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71.
David McElroy Douglas A. Chamberlain Eunpyo Moon Kate J. Wilson 《Molecular breeding : new strategies in plant improvement》1995,1(1):27-37
The use of reporter genes to characterise sequence elements that act to regulate gene expression in transgenic plants has been vital to the development of foreign gene expression strategies for use in cereal transformation. ThegusA locus ofEscherichia coli, which encodes the enzyme-glucuronidase (GUS), is by far the most popular reporter gene used in plant transformation. In this paper we extend the utility of the GUS reporter gene system in cereal transformation by describing and evaluating a number of novel constructs suitable for use in direct gene transfer experiments. These plasmids are all available from the Molecular Genetic Resource Service of the Center for the Application of Molecular Biology to International Agriculture. 相似文献
72.
We have analyzed the distribution of putative cholinergic neurons in whole-mount preparations of adult Drosophila melanogaster. Putative cholinergic neurons were visualized by X-gal staining of P-element transformed flies carrying a fusion gene consisting of 5′ flanking DNA from the choline acetyltransferase (ChAT) gene and a lacZ reporter gene. We have previously demonstrated that cryostat sections of transgenic flies carrying 7.4 kb of ChAT 5′ flanking DNA show reporter gene expression in a pattern essentially similar to the known distribution of ChAT protein. Whole-mount staining of these same flies by X-gal should thus represent the overall distribution of ChAT-positive neurons. Extensive staining was observed in the cephalic, thoracic, and stomodeal ganglia, primary sensory neurons in antenna, maxillary palps, labial palps, leg, wing, and male genitalia. Primary sensory neurons associated with photoreceptors and tactile receptors were not stained. We also examined the effects of partial deletions of the 7.4 kb fragment on reporter gene expression. Deletion of the 7.4 kb fragment to 1.2 kb resulted in a dramatic reduction of X-gal staining in the peripheral nervous system (PNS). This indicates that important regulatory elements for ChAT expression in the PNS exist in the distal region of the 7.4 kb fragment. The distal parts of the 7.4 kb fragment, when fused to a basal heterologous promoter, can independently confer gene expression in subsets of putative cholinergic neurons. With these constructs, however, strong ectopic expression was also observed in several non-neuronal tissues. © 1995 John Wiley & Sons, Inc. 相似文献
73.
Guo-Ling Nan Adelheid R. Kuehnle 《In vitro cellular & developmental biology. Plant》1995,31(3):131-136
Summary Five parameters were examined for their effect on transformation ofDendrobium tissues by microprojectile bombardment. The superpromoter in pBI426 produced at least 1.5 times as many transient transformants
as the single cauliflower mosaic virus 35S promoter in pBI121 (37 to 69% vs. 0 to 44%) with dark and frequent GUS (β-glucuronidase) staining. Tissue, genotype, and type of microparticle significantly affected transient GUS activity. Higher
expression was seen in protocormlike bodies and in hybrid UH44 compared to etiolated shoots and protocorms and to hybrids
M61 and K1329-39. Microparticles of 1.6-μm Bio-Rad gold were more effective than 1.0-μm ASI gold. Transient GUS activity did
not differ among protocormlike bodies bombarded using helium propellant pressures of 650, 900, or 1100 psi. Transgenic plants
were recovered fromDendrobium UH800 protocormlike bodies bombarded with pBI426-coated, 1.1-μm tungsten particles using an early-model gunpowder-driven
apparatus with an estimated stable transformation rate of 11.7%. One transgenic plant ofDendrobium UH44 was recovered from etiolated shoot explants bombarded with pBI121-coated, 1.1-μm tungsten particles using the Dupont
PDS-1000 with a stable transformation rate of 0.17%. Positive selection results showed 100 to 200 mg·liter−1 kanamycin to be appropriate for regeneration of transgenic plants from protocormlike bodies, protocorms, and etiolated shoot
explants over a 3- to 9.5-mo. period. 相似文献
74.
Kan Wang Paul Drayton Bronwyn Frame Jim Dunwell John Thompson 《In vitro cellular & developmental biology. Plant》1995,31(2):101-104
A number of different methods, involving direct DNA delivery are now available for plant transformation. Here we review the most recently developed technique which involves the mixing of silicon carbide whiskers with plant cells and plasmid DNA. Fertile transgenic plants have now been produced using whisker-mediated transformation, and this method can now be considered as a simple, inexpensive alternative for plant transformation. A brief review on transformation of animal cells andChlamydomonas using whiskers technology is also included. 相似文献
75.
Plasmid transfer to indigenous marine bacterial populations by natural transformation 总被引:3,自引:0,他引:3
Abstract Horizontal gene transfer among microbial populations has been assumed to occur in the environment, yet direct observations of this phenomenon are rare or limited to observations where the mechanism(s) could not be explicitly determined. Here we demonstrate the transfer of exogenous plasmid DNA to members of indigenous marine bacterial populations by natural transformation, the first report of this process for any natural microbial community. Ten percent of marine bacterial isolates examined were transformed by plasmid DNA while 14% were transformed by chromosomal DNA. Transformation of mixed marine microbial assemblages was observed in 5 of 14 experiments. In every case, acquisition of the plasmid by members of the indigenous flora was accompanied by modification (probably from genetic rearrangement or methylation) that altered its restriction enzyme digestion pattern. Estimation of transformation rates in estuarine environments based upon the distribution of competency and transformation frequencies in isolates and mixed populations ranged from 5 × 10−4 to 1.5 transformants/1 day. Extrapolation of these rates to ecosystem scales suggests that natural transformation may be an important mechanism for plasmid transfer among marine bacterial communities. 相似文献
76.
Eric Hbert Michel Monsigny 《Biology of the cell / under the auspices of the European Cell Biology Organization》1994,81(1):73-76
Summary— The increase in galectin-3 lectin content observed in tumours or in in vitro transformed cells suggests that this lectin is important in the transformation process. In the present study, we investigated the mRNA expression level of the galectin-3, galectin-I and macrophage mannose receptor in normal and ras-transformed NIH 3T3 cells in relation to their transformation state. The galectin3 mRNA content in ras-transformed cells is increased in fully transformed cells, with a maximum in ras-transformed cells that have lost their growth anchorage-dependence. Under the same conditions, the galectin-1 mRNA level which was high in normal cells, increased slightly in transformed cells. The mRNA for the macrophage mannose receptor was not detected in 3T3 cells or in their ras-transformed counterparts. 相似文献
77.
Light-and electron-microscopic autoradiography have been used to study fibroblast transformation into endothelial cells in the formation of new blood vessels during wound healing in rabbit ear chambers. When cultured fibroblasts labeled with tritium thymidine were transplanted autologously into the chambers, newly formed blood vessels contained endothelial cells labeled with tritium thymidine. This result suggests that fibroblasts play a pivotal role in angiogenesis, as progenitors of endothelial cells in newly formed blood vessels. 相似文献
78.
Ingrid Ahrenholtz Michael G. Lorenz Wilfried Wackernagel 《Archives of microbiology》1994,161(2):176-183
A quantitative endonuclease assay, which relies on the introduction of single and double strand breaks into supercoiled plasmid DNA, was used to study the activity of the extracellular nuclease of Serratia marcescens SM6 in buffer and in groundwater. The parallel enzyme concentration-dependent production of relaxed and linear plasmid molecules suggests that the nuclease produces single and double strand breaks in duplex DNA. Bovine serum albumin stimulated the nuclease activity towards DNA and RNA and increased the stability of the enzyme against thermal inactivation. The DNase activity at 4 °C and 50 °C was almost half of that at the optimum temperature (37 °C). The nuclease was active in groundwater, although the specific activity was lower than in buffer. In a groundwater aquifer microcosm, mineral-adsorbed transforming DNA was substantially less accessible to the nuclease than was dissolved DNA. The data suggest that the extracellular nuclease of Serratia marcescens may contribute to DNA turnover in the environment and that adsorption of DNA to minerals provides protection against the nuclease.Abbreviations GW groundwater
GWA groundwater aquifer 相似文献
79.
Enrique Cerdá-Olmedo Rafael Fernández-Martín Javier Ávalos 《Antonie van Leeuwenhoek》1994,65(3):217-225
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.Abbreviations AMO 1618
2-isopropyl-4-(trimethylammonium chloride)-5-methylphenylpiperidine-1-carboxylate
- hydroxykaurenoic acid
ent-kaur-16-en-7-ol-19-oic acid
- kaurenal
ent-kaur-16-en-19-al
- kaurene
ent-kaur-16-ene
- kaurenoic acid
ent-kaur-16-en-19-oic acid
- kaurenol
ent-kaur-16-en-19-ol
- paclobutrazol
1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-lyl)pentan-3-ol
- pefurazoate
pent-4-enyl-N-furfuryl-N-imidazol-1-ylcarbonyl-DL-homoa laninate
- tetcyclacis
5-(4-chlorophenyl)-3,4,5,9,10-pentaazatetracyclo-5,4,102.6,O8.11-dodeca-3,9-diene
- triarimol
-(2,4-dichlorophenyl)--phenyl-5-pyrimidine methyl alcohol 相似文献
80.
L. Martinelli G. Mandolino 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,88(6-7):621-628
Isolated somatic embryos from petiole-derived callus cultures ofVitis rupestris Scheele have been employed in experiments on genetic transformation. Co-cultivation of somatic embryos during embryogenesis induction withAgrobacterium tumefaciens strain LBA4404, which contains the plasmid pBI121 carrying the neomycin phosphotranspherase and the-glucuronidase genes, produced transformed cellular lines capable of recurrent somatic embryogenesis. Precocious selection for high levels of kanamycin (100 mgl-1) was an important part of our transformation protocol. Transformed lines still have strong-glucuronidase expression as well as stable insertion of the marker genes after 3 years of in-vitro culture, during which they have maintained their capacity to organize secondary embryos and to regenerate transgenic plants with an agreeable efficiency (13%). 相似文献