XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:90-1

Investigação

90-1	CRYPTIC SEX IN THE FUNGAL PATHOGEN CANDIDA ALBICANS
Authors:	Bennett Richard (BROWN - Brown University)

Abstract

Our laboratory studies the opportunistic pathogen Candida albicans, as well as the closely related species C. tropicalis and C. parapsilosis. These fungi are hemiascomycete yeast that are usually harmless commensals in the human body, but are also capable of causing life-threatening bloodstream infections. The focus of our research is the mechanism of sexual reproduction in Candida species, and the potential roles of these pathways in promoting infection and pathogenesis. One striking feature of mating in C. albicans is that it is regulated by the white-opaque phenotypic switch. C. albicans a and alpha cells can undergo reversible and heritable switching between white and opaque states. Cells in the opaque state are competent for mating, whereas cells in the white state are more virulent in bloodstream infections but are incapable of mating. Pheromone signaling between opaque a and opaque alpha cells coordinates the mating process, resulting in tetraploid mating products. We recently demonstrated a novel mode of self-fertilization in C. albicans whereby opaque a cells could self-mate due to autocrine pheromone signaling. Furthermore, we show that pheromones from one Candida species are active in inducing same-sex mating of a different Candida species. Inter-species signaling could therefore be important in driving sexual mating events in nature. Finally, we are interested in how mating genes can regulate processes important for colonization and infection. One striking example of this is that cell surface factors induced during the mating process can promote adhesion and biofilm formation, a critical step in the development of device-associated infections. We therefore discuss the broader roles of pheromone-signaling, phenotypic switching, and sexual reproduction in the context of fungal pathogenesis and disease.

Keyword: Mating, Phenotypic Switch, Sexual Reproduction

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