title: A set of haploid strains available for genetic studies of Saccharomyces cerevisiae flor yeasts.
abstract: Flor yeasts of Saccharomyces cerevisiae have been extensively studied for biofilm formation, however the lack of specific haploid model strains has limited the application of genetic approaches such as gene knockout, allelic replacement and Quantitative Trait Locus mapping for the deciphering of the molecular basis of velum formation under biological ageing. The aim of this work was to construct a set of flor isogenic haploid strains easy to manipulate genetically. The analysis of the allelic variations at 12 minisatellite loci of 174 Saccharomyces cerevisiae strains allowed identifying three flor parental strains with different phylogenic positions. These strains were characterized for sporulation efficiency, growth on galactose, adherence to polystyrene, agar invasion, growth on wine and ability to develop a biofilm. Interestingly, the inability to grow on galactose was found associated with a frameshift in GAL4 gene that seems peculiar of flor strains. From these wild flor strains, isogenic haploid strains were constructed by deleting HO gene with a loxP-KanMX-loxP cassette followed by the removal of the kanamycin cassette. Haploid strains obtained were characterized for their phenotypic and genetic properties and compared with the parental strains. Preliminary results showed that the haploid strains represent new tools for genetic studies and breeding programs on biofilm formation.
authors.affiliation: Department of Agricultural Sciences, University of Sassari, 07100 Sassari, Italy National Institute of Agronomical Research-SupAgro, University of Montpellier, 34060 Montpellier, France acoi@uniss.it.
authors.forename: Anna Lisa
authors.initials: AL
authors.lastname: Coi
authors.affiliation: National Institute of Agronomical Research-SupAgro, University of Montpellier, 34060 Montpellier, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Legras
authors.affiliation: Department of Agricultural Sciences, University of Sassari, 07100 Sassari, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Zara
authors.affiliation: National Institute of Agronomical Research-SupAgro, University of Montpellier, 34060 Montpellier, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Dequin
authors.affiliation: Department of Agricultural Sciences, University of Sassari, 07100 Sassari, Italy.
authors.forename: Marilena
authors.initials: M
authors.lastname: Budroni
mesh_terms: D005827:Genetics, Microbial / Q000379:methods*; D005838:Genotype; D006238:Haploidy; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology
keywords: Saccharomyces cerevisiae; Sherry wine; biofilm; flor strain; haploid strains; velum