A recombination suppressor contributes to ecological speciation in Ostrinia moths

Despite unparalleled access to species’ genomes in our post-genomic age, we often lack adequate biological explanations for a major hallmark of the speciation process—genetic divergence. In the presence of gene flow, chromosomal rearrangements such as inversions are thought to promote divergence and facilitate speciation by suppressing recombination. Using a combination of genetic crosses, phenotyping of a trait underlying ecological isolation, and population genetic analysis of wild populations, we set out to determine whether evidence supports a role for recombination suppressors during speciation between the Z and E strains of European corn borer moth (Ostrinia nubilalis). Our results are consistent with the presence of an inversion that has contributed to accumulation of ecologically adaptive alleles and genetic differentiation across roughly 20% of the Ostrinia sex chromosome (~4 Mb). Patterns in Ostrinia suggest that chromosomal divergence may involve two separate phases—one drivi...

在后基因组时代（post-genomic age），尽管我们获取物种基因组的途径已无可匹敌，但对于物种形成（speciation）过程的核心特征——遗传分化（genetic divergence），我们往往仍缺乏充分的生物学解释。在存在基因流（gene flow）的情况下，倒位（inversion）这类染色体重排（chromosomal rearrangement）被认为可通过抑制重组（recombination）来促进分化、推动物种形成。本研究结合遗传杂交、介导生态隔离（ecological isolation）的性状的表型分型（phenotyping），以及野生种群的群体遗传分析（population genetic analysis），旨在验证欧洲玉米螟（Ostrinia nubilalis）的Z与E品系间的物种形成过程中，重组抑制因子是否发挥了作用。本研究结果与某一倒位的存在相符：该倒位促成了生态适应性等位基因（allele）的积累，并在欧洲玉米螟约20%的性染色体（sex chromosome）区域（约4 Mb）内引发了遗传分化。欧洲玉米螟的相关模式表明，染色体重分化可能包含两个独立阶段——其一为驱动[原文内容未完整呈现]