The utility of QTL-Linked markers to detect selective sweeps in natural populations -: a case study of the EDA gene and a linked marker in threespine stickleback
The utility of QTL-Linked markers to detect selective sweeps in natural populations -: a case study of the EDA gene and a linked marker in threespine stickleback
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DOI：
10.1111/j.1365-294x.2006.03099.x
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发表时间：
2006-12-01
影响因子：
4.9
通讯作者：
Merila, J.
中科院分区：
文献类型：
--
作者：
Cano, J. M.;Matsuba, C.;Merila, J.
编码基因的序列多态性和数量性状基因座（QTL）连锁标记的变异性可以用来揭示参与适应过程的性状的进化机制。我们研究了EDA基因的序列变异和等位基因变异的18个微卫星-其中之一（Gac 4174）是与EDA QTL -在低，部分和完全平板的变种从8个threespine刺鱼欧洲人口。结果同意与以前的研究，EDA多态性是密切相关的板数变化：EDA序列分组群体低，完全平板型，而微卫星未能做到这一点。此外，部分镀鱼杂合相对于独特的EDA等位基因完全和低镀变形，表明完全镀变形等位基因是不完全占主导地位的控制侧板数量的表达。用数量遗传学方法研究了平板数的群体分化，结果表明，群体分化程度超过了单纯遗传漂变的程度（Q（ST）> F-ST）。我们的研究结果支持了适应性遗传分化的板块变形和独特的EDA基因多态性发生在类似的网站在整个分布范围的这个物种的观点。然而，在Gac 4174微卫星位点的等位基因频率分化，在实验杂交板数变化的信息，没有不同的中性标记，因此无法检测负责人口分化的自然选择的签名。
Sequence polymorphisms in coding genes and variability in quantitative trait loci (QTL)-linked markers can be used to uncover the evolutionary mechanisms of traits involved in adaptive processes. We studied sequence variation in the EDA gene and allelic variation in 18 microsatellites - one of which (Gac4174) is linked with the EDA QTL - in low, partially and completely plated morphs from eight threespine stickleback European populations. The results agree with previous studies in that EDA polymorphism is closely related to plate number variation: EDA sequences grouped populations into low and completely plated morphs, whereas microsatellites failed to do so. Furthermore, partially plated fish were heterozygous with respect to the distinctive EDA alleles for completely and low plated morphs, indicating that completely plated morph alleles are not entirely dominant in controlling the expression of lateral plate number. An examination of population differentiation in plate number with quantitative genetic methods revealed that the degree of differentiation exceeded that expected from genetic drift alone (Q(ST) > F-ST). Our results support the adaptive genetic differentiation of plate morphs and the view that distinctive EDA gene polymorphism occurs in similar sites across the distribution range of this species. Yet, allele frequency differentiation in the Gac4174 microsatellite locus, informative in experimental crosses for plate number variation, did not differ from that of neutral markers and, was therefore unable to detect the signature of natural selection responsible for population divergence.