Primate exome sequencing reveals new targets of positive selection

Comparison of protein coding DNA sequences from diverse primates can provide insight into these species' evolutionary history and uncover the molecular basis for their phenotypic differences. Here we use targeted capture methods designed for human to sequence the protein coding regions, or exomes, of four non-human primate species (three Old World monkeys and one New World monkey) using massively parallel sequencing. Using this expanded set of primate sequences, we performed a genome-wide scan for genes experiencing positive selection and identified a novel class of adaptively evolving genes involved in the conversion of epithelial cells in skin, hair and nails to keratin. Interestingly, the genes we identify under positive selection also exhibit significantly increased allele frequency differences among human populations, suggesting that they play a role in both recent and long-term adaptation. We also identify several genes that have been lost on specific primate lineages, which illustrate the broad utility of this dataset for other evolutionary analyses.