UV-induced instability in Candida albicans hybrids.

Auxotrophic variants were obtained following UV-irradiation of Candida albicans hybrids which were heterozygous (+/+/-/-/) for various genetic markers (met, ade, his, lys). Some variants contained less DNA (per cell) than did the hybrids from which they originated; such variants were considered to arise in a process which resulted in generalized reduction in ploidy. These results provide the basis for a cyclic parasexual system (2n X 2n----4n----2n) for genetic analysis in this amictic diploid species.