PRJNA672926
Genome-wide analysis of double-strand break repair by homologous recombination
DNA repair by homologous recombination maintains genome stability in response to damage. Here, we have used genomic sequencing to analyze at nucleotide resolution the dynamics of DNA-end resection, re-synthesis and gene conversion during repair of an induced double strand break (DSB) in Saccharomyces cerevisiae. We show that resection initiates preferentially in one direction before proceeding bidirectionally for about 15 kb. By contrast, DNA re-synthesis is symmetrical, although gene conversion is unidirectional, and spans only 600 nucleotides approximately. Quantitative comparison of resection and re-polymerization rates between mutants lacking Exo1, Rad51, Sgs1 and Srs2 has uncovered new and specific functions for each of them. Some of these mutants also develop alterations remote from the DSB, such as subtelomeric instability and overreplication of repetitive Ty elements. Altogether, this genome-wide approach allows direct visualization of the repair process in different genetic backgrounds and physiological conditions.