Evolution and Differentiation of MSHR Gene in Different Species

Coat color offers some prospects for evolutionary studies due to its large amount of presumably adaptive coat color variation and conserved genetic mechanisms of generating different coat colors in different species. Melanocyte-stimulating hormone receptor (MSHR) gene is responsible for intraspecific and interspecific color variation in mammals and birds. A total number of 206 MSHR gene sequences belonging to 84 species, 58 genera, and 20 families were analyzed to investigate its evolution and differentiation in different species. Most of the species have 954 bp and stop codon TGA. Species in Callithrix and Callimico have a stop codon mutation from TGA to TGG and elongate 81 bp with TAG as stop codon. Species in Phasianidae, Fringillidae, and Lemuridae also use TAG as stop codon. The Sus scrofa had an insertion of AACCAGACC encoding Asn-Gln-Thr from 85 to 93 bp. In Bovidae, a brown strain of cow with 966 bp due to the 12-bp duplication of GGCATTGCCCGG from 670 to 681 bp encoding for Gly-Ile-Ala-Arg was found. Teiidae has the smallest number of total mutations (6), silent mutations (3), nonsynonymous mutations (3), average number of nucleotide differences (1.519), synonymous nucleotide diversity (pi(s) = 0.0030), and nonsynonymous nucleotide diversity (pi(a) = 0.0029), and Hominidae, Lemuridae, Canidae, and Teiidae have higher ratio of pi(a)/pi(s) (0.537-0.973). The reconstructed phylogenetic tree of MSHR gene of families is basically consistent with the taxonomy of National Center for Biotechnology Information.