Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309, USA.
Museum of Natural Science and Department of Biological Science, Louisiana State University, Baton Rouge, LA, 70803, USA.
Nat Commun. 2021 Nov 25;12(1):6833. doi: 10.1038/s41467-021-27173-z.
The genetic architecture of a phenotype can have considerable effects on the evolution of a trait or species. Characterizing genetic architecture provides insight into the complexity of a given phenotype and, potentially, the role of the phenotype in evolutionary processes like speciation. We use genome sequences to investigate the genetic basis of phenotypic variation in redpoll finches (Acanthis spp.). We demonstrate that variation in redpoll phenotype is broadly controlled by a ~55-Mb chromosomal inversion. Within this inversion, we find multiple candidate genes related to melanogenesis, carotenoid coloration, and bill shape, suggesting the inversion acts as a supergene controlling multiple linked traits. A latitudinal gradient in ecotype distribution suggests supergene driven variation in color and bill morphology are likely under environmental selection, maintaining supergene haplotypes as a balanced polymorphism. Our results provide a mechanism for the maintenance of ecotype variation in redpolls despite a genome largely homogenized by gene flow.
表型的遗传结构对一个特征或物种的进化有很大的影响。描述遗传结构可以深入了解给定表型的复杂性，以及该表型在物种形成等进化过程中的作用。我们使用基因组序列来研究红腹滨鹬（Acanthis spp.）表型变异的遗传基础。我们证明，红腹滨鹬表型的变异广泛受一个约 55Mb 的染色体倒位控制。在这个倒位中，我们发现了多个与黑色素生成、类胡萝卜素着色和喙形相关的候选基因，表明这个倒位作为一个超级基因控制着多个连锁特征。一个在生态型分布上的纬度梯度表明，超级基因驱动的颜色和喙形态的变异可能受到环境选择的影响，从而维持超级基因的单倍型作为平衡的多态性。我们的研究结果为尽管红腹滨鹬的基因组在很大程度上受到基因流的同质化，但仍能维持其生态型变异提供了一种机制。
