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The budding yeast life cycle: More complex than anticipated?
Author(s) -
Fischer Gilles,
Liti Gianni,
Llorente Bertrand
Publication year - 2021
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.3533
Subject(s) - biology , ploidy , loss of heterozygosity , saccharomyces cerevisiae , mating of yeast , genetics , inbreeding , homothallism , mating type , mating , meiosis , evolutionary biology , population , yeast , gene , allele , demography , sociology
The budding yeast, Saccharomyces cerevisiae , has served as a model for nearly a century to understand the principles of the eukaryotic life cycle. The canonical life cycle of S . cerevisiae comprises a regular alternation between haploid and diploid phases. Haploid gametes generated by sporulation are expected to quickly restore the diploid phase mainly through inbreeding via intratetrad mating or haploselfing, thereby promoting genome homozygotization. However, recent large population genomics data unveiled that heterozygosity and polyploidy are unexpectedly common. This raises the interesting paradox of a haplo‐diplobiontic species being well‐adapted to inbreeding and able to maintain high levels of heterozygosity and polyploidy, thereby suggesting an unanticipated complexity of the yeast life cycle. Here, we propose that unprogrammed mating type switching, heterothallism, reduced spore formation and viability, cell–cell fusion and dioecy could play key and uncharted contributions to generate and maintain heterozygosity through polyploidization.