The genus Syringospora Quinquad emend

Abstract

Further and more conclusive investigations on the life-cycle ofCandida albicans by means of DNA analyses and micromanipulation are reported.

Six main stages are recognizable in the life-cycle of the species under consideration. The sexually active haplophase consists of small cells which either convert to the diplophase by somatogamous autogamy or mutate to the sexually quiescent haplophase with circa 8 × 10⁻¹⁵ g DNA/cell. The nascent diplophase may develop further by budding, convert into chlamydospores or give rise to asexual endospores by internal budding. After a period of dormancy, the budding, uninucleate diplophase with circa 19 × 10⁻¹⁵ g DNA/cell converts when transferred toFowell's acetate agar either into uninucleate chlamydospores or, after becoming multinucleate, into gonotoconts on which the haplophase is delimited externally as buds or as conidia delimited on short sterigmata. By the cultivation of single isolated conidia it was possible to confirm that they were haploid and that heterothallism was absent. The characteristic chalmydospores formed by cultures on corn meal agar were observed to germinate on non-nutritive, 2% washed agar media. Germination occurred by bud formation which gave rise to the haplophase without the formation of a septate promycelium. Since these chlamydospores appear to function as gonotoconts, they are considered to be homologous with the teliospores of theUstilaginales.

This species, together with two others also described, are consequently assigned to the redefined genusSyringospora Quinquad which is provisionally assigned to the tulasnelloid fungi.