Rad51 stabilizes the ends of two adjacent DSBs in yeast

Abstract

DNA double-strand breaks (DSBs) are a major form of DNA damage, and its accurate repair is critical for maintaining genomic stability and preventing cancer. Repair of DSBs is mainly through two pathways, homology-directed DNA repair (HDR) and non-homologous end joining (NHEJ). Compared with NHEJ, HDR has higher fidelity, so the study of interrelated factors in homologous recombination pathway is of particularly important. In this paper, we constructed an I-SceI model controlled by a galactose promoter that produces a DSB or two adjacent DSBs on a single chromosome. Rad50 and Rad51 genes are further deleted in these models. Sensitivity experiments show that Rad51 stabilizes the ends of two adjacent DSBs in yeast. Deletion of Rad51 gene causes the sequence between two adjacent DSBs to drop out directly to form a large gap. If this gap is larger, the efficiency of NHEJ will be greatly reduced, resulting in the deaths of the strain. Our research shows that Rad51 stabilizes the ends of two adjacent DSBs in yeast.