[Genetic effects of sulfur-35 decay in Saccharomyces cerevisiae cells. V. Comparative study of the lethal and mutagenic effectiveness of the decay of 35S and 32P incorporated into cells of the radiosensitive mutant xrs2].

The lethal effect of 35S and 32P decays on cells of yeast radiation-sensitive mutant xrs2 was studied. The mutant is 7 times more sensitive than the wild type to transmutation of both isotopes. The survival curve for xrs2 was exponential. In spite of the lethal effect, mutant cells are not more mutable than the wild type under decays of both isotopes (the number of mutations in ade1 and ade2 genes was counted), xrs2 and wild type strains differ in kinds of mutations induced by the decay of incorporated 35S in ade2 locus. Namely, there are 82% of base substitutions and 18% of other types mutations induced in xrs2 strain despite 97% and 3% respectively for the wild type strain. Also it was shown that complete and mosaic mutants, induced by the the 35S decay in xrs2 strain, differ in a pattern of interallelic complementation.