title: a/alpha-specific effect on the mms3 mutation on ultraviolet mutagenesis in Saccharomyces cerevisiae.
abstract: A new gene involved in error-prone repair of ultraviolet (UV) damage has been identified in Saccharomyces cerevisiae by the mms3-1 mutation. UV-induced reversion is reduced in diploids that are homozygous for mms3-1, only if they are also heterozygous (MATa/MAT alpha) at the mating type locus. The mms3-1 mutation has no effect on UV-induced reversion either in haploids or MATa/MATa or MAT alpha/MAT alpha diploids. The mutation confers sensitivity to UV and methyl methane sulfonate in both haploids and diploids. Even though mutation induction by UV is restored to wild-type levels in MATa/MATa mms3-1/mms3-1 or MAT alpha/MAT alpha mms3-1/mms3-1 diploids, such strains still retain sensitivity to the lethal effects of UV. Survival after UV irradiation in mms3-1 rad double mutant combinations indicates that mms3-1 is epistatic to rad6-1 whereas non-epistatic interactions are observed with rad3 and rad52 mutants. When present in the homozygous state in MATa/MAT alpha his1-1/his1-315 heteroallelic diploids, mms3-1 was found to lower UV-induced mitotic recombination.
mesh_terms: D004843:Epistasis, Genetic; D005796:Genes; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D008938:Mitosis; D009154:Mutation; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D008741:Methyl Methanesulfonate