Induction of Mating in Candida albicans by Construction of MTL a and MTL α Strains

Abstract

Although the diploid fungus Candida albicans, a human pathogen, has been thought to have no sexual cycle, it normally possesses mating-type–like orthologs (MTL) of both of theSaccharomyces cerevisiae mating-type genes (MAT) a and α. When strains containing only MTL a or MTLα were constructed by the loss of one homolog of chromosome 5, the site of theMTL loci, MTL a and MTLα strains mated, but like mating types did not. Evidence for mating included formation of stable prototrophs from strains with complementing auxotrophic markers; these contained both MTLalleles and molecular markers from both parents and were tetraploid in DNA content and mononucleate.