Non‐synonymous SNPs in MC1R gene are associated with the extended black variant in domestic ducks (Anas platyrhynchos)

Abstract

In this study, we performed a sequence characterization of the duck melanocortin 1 receptor (alpha-melanocyte stimulating hormone receptor) (MC1R) gene to analyze the relationship between MC1R polymorphism and the extended black variant in domestic ducks based on the extended black (E) and non-extended black (e(+) ) allele hypothesis of the duck MC1R gene. Both c.52G>A and c.376G>A substitutions are highly associated with the duck extended black variant (P < 0.01), but the novel c.52G>A substitution is more of a fit for the allele hypothesis of the duck MC1R gene.

Identification of <i>MC1R </i>SNPs and their Association with Plumage Colors in Asian Duck

“…MC1R gene is associated with extended black feather color (Yu et al, 2012). We observed four non-synonymous substitutions (p.Lys18Glu, p.Ile126Val, p.Thr137Ala, and p.Arg217Cys) in the MC1R gene in Asian ducks (Xia 2008;Huang 2010;Yu et al, 2012), and p.Arg217His substitution was observed exclusively in Bangladeshi duck breeds.…”

“…In this study, one substitution (p. Glu18Lys), located in the extracellular N-terminus of MC1R could increase the eumelanin synthesis via stimulating MC1R activity (Yu et al, 2012), while in rock pocket mice it was demonstrated that a different substitution (p.Arg18Cys) Effect on protein function due to substitution* Amino acid change Nucleotide position * Variants with a score above −2.5 are considered "neutral" and variants with a score equal to or below −2.5 are considered "deleterious" (Choi et al, 2012) c.409G＞A at the same site is associated with reduction of eumelanin . Yu et al (2012) reported that p.Glu18Lys substitution might have a salt bridge connection with the N-terminus extracellular membrane and the MC1R protein function, stimulating the eumelanin production. A mutation c.96G＞A generated a premature stop codon (p. W32X) occurs in the extracellular N-terminus in turkeys (Vidal et al, 2010), which is near to the p.Lys18Glu substitution observed in ducks.…”

“…In this study, we found five pigmentation phenotypes among the seven Asian duck populations, and divided them into three groups on the basis of E locus (Yu et al, 2012). Nageswari (an indigenous black duck variety of Bangladesh) which is locally called "Nagi" because of snake deity head with black bill and bean (Fig.…”

“…The recessive white loci have an epistatic effect on the E locus of MC1R gene and might also be located on other plumage color related genes. Therefore, the identification of the causative mutations of recessive white is difficult in white domestic duck breeds (Lancaster, 1990;Yu et al, 2012). Experimental studies on chickens described that E locus of the MC1R gene, located on chromosome 11, is controlling to the plumage color variants (Kerje et al, 2003).…”

A Val85Met Mutation in Melanocortin-1 Receptor Is Associated with Reductions in Eumelanic Pigmentation and Cell Surface Expression in Domestic Rock Pigeons (Columba livia)

“…Birds exhibit widespread color variation among species, and less commonly, they show substantial variation within species. In the latter cases, amino acid substitutions in Mc1r are associated with color polymorphisms in several distantly related species, including both wild [5–11] and domestic populations [12–17]. In the wild, Mc1r -mediated pigment variation is associated with differences in mate choice (e.g., [6,9]), thermoregulation [5], and immune system response [10].…”