concentration of the sugar. When incubated with soil, labelled L. gibba behaved in a manner similar to that of labelled ryegrass roots which had been produced by a more elaborate technique using a 14CO2 labelled atmosphere. During incubation with soil for 224 days the L. gibba material (specific activity 6133 Bq mg-1 d. wt) lost 64% of its radioactivity as 14CO2 and ryegrass (specific activity 6634 Bq mg-1 d. wt) lost 49%. Alkaline extracted humic and fulvic acids from soil had specific activities for the L. gibba incubation of 3409 and 407 Bq mg-1 solid and for ryegrass roots of 4609 and 546 Bq mg-1 solid respectively. The production of 13C or 14C-labelled L. gibba can be undertaken using only simple equipment producing material the specific radioactivity of which can be controlled by adjusting the activity of the sugar energy source.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00010144
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  • 199
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    Cloning of ω3 desaturase from cyanobacteria and its use in altering the degree of membrane-lipid unsaturation (1994)
    Springer
    Plant molecular biology 26 (1994), S. 249-263 
    Details
    ISSN: 1573-5028
    Keywords: desB gene ; desaturase ; fatty acid ; Synechococcus sp. PCC 7942 ; Synechocystis sp. PCC 6803 ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cyanobacteria respond to a decrease in temperature by desaturating fatty acids of membrane lipids to compensate for the decrease in membrane fluidity. Among various desaturation reactions in cyanobacteria, the desaturation of the ω3 position of fatty acids is the most sensitive to the change in temperature. In the present study, we isolated a gene, designated desB, for the ω3 desaturase from the cyanobacterium, Synechocystis sp. PCC 6803. The desB gene encodes a protein a 359 amino-acid residues with molecular mass of 41.9 kDa. The desB gene is transcribed as a monocistronic operon that produced a single transcript of 1.4 kb. The level of the desB transcript in cells grown at 22°C was 10 times higher than that in cells grown at 34°C. In order to manipulate the fatty-acid unsaturation of membrane lipids, the desB gene in Synechocystis sp. PCC 6803 was mutated by insertion of a kanamycin-resistance gene cartridge. The resultant mutant was unable to desaturate fatty acids at the ω3 position. The desA gene, which encodes the Δ12 desaturase of Synechocystis sp. PCC 6803, and the desB gene were introduced into Synechococcus sp. PCC 7942. Whilst the parent cyanobacterium can only desaturate membrane lipids at the Δ9 position of fatty acids, the resultant transformant was able to desaturate fatty acids of membrane lipids at the Δ9, Δ12 and ω3 positions. These results confirm the function of the desB gene and demonstrate that it is possible to genetically manipulate the fatty-acid unsaturation of membrane lipids in cyanobacteria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00039536
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  • 200
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    Electronic Resource
    Identification of conserved domains in the Δ12 desaturases of cyanobacteria (1994)
    Springer
    Plant molecular biology 24 (1994), S. 643-650 
    Details
    ISSN: 1573-5028
    Keywords: Anabaena variabilis ; fatty-acid desaturation ; Synechococcus PCC7002 ; Synechococcus PCC7942 ; Synechocystis PCC6714 ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cyanobacterial genes for enzymes that desaturate fatty acids at the Δ12 position, designated desA, were isolated from Synechocystis PCC6714, Synechococcus PCC7002 and Anabaena variabilis by crosshybridization with a DNA probe derived from the desA gene of Synechocystis PCC6803. The genes of Synechocystis PCC6714, Synechococcus PCC7002 and A. variabilis encode proteins of 349, 347 and 350 amino acid residues, respectively. The transformation of Synechococcus PCC7942 with the desA genes from Synechocystis PCC6714, Synechococcus PCC7002 and A. variabilis was associated with the ability to introduce a second double bond at the Δ12 position of fatty acids. The amino acid sequence of the products of the desA genes revealed the presence of four conserved domains. Since one of the conserved domains was also found in the amino acid sequences of ω3 desaturases of Brassica napus and mung bean, this domain may play an essential role in the introduction of a double bond into fatty acids bound to membrane lipids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00023560
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