pol30-6 and pol30-79 caused high rates of mitotic recombination and gene conversion in diploids. (A) Representative CRASH colonies of each indicated genotype. The pol30-6 homozygote MATa/MATα diploid (JRY11686) and the pol30-79 homozygote MATa/MATα diploid (JRY11688) both had extrabright sectors and nonfluorescent sectors (examples illustrated by arrows). No, or very few, sectors were observed in POL30 MATa/MATα (JRY11159), POL30 matΔ/ MATα (JRY11718), pol30-6 matΔ/MATα (JRY11719), or pol30-79 matΔ/MATα (JRY11720). Hemizygosity of POL30 (JRY11745), pol30-6 (JRY11822), or pol30-79 (JRY11823) in MATa/ MATα diploids had no effect on the mitotic recombination phenotype. (B) Patch-mating assay. Each indicated strain was patched onto complete medium plates seeded with a freshly plated lawn of either MATa or MATα haploid cells with complementary auxotrophies. After ∼18 hr, mating patches were replica plated onto minimal medium plates. Growth occurs within the patch only if the indicated strains mated with the mating tester lawn. WT, wild type.