关键词: 选择, 分子进化, 黑素皮质素1型受体(MC1R)基因, 犬

Abstract:

Melanocortin 1 receptor (MC1R) gene regulates pigment synthesis in mammals, and therefore is regarded as an important candidate gene for dog coat color. Based on MC1R amino acids and cDNA sequences of 10 vertebrate animals released by NCBI, molecular evolution of dog MC1R gene was analyzed with bioinformatic software and internet resource. Results showed that 10 vertebrate animals were divided into two major groups, a compact group A (7 mammals) and an incompact group B (chicken, zebrafish and fugu). This phylogenetic tree was consistent with putative evolutionary relationship within these 10 species. Positive selection was detected during the evolutionary process of dog (also cat and pig) from cattle by PAML branch model (w = 90.8177), and five amino acids of 2V, 25E, 184N, 197V and 314L of dog MC1R were predicted under positive selection by site model. Comparative linkage analysis of chromosome showed that “ZFP276-MC1R-GAS8” linkage group was conservative in human, chimpanzee, chicken and dog.