title: Eukaryote-to-eukaryote gene transfer events revealed by the genome sequence of the wine yeast Saccharomyces cerevisiae EC1118.
abstract: Saccharomyces cerevisiae has been used for millennia in winemaking, but little is known about the selective forces acting on the wine yeast genome. We sequenced the complete genome of the diploid commercial wine yeast EC1118, resulting in an assembly of 31 scaffolds covering 97% of the S288c reference genome. The wine yeast differed strikingly from the other S. cerevisiae isolates in possessing 3 unique large regions, 2 of which were subtelomeric, the other being inserted within an EC1118 chromosome. These regions encompass 34 genes involved in key wine fermentation functions. Phylogeny and synteny analyses showed that 1 of these regions originated from a species closely related to the Saccharomyces genus, whereas the 2 other regions were of non-Saccharomyces origin. We identified Zygosaccharomyces bailii, a major contaminant of wine fermentations, as the donor species for 1 of these 2 regions. Although natural hybridization between Saccharomyces strains has been described, this report provides evidence that gene transfer may occur between Saccharomyces and non-Saccharomyces species. We show that the regions identified are frequent and differentially distributed among S. cerevisiae clades, being found almost exclusively in wine strains, suggesting acquisition through recent transfer events. Overall, these data show that the wine yeast genome is subject to constant remodeling through the contribution of exogenous genes. Our results suggest that these processes are favored by ecologic proximity and are involved in the molecular adaptation of wine yeasts to conditions of high sugar, low nitrogen, and high ethanol concentrations.
authors.affiliation: Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1083 Sciences Pour l'Oenologie, F-34060 Montpellier, France.
authors.forename: Maite
authors.initials: M
authors.lastname: Novo
authors.forename: Frédéric
authors.initials: F
authors.lastname: Bigey
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Beyne
authors.forename: Virginie
authors.initials: V
authors.lastname: Galeote
authors.forename: Frédérick
authors.initials: F
authors.lastname: Gavory
authors.forename: Sandrine
authors.initials: S
authors.lastname: Mallet
authors.forename: Brigitte
authors.initials: B
authors.lastname: Cambon
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Legras
authors.forename: Patrick
authors.initials: P
authors.lastname: Wincker
authors.forename: Serge
authors.initials: S
authors.lastname: Casaregola
authors.forename: Sylvie
authors.initials: S
authors.lastname: Dequin
mesh_terms: D015825:Chromosomes, Fungal / Q000235:genetics; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005057:Eukaryotic Cells / Q000378:metabolism*; D005656:Fungal Proteins / Q000145:classification / Q000235:genetics; D022761:Gene Transfer, Horizontal; D005800:Genes, Fungal / Q000235:genetics; D016681:Genome, Fungal / Q000235:genetics*; D010802:Phylogeny; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000145:classification / Q000235:genetics; D017422:Sequence Analysis, DNA / Q000379:methods; D026801:Synteny; D014920:Wine / Q000382:microbiology; D015003:Yeasts / Q000235:genetics
chemical_list: D004271:DNA, Fungal; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins