Dissecting the role of a large chromosomal inversion in life history divergence throughout the Mimulus guttatus species complex
Dissecting the role of a large chromosomal inversion in life history divergence throughout the Mimulus guttatus species complex
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DOI：
10.1111/mec.14804
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发表时间：
2019-03-01
影响因子：
4.9
通讯作者：
Willis, John H.
中科院分区：
文献类型：
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作者：
Coughlan, Jennifer M.;Willis, John H.
染色体倒位在适应中起着重要的作用，但其在许多自然种群中的作用机制仍不清楚。倒位可以抑制局部有益等位基因之间的重组，从而防止适应不良的重组与不太适合，移民等位基因。重组抑制假说已经获得了很多理论支持，但缺乏实证检验。在这里，我们评估了一个染色体倒位，区分一年生和多年生形式的Mimulus guttatus的进化历史和表型效应。我们发现，多年生植物可能具有反演的派生方向。此外，这种多年生的方向发生在第二个多年生物种，M。decorus，其中它是强烈相关的生活史之间的共同发生M。decorus和一年生M.点滴重组抑制假说的一个预测是，有助于局部适应的基因座将早于反转。为了测试影响多年生性的基因座是否早于这种反转，我们绘制了一年生M之间不同生活史性状的QTL。guttatus和一个更远的关系，共线多年生物种，M。tilingii。与重组抑制假说相一致，我们发现，该区域与生活史在没有倒位，这种关联可以被分解成至少两个QTL。然而，LG8倒位区对生活史的绝对表型效应在M. tilingii比多年生植物具有反转。因此，虽然我们找到了重组抑制假说的支持，但这种逆转对这一群体生活史分歧的贡献可能是复杂的。
Chromosomal inversions can play an important role in adaptation, but the mechanism of their action in many natural populations remains unclear. An inversion could suppress recombination between locally beneficial alleles, thereby preventing maladaptive reshuffling with less-fit, migrant alleles. The recombination suppression hypothesis has gained much theoretical support but empirical tests are lacking. Here, we evaluated the evolutionary history and phenotypic effects of a chromosomal inversion which differentiates annual and perennial forms of Mimulus guttatus. We found that perennials likely possess the derived orientation of the inversion. In addition, this perennial orientation occurs in a second perennial species, M. decorus, where it is strongly associated with life history differences between co-occurring M. decorus and annual M. guttatus. One prediction of the recombination suppression hypothesis is that loci contributing to local adaptation will predate the inversion. To test whether the loci influencing perenniality pre-date this inversion, we mapped QTLs for life history traits that differ between annual M. guttatus and a more distantly related, collinear perennial species, M. tilingii. Consistent with the recombination suppression hypothesis, we found that this region is associated with life history in the absence of the inversion, and this association can be broken into at least two QTLs. However, the absolute phenotypic effect of the LG8 inversion region on life history is weaker in M. tilingii than in perennials which possess the inversion. Thus, while we find support for the recombination suppression hypothesis, the contribution of this inversion to life history divergence in this group is likely complex.