title: Crosses between Saccharomyces cerevisiae and Saccharomyces bayanus generate fertile hybrids.
abstract: Crossings between strains of Saccharomyces cerevisiae and Saccharomyces bayanus were carried out. Genetic, molecular and electrophoretic karyotyping data indicated that interspecific hybrids were obtained. The hybrid cells segregated "grande" and "petite" colonies, and the latter ranged between 20 and 50%; unlike "grande" colonies, "petite" colonies did not sporulate and did not ferment maltose. In the hybrids, the extent of sporulation varied between 10 and 20%; only very rare asci (around 10(-4)) held viable ascospores. Clones from the viable ascospores sporulated and produced asci with viable ascospores able to give mating with spores from both hybrid derivatives and parental species. Fertile asci could derive from allotetraploid cells generated by endomitotic events in allodiploid cells, a mechanism that enables overcoming the species barrier between S. cerevisiae and S. bayanus.
authors.affiliation: Department of Animal Biology and Genetics, University of Florence, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Sebastiani
authors.forename: Claudia
authors.initials: C
authors.lastname: Barberio
authors.forename: Enrico
authors.initials: E
authors.lastname: Casalone
authors.forename: Duccio
authors.initials: D
authors.lastname: Cavalieri
authors.forename: Mario
authors.initials: M
authors.lastname: Polsinelli
mesh_terms: D003433:Crosses, Genetic; D007621:Karyotyping / Q000379:methods; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012440:Saccharomyces / Q000145:classification* / Q000235:genetics / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000145:classification* / Q000235:genetics / Q000502:physiology; D013172:Spores, Fungal / Q000235:genetics / Q000502:physiology; D014920:Wine / Q000382:microbiology