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91.
Peter Alliger Wolfgang Traut Eric Carstens Ellen Fanning 《Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression》1988,951(2-3)
A monkey cell factor that interacts specifically with double- and single-stranded DNA sequences in the early domain of the simian virus 40 (SV40) core origin of replication was identified using gel-retention assays. The protein was enriched over 1200-fold using ion-exchange and affinity chromatography on single-strand DNA cellulose. Binding of protein to mutant origin DNA restriction fragments was correlated with replication activity of the mutant DNAs. Exonuclease footprint experiments on single-stranded DNA revealed prominent pause sites in the early domain of the core origin. The results suggest that this cellular protein may be involved in SV40 DNA replication. 相似文献
92.
Anti-bromodeoxyuridine monoclonal antibody: an alternative tool for the identification of replicated DNA at the electron microscope level 总被引:1,自引:0,他引:1
M Thiry D Dombrowicz 《Biology of the cell / under the auspices of the European Cell Biology Organization》1988,62(1):99-102
A new method for identifying the replicated DNA at the electron microscope level is described. Cells were first exposed in vitro to 5-bromodeoxyuridine (BUdR) in conjunction with 5-fluorodeoxyuridine (FUdR) and BUdR incorporated into DNA was then detected on Lowicryl-embedded sections by immunogold technique using a monoclonal anti-BUdR antibody. After using this method, chromatin and chromosomes are strongly labelled. 相似文献
93.
J Piskur 《Molecular & general genetics : MGG》1988,214(3):425-432
Summary Mitochondrial DNAs (mtDNA) from four stable revertant strains generated from high frequency petite forming strains of Saccharomyces cerevisiae have been shown to contain deletions which have eliminated intergenic sequences encompassing ori1, ori2 and ori7. The deleted sequences are dispensable for expression of the respiratory phenotype and mutant strains exhibit the same relative amount of mtDNA per cell as the wild-type (wt) parental strain. These deletion mutants were also used to study the influence of particular intergenic sequences on the transmission of closely linked mitochondrial loci. When the mutant strains were crossed with the parental wt strains, there was a strong bias towards the transmission into the progeny of mitochondrial genomes lacking the intergenic deletions. The deficiency in the transmission of the mutant regions was not a simple function of deletion length and varied between different loci. In crosses between mutant strains which had non-overlapping deletions, wt mtDNA molecules were formed by recombination. The wt recombinants were present at high frequencies among the progeny of such crosses, but recombinants containing both deletions were not detected at all. The results indicate that mitochondrial genomes can be selectively transmitted to progeny and that two particular intergenic regions positively influence transmission. Within these regions other sequences in addition to ori/rep affect transmission.This paper is dedicated to colleagues J. Jana, D. Tasi, I. Bortner, and F. Zavrl 相似文献
94.
J Doskocil H Storchová J Stokrová J Forstová J Meyer 《Molecular & general genetics : MGG》1988,214(2):343-347
Summary Natural recombinant genomes between several, phenotypically distinct forms of phages and were isolated and characterized by DNA restriction fragment mapping and electron microscopic heteroduplex analysis. The phenotypes of the recombinants were correlated with the physical maps of the genomes, and several genetic functions were therfore defined and mapped. All genes necessary for the assembly of infectious virus particles map in a contiguous tract of DNA comprising about 20 kb, or nearly one third of the genome length. No DNA homology occurs within these domains of the two genomes, so that homologous recombination does not take place here and phenotypic mixing of the phages is eo ipso excluded. Other regions of heterology contain regulatory genes responsible for the lytic or temperate character of the phages, and for exclusion of phage by . 相似文献
95.
Summary The EcoK restriction of unmodified phage is 1000-fold alleviated in Escherichia coli grown in the presence of base analogs 2-aminopurine (2AP) and 5-bromouracil (5BU). 2AP treatment of bacteria affects specificially the type I restriction systems (EcoA, EcoB, EcoD and EcoK) and does not influence type II (EcoRI) and type III (EcoP1) restriction. 2AP-induced alleviation of restriction occurs in bacteria which are deficient in the SOS response (recA and lexA) and mismatch repair (mutH, mutL and mutS) and can be distinguished from the alleviation of restriction observed in dam
- strains. We suggest that mismatches induced by 2AP and 5BU may function as an inducing signal for the alleviation of restriction observed in the presence of base analogs. 相似文献
96.
Summary The complete physical map of the mitochondrial genome of the Owen cytoplasm of sugar beet has been determined from overlapping cosmid clones. The genome is 386 kb in size and has a multicircular organisation generated by homologous recombination across repeated DNA elements. The location of the rRNA genes and several polypeptide genes has been determined. In addition the mitochondrial genome was found to contain a sequence of chloroplast DNA including part of the 16 S rRNA gene. 相似文献
97.
98.
T. Endo T. Komiya M. Mino K. Nakanishi S. Fujita Y. Yamada 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1988,76(5):641-646
Summary The genetic instability of an intertribal hybrid cell line, Duboisia hopwoodii + Nicotiana tabacum, obtained by mechanical isolation of a single hybrid cell was studied. Ten subclones of calli derived from this hybrid cell line were cultured for 3 years, and their genetic makeup clarified as to nuclear DNA content, chromosome constitution, and peroxidase isozymes. Nuclear DNA content differed in each subclone. In most subclones, mean DNA content was lower than the mean DNA content in the original hybrid cell line determined 1 year after fusion. This decrease in DNA content is partly attributable to the elimination of tobacco chromosomes that occurred in all subclones. The extent to which tobacco chromosomes were eliminated varied among the subclones — evidence that chromosome elimination occurred slowly. Peroxidase isozyme analysis indicated the loss of a tobacco-specific isozyme, thus confirming results obtained by chromosome analysis. Shoots regenerated from two hybrid subclones after 2 years were also heterogeneous in morphology and nuclear DNA content. 相似文献
99.
Spyridon Vamvakas Wolfgang Dekant Dietmar Schiffmann Dietrich Henschler 《Cell biology and toxicology》1988,4(4):393-403
S-(chloroethyl)-cysteine (CEC) and S-(1,2-dichlorovinyl)cysteine (DCVO) have been proposed as intermediates in the metabolic transformation of the carcinogens 1,2-dichloroethane and 1,1,2-trichloroethylene. We have tested the ability of CEC and DCVC to induce DNA repair and genotoxic effects at the chromosomal level by comparative assessment of unscheduled DNA synthesis induction and micronucleus formation in Syrian hamster embryo fibroblasts. CEC induced a potent and dose-dependent response in both assays, whereas DCVC treatment resulted in a comparatively weak induction of DNA repair and failed to raise micronucleus formation above control rates. Inhibition of cysteine conjugate \gB-lyase diminished the effect of DCVC, but had no influence on the genotoxicity of CEC either in the unscheduled DNA synthesis or micronucleus assay.Abbreviations AOAA
aminooxyacetic acid
- CEC
S-(chloroethyl)-cysteine; \gB-lyase, cysteine conjugate -lyase
- DCE
1,2-dichloroethane
- DCVC
S(1,2-dichlorovinyl)-cysteine
- GSH
glutathione
- HU
hydroxyurea
- IBR
IBR-modified Dulbecco's Eagle's reinforced medium
- MN2
micronuclei/2,000 cells
- 4-NQO
4-nitroquinoline-1-oxide
- SHE
Syrian hamster embryo fibroblasts; 3H-Thd, 3H-thymidine
- TCE
1,1,2-trichloroethylene
- UDS
unscheduled DNA synthesis 相似文献
100.