Department of Chemical & Systems Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
Nat Commun. 2019 Mar 15;10(1):1222. doi: 10.1038/s41467-019-09166-1.
Quantitative genetics aims to map genotype to phenotype, often with the goal of understanding how organisms evolved. However, it remains unclear whether the genetic variants identified are exemplary of evolution. Here we analyzed progeny of two wild Saccharomyces cerevisiae isolates to identify 195 loci underlying complex metabolic traits, resolving 107 to single polymorphisms with diverse molecular mechanisms. More than 20% of causal variants exhibited patterns of emergence inconsistent with neutrality. Moreover, contrary to drift-centric expectation, variation in diverse wild yeast isolates broadly exhibited this property: over 30% of shared natural variants exhibited phylogenetic signatures suggesting that they are not neutral. This pattern is likely attributable to both homoplasy and balancing selection on ancestral polymorphism. Variants that emerged repeatedly were more likely to have done so in isolates from the same ecological niche. Our results underscore the power of super-resolution mapping of ecologically relevant traits in understanding adaptation and evolution.
数量遗传学旨在将基因型映射到表型，其目的通常是了解生物是如何进化的。然而，目前尚不清楚所鉴定的遗传变异是否是进化的典范。在这里，我们分析了两个野生酿酒酵母分离株的后代，以鉴定 195 个与复杂代谢性状相关的基因座，确定了 107 个具有不同分子机制的单一多态性。超过 20%的因果变异表现出与中性不一致的出现模式。此外，与以漂变为中心的预期相反，不同野生酵母分离株的变异广泛表现出这种特性：超过 30%的共享自然变异具有系统发育特征，表明它们不是中性的。这种模式可能归因于同源性和对祖先多态性的平衡选择。在同一生态位的分离株中反复出现的变异更有可能是这样的。我们的研究结果突出了在理解适应和进化方面对具有生态相关性的性状进行超分辨率映射的力量。
