RT Journal Article SR Electronic T1 Increased Mutagenesis and Unique Mutation Signature Associated with Mitotic Gene Conversion JF Science JO Science FD American Association for the Advancement of Science SP 82 OP 85 DO 10.1126/science.1191125 VO 329 IS 5987 A1 Hicks, Wade M. A1 Kim, Minlee A1 Haber, James E. YR 2010 UL http://science.sciencemag.org/content/329/5987/82.abstract AB To examine the fidelity of DNA synthesis during double-strand break (DSB) repair in Saccharomyces cerevisiae we studied gene conversion in which both strands of DNA are newly synthesized. The mutation rate increases up to 1400 times over spontaneous events, with a significantly different mutation signature. Especially prominent are microhomology-mediated template switches. Recombination-induced mutations are largely independent of mismatch repair, by DNA polymerases Polζ, Polη, and Pol32, but result from errors made by Polδ and Polε. These observations suggest that increased DSB frequencies in oncogene-activated mammalian cells may also increase the probability of acquiring mutations required for transition to a cancerous state.