Do highly divergent loci reside in genomic regions affecting reproductive isolation? A test using next-generation sequence data in Timema stick insects.
Do highly divergent loci reside in genomic regions affecting reproductive isolation? A test using next-generation sequence data in Timema stick insects.
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DOI：
10.1186/1471-2148-12-164
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发表时间：
2012-08-31
影响因子：
3.4
通讯作者：
Gompert Z
中科院分区：
文献类型：
--
作者：
Nosil P;Parchman TL;Feder JL;Gompert Z
在物种形成过程中，基因流的遗传分化在整个基因组中是异质的，某些区域表现出比其他区域更强的分化。通常认为异常分化的区域经历减少的渐渗，即，减少等位基因从一个种群到另一个种群的流动，因为这些区域受到趋异选择的影响或导致生殖隔离。相反，基因组的其余部分可以通过高度渐渗来均质化。虽然许多研究已经证明了基因组在遗传分化中的变异，但很少有明确量化渐渗的这一假设的测试。在这里，我们提供了这样一个测试，使用38,304个SNP在种群的Timema cristinae棒昆虫。我们量化的基因座是否在地理上分离（“异域”）的人口表现出不寻常的模式渗入混合人口之间的高度分歧。在一定程度上，这是真的，异地种群之间的高度分歧的基因座有助于混合种群的生殖隔离。正如预测的那样，我们发现了一个很大的关联基因座特异性分歧之间的异域种群和混合种群的基因座特异性渐渗。然而，许多位点偏离这种关系，有时强烈。我们还报告了由于局部适应而对外来等位基因进行选择的证据。异地种群间的强分化位点有时会导致混合种群的生殖隔离。然而，在遗传结构方面（如基因的组织、重组率变化、有助于适应的变异体的数量和效应大小等），在随机进化过程中，如漂变，可能导致基因座的强烈分化，而这些分化并不总是导致生殖隔离。这一结果对“物种形成的基因组岛”理论具有启示意义。
Genetic divergence during speciation with gene flow is heterogeneous across the genome, with some regions exhibiting stronger differentiation than others. Exceptionally differentiated regions are often assumed to experience reduced introgression, i.e., reduced flow of alleles from one population into another because such regions are affected by divergent selection or cause reproductive isolation. In contrast, the remainder of the genome can be homogenized by high introgression. Although many studies have documented variation across the genome in genetic differentiation, there are few tests of this hypothesis that explicitly quantify introgression. Here, we provide such a test using 38,304 SNPs in populations of Timema cristinae stick insects. We quantify whether loci that are highly divergent between geographically separated (‘allopatric’) populations exhibit unusual patterns of introgression in admixed populations. To the extent this is true, highly divergent loci between allopatric populations contribute to reproductive isolation in admixed populations. As predicted, we find a substantial association between locus-specific divergence between allopatric populations and locus-specific introgression in admixed populations. However, many loci depart from this relationship, sometimes strongly so. We also report evidence for selection against foreign alleles due to local adaptation. Loci that are strongly differentiated between allopatric populations sometimes contribute to reproductive isolation in admixed populations. However, geographic variation in selection and local adaptation, in aspects of genetic architecture (such as organization of genes, recombination rate variation, number and effect size of variants contributing to adaptation, etc.), and in stochastic evolutionary processes such as drift can cause strong differentiation of loci that do not always contribute to reproductive isolation. The results have implications for the theory of ‘genomic islands of speciation’.
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影响因子：
3.8
作者：
Noor, M. A. F.;Bennett, S. M.
通讯作者：
Bennett, S. M.
DOI：
10.1098/rstb.2011.0245
发表时间：
2012-02-05
影响因子：
6.3
作者：
Hohenlohe, Paul A.;Bassham, Susan;Cresko, William A.
通讯作者：
Cresko, William A.
影响因子：
3.3
作者：
MALLET, J;BARTON, NH
通讯作者：
BARTON, NH
影响因子：
4.4
作者：
Araya CL;Payen C;Dunham MJ;Fields S
通讯作者：
Fields S
影响因子：
4.9
作者：
Gompert, Zachariah;Buerkle, C. Alex
通讯作者：
Buerkle, C. Alex