[Molecular nature of direct gene mutations induced by gamma and ultraviolet irradiation in Saccharomyces cerevisiae yeasts].

The spectrum of gamma- and UV-induced mutations for ADE2 locus of the yeast Saccharomyces cerevisiae was determined as follows (respectively): 27 and 41% GC leads to AT transitions, 8 and 11% AT leads to GC transitions, 59 and 40% transversions, 6 and 8% frameshifts. Our results indicate a specificity of UV-light for GC leads to AT transitions. Experimental data are discussed in a view of molecular mechanisms of radiation mutagenesis.