The cohesin protein complex holds sister chromatids together after synthesis until mitosis. It also contributes to post-replicative DNA repair in yeast and higher eukaryotes and accumulates at sites of laser-induced damage in human cells. Our goal was to determine whether the cohesin subunits SMC1 and Rad21 contribute to DNA double-strand break repair in X-irradiated human cells in the G2 phase...

Introduction: Ionizing radiation is widely used in industry and medicine; however, it causes a significant health hazard by making microscopic damage to living tissue. Various biological parameters, including cell survival fraction and relative biological effectiveness, are taken into account to assess the severity and extent of biological damages. Microdosimetry suffe...

The study of DNA double-strand break (DSB) repair has been greatly facilitated by the use of rare-cutting endonucleases, which induce a break precisely at their cut sites that can be strategically placed in the genome. We previously established such a system in Drosophila and showed that the yeast I-SceI enzyme cuts efficiently in Drosophila cells and those breaks are effectively repaired by co...

The TP120 plasmid is known to determine enhanced UV survival in E. coli wild type an uvrB and PolA mutants but not in RecA mutant. In order to analyze the function involved in the SOS repair, we have constructed a new plasmid named pR derived by cleavage of TP120 with Hind III endonuclease. This new plasmid maintains the Ap and UV resistance. The insertion of Tn5 transposon in the plasmid allow...

DNA ligases catalyse the joining of DNA single- and double-strand breaks. Saccharomyces cerevisiae Cdc9p is a homologue of mammalian DNA ligase I and is required for DNA replication, recombination and single-strand break repair. The other yeast ligase, Lig4p/Dnl4p, is a homologue of mammalian DNA ligase IV, and functions in the non-homologous end-joining (NHEJ) pathway of DNA double-strand brea...

Homologous recombination (HR) is an evolutionarily conserved process that plays a pivotal role in the equilibrium between genetic stability and diversity. HR is commonly considered to be error-free, but several studies have shown that HR can be error-prone. Here, we discuss the actual accuracy of HR. First, we present the product of genetic exchanges (gene conversion, GC, and crossing over, CO)...