The Genome Sequence of Saccharomyces eubayanus and the Domestication of Lager-Brewing Yeasts

Mol Biol Evol. 2015 Nov;32(11):2818-31. doi: 10.1093/molbev/msv168. Epub 2015 Aug 11.

Abstract

The dramatic phenotypic changes that occur in organisms during domestication leave indelible imprints on their genomes. Although many domesticated plants and animals have been systematically compared with their wild genetic stocks, the molecular and genomic processes underlying fungal domestication have received less attention. Here, we present a nearly complete genome assembly for the recently described yeast species Saccharomyces eubayanus and compare it to the genomes of multiple domesticated alloploid hybrids of S. eubayanus × S. cerevisiae (S. pastorianus syn. S. carlsbergensis), which are used to brew lager-style beers. We find that the S. eubayanus subgenomes of lager-brewing yeasts have experienced increased rates of evolution since hybridization, and that certain genes involved in metabolism may have been particularly affected. Interestingly, the S. eubayanus subgenome underwent an especially strong shift in selection regimes, consistent with more extensive domestication of the S. cerevisiae parent prior to hybridization. In contrast to recent proposals that lager-brewing yeasts were domesticated following a single hybridization event, the radically different neutral site divergences between the subgenomes of the two major lager yeast lineages strongly favor at least two independent origins for the S. cerevisiae × S. eubayanus hybrids that brew lager beers. Our findings demonstrate how this industrially important hybrid has been domesticated along similar evolutionary trajectories on multiple occasions.

Keywords: Saccharomyces eubayanus; domestication; genome assembly; hybridization; lager brewing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Beer / microbiology
  • Chromosome Mapping
  • Evolution, Molecular
  • Genome, Fungal
  • Genomics
  • Hybridization, Genetic
  • Molecular Sequence Data
  • Phylogeny
  • Saccharomyces / genetics*
  • Saccharomyces cerevisiae / genetics

Associated data

  • GENBANK/JMCK00000000