Establishment of new mutations under divergence and genome hitchhiking
Establishment of new mutations under divergence and genome hitchhiking
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DOI：
10.1098/rstb.2011.0256
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发表时间：
2012-02-05
影响因子：
6.3
通讯作者：
Nosil, Patrik
中科院分区：
文献类型：
--
作者：
Feder, Jeffrey L.;Gejji, Richard;Nosil, Patrik
需要解决物种形成过程中全基因组分歧模式的理论模型来帮助我们理解产生经验模式的进化过程。在这里，我们研究了一个关于物种形成与基因流动的关键问题：新突变与已经分化的基因的物理联系（r < 0.5）在多大程度上有助于分化的基因组岛的建立？我们使用模拟和分析的方法来划分的概率建立一个新的分歧选择突变时，突变（i）是第一次出现在一个未分化的基因组（选择的直接效应），（ii）与任何选择的基因座无关（r = 0.5），但在一个基因组中，有一些已经分歧的基因（全基因组范围内基因流减少的影响，以促进分歧，我们称之为“基因组搭便车”），和（iii）出现在物理连锁的分歧基因座（分歧搭便车）。我们发现，直接作用于新突变的选择强度通常是建立的最重要的预测因子，而分歧和基因组搭便车的影响较小。我们概述了分歧和基因组搭便车可以帮助突变建立的具体条件。这些结果产生了关于物种形成过程中不同点的基因组分歧的预测，以及进一步工作的途径。
Theoretical models addressing genome-wide patterns of divergence during speciation are needed to help us understand the evolutionary processes generating empirical patterns. Here, we examine a critical issue concerning speciation-with-gene flow: to what degree does physical linkage (r < 0.5) of new mutations to already diverged genes aid the build-up of genomic islands of differentiation? We used simulation and analytical approaches to partition the probability of establishment for a new divergently selected mutation when the mutation (i) is the first to arise in an undifferentiated genome (the direct effect of selection), (ii) arises unlinked to any selected loci (r = 0.5), but within a genome that has some already diverged genes (the effect of genome-wide reductions in gene flow for facilitating divergence, which we term 'genome hitchhiking'), and (iii) arises in physical linkage to a diverged locus (divergence hitchhiking). We find that the strength of selection acting directly on a new mutation is generally the most important predictor for establishment, with divergence and genomic hitchhiking having smaller effects. We outline the specific conditions under which divergence and genome hitchhiking can aid mutation establishment. The results generate predictions about genome divergence at different points in the speciation process and avenues for further work.