Repeated divergent selection on pigmentation genes in a rapid finch radiation

Abstract

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.Fil: Campagna, Leonardo. Cornell University; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Repenning, Márcio. Pontificia Universidade Católica do Rio Grande do Sul. Museu de Ciências e Tecnologia; BrasilFil: Silveira, Luís Fábio. Universidade de Sao Paulo; BrasilFil: Fontana, Carla Suertegaray. Pontificia Universidade Católica do Rio Grande do Sul; BrasilFil: Tubaro, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Lovette, Irby. Cornell University; Estados Unido