Data from: Genomic clustering of adaptive loci during parallel evolution of an Australian wildflower

The buildup of the phenotypic differences that distinguish species has long intrigued biologists. These differences are often inherited as stable polymorphisms that allow the co-segregation of adaptive variation within species, and facilitate the differentiation of complex phenotypes between species. It has been suggested that the clustering of adaptive loci could facilitate this process but evidence is still scarce. Here we used QTL analysis to study the genetic basis of phenotypic differentiation between coastal populations of the Australian wildflower Senecio lautus. We found that a genomic region consistently governs variation in several of the traits that distinguish these contrasting forms. Additionally, some of the taxon specific traits controlled by this QTL cluster have evolved repeatedly during the adaptation to the same habitats, suggesting that it could mediate divergence between locally adapted forms. This cluster contains footprints of divergent natural selection across the range of S. lautus, which suggests that it could have been instrumental for the rapid diversification of this species.

区分不同物种的表型差异的形成过程，长久以来一直吸引着生物学家的关注。这类差异通常以稳定多态性（stable polymorphisms）的形式遗传，可实现物种内适应性变异的共分离，并推动物种间复杂表型的分化。有假说提出，适应性基因座的成簇分布或许能助力这一过程，但目前相关实证证据仍较为匮乏。本研究借助数量性状基因座（Quantitative Trait Locus, QTL）分析，对澳大利亚野生花卉Senecio lautus的沿海种群间表型分化的遗传基础展开研究。研究发现，一段基因组区域持续调控着区分这两类截然不同种群的多个性状的变异。此外，由该QTL簇调控的部分类群特异性性状，在适应相同生境的过程中反复演化，这表明该基因组区域或许介导了本地适应性种群间的分化。该基因组簇在Senecio lautus的整个分布范围内均带有趋异自然选择的印记，这意味着它可能对该物种的快速分化起到了关键推动作用。