Genomic dissection of the cell-type-specification circuit in Saccharomyces cerevisiae.

The budding yeast Saccharomyces cerevisiae has three cell types (a cells, alpha cells, and a/alpha cells), each of which is specified by a unique combination of transcriptional regulators. This transcriptional circuit has served as an important model for understanding basic features of the combinatorial control of transcription and the specification of cell type. Here, using genome-wide chromatin immunoprecipitation, transcriptional profiling, and phylogenetic comparisons, we describe the complete cell-type-specification circuit for S. cerevisiae. We believe this work represents a complete description of cell-type specification in a eukaryote.