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P. Cruz C. H. Mejia‐Ruiz R. Perez‐Enriquez A. M. Ibarra 《Molecular ecology resources》2002,2(3):239-241
Five polymorphic microsatellite loci were characterized for Penaeus (Litopenaeus) vannamei. Loci were isolated using a partial Sau3A1 genomic library by the sequencing of randomly selected clones and by a biotinylated (CT)10 and (GT)10 probes screening procedure. The last strategy resulted in the most useful data. About 40% of the clones showed a previously reported satellite/microsatellite (PVS1), reducing the chance of finding new microsatellite regions. Whereas two of the microsatellite loci with more than 10 alleles will be useful for mating analysis in a breeding program, the others might prove useful for population genetic studies. 相似文献
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Methylenetetrahydrofolate dehydrogenase - methenyltetrahydrofolate cyclohydrolase - formyltetrahydrofolate synthetase was purified to homogeneity from mouse liver, taking advantage of its very high affinity for 2',5'-ADP-Sepharose. Antibodies raised to this trifunctional enzyme and to the bifunctional NAD-dependent dehydrogenase-cyclohydrolase from mouse Ehrlich ascites tumour cells were found not to cross-react with the purified proteins on Western blots. Each of these polyclonal antibodies detects the appropriate protein in extracts of Ehrlich ascites tumour cells after sodium dodecyl sulfate - polyacrylamide gel electrophoresis and electrophoretic transfer of the proteins to nitrocellulose. The procedure has also been used to obtain a purified preparation of the trifunctional enzyme from human liver obtained at autopsy. 相似文献
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Cadmium (Cd) is a non-essential, highly toxic heavy metal and a ubiquitous environmental contaminant. Evidence exists that Cd can affect parameters which are of great importance in the response towards xenobiotics. However, there is a lack of information about the mechanisms that take place at the cellular and molecular levels upon dual exposure to Cd and other toxins. The purpose of the present work was therefore to examine the biochemical interactions between Cd and a well-known genotoxic hepatocarcinogen, 2-acetylaminofluorene (AAF) in isolated rat hepatocytes. The cells were incubated for 10 hr with a sub-cytotoxic concentration (0.22 M) of 109Cd. This was followed by a 10 hr exposure to 1 M [3H]AAF. Cellular distribution of Cd and 3H was determined. Sephadex G-75 elution profiles of the cytosol showed that Cd was almost entirely associated with the intermediate molecular weight (IMW) fractions containing metallothionein (MT) (>80%), and with high molecular weight proteins. In parallel, the highest proportion of 3H was found in the low molecular weight components. Further analysis of IMW fractions by DEAE A-25 anion-exchange chromatography revealed that, in addition to Cd, there was some 3H which coeluted along with MT-I and MT-II isoforms, but preferentially with MT-I. Moreover, Cd pretreatment caused a 1.6-fold increase in MT level, as measured by the silver-saturation assay. Under these conditions, there was a 17% lower binding of 3H to the DNA. This reduced binding was neither accompanied by diminished AAF uptake nor by inhibition of cytochrome P-450 activity. Taken together, these results suggest that Cd exposure has a protective effect against the genotoxicity of AAF. MT, whose synthesis is induced, could play a role in the Cd-AAF interaction through scavenging of reactive metabolites.Abbreviations AAF
2-acetylaminofluorene
- Cd
cadmium
- DMSO
dimethyl sulfoxide
- HBSS
Hank's balanced salt solution
- LDH
lactate dehydrogenase
- MT
metallothionein
- UDS
unscheduled DNA synthesis 相似文献
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Francine Denizeau Michel Marion Gaston Chevalier Michel G. Cote 《Cell biology and toxicology》1985,1(2):23-32
The biological activity of natural and synthetic mineral fibers has been examined. Natural attapulgite [(Mg, Al)2Si4O10(OH).4H20], synthetic xonotlite [Ca3Si3O8(OH)2] and natural sepiolite [Mg2Si3O8.2H2O] were selected. Genotoxic effects were investigated by means of a well established cellular model based upon the measurement of unscheduled DNA synthesis (UDS) in rat hepatocytes in primary culture. The intrinsic capacity of the fibers (1 and 10 µ/ml) to induce UDS was first tested. None of the fiber types showed detectable UDS-eliciting activity. Also, the possible modulation of the cellular response to genotoxic agents by the materials was examined by exposing the cells to mixtures of 2-acetylaminofluorene (AAF) (0.05 and 0.25 µg/ml) and fibers (1 and 10 µg/ml). In these experiments, the UDS response was significantly diminished in the presence of xonotlite. This phenomenon may reflect changes in the uptake and/or metabolism of AAF or may result from an inhibition of DNA repair processes, the latter suggesting a possible cocarcinogenic potential for this synthetic silicate. These results point to the immediate necessity of studying more extensively the biological effects of fibrous materials that can be used as substitutes for asbestos.Abbreviations AAF
2-acetylaminofluorene
- DMSO
dimethyl-sulfoxide
- FBS
fetal bovine serum
- IRDA
Institut de Recherche et de Développement sur l'Amiante
- LDH
lactate dehydrogenase
- UDS
unscheduled
- DNA
synthesis
- WME
Williams' Medium E
This work was supported by the Institut de Recherche et de Développement sur l'Amiante (IRDA), Sherbrooke, Canada. 相似文献
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Identification and expression of water stress- and abscisic acid-regulated genes in a drought-tolerant sunflower genotype 总被引:17,自引:0,他引:17