Cellular inactivation and mitotic recombination induced by ultraviolet radiation in aneuploid and euploid strains of Candida albicans.

Prototrophic aneuploid and euploid derivatives of wild type Candida albicans strains 207 were produced by fusing protoplasts of complementing auxotrophs obtained from strain 207. Comparisons of cell survivals and incidences of mitotic recombinants occurring after ultraviolet irradiation (UV) of these strains indicate that (i) aneuploids are categorically less efficient than euploids for repair of pyrimidine dimers induced in DNA by UV and that (ii) such repair is enhanced by growing irradiated cells at 25 degrees C, on minimal medium or in the presence of ergosterol rather than at 37 degrees C, on amino acid enriched medium or medium unsupplemented with ergosterol. In addition, the comparisons establish than one cannot discriminate between strains of C. albicans which differ in cellular DNA contents or genomic constitutions on the basis of their UV survival curves.