Figure 1.

(A) The standard model for the transcriptional control of haploid mating-type genes in S. cerevisiae. The operator elements, contained within a-specific gene (asg) and α-specific gene (αsg) promoters, are schematized as colored boxes, which correspond to binding sites for α1 (blue), α2 (red), and Mcm1 (yellow). (B) Simplified phylogenetic tree, based on concatenated sequences of 153 genes present in all species shown, depicts the sensu stricto yeasts and some related yeast species. “WGD” denotes the whole-genome duplication that occurred along the branch leading to C. glabrata and the Saccharomyces species. Modified from Fitzpatrick et al. (2006).