Topic
Sister chromatid exchange
About: Sister chromatid exchange is a research topic. Over the lifetime, 3187 publications have been published within this topic receiving 90029 citations. The topic is also known as: replication-born DSB repair by SCE & GO:1990414.
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TL;DR: Peripheral blood lymphocytes from 32 male rotogravure workers with daily exposure to toluene were studied for chromosome aberrations and sister chromatid exchange and a significant increase was observed among smokers, both exposed and occupationally unexposed, compared to nonsmoking referents.
Abstract: Peripheral blood lymphocytes from 32 male rotogravure workers with daily exposure to toluene were studied for chromosome aberrations and sister chromatid exchange. Neither of these two cytogenetic parameters differed significantly from the corresponding frequencies in 15 unexposed control subjects. However, a significant increase in sister chromatid exchange was observed among smokers, both exposed and occupationally unexposed, compared to nonsmoking referents.
76 citations
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TL;DR: The eastern mudminnow, U. pygmaea, appeared to be a useful test animal for the detection of the cytogenetic effects of chemical pollution in the aquatic environment and an effect was found on the frequency of both sister chromatid exchange and chromosome aberrations.
76 citations
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TL;DR: The results indicate that BD is genotoxic in the bone marrow of the mouse but not the rat, paralleled the chronic bioassays which showed mice to be more susceptible than rats to BD carcinogenicity.
Abstract: Male B6C3F1 mice and Sprague-Dawley rats were exposed for 2 days, 6 h/day to 1,3-butadiene (BD) by inhalation (nose only) and their bone marrow cells were evaluated for the induction of micronuclei (MN) and sister chromatid exchanges (SCEs). A significant dose-dependent increase in MN induction was observed in mice. At 100 p.p.m., the frequency of micronucleated polychromatic erythrocytes was 6-fold above control with a maximal induction of 38-fold at 10,000 p.p.m. A significant increase in SCEs was also observed in mouse bone marrow cells starting at 100 p.p.m. with a 4-fold increase over the control evident at 10,000 p.p.m. The highest tested no observed effect level for both endpoints was 50 p.p.m. In contrast, rat bone marrow cells did not exhibit significant increases in micronucleated polychromatic erythrocytes or SCEs. These results indicate that BD is genotoxic in the bone marrow of the mouse but not the rat. This paralleled the chronic bioassays which showed mice to be more susceptible than rats to BD carcinogenicity.
75 citations
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TL;DR: It is shown that the fibroblast cell strain, 46BR, derived from an immunodeficient patient has a defect in joining Okazaki-type fragments during DNA replication, supporting the interpretation that the basic defect is in ligation of DNA strands.
Abstract: A fibroblast cell strain, 46BR, derived from an immunodeficient patient is hypersensitive to the lethal effects of a wide range of DNA-damaging agents. It is also defective in strand-break rejoining after treatment with dimethyl sulfate and UV light. The present study shows that the cells have a defect in joining Okazaki-type fragments during DNA replication, supporting the interpretation that the basic defect is in ligation of DNA strands. The baseline level of sister chromatid exchange is slightly higher than in normal cells but it does not approach that of Bloom's syndrome or dyskeratosis congenita cells. Sensitivity to the induction of sister chromatid exchange and the hypersensitivity to the lethal effects of a set of DNA-damaging agents are correlated, implying that the basic defect influences both end points in a similar manner. No 6-thioguanine-resistant mutants could be induced by either gamma- or UV-irradiation in these cells, suggesting that error-prone repair pathways for damage induced by these agents may contain a common ligation step in human cells.
75 citations
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TL;DR: In BLM-deficient cells, pyrimidine pool normalization leads to reduction of sister chromatid exchange frequency and is sufficient for full restoration of replication fork velocity but not the fork restart defect, thus identifying the part of the Bloom syndrome phenotype because of p Skyrimidine pool imbalance.
Abstract: Defects in DNA replication are associated with genetic instability and cancer development, as illustrated in Bloom syndrome. Features of this syndrome include a slowdown in replication speed, defective fork reactivation and high rates of sister chromatid exchange, with a general predisposition to cancer. Bloom syndrome is caused by mutations in the BLM gene encoding a RecQ helicase. Here we report that BLM deficiency is associated with a strong cytidine deaminase defect, leading to pyrimidine pool disequilibrium. In BLM-deficient cells, pyrimidine pool normalization leads to reduction of sister chromatid exchange frequency and is sufficient for full restoration of replication fork velocity but not the fork restart defect, thus identifying the part of the Bloom syndrome phenotype because of pyrimidine pool imbalance. This study provides new insights into the molecular basis of control of replication speed and the genetic instability associated with Bloom syndrome. Nucleotide pool disequilibrium could be a general phenomenon in a large spectrum of precancerous and cancer cells.
74 citations