[Effect of uvs1, uvs2 and xrs mutations on the radiosensitivity of and frequency of induced mitotic recombination in diploid yeast cells].

Effect of radiosensitivity mutations uvs1, uvs2 and xrs in homozygous state in yeast Saccharomyces cerevisiae on UV and X-ray sensitivity and on the induced mitotic recombination is studied. Diploids uvs2 uvs2 xrs xrs are much more UV-sensible than diploids UVS2 UVS2 xrs xrs or UVS2 uvs2 xrs xrs. Diploids uvs1 uvs1 uvs2 uvs2 and uvs1 uvs1 UVS2 UVS2 have the same radiosensitivity. These data show that mutations uvs1, uvs2 and xrs block different ways of the elimination of UV-induced damages. The diploid uvs2 uvs2 xrs3 xrs3 is much more X-ray sensible, than the diploid UVS2 UVS2 xrs3 xrs3. It shows that mutations uvs2 and xrs3 block different ways of the elimination of X-ray induced damages. All double mutant diploids are characterized by a higher frequency of UV-induced mitotic recombination, than the diploid UVS UVS XRS XRS and the UV-sensitive diploid uvs2 uvs2 XRS XRS. The diploid uvs2 uvs2 xrs5 xrs5 is characterized by an extraordinary high frequency of X-RAY INDUCED MITOTIC RECOMBINATION.