title: Comparative polygenic analysis of maximal ethanol accumulation capacity and tolerance to high ethanol levels of cell proliferation in yeast.
abstract: The yeast Saccharomyces cerevisiae is able to accumulate ≥17% ethanol (v/v) by fermentation in the absence of cell proliferation. The genetic basis of this unique capacity is unknown. Up to now, all research has focused on tolerance of yeast cell proliferation to high ethanol levels. Comparison of maximal ethanol accumulation capacity and ethanol tolerance of cell proliferation in 68 yeast strains showed a poor correlation, but higher ethanol tolerance of cell proliferation clearly increased the likelihood of superior maximal ethanol accumulation capacity. We have applied pooled-segregant whole-genome sequence analysis to identify the polygenic basis of these two complex traits using segregants from a cross of a haploid derivative of the sake strain CBS1585 and the lab strain BY. From a total of 301 segregants, 22 superior segregants accumulating ≥17% ethanol in small-scale fermentations and 32 superior segregants growing in the presence of 18% ethanol, were separately pooled and sequenced. Plotting SNP variant frequency against chromosomal position revealed eleven and eight Quantitative Trait Loci (QTLs) for the two traits, respectively, and showed that the genetic basis of the two traits is partially different. Fine-mapping and Reciprocal Hemizygosity Analysis identified ADE1, URA3, and KIN3, encoding a protein kinase involved in DNA damage repair, as specific causative genes for maximal ethanol accumulation capacity. These genes, as well as the previously identified MKT1 gene, were not linked in this genetic background to tolerance of cell proliferation to high ethanol levels. The superior KIN3 allele contained two SNPs, which are absent in all yeast strains sequenced up to now. This work provides the first insight in the genetic basis of maximal ethanol accumulation capacity in yeast and reveals for the first time the importance of DNA damage repair in yeast ethanol tolerance.
authors.affiliation: Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Flanders, Belgium.
authors.forename: Thiago M
authors.initials: TM
authors.lastname: Pais
authors.forename: María R
authors.initials: MR
authors.lastname: Foulquié-Moreno
authors.forename: Georg
authors.initials: G
authors.lastname: Hubmann
authors.forename: Jorge
authors.initials: J
authors.lastname: Duitama
authors.forename: Steve
authors.initials: S
authors.lastname: Swinnen
authors.forename: Annelies
authors.initials: A
authors.lastname: Goovaerts
authors.forename: Yudi
authors.initials: Y
authors.lastname: Yang
authors.forename: Françoise
authors.initials: F
authors.lastname: Dumortier
authors.forename: Johan M
authors.initials: JM
authors.lastname: Thevelein
mesh_terms: D000434:Alcoholic Beverages / Q000382:microbiology; D000483:Alleles; D049109:Cell Proliferation; D002874:Chromosome Mapping; D004249:DNA Damage / Q000187:drug effects / Q000235:genetics; D004260:DNA Repair / Q000187:drug effects / Q000235:genetics; D004361:Drug Tolerance / Q000235:genetics; D000431:Ethanol / Q000378:metabolism* / Q000494:pharmacology; D016678:Genome; D020641:Polymorphism, Single Nucleotide; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D040641:Quantitative Trait Loci / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics
chemical_list: D029701:Saccharomyces cerevisiae Proteins; C554167:URA3 protein, S cerevisiae; D000431:Ethanol; C075981:KIN3 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases