Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.
Department of Biology, University of Fribourg, Fribourg, Switzerland.
Mol Ecol. 2022 Sep;31(17):4435-4439. doi: 10.1111/mec.16609. Epub 2022 Jul 26.
Chromosomal inversions are often thought to facilitate local adaptation and population divergence because they can link multiple adaptive alleles into non-recombining genomic blocks. Selection should thus be more efficient in driving inversion-linked adaptive alleles to high frequency in a population, particularly in the face of maladaptive gene flow. But what if ecological conditions and hence selection on inversion-linked alleles change? Reduced recombination within inversions could then constrain the formation of optimal combinations of pre-existing alleles under these new ecological conditions. Here, we outline this idea of inversions limiting adaptation and divergence when ecological conditions change across time or space. We reason and use simulations to illustrate that the benefit of inversions for local adaptation and divergence under one set of ecological conditions can come with a concomitant constraint for adaptation to novel sets of ecological conditions. This limitation of inversions to adaptation may contribute to the maintenance of polymorphism within species.
染色体倒位通常被认为有助于局部适应和种群分化，因为它们可以将多个适应性等位基因链接到非重组的基因组块中。因此，在面对适应不良的基因流时，选择应该更有效地将倒位相关的适应性等位基因推向种群中的高频率。但是，如果生态条件发生变化，从而导致与倒位相关的等位基因的选择发生变化，会怎样呢？倒位内部的重组减少，可能会限制在这些新的生态条件下，预先存在的等位基因形成最佳组合。在这里，我们概述了这样一种观点，即在生态条件随时间或空间变化时，倒位会限制适应性和分化。我们推理并使用模拟来说明，在一组生态条件下，倒位对局部适应和分化的好处可能伴随着对新的生态条件的适应的相应限制。这种倒位对适应性的限制可能有助于维持物种内的多态性。
