An Out-of-Patagonia dispersal explains most of the worldwide genetic distribution in Saccharomyces eubayanus

Abstract

25Saccharomyces eubayanus represents missing cryotolerant ancestor of lager yeast hybrid 26 and can be found in Patagonia in association with Nothofagus forests. The limited number 27 of isolates and associated genomes available has prevented to resolve the S. eubayanus 28 origin and evolution. Here, we present a sampling effort at an unprecedented scale and 29 report the isolation of 160 strains from ten sampling sites along 2,000 km distance in South 30America. We sequenced the genome of 82 strains and, together with other 25 available 31 genomes, performed comprehensive phylogenetic analysis. Our results revealed the 32 presence of three main Patagonia-B lineages together with dozens of admixed strains 33 distributed in three mosaic clusters. The PB-1 lineage isolated from Tierra del Fuego 34 exhibited the highest genetic diversity, lowest LD blocks and highest Fis values compared 35 to the other lineages, suggesting a successful adaptation to cold temperatures in extreme 36 environments and greater inbreeding rates in Tierra del Fuego. Differences between 37 lineages and strains were found in terms of aneuploidy and pangenome content, evidencing 38 a lateral gene transfer event in PB-2 strains from an unknown donor species. Overall, the 39 Patagonian lineages, particularly southern populations, showed a greater global genetic 40 diversity compared to Holarctic and Chinese lineages, supporting the scenario of a S. 41 eubayanus colonization from Patagonia and then spread towards northern and western 42 regions, including the Holarctic (North America and China) and New Zealand. Interestingly, 43 fermentative capacity and maltose consumption resulted negatively correlated with latitude, 44 indicating a better fermentative performance in norther populations. Our genome analysis 45 together with previous reports in the sister species S. uvarum strongly suggests that the S.

Postglacial migration shaped the genomic diversity and global distribution of the wild ancestor of lager-brewing hybrids

“…Under this model, PA and PB would have bifurcated in Patagonia, possibly in separate glacial refugia. The east side of the Andes in northern Patagonia was likely the refugium of the PA population, while it is possible that the west side of the Andes in southern Patagonia was the refugium of the PB population [41]. The oldest migration event out of Patagonia would have been the dispersal of the ancestor of the Holarctic subpopulation, drawn from the PB gene pool, to the Northern Hemisphere.…”

Molecular profiling of beer wort fermentation diversity across natural Saccharomyces eubayanus isolates

“…The first isolation of S. eubayanus in South America in 2011 was particularly puzzling given the Central European roots of lager beer (Libkind, et al, 2011). Since then, this species has however been found in New Zealand, Canada, United States, East Asia and Chile (Bing, et al, 2014;Gayevskiy and Goddard, 2016;Peris, et al, 2016;Nespolo, et al, 2019), demonstrating its presence in cold regions across the globe. In fact, S. eubayanus can efficiently grow at a range of lower temperatures (4-25°C) compared with S. cerevisiae, providing unique opportunities for brewing (Mertens, et al, 2015).…”

“…The recent isolation of S. eubayanus from Argentinian Patagonia (Libkind, et al, 2011;Eizaguirre, et al, 2018) is a promising step towards utilizing a new set of strains for brewing, either directly or through the generation of new Saccharomyces hybrids from crosses with S. cerevisiae (Krogerus, et al, 2015;Gallone, et al, 2019;Langdon, et al, 2019). However, only few studies have addressed the fermentative capacity in S. eubayanus, mostly due to the reduced number of available strains, being only recently explored in cider (Magalhaes, et al, 2017), wine (Alonso-Del-Real, et al, 2017) and beer (Krogerus et al, 2017a(Krogerus et al, ,2017bEizaguirre, et al, 2018;Nespolo, et al, 2019). The challenge is evident as shown by recent studies demonstrating genetic differences across S. eubayanus populations (Peris, et al, 2016;Eizaguirre, et al, 2018;Nespolo, et al, 2019), potentially indicative of a large phenotypic diversity among all isolates.…”

Genomic diversity and global distribution of Saccharomyces eubayanus, the wild ancestor of hybrid lager-brewing yeasts

“…In Patagonia, some sampling sites harbor more genetic 429 diversity than all non-Patagonian locations together ( Figure 5B). Although we found the most 430 genetic diversity and largest number of subpopulations north of 43°S, the pattern of genetic 431 diversity appears to be reversed on the west side of the Andes, at least for the PB-1 432 subpopulation (Nespolo et al 2019). This discrepancy could be due to differences in how glacial 433 refugia were distributed (Sérsic et Multiple more recent migration events could have resulted in the few PB-1 strains found in New 444…”