INIBIOMA   20415
INSTITUTO DE INVESTIGACIONES EN BIODIVERSIDAD Y MEDIOAMBIENTE
Unidad Ejecutora - UE
artículos
Título:
Population Structure and Reticulate Evolution of Saccharomyces eubayanus and Its Lager-Brewing Hybrids
Autor/es:
PERIS, D.; SYLVESTER, K.; LIBKIND, DIEGO; GONCALVES, P; SAMPAIO, JP; ALEXANDER, W. ; HITTINGER, C
Revista:
MOLECULAR ECOLOGY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2014 p. 2031 - 2045
ISSN:
0962-1083
Resumen:
Reticulate evolution can be a major driver of diversification into new niches, especially
in disturbed habitats and at the edges of ranges. Industrial fermentation strains of
yeast provide a window into these processes, but progress has been hampered by a
limited understanding of the natural diversity and distribution of Saccharomyces species
and populations. For example, lager beer is brewed with Saccharomyces pastorianus,
an alloploid hybrid of S. cerevisiae and S. eubayanus, a species only recently
discovered in Patagonia, Argentina. Here, we report that genetically diverse strains of
S. eubayanus are readily isolated from Patagonia, demonstrating that the species is well
established there. Analyses of multilocus sequence data strongly suggest that there are
two diverse and highly differentiated Patagonian populations. The low nucleotide
diversity found in the S. eubayanus moiety of hybrid European brewing strains suggests
that their alleles were drawn from a small subpopulation that is closely related
to one of the Patagonian populations. For the first time, we also report the rare isolation
of S. eubayanus outside Patagonia, in Wisconsin, USA. In contrast to the clear
population differentiation in Patagonia, the North American strains represent a recent
and possibly transient admixture of the two Patagonian populations. These complex
and varied reticulation events are not adequately captured by conventional phylogenetic
methods and required analyses of Bayesian concordance factors and phylogenetic
networks to accurately summarize and interpret. These findings show how genetically
diverse eukaryotic microbes can produce rare but economically important hybrids with
low genetic diversity when they migrate from their natural ecological context.