Increased Mutagenesis and Unique Mutation Signature Associated with Mitotic Gene Conversion

Abstract

Dodgy Repair A double-strand break (DSB) in genomic DNA poses a serious threat to genome stability, and yet vertebrate cells may suffer 10 or more DSBs every time the genome is replicated. Pathways have thus evolved that can recognize and repair DSBs before they reek havoc in the cell. Hicks et al. (p. 82 ) show that this repair can come at a price. DSBs were induced in the budding yeast genome. Repair of a break was accompanied by a massive increase in the rate of mutation in the vicinity of the break. The mutations generated displayed a specific “signature” that included the copying of divergent sequences from other chromosomes.