Novel DNA markers and coat color differentiation in Sulawesi macaques

抄録

Sulawesi macaques, seven endemic species in Sulawesi Island, Indonesia are optimal for studying the mechanism of genes shaping species differentiation. They have rapidly speciated from the common ancestor in a relatively short period and morphologically diversified. Exceptionally, they exhibited distinct dark coat color but with difference in color pattern between species. To clarify the genetic basis shaping specificity of species in Sulawesi macaques, we sequenced the exome of five species and screen out the differentiated SNPs. In total, we collected 46 saliva samples of five species in Sulawesi Island. After determined the exome sequence using human exome library, we computed the sites Fst (fixation index) value between each two neighboring species and filter the fixed SNPs as high differentiated sites. We found that hundreds of genes contained fixed SNPs between each pairwise neighboring species. These genes might be responsible to the species differentiation and evolve in directional selection on the traits. Further we investigated the pigmentation-related genes and confirmed the functional divergence of the genes in vitro. We found pigmentation-related genes were significantly enriched with fixed SNPs. We studied the cAMP induced ability of the melanocortin-1 receptor (MC1R), which regulates the synthesis and density of melanin production. The MC1R exhibited fixed amino acid sequence in each species and showed specific functional features in each species. These results demonstrate the genetic basis of the specificity species in Sulawesi macaques and the possibility of coat color divergence mechanism.