Adaptive divergence in wine yeasts and their wild relatives suggests a prominent role for introgressions and rapid evolution at non coding sites

In Saccharomyces cerevisiae, the main yeast in wine fermentation, the opportunity to examine divergence at the molecular level between a domesticated lineage and its wild counterpart arose recently due to the identification of the closest relatives of wine strains, a wild population associated with Mediterranean oaks. Since genomic data is available for a considerable number of representatives belonging to both groups, we used population genomics to estimate the degree and distribution of nucleotide variation between wine yeasts and their closest wild relatives. We found widespread genome-wide divergence, particularly at non-coding sites, which, together with above average divergence in trans-acting DNA binding proteins, may suggest an important role for divergence at the level of transcriptional regulation. Nine outlier regions putatively under strong divergent selection were highlighted by a genome wide scan under stringent conditions. Several cases of introgressions originating in th...