MULTIPLE CHROMOSOMAL AND PHENOTYPIC CHANGES IN SPONTANEOUS MUTANTS OFCANDIDA-ALBICANS

Previous studies have revealed the occurrence of multiple chromosomal alterations among spontaneous colony form mutants and clinical isolate s of Candida albicans. In this report we show that such karyotype alte rations are also seen in spontaneous and induced non-germinative mutan ts of the fungus. To determine if phenotypic changes other than colony form and microscopic morphology accompanied the rearrangements of the electrophoretic karyotype, we studied the following characteristics o f the non-germinative and some of the colony form mutants: formation o f pseudohyphae, chlamydospore production, germ tube formation, colony morphology, auxotrophy, growth at various temperatures, and colony mor phology and pigment formation on selected media (bismuth sulphite and Phloxine B). We established that phenotypic and karyotypic variability among spontaneous, non-germinative mutants was no different than such variability among spontaneous colony form mutants. Thus, non-germinat ion may represent another phenotypic consequence of genomic instabilit y in C. albicans. The variability in different phenotypic attributes t hat occurred amongst the mutants was not associated with any given kar yotype. Moreover, neither the low nor the high phenotypic variabilitie s observed were explained by the relatively high number of alterations in a limited number of chromosomes.