Colours hidden in the forest: evolutionary genomics of colour patterns in neotropical frogs

Abstract

The study of the evolutionary processes that originate phenotypic diversity is one of the most important endeavours in biology because it can offer insights into the process of adaptation in natural populations. Colouration patterns are remarkable traits for studying the mutational mechanisms underlying phenotypic diversity and how these affect patterns of evolutionary change. Among vertebrates, amphibians are one of the most interesting groups, exhibiting a vast variation in colouration, whose function has been mainly associated with thermoregulation, UV protection, conspecific communication, and predator avoidance. Despite significant advances have been made on this topic in both invertebrates and vertebrates, the genetic basis of colouration in amphibians is still surprisingly unknown. The South American leaf-frogs of the Phyllomedusa burmeisteri group, which have been widely studied by our research team, is a compelling case to study the evolution of colour pattern diversity in amphibians. First, they present striking variation in the patterns of bright colours at the hidden surfaces of thighs, which have been interpreted as a case of aposematism, one of the most widespread defensive strategy among Neotropical amphibians. Second, colour morphs variants coexist in some populations, offering, thus a unique opportunity for genetic mapping studies. Finally, these species meet in a well-defined contact zone, making this system an excellent model to understand the impact of colour polymorphism in the dynamics of speciation, and how selection shapes both phenotypic and genetic variation. The proposed research seeks to investigate the GENETIC BASES AND EVOLUTIONARY PROCESSES UNDERLYING COLOUR VARIATION IN AMPHIBIANS. To this end, we will 1) perform a genome-wide association analysis using high-throughput DNA sequencing techniques, including exome capture and RNA sequencing; 2) study gene expression of associated genes in several developmental stages; and 3) investigate patterns of allele frequency change across the contact zone for causative loci and randomly chosen markers. Beyond these specific goals, we are convinced that the genomic data generated for the target species will be an important resource for further evolutionary studies, conservation efforts, and in particular for human medicinal research, since phyllomedusids are a rich source of peptides with great nanobiotechnological applications. With an International team of researchers with complementary skills and expertise, with 10-years' experience in developing joint research, we expect to be at the forefront of this underexplored evolutionary field, publishing articles in leading international journals and produce outreach publications for enhancing awareness and/or disseminating research based information to the general public. This proposal will offer the opportunity for advance training to MSc and PhD students, and provide one postdoctoral contract. (AU)