Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, USA.
Ecology, Evolution and Genetics Research Group, Biology Department, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium.
Nat Commun. 2024 Nov 29;15(1):10397. doi: 10.1038/s41467-024-54534-1.
Chromosomal inversions have been implicated in a remarkable range of natural phenomena, but it remains unclear how much they contribute to standing genetic variation. Here, we evaluate 64 inversions that segregate within a single natural population of the yellow monkeyflower (Mimulus guttatus). Nucleotide diversity patterns confirm low internal variation for the derived orientation (predicted by recent origin), elevated diversity between orientations (predicted by natural selection), and localized fluctuations (predicted by gene flux). Sequence divergence between orientations varies idiosyncratically by position, not following the suspension bridge pattern predicted if the breakpoints are the targets of selection. Genetic variation in gene expression is not inflated close to inversion breakpoints but is clearly partitioned between orientations. Like sequence variation, the pattern of expression variation suggests that the capture of coadapted alleles is more important than the breakpoints for the fitness effects of inversions. This work confirms several evolutionary predictions for inversion polymorphisms, but clarity emerges only by synthesizing estimates across many loci.
染色体倒位与许多自然现象有关，但它们对遗传变异的贡献程度仍不清楚。在这里，我们评估了在黄色蔓长春花（Mimulus guttatus）的一个单一自然种群中分离的 64 个倒位。核苷酸多样性模式证实了衍生方向（由最近的起源预测）的内部变异较低，取向之间的多样性升高（由自然选择预测），以及局部波动（由基因流预测）。取向之间的序列分歧位置特异性变化，而不是如果断点是选择的目标，则预测的悬索桥模式。基因表达的遗传变异在接近倒位断点处没有膨胀，但在取向之间明显划分。与序列变异一样，表达变异的模式表明，适应等位基因的捕获对于倒位的适应度效应比断点更为重要。这项工作证实了倒位多态性的几个进化预测，但只有通过综合多个基因座的估计值才能得出清晰的结论。
