Loss of heterozygosity is induced in Candida albicans by ultraviolet irradiation.

Candida albicans is a human fungal pathogen and has been extensively studied because of its clinical importance. Comprehensive gene analyses have, however, made little progress. This is because of the diploid and asexual characteristics of the fungus that hamper gene disruptions. In this study, we found that ultraviolet (UV) irradiation, as well as mutagen treatment, strongly stimulated loss of heterozygosity (LOH) in strains harboring artificially constructed heterozygosity. UV-induced LOH occurred more frequently in cells within the logarithmic phase of growth compared to those within the stationary phase of growth. This was observed at all loci tested on chromosome 7, except for a locus neighboring the centromere. C. albicans RAD52, whose orthologue in Saccharomyces cerevisiae was reported to be involved in DNA repair by homologous recombination, was shown to be required for UV-induced LOH. These results suggest that high efficiency LOH caused by UV irradiation could be a prominent tool for gene analyses in C. albicans.