Dicentric chromosomes undergo breakage during mitosis as a result of the attachment of two centromeres on one sister chromatid to opposite spindle poles. Studies utilizing a conditional dicentric chromosome III in Saccharomyces cerevisiae have shown that dicentric chromosome repair occurs primarily by deletion of one centromere via a RAD52-dependent recombination pathway. We report that dicentr...

Two sequences (ARS18 and ARS68) displaying autonomous replication activity were previously cloned in the yeast Yarrowia lipolytica. The smallest fragment (1-1.3 kb) required for extrachromosomal replication of a plasmid is significantly larger in Y. lipolytica than in Saccharomyces cerevisiae. Neither autonomously replicating sequence (ARS) is homologous with known ARS or centromere (CEN) conse...

Cancer chemoprevention is considered to be a promising approach for cancer control, as it has been identified by both epidemiological and molecular studies that environmental factors are the major causes of cancer. Chemoprevention can be defined as the use of agents to prevent, inhibit or reverse the process of carcinogenesis. Several epidemiological studies have shown that fruits, vegetables a...

In this study, we assessed the toxic effects of formaldehyde (FA) on mouse bone marrow mesenchymal stem cells (BM-MSCs). Cytotoxicity was measured by using MTT assay. DNA strand breakage was detected by standard alkaline comet assay and comet assay modified with proteinase K (PK). DNA-protein crosslinks (DPCs) were detected by KCl-SDS precipitation assay. We found that FA at a concentration fro...

Proper meiotic chromosome segregation, essential for sexual reproduction, requires timely formation and removal of sister chromatid cohesion and crossing-over between homologs. Early in meiosis cohesins hold sisters together and also promote formation of DNA double-strand breaks, obligate precursors to crossovers. Later, cohesin cleavage allows chromosome segregation. We show that in fission ye...

Most DNA double-strand breaks (DSBs) in S- and G2-phase cells are repaired accurately by Rad51-dependent sister chromatid recombination. However, a minority give rise to gross chromosome rearrangements (GCRs), which can result in disease/death. What determines whether a DSB is repaired accurately or inaccurately is currently unclear. We provide evidence that suggests that perturbing replication...

I N the ten years since I last addressed an International Congress of Genetics, considerable progress has been made in understanding the process of recombination, and yet many of its central features still elude us. I would like to summarize briefly some of the main advances of the last decade, and to indicate where these discoveries seem to be leading us. An outstanding advance was the demonst...

We have been quantitating, as a marker of cancer susceptibility, induced chromatid breaks in lymphocyte cultures exposed to chemical mutagens. This report highlights the consistency of the results from two casecontrol studies, using different methods of presenting the data. In both the lung cancer case-control study, which used bleomycin, a radiomimetic agent, as the test mutagen, and the melan...

chromosomal appearance of 12 holstein bulls selected for artificial inseminations were examined bysister chromatid exchanges (sces). for differential staining of sister chromatids bromodeoxyuridine (brdu)was inoculated in lymphocyte cultures. the mean, maximum and minimum number of sce per cell weredetermined 6.8 ± 1.14, 8.3 ± 1.1 and 5.7 ± 1.5, respectively. sce frequencies of all animals were...