During somatic life and hereditary transmission, DNA can suffer programmed, spontaneous or environmentally-induced lesions which must be repaired in order to conserve the integrity of the genetic material and allow cell survival. Most damage is usually accurately repaired, but defects in repair systems can allow single base alterations and larger scale rearrangements to occur.
Specific sequences can also be particularly prone to rearrangement.
Some repetitive DNA tracts such as microsatellites and minisatellites are naturally unstable, and in humans alterations in these sequences are often associated with various genetic diseases and cancer. Our group aims to identify and characterize the biological processes that maintain genomic integrity and that ensure the faithful transmission of genetic information during meiosis. We have detected 72 DSB regions located in intergenic promoter-containing regions. Numerous genes whose inactivation abolishes meiotic DSB formation have been identified. Although it is not known whether DSBs initiate meiotic recombination in other eukaryotes, the existence of sequences encoding proteins similar to Spo11 in the fission yeast S. pombe , C. elegans, Drosophila, mouse and man strongly implies that the mechanism of recombination initiation discovered in the yeast S. cerevisiae is evolutionarily conserved.