Abstract

The regulation of gene transcription allows yeast cells to respond properly to changing environmental conditions. Several protein complexes take part in this process. They involve RNA polymerase complexes, chromatin remodeling complexes, mediators, general transcription factors and specific transcriptional regulators. Using Saccharomyces cerevisiae as reference, the genomes of six species (Ashbya gossypii, Kluyveromyces lactis, K. waltii, Candida albicans, C. glabrata and Schizosaccharomyces pombe) that are human pathogens or important for the food industry were analyzed for their complement of genes encoding the homologous transcriptional regulators. The number of orthologs identified in a given species correlated with its phylogenetic distance from S. cerevisiae. Many duplicated genes encoding transcriptional regulators in S. cerevisiae and C. glabrata were reduced to one copy in species diverged before the ancestral whole genome duplication. Some transcriptional regulators appear to be specific for S. cerevisiae and probably reflect the physiological differences among species. Phylogenetic analysis and conserved gene order relationships indicate that a similar set of gene families involved in the control of multidrug resistance and oxidative stress response already existed in the common ancestor of the compared fungal species.