Population genomics of rapid evolution in natural populations: polygenic selection in response to power station thermal effluents
Population genomics of rapid evolution in natural populations: polygenic selection in response to power station thermal effluents
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DOI：
10.1186/s12862-019-1392-5
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发表时间：
2019-02-26
影响因子：
3.4
通讯作者：
Oleksiak, Marjorie F.
中科院分区：
文献类型：
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作者：
Dayan, David I.;Du, Xiao;Oleksiak, Marjorie F.
背景快速进化的例子在自然界中很常见，但很难用标准的种群遗传适应模型来解释。相反，从现有的遗传变异中进行选择，可以通过软扫描或多基因适应来实现快速适应。这个过程中的性质的经验证据是目前有限的，但积累。ResultsWe提供的基因组范围内的快速进化的底heteroclitus人口受到最近升高的温度，由于沿海发电站的热污水使用5449 SNP在两个污水影响和四个参考人群。人口基因组结构的贝叶斯和多变量分析揭示了遗传变异的很大一部分，这是最吝啬的解释选择在现场的热流出物。F-ST离群值方法结合额外的保守要求，可识别暴露人群和密切相关参考人群中超过中性预期的显著等位基因频率差异。这些候选位点附近的基因组变异模式表明，生活在热流出物附近的个人已经迅速发展，从常设遗传变异，通过小等位基因频率的变化，在许多位点的模式与多基因选择的常设遗传variation.ConclusionsWhile选择在这些人群中的最终轨迹是未知的，我们只调查了少数基因组位点，我们的研究结果表明，多基因适应模型可能在大型自然种群中发挥重要作用，这些种群由于环境变化而经历了最近的选择，这些环境变化引起了广泛的生理影响。
BackgroundExamples of rapid evolution are common in nature but difficult to account for with the standard population genetic model of adaptation. Instead, selection from the standing genetic variation permits rapid adaptation via soft sweeps or polygenic adaptation. Empirical evidence of this process in nature is currently limited but accumulating.ResultsWe provide genome-wide analyses of rapid evolution in Fundulus heteroclitus populations subjected to recently elevated temperatures due to coastal power station thermal effluents using 5449 SNPs across two effluent-affected and four reference populations. Bayesian and multivariate analyses of population genomic structure reveal a substantial portion of genetic variation that is most parsimoniously explained by selection at the site of thermal effluents. An F-ST outlier approach in conjunction with additional conservative requirements identify significant allele frequency differentiation that exceeds neutral expectations among exposed and closely related reference populations. Genomic variation patterns near these candidate loci reveal that individuals living near thermal effluents have rapidly evolved from the standing genetic variation through small allele frequency changes at many loci in a pattern consistent with polygenic selection on the standing genetic variation.ConclusionsWhile the ultimate trajectory of selection in these populations is unknown and we survey only a minority of genomic loci, our findings suggest that polygenic models of adaptation may play important roles in large, natural populations experiencing recent selection due to environmental changes that cause broad physiological impacts.