The genomics of mimicry: gene expression throughout development provides insight into convergent phenotypes in a Müllerian mimicry system

A common goal in evolutionary biology is to discern the mechanisms that produce the astounding diversity of color and pattern seen across the tree of life. Aposematic species, those with a conspicuous phenotype coupled with some form of defense, are excellent models for understanding these mechanisms. Mimicry systems can provide an even better model for understanding the mechanisms of color and toxin production in aposematic species, especially if comimics have divergent evolutionary histories. Here we investigate the genetic mechanisms by which color and pattern are produced in a Müllerian mimicry complex of poison frogs. We did this by first assembling a high-quality de novo genome assembly for the mimic poison frog Ranitomeya imitator. We then leveraged this genome to conduct gene expression analyses throughout development of four color morphs of R. imitator and two color morphs from both R. fantastica and R. variabilis which R. imitator mimics. We identified a large number of pigmentation and patterning genes that are differentially expressed throughout development, many of them related to melanocyte development, melanin synthesis, iridophore development, and guanine synthesis.