title: Fast method for identifying inter- and intra-species Saccharomyces hybrids in extensive genetic improvement programs based on yeast breeding.
abstract: OBJECTIVE
  The present work proposes a two-step molecular strategy to select inter- and intra-species Saccharomyces hybrids obtained by spore-to-spore mating, one of the most used methods for generating improved hybrids from homothallic wine yeasts.
  
  
  RESULTS
  As low spore viability and haplo-selfing are the main causes of failed mating, at first, we used colony screening PCR (csPCR) of discriminative gene markers to select hybrids directly on dissection plate and discard homozygous diploid colonies arisen from one auto-diploidized progenitor. Then, pre-selected candidates were submitted to recursive streaking and conventional PCR in order to discriminate between the hybrids with stable genomic background and the false-positive admixtures of progenitor cells both undergone haplo-selfing. csPCRs of internal transcribed spacer (ITS) 1 or 2, and the subsequent digestion with diagnostic endonucleases HaeIII and RsaI, respectively, were efficient to select six new Saccharomyces cerevisiae × Saccharomyces uvarum hybrids from 64 crosses. Intragenic minisatellite regions in PIR3, HSP150, and DAN4 genes showed high inter-strain size variation detectable by cost-effective agarose gel electrophoresis and were successful to validate six new intra-species S. cerevisiae hybrids from 34 crosses.
  
  
  CONCLUSIONS
  Both protocols reduce significantly the number of massive DNA extractions, prevent misinterpretations caused by one or both progenitors undergone haplo-selfing, and can be easily implemented in yeast labs without any specific instrumentation.
  
  
  CONCLUSIONS
  The study provides a method for the marker-assisted selection of several inter- and intra-species yeast hybrids in a cost-effective, rapid and reproducible manner.
authors.affiliation: Department of Life Sciences, Unimore Microbial Culture Collection, Reggio Emilia, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Solieri
authors.affiliation: Department of Life Sciences, Unimore Microbial Culture Collection, Reggio Emilia, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Verspohl
authors.affiliation: Department of Life Sciences, Unimore Microbial Culture Collection, Reggio Emilia, Italy.
authors.forename: T
authors.initials: T
authors.lastname: Bonciani
authors.affiliation: Department of Agriculture, Food and Environment, University of Catania, Catania, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Caggia
authors.affiliation: Department of Life Sciences, Unimore Microbial Culture Collection, Reggio Emilia, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Giudici
mesh_terms: D005285:Fermentation; D005819:Genetic Markers; D006824:Hybridization, Genetic; D016133:Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D014920:Wine / Q000032:analysis / Q000382:microbiology
chemical_list: D005819:Genetic Markers
keywords: Saccharomyces cerevisiae; Saccharomyces uvarum; colony PCR; hybrid; mating; minisatellite regions; rDNA internal transcribed spacer; spore