Properties of spontaneous mitotic recombination occurring in the presence of therad52-1mutation ofSaccharomyces cerevisiae

Abstract

Summary: All major recombination pathways in the yeastSaccharomyces cerevisiaerequire theRAD52gene product. We have examined the effect of therad52-1mutation on spontaneous mitotic recombination between heteroalleles, and found that prototrophs are produced at frequencies significantly above reversion. This residual recombination occurs at a relatively uniform level at all of the loci examined. To help understand the role thatRAD52plays in mitotic recombination, we examined recombination between all pairwise combinations of six mutant alleles of theLYS2gene. Therad52-1mutation decreased the variation in amount of recombination between the various pairwise combinations as well as lowering the overall frequency of recombination. The reduced variation results in a different pattern of recombination inrad52-1cells than in wild type. One interpretation of these results is that theRAD52gene product, directly or indirectly, plays a role in the formation or the resolution of mismatches in heteroduplex DNA.