The mutations within MC1R, TYRP1, ASIP genes and their effects on phenotypes of coat color in wild pigs (Sus scrofa ussuricus )

Abstract

Animal coloration is a powerful model for studying the genetic mechanisms that determine animal phenotypes. But, there has not been comprehensive characterization of the molecular basis of the complex patterns of coat color phenotype variation in wild boars. This study results indicated that the wild-type allele E+ of the MC1R gene was a dominant allele in wild boars and was not responsible for black, brown or other coat color phenotypes. A novel mutation c.695 T > C was identified in the 3¢-UTR of the ASIP gene. The association analysis showed that the C mutation allele was highly significantly associated with wild-type coat colors between wild boars and Western pig breeds (P=1.35E-33). A non-synonymous g.2254 G > A substitution was found in exon 2 of the TYRP1 gene (p.143His>Arg). The association analysis demonstrated that the G mutation allele was also significantly associated with wild-type coat colors between wild boars and Western pig breeds (P = 5.09E-10). In short, a few mutation sites in MC1R, ASIP, and TYRP1 genes were identified and surveyed several polymorphisms molecular variations in Chinese wild boars. In our identified mutations have caused the morphological diversity in wild boars, but did not influence coat color phenotype variation in some domesticated pig breeds. The conclusion was obtained that some mutations in color-associated genes were associated with wild-type coat colors in wild boar population, and that similar coat colorations observed in domesticated pig and wild boars can be the product of underlying differences in the genetic basis of color variants.