ROSENBLUM, Erica Bree*; HOEKSTRA, Hopi E.; NACHMAN, Michael W.; University of California, Berkeley; University of California, San Diego; University of Arizona: Reptile Color Variation and Mc1r

Recent advances in understanding the genetics of pigmentation make color variation a tractable system to study the molecular basis for ecologically relevant traits across vertebrates. Here, we evaluate the role in reptiles of the melanocortin-1 receptor gene (Mc1r) which is known to be responsible for color variation in natural mammalian and avian populations. We sequenced Mc1r in seven North American squamate species with melanic or blanched forms and conducted association studies to determine if this gene plays a role in dorsal color variation in these taxa. Results indicate that although Mc1r is not implicated in color morphology in most of the focal species, amino acid variation is associated with color in one Teiid lizard, Aspidoscelis inornata. Several lines of evidence are presented which indicate that Mc1r may be involved in producing blanched phenotypes in this species. We also evaluate patterns of molecular evolution for Mc1r in reptiles and find that patterns of divergence and constraint in this gene are consistent with those previously observed in mammals. We highlight the utility of a candidate gene approach to better understand the functional relationships and molecular evolution of genes involved in vertebrate adaptations.