Eukaryote-to-eukaryote gene transfer events revealed by the genome sequence of the wine yeast Saccharomyces cerevisiae EC1118.
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.
Novo
Maite
M
Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1083 Sciences Pour l'Oenologie, F-34060 Montpellier, France.
Bigey
Frédéric
F
Beyne
Emmanuelle
E
Galeote
Virginie
V
Gavory
Frédérick
F
Mallet
Sandrine
S
Cambon
Brigitte
B
Legras
Jean-Luc
JL
Wincker
Patrick
P
Casaregola
Serge
S
Dequin
Sylvie
S
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
D004271:DNA, Fungal; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins