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Rapid asymmetrical evolution of Saccharomyces cerevisiae wine yeasts
Author(s) -
Ambrona Jesús,
Vinagre Antonia,
Ramírez Manuel
Publication year - 2005
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/yea.1331
Subject(s) - biology , loss of heterozygosity , saccharomyces cerevisiae , yeast , phenotype , wine , yeast in winemaking , genetics , locus (genetics) , gene , allele , food science
Abstract Genetic instability causes very rapid asymmetrical loss of heterozygosity (LOH) at the cyh2 locus and loss of killer K2 phenotype in some wine yeasts under the usual laboratory propagation conditions or after long freeze‐storage. The direction of this asymmetrical evolution in heterozygous cyh2 R /CYH2 S hybrids is determined by the mechanism of asymmetrical LOH. However, the speed of the process is affected by the differences in cell viability between the new homozygous yeasts and the original heterozygous hybrid cells. The concomitant loss of ScV‐M2 virus in the LOH process may increase cell viability of cyh2 R / cyh2 R yeasts and so favour asymmetrical evolution. The presence of active killer K2 toxin, however, abolishes the asymmetrical evolution of the hybrid populations. This phenomenon may cause important sudden phenotype changes in industrial and pathogenic yeasts. Copyright © 2005 John Wiley & Sons, Ltd.