Genetic analysis of Candida albicans morphological mutants.

In contrast to some other strains, Candida albicans 1001 gave rise, upon UV irradiation, to mutants displaying a 'rough colony' morphology associated with a permanent alteration in morphogenesis which determined growth of the cells mostly as pseudohyphae. One of these mutants, C. albicans 1001FR, could form sectored (rough/smooth) colonies spontaneously, and with increasing frequency by treatment with mild UV doses (32-64 microJ mm-2). Rough sectors corresponded to stable 'rough-filamentous' strains which never segregated smooth strains. On the other hand, smooth sectors consisted mainly of yeast cells which could occasionally revert to a rough-filamentous phenotype. We suggest that C. albicans 1001 is heterozygous for some gene involved in the control of morphogenesis, and that the described mutants should be of help in the characterization of the genetic control of dimorphism in C. albicans.