The genetic architecture of local adaptation and reproductive isolation in sympatry within the Mimulus guttatus species complex
The genetic architecture of local adaptation and reproductive isolation in sympatry within the Mimulus guttatus species complex
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DOI：
10.1111/mec.13763
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发表时间：
2017-01-01
影响因子：
4.9
通讯作者：
Willis, John H.
中科院分区：
文献类型：
--
作者：
Ferris, Kathleen G.;Barnett, Laryssa L.;Willis, John H.
自现代综合进化以来，局部适应的遗传结构一直是进化生物学家的核心兴趣。除了经典理论的适应性突变的影响大小的Fisher，木村和奥尔，最近的理论地址的遗传结构的局部适应面对正在进行的基因流。这一理论预测，随着种群间大量的基因流动，局部适应应该主要通过大效应基因座的突变或小效应基因座的紧密连锁群来进行。在这项研究中，我们调查的遗传结构分歧的开花时间，交配系统相关的性状，和叶片形状之间的Mimulus laciniatus和一个同域群体的近亲M。点滴这三个特征可能与M. laciniatus的适应干燥，暴露的花岗岩露头环境。开花时间和交配系统的差异也是生殖隔离障碍，使它们成为“神奇性状”。在这个群体中的表型杂交提供了最近的基因流的证据。使用下一代测序，我们在基因组中产生密集的SNP标记，并绘制涉及开花时间，花大小和叶形状的数量性状位点（QTL）。我们发现，在所有三个性状的种间分歧是由于少数QTL的大的影响，包括一个高度多效性QTL的8号染色体上。该QTL区域包含多效性候选基因TCP4，并参与其他Mimulus物种的生态重要表型。我们的研究结果与理论一致，表明当地的适应和生殖隔离与基因流应是由于少数位点的大和多效性的影响。
The genetic architecture of local adaptation has been of central interest to evolutionary biologists since the modern synthesis. In addition to classic theory on the effect size of adaptive mutations by Fisher, Kimura and Orr, recent theory addresses the genetic architecture of local adaptation in the face of ongoing gene flow. This theory predicts that with substantial gene flow between populations local adaptation should proceed primarily through mutations of large effect or tightly linked clusters of smaller effect loci. In this study, we investigate the genetic architecture of divergence in flowering time, mating system-related traits, and leaf shape between Mimulus laciniatus and a sympatric population of its close relative M. guttatus. These three traits are probably involved in M. laciniatus' adaptation to a dry, exposed granite outcrop environment. Flowering time and mating system differences are also reproductive isolating barriers making them ` magic traits'. Phenotypic hybrids in this population provide evidence of recent gene flow. Using next-generation sequencing, we generate dense SNP markers across the genome and map quantitative trait loci (QTLs) involved in flowering time, flower size and leaf shape. We find that interspecific divergence in all three traits is due to few QTL of large effect including a highly pleiotropic QTL on chromosome 8. This QTL region contains the pleiotropic candidate gene TCP4 and is involved in ecologically important phenotypes in other Mimulus species. Our results are consistent with theory, indicating that local adaptation and reproductive isolation with gene flow should be due to few loci with large and pleiotropic effects.