title: [Effect of radiosensitivity gene irradiation and genotype on yeast cytoduction].
abstract: Effects of gamma- and UV-irradiation of one parent on progenies of yeast crosses are studied. In the crosses of the type: p+ a alc4 X p-alpha ade2 (alc4--nuclear respiration deficiency) zygotic colonies (white) and haploid p+ cytoductant colonies (red) were scored. The irradiation of p+ parent increases the cytoductant frequency up to 17%. When both parents are radiation-sensitive (xrs1, allelic to rad54), the frequency of cytoduction reaches 90%. Crosses p+xrs1 X p-xrs+ or p+xrs+ X p-xrs1 are similar to crosses of wild types. The same results were observed in the case of xrs4 mutants as well as for UV-irradiation. In the progenies of crosses irradiated p+ a alc4 (xrs+ or xrs1) X non-irradiated p-alpha ade2 ura (xrs+ or xrs1) the genotype of red colonies was analysed: in most cases (82.3%-99.8%) they were p+ alpha ade2 ura, that was true haploid cytoductants. It is concluded that irradiation induces particular damages of yeast nuclei leading to a block of normal karyogamy and thus to a cytoductant formation. The highest frequency of cytoduction was observed in crosses of radiosensitive mutants.
mesh_terms: D003433:Crosses, Genetic; D005720:Gamma Rays; D005796:Genes / Q000528:radiation effects*; D005838:Genotype; D009154:Mutation; D011836:Radiation Tolerance; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000528:radiation effects*; D014466:Ultraviolet Rays; D014965:X-Rays
vernacular_title: Izuchenie vliianiia oblucheniia i genotipa po genam radiochuvstvitel'nosti na tsitoduktsiiu u drozhzheĭ.