Establishment of a screening system for essential genes from the pathogenic yeastCandida glabrata: identification of a putativeTEM1homologue

Abstract

To establish a system for screening and identification of essential genes from the pathogenic haploid yeast Candida glabrata by using temperature-sensitive (ts) mutants. Based on the general concepts that ts mutations are generated within essential genes in the genome by virtue of point mutation, we attempted to establish a system where essential genes were screened and identified from the C. glabrata genomic DNA library by the complementation of ts point mutations. By using this system, we successfully identified a putative TEM1 homologue as an essential gene by the complementation of a point mutation (-GAT-/-AAT- corresponding to Asp-143/Asn substitution) within its coding region in a ts mutant, T-3. We were able to establish a system for screening and identification of the essential genes, such as the TEM1 homologue, from the pathogenic yeast C. glabrata, as the gene that complements ts mutation. The identification of essential genes, by using the present system, may provide novel potential antifungal targets.