Most organisms belonging to the Saccharomycotina subphylum have high genetic diversity and a vast repertoire of metabolisms and lifestyles. Lachancea cidri is an ideal yeast model for exploring the interplay between genetics, ecological function and evolution. Lachancea cidri diverged from the Saccharomyces lineage before the whole-genome duplication and is distributed across the South Hemisphere, displaying an important ecological success. We applied phylogenomics to investigate the genetic variation of L. cidri isolates obtained from Australia and South America. Our approach revealed the presence of two main lineages according to their geographic distribution (Aus and SoAm). Estimation of the divergence time suggests that SoAm and Aus lineages diverged near the last glacial maximum event during the Pleistocene (64-8 KYA). Interestingly, we found that the French reference strain is closely related to the Australian strains, with a recent divergence (405-51 YA), likely associated to human movements. Additionally, we identified different lineages within the South American population, revealing that Patagonia contains a similar genetic diversity comparable to that of other lineages in S. cerevisiae. These findings support the idea of a Pleistocene-dated divergence between South Hemisphere lineages, where the Nothofagus and Araucaria ecological niches likely favoured the extensive distribution of L. cidri in Patagonia.

中文翻译：

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南半球非常规酵母 L. cidri 种群之间更新世晚期的差异

大多数属于酵母菌亚门的生物体具有高度的遗传多样性和大量的新陈代谢和生活方式。Lachancea cidri是探索遗传学、生态功能和进化之间相互作用的理想酵母模型。Lachancea cidri在全基因组复制之前从酵母属谱系中分离出来，分布在整个南半球，显示出重要的生态成功。我们应用系统基因组学来研究L的遗传变异。柑橘从澳大利亚和南美洲获得的分离株。我们的方法根据地理分布（Aus 和 SoAm）揭示了两个主要谱系的存在。对分歧时间的估计表明，SoAm 和 Aus 谱系在更新世 (64-8 KYA) 期间的最后一次冰川最大事件附近发生分歧。有趣的是，我们发现法国参考菌株与澳大利亚菌株密切相关，最近出现分歧 (405-51 YA)，可能与人类活动有关。此外，我们在南美种群中发现了不同的谱系，表明巴塔哥尼亚包含与S中其他谱系相似的遗传多样性。酿酒酵母. 这些发现支持南半球谱系之间存在更新世年代差异的观点，其中Nothofagus和南洋杉生态位可能有利于L的广泛分布。巴塔哥尼亚的柑橘。