Fuller Evolutionary Biology Program, Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA.
Department of Ecology and Evolutionary Biology, Cornell University, 215 Tower Road, Ithaca, NY 14853, USA.
Sci Adv. 2017 May 24;3(5):e1602404. doi: 10.1126/sciadv.1602404. eCollection 2017 May.
Instances of recent and rapid speciation are suitable for associating phenotypes with their causal genotypes, especially if gene flow homogenizes areas of the genome that are not under divergent selection. We study a rapid radiation of nine sympatric bird species known as capuchino seedeaters, which are differentiated in sexually selected characters of male plumage and song. We sequenced the genomes of a phenotypically diverse set of species to search for differentiated genomic regions. Capuchinos show differences in a small proportion of their genomes, yet selection has acted independently on the same targets in different members of this radiation. Many divergent regions contain genes involved in the melanogenesis pathway, with the strongest signal originating from putative regulatory regions. Selection has acted on these same genomic regions in different lineages, likely shaping the evolution of cis-regulatory elements, which control how more conserved genes are expressed and thereby generate diversity in classically sexually selected traits.
近期和快速物种形成的实例适合将表型与它们的因果基因型联系起来，特别是如果基因流使基因组中不受分歧选择影响的区域同质化。我们研究了一个快速辐射的九个同域鸟种，称为卡普奇诺食种雀，它们在雄性羽毛和歌声的性选择特征上有所分化。我们对一组表型多样的物种进行了基因组测序，以寻找分化的基因组区域。卡普奇诺食种雀的基因组中只有一小部分存在差异，但选择在这个辐射的不同成员中独立作用于相同的靶标。许多分化区域包含参与黑色素生成途径的基因，最强的信号来自于假定的调控区域。选择在不同的谱系中作用于这些相同的基因组区域，可能塑造了顺式调控元件的进化，这些元件控制着更为保守的基因的表达方式，从而在经典的性选择特征中产生多样性。
