EFFECTS OF THE RAD52 GENE ON RECOMBINATION IN SACCHAROMYCES CEREVISIAE

Abstract

ABSTRACT Effects of the rad52 mutation in Saccharomyces cerevisiae on meiotic, γ-ray-induced, UV-induced and spontaneous mitotic recombination were studied. The rad52/rad52 diploids undergo premeiotic DNAsynthesis; sporulation occurs hut inviable spores are produced. Both intra and intergenic recombination during meiosis were examined in cells transferred from sporulation medium to vegetative medium at different time intervals. No intragenic recombination was observed at the hisl-ljhis1-315 and trp5-2/trp5-48 hetero-alleles. Gene-centromere recombination also was not observed in rad52/rad52 diploids. No γ-ray- or UV-induced intragenic mitotic recombination is seen in rad52/rad52 diploids. The rate of spontaneous mitotic recombination is lowered five-fold at the hisf -1/hisf-315 and leu1-c/leu1-12 heteroalleles. Spontaneous reversion rates of both hisf-1 and hisf-315 were elevated 10to 20 fold in rad52/rad52 diploids.—The RAD52 gene function is required for spontaneous mitotic recombination, UV- and γ-ray-induced mitotic recombination and meiotic recombination.