Regulation of meiotic gene expression is functional in the human fungal pathogen Candida glabrata.

Abstract

The human fungal pathogen Candida glabrata is closely related to the budding yeast Saccharomyces cerevisiae. The sexual cycle in S. cerevisiae has been extensively characterized. Haploid cells 'a' and alpha secrete pheromones involved in mating of the opposite cell type leading to the formation of a diploid cell. Under harsh conditions, diploid cells undergo meiosis for the formation of four haploid spores. In C. glabrata, cells are also found as 'a' and alpha and this organism possesses most S. cerevisiae homologous genes involved in meiosis and mating. However, mating has never been observed in C. glabrata. In S. cerevisiae, the non-essential UME6 gene is involved in controlling the expression of meiotic genes. We have previously shown that Zcf11, a putative homolog of Ume6, is encoded by an essential gene but its function is unknown. Here, we show that the expression of UME6 in C. glabrata can partially complement a Zcf11 knock-down and that these factors recognize the same DNA sequence. Importantly, expression profiling using a Zcf11 knock-down strain revealed that this factor is a negative regulator of meiotic genes expression as well as some genes involved in mating. Thus, regulation of the expression of meiotic genes is functional in this organism reinforcing the view that C. glabrata may have a sexual cycle under specific conditions.