Replication forks stall at different DNA obstacles such as those originated by transcription. Fork stalling can lead to DNA double-strand breaks (DSBs) that will be preferentially repaired by homologous recombination when the sister chromatid is available. The Rrm3 helicase is a replisome component that promotes replication upon fork stalling, accumulates at highly transcribed regions and preve...

BACKGROUND Susceptibility to bleomycin-induced chromatid breaks in cultured peripheral blood lymphocytes may reflect the way a person deals with carcinogenic challenges. This susceptibility (also referred to as mutagen sensitivity) has been found to be increased in patients with environmentally related cancers, including cancers of the head and neck, lung, and colon, and, in combination with ca...

Cytogenetic analysis of peripheral blood lymphocytes was used to compare 58 shoe workers (57 men and one woman) exposed to benzene and 20 subjects selected from the general population not exposed to particular mutagenic or carcinogenic agents (control group). Frequencies of damaged cells, including gaps, breaks, and rearrangements (acentric fragment, deletion, translocation) were scored for bot...

human embryonic stem cells (hESCs) are able to differentiate in all different specialized tissues [1]. Yet, as all living cells, they have to cope with endogenous or exogenous DNA damage. Their efficacy in DNA repair is somewhat controversial. Clearly hESCs can achieve the indispensable genome stability either by more effective repair or, on the contrary, by increasing apoptosis thus eliminatin...

Background: Chromosomal alterations play an important role in carcinogenesis. Enhanced chromosomal radiosensitivity is shown for many cancer predisposition conditions including breast cancer. In this study chromosomal radiosensitivity and the frequency of background sister chromnatid exchanges (SCE) in lymphocytes of normal individuals and breast cancer patients was compared. Materials...

Sister chromatid exchanges in chromosomes from human lymphocytes grown two replication cycles in medium containing 5-bromodeoxyuridine can be detected by fluorescence microscopy after staining with the bisbenzimidazole dye 33258 Hoechst. These exchanges are much more frequent than chromosome or chromatid breaks and appear to be partly but not entirely due to 5-bromodeoxyuridine incorporation. S...

Thirteen cell lines derived from human tumors of diverse tissue origin and histopathology were compared with 12 lines of normal skin fibroblasts with respect to chromatid damage induced by 25, 50, or 100 R of X-irradiation during the G2 period of the cell cycle. Only cells in metaphase were examined, and these had been irradiated 1.5 hr before fixation. When irradiated under identical condition...

The rate of chromatid breaks was studied in cows with a history of sub-fertility by means of a test based on measurement of the average of breaks induced in lymphocytes of peripheral blood cultures. Fourteen female specimens were divided into two groups: fertile and sub-fertile. Peripheral blood lymphocytes were cultured and prepared for cytogenetic analysis. Two types of culture were establish...