Collaborative Research: Genomic and phenotypic analyses of color pattern divergence in a mimetic radiation of poison frogs

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

Nature abounds with organisms that display bright colors, yet it is not always obvious why. Some animals evolve to advertise to potential predators that they are poisonous (warning coloration). Different toxic species may converge on the same color pattern, giving both an advantage by more effectively advertising to predators. This is known as Müllerian mimicry, a focus of interest because it involves multiple phenomena that lie at the heart of our understanding of evolutionary processes. The genetic basis of mimicry is of special interest, because it provides a window into how these key evolutionary processes unfold. This research will focus on discovering the genetic underpinnings of Müllerian mimicry in a species of poison frog that has undergone an evolutionary radiation across different geographic regions of Peru. In each region, the mimic poison frog has evolved a different color pattern (such as stripes, bands, or spots), to resemble another species in that region. The evolution of these new color patterns may be driving reproductive isolation between populations of the mimic poison frog, leading to speciation and the creation of new biodiversity. The project is a collaborative endeavor between researchers at three large public universities and will involve broad participation by undergraduate and graduate students, and a postdoctoral scientist. The results of the project will be used to enhance K12 education through classroom presentations, public lectures and museum displays. This project focuses on four specific aims: 1. Identify key genetic factors involved in color pattern development in the mimic poison frog by investigating differential gene expression across developmental stages and color pattern morphs, using next generation sequencing to produce stage-specific transcriptomes for each morph, which will be assembled to analyze patterns of differential gene expression. 2. Identify the causal gene(s) underlying differences in color pattern between morphs using genome-wide marker arrays (exome capture sequences) to screen transition zone samples (from three transition zones) and enable admixture mapping to discover candidate genes. 3. Test the association of specific candidate loci with color pattern using multigenerational pedigrees. 4. Test specific hypotheses regarding selection and demographic processes in the transition zones and between mimics and models, using new analytical tools. Together these complementary, mutually reinforcing approaches will elucidate the genetic underpinnings and population genomics of color pattern evolution and diversity in this mimetic radiation of poison frogs.