Genetic hitchhiking in a subdivided population of Mytilus edulis.
Genetic hitchhiking in a subdivided population of Mytilus edulis.
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DOI：
10.1186/1471-2148-8-164
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发表时间：
2008-05-30
影响因子：
3.4
通讯作者：
Bierne, Nicolas
中科院分区：
文献类型：
--
作者：
Faure, Matthieu F.;David, Patrice;Bonhomme, Francois;Bierne, Nicolas
很少有模型的遗传搭便车在细分群体已经开发和罕见的经验性的例子是更惊人的。我们在这里提供的证据遗传搭便车在一个细分群体的海洋贻贝紫贻贝。在比斯开湾（法国），一片M。edulis种群恰好与其北海同种种被一个仅由姐妹种M占据的广阔区域分开。galloprovincialis。虽然两种M. edulis区域在10个标记位点上基本上不显着（平均FST~0.007），在单个位点上观察到强烈的遗传分化（FST = 0.25）。我们验证了这个位点的离群值状态，并分析了DNA序列多态性，以确定负责异常分化的选择的性质。我们首次证明了M. galloprovincialis等位基因在两个群体中的作用都很弱，对它们的分化没有显著影响。第二，我们观察到在两个M内选择性扫描的基因签名。edulis种群的等位基因的星形分支的形式。这支几乎是固定在北海和分离在比斯开湾的频率适中，解释了他们的遗传分化。不完全固定揭示了选择不是直接作用于位点，而是研究的序列在固定的过程中与连锁位点上的正选择等位基因重组。最后，使用确定性模型，我们表明，在一个连锁位点的有利等位基因的前进波，当跨越足够强的障碍，基因流，产生一个步骤的中性等位基因频率之间观察到的步骤两个M。edulis种群在离群位点。在我们的例子中，屏障的位置现在被一大片异源特异性M物质化了。galloprovincialispopulations.高FST离群基因座通常被解释为正在进行的分歧的局部适应的结果。结合模型和数据，我们表明，在结构化的人口中，选择性扫描后，也可以显着增加非人口分化。我们的研究说明了一个惊人的地理格局的中性多样性，可以出现从过去的间接搭便车选择在一个结构化的人口。本文中报道的核苷酸序列可在GenBank™数据库中以登录号EU 684165-EU 684228获得。
Few models of genetic hitchhiking in subdivided populations have been developed and the rarity of empirical examples is even more striking. We here provide evidences of genetic hitchhiking in a subdivided population of the marine mussel Mytilus edulis. In the Bay of Biscay (France), a patch of M. edulis populations happens to be separated from its North Sea conspecifics by a wide region occupied only by the sister species M. galloprovincialis. Although genetic differentiation between the two M. edulis regions is largely non-significant at ten marker loci (average FST~0.007), a strong genetic differentiation is observed at a single locus (FST = 0.25). We validated the outlier status of this locus, and analysed DNA sequence polymorphism in order to identify the nature of the selection responsible for the unusual differentiation. We first showed that introgression of M. galloprovincialis alleles was very weak in both populations and did not significantly affect their differentiation. Secondly, we observed the genetic signature of a selective sweep within both M. edulis populations in the form of a star-shaped clade of alleles. This clade was nearly fixed in the North Sea and was segregating at a moderate frequency in the Bay of Biscay, explaining their genetic differentiation. Incomplete fixation reveals that selection was not direct on the locus but that the studied sequence recombined with a positively selected allele at a linked locus while it was on its way to fixation. Finally, using a deterministic model we showed that the wave of advance of a favourable allele at a linked locus, when crossing a strong enough barrier to gene flow, generates a step in neutral allele frequencies comparable to the step observed between the two M. edulis populations at the outlier locus. In our case, the position of the barrier is now materialised by a large patch of heterospecific M. galloprovincialis populations. High FST outlier loci are usually interpreted as being the consequence of ongoing divergent local adaptation. Combining models and data we show that among-population differentiation can also dramatically increase following a selective sweep in a structured population. Our study illustrates how a striking geographical pattern of neutral diversity can emerge from past indirect hitchhiking selection in a structured population. Nucleotide sequences reported in this paper are available in the GenBank™ database under the accession numbers EU684165 – EU684228.
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DOI：
10.1098/rstb.2000.0716
发表时间：
2000-11-29
影响因子：
6.3
作者：
Barton, NH
通讯作者：
Barton, NH
影响因子：
9.8
作者：
Akey JM;Eberle MA;Rieder MJ;Carlson CS;Shriver MD;Nickerson DA;Kruglyak L
通讯作者：
Kruglyak L
影响因子：
4.9
作者：
Bierne, N;Daguin, C;Borsa, P
通讯作者：
Borsa, P
影响因子：
1.5
作者：
Charlesworth, B;Nordborg, M;Charlesworth, D
通讯作者：
Charlesworth, D
影响因子：
3.8
作者：
Barton, NH
通讯作者：
Barton, NH