Polymorphism, Divergence, and the Role of Recombination in Saccharomyces cerevisiae Genome Evolution
Polymorphism, Divergence, and the Role of Recombination in Saccharomyces cerevisiae Genome Evolution
复制标题
DOI：
10.1093/molbev/msq356
复制
发表时间：
2011-05-01
影响因子：
10.7
通讯作者：
Moses, Alan M.
中科院分区：
文献类型：
--
作者：
Cutter, Asher D.;Moses, Alan M.
在分子进化和群体遗传学中，一个有争议的问题是重组作为自然选择的推动者和基因组突变输入的潜在来源的作用。特别是出芽酵母酿酒酵母（Saccharomyces cerevisiae），作为基因组分析的早期系统，为这一主题注入了见解和困惑，随后的报告相互矛盾。在这里，我们重新审视重组在突变和选择中的作用，并利用最近的酿酒酵母群体多态性和重组的全基因组图谱。我们证实重组相关突变不会在酵母中留下基因组标记，并得出结论，先前观察到的、神秘的、负的重组分化相关性在很大程度上是弱选择和其他基因组协变量的结果。我们还从多态性模式中证实了偏倚基因转换的存在。此外，我们发现在假定的中性进化位点上，重组与群体多态性之间存在显著的正相关关系，而不受其他因素和基因组规模的影响。我们得出结论，广泛的自然选择在酵母基因组中留下了分离遗传变异的印记，但这种印记比果蝇和隐杆线虫弱得多。
A contentious issue in molecular evolution and population genetics concerns the roles of recombination as a facilitator of natural selection and as a potential source of mutational input into genomes. The budding yeast Saccharomyces cerevisiae, in particular, has injected both insights and confusion into this topic, as an early system subject to genomic analysis with subsequent conflicting reports. Here, we revisit the role of recombination in mutation and selection with recent genome-wide maps of population polymorphism and recombination for S. cerevisiae. We confirm that recombination-associated mutation does not leave a genomic signature in yeast and conclude that a previously observed, enigmatic, negative recombination-divergence correlation is largely a consequence of weak selection and other genomic covariates. We also corroborate the presence of biased gene conversion from patterns of polymorphism. Moreover, we identify significant positive relations between recombination and population polymorphism at putatively neutrally evolving sites, independent of other factors and the genomic scale of interrogation. We conclude that widespread natural selection across the yeast genome has left its imprint on segregating genetic variation, but that this signature is much weaker than in Drosophila and Caenorhabditis.