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.

Increased incidence of chromosomal aberrations and sister chromatid exchanges in workers exposed to chromic acid (CrO3) in electroplating factories

Abstract: Chromosomal aberrations in cultured lymphocytes obtained from workers occupationally exposed to chromic acid (CrO3) were detected. Four separate groups of workers were examined, two of which were engaged in plating factories employing nickel in addition to chromium, and two coming from plating factories where only chromium was used. In the latter groups the frequency of sister chromatid exchanges (SCEs) were also detected in the cultured lymphocytes. A statistically significant increase of chromosomal aberrations, mostly of the chromosome-type, was found in two of the exposed groups of workers compared to the level observed in control donors. The frequency of SCEs in the exposed groups was higher than in controls, particularly in the factor which employed the younger workers. Besides the negative correlation with the age of workers, a positive correlation between the frequency of SCEs and the level of urinary chromium was found and such a correlation was strongly enchanced by smoking. The present data support the view that CrO3, like other soluble hexavalent chromium compounds, is genetically active in vivo.

Analysis of chromosome aberrations and sister-chromatid exchanges in peripheral blood lymphocytes of workers with occupational exposure to the mancozeb-containing fungicide Novozir Mn80.

Abstract: Chromosome aberrations and sister-chromatid exchanges (SCEs) were analyzed in short-term cultures of peripheral lymphocytes of 44 workers occupationally exposed to mancozeb during the production of the pesticide Novozir Mn80 and 30 control persons. The results suggest that mancozeb exposure was associated with a significant increase in the frequencies of cells with structural chromosome aberrations (2.07% vs. 1.10% in the controls), and the number of SCEs per cell (9.19 ± 1.81 vs . 7.82 ± 1.04 in the controls).

Sister chromatid exchange and chromosome aberration analyses in mice after in vivo exposure to acrylonitrile, styrene, or butadiene monoxide.

Abstract: The use of polymers in plastic and rubber products has generated concern that monomers potentially active in biological systems may be eluted from these substances. We have evaluated two such monomers, acrylonitrile and styrene, for the induction of chromosome damage in mice. Butadiene monoxide, a presumed metabolite of a third important monomer, 1,3-butadiene, was also tested. These chemicals were administered as a single intraperitoneal injection; sister chromatid exchanges and chromosome aberrations were analyzed in bone marrow cells. Acrylonitrile and styrene were largely negative for these endpoints when tested at doses ranging to 60 mg/kg and 1,000 mg/kg, respectively. Butadiene monoxide, which previously has not been tested in a mammalian system, was determined to be a very effective inducer of sister chromatid exchanges and chromosome aberrations. Both endpoints showed a clear dose response and a greater than ten-fold increase over control levels at high doses. These studies represent an initial step in our efforts to evaluate genetic risk associated with exposure to common polymeric chemicals.

Sister chromatid exchange frequency in cultured isolated porcine urinary bladder epithelial cells (PUBEC) treated with ochratoxin A and alpha

Abstract: The mycotoxin ochratoxin A (OTA) and its metabolite ochratoxin alpha (OT-alpha) were investigated, to examine their potency to induce sister chromatid exchages (SCE) in cultured poricine urinary baldder epithedial cells (PUBEC) (primary cluture). Serum-free cultured PUBEC were incubated for 5 h with either OTA or OT-alpha, respectively, and subsequently cutured in the presence of 5-bromo-2-deoxyuridine (BrdU). After two cell cycles, mitosis was inhibited by the colchicine derivative Colcemid, cells were fixed and chromosomes were prepared for SCE analysis. For OTA, a dose-dependent increase in SCE frequency was measured in concentrations between 100 pM and 100 nM OTA. At 100nM OTA, SCE frequency increased by about 41%, compared to the base SCE level (7.27 SCEs per chromosome set, solvent control). Higher concentrations of OTA were cytotoxic. The metabolite OT-alpha also increased SCE frequency, but at higher concentrations. At a concentration of 10μM OT-alpha, an increase of about 55% was detected. OT-alpha showed no cytotoxic effect. There results indicate that OTA is genotoxic in this in vitro system, which represents the urinary bladder epithelium, a target organ of OTA in vivo. It could also be shown that OT-alpha, which is said to be non-toxic, is genotoxic in this assay at higher concentrations.

Overexpression of human DNA repair protein N-methylpurine-DNA glycosylase results in the increased removal of N-methylpurines in DNA without a concomitant increase in resistance to alkylating agents in Chinese hamster ovary cells.

Abstract: N-Alkylpurines induced in DNA by simple monofunctional alkylating agents are known to be cytotoxic and possibly indirectly mutagenic. These adducts are removed by the ubiquitous N-methylpurine-DNA glycosylase (MPG) in a multistep repair pathway. Chinese hamster ovary (CHO) cell clones expressing 2- to 16-fold enhanced levels of MPG activity were isolated from cells stably transfected with human MPG cDNA expression plasmids. The in vivo removal of 3-methyladenine and 7-methylguanine from some of these lines was analyzed and was observed to reflect their MPG levels. These cell lines did not develop increased resistance, as compared to the control, in regards to cytotoxic, mutagenic and sister chromatid exchange inducing effects of the alkylating agents that induce 3-alkyladenine and 7-alkylguanine as the major alkyl adducts in DNA. These results suggest that the MPG activity is not limiting in the multi-step repair pathway of N-alkylpurines in CHO cells.