Genome-wide tests for introgression between cactophilic Drosophila implicate a role of inversions during speciation.
Genome-wide tests for introgression between cactophilic Drosophila implicate a role of inversions during speciation.
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DOI：
10.1111/evo.12650
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发表时间：
2015-05
期刊：
影响因子：
--
通讯作者：
Etges WJ
中科院分区：
文献类型：
--
作者：
Lohse K;Clarke M;Ritchie MG;Etges WJ
基因流物种形成模型表明，替代染色体排列之间重组的减少可以促进局部适应性基因在基因流中的固定，并有助于物种形成。然而，令人沮丧的是，事实证明，很难凭经验证明倒位会减少基因流，并在物种分化开始期间或之后不久出现，而不是代表祖先多态性。在这里，我们对一对嗜果蝇（Drosophila mojavensis 和 D. arizonae）的全基因组数据进行了分析，这两种果蝇在野外进行生殖分离，并且在三个染色体上存在几个大的倒位。我们发现与共线染色体相比，重排时的分歧增加。利用短序列块中分歧位点的密度，我们拟合了一系列明确的物种分歧模型，其中基因流仅限于分歧后的初始阶段，并且基因组的共线部分和重排部分之间可能有所不同。这些分析表明，D. mojavensis 和 D. arizonae 经历了大约 270 KY 前停止的分化后基因流，并且在具有固定倒位的染色体中显着减少。此外，我们表明这些倒转很可能起源于物种分化时期，这与假设倒转在基因流物种形成中发挥作用的理论模型是一致的。
Models of speciation‐with‐gene‐flow have shown that the reduction in recombination between alternative chromosome arrangements can facilitate the fixation of locally adaptive genes in the face of gene flow and contribute to speciation. However, it has proven frustratingly difficult to show empirically that inversions have reduced gene flow and arose during or shortly after the onset of species divergence rather than represent ancestral polymorphisms. Here, we present an analysis of whole genome data from a pair of cactophilic fruit flies, Drosophila mojavensis and D. arizonae, which are reproductively isolated in the wild and differ by several large inversions on three chromosomes. We found an increase in divergence at rearranged compared to colinear chromosomes. Using the density of divergent sites in short sequence blocks we fit a series of explicit models of species divergence in which gene flow is restricted to an initial period after divergence and may differ between colinear and rearranged parts of the genome. These analyses show that D. mojavensis and D. arizonae have experienced postdivergence gene flow that ceased around 270 KY ago and was significantly reduced in chromosomes with fixed inversions. Moreover, we show that these inversions most likely originated around the time of species divergence which is compatible with theoretical models that posit a role of inversions in speciation with gene flow.
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影响因子：
64.8
作者：
Joron, Mathieu;Frezal, Lise;Jones, Robert T.;Chamberlain, Nicola L.;Lee, Siu F.;Haag, Christoph R.;Whibley, Annabel;Becuwe, Michel;Baxter, Simon W.;Ferguson, Laura;Wilkinson, Paul A.;Salazar, Camilo;Davidson, Claire;Clark, Richard;Quail, Michael A.;Beasley, Helen;Glithero, Rebecca;Lloyd, Christine;Sims, Sarah;Jones, Matthew C.;Rogers, Jane;Jiggins, Chris D.;Ffrench-Constant, Richard H.
通讯作者：
Ffrench-Constant, Richard H.
影响因子：
7
作者：
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作者：
Charlesworth, B
通讯作者：
Charlesworth, B
影响因子：
2.1
作者：
Khadem, M.;Camacho, R.;Nobrega, C.
通讯作者：
Nobrega, C.
影响因子：
4.5
作者：
Comeron JM;Ratnappan R;Bailin S
通讯作者：
Bailin S