Poster Presentation Society for Molecular Biology and Evolution Conference 2016

Characterizing introgressed sequences in S. cerevisiae (#621)

Anne Clark 1 , Josh Akey 1
  1. University of Washington, Seattle, WASHINGTON, United States

Hybrid yeast are of interest both in basic research and in economically important fermentation processes. Little is known, however, about how often hybridization occurs in wild yeast populations, or what role the sequences transferred between species through these hybridization events play in evolutionary adaptation. With advances in sequencing technology, a much greater diversity of budding yeast genomes are being sequenced, allowing us to look more systematically at introgressed sequences. We have developed a hidden Markov model framework for identifying regions of S. cerevisiae genomes that are likely to have been introgressed from S. paradoxus or more distantly related species. We establish the sensitivity and specificity of the approach through simulations of hybridization under a variety of demographic models. We will present results that demonstrate our approach is effective under certain assumptions about the evolutionary history of budding yeast. We will also discuss findings from applying the framework to a set of 100 diverse S. cerevisiae whole genome sequences, highlighting specific introgressed genes that are of interest for further functional characterization. Finally, we will demonstrate how some aspects of the evolutionary history of budding yeast may be inferred from the distribution of predicted introgressed sequence lengths. This work provides insight into the evolutionary role of hybridization in wild yeast, as well as specific examples of sequences transferred through hybridization.