Genetics of adaptation in colourful poison frogs

• Applicant: Professorin Dr. Heike Pröhl
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions ; General Genetics and Functional Genome Biology
• Term: from 2014 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 263544360

The genetics of colouration has been studied in mammals, birds, fish and reptiles but studies on amphibians are scarce. Besides extensive variability in colour pattern nothing is known about the underlying genetic components involved in creating colour diversity within and among amphibian species. In this context the diversity of colouration patterns linked to predator avoidance strategies in Neotropical poison frogs is an exciting opportunity to study the genetics of ecological adaptation. Poison frogs differ in colouration patterns among populations and strong evidence exists that colouration is adaptive, probably driven by predator selection. Divergence in adaptive colouration, behaviour and toxicity in combination with assortative mating (by colour) very likely contributes to the formation of prezygotic isolation mechanisms among colour morphs. The objective of this proposal is to characterize the colouration genes for the extremely colour polymorphic Neotropical strawberry poison frog Oophaga. pumilio. In this frog bright aposematic as well as duller cryptic colour morphs are present in different Panamanian populations. For this project I will collect skin samples from three populations diverged in colour patterns: a red one, a green one and a blue one. I will perform RNAseq analysis to obtain dorsal skin-derived cDNA. cDNA samples will be send to a sequencing service that will perform next generation sequencing to analyse differences in expression levels in genes involved in colouration. I expect that genes involved in the carotenoid /pteridine uptake, synthesis or storage differ in their expression level among colour morphs. I will confirm results for loci with significant expression differences by performing quantitative Real time-RT-PCR (RT=reverse transcription). Thus, I will determine the key gene expression differences underlying colour variation in this species. This critical information will be of major interest in its own right, as it will identify which parts of the molecular pathways to pigment formation are evolving adaptively in this species. It will also open up many interesting avenues for future investigation that will lead to a better understanding of causes and consequences of adaptive colouration.

• DFG Programme: Research Grants