Developmental phenotypic-genotypic associations of tyrosinase and melanocortin 1 receptor genes with changing profiles in chicken plumage pigmentation

Abstract

The tyrosinase (TYR) and melanocortin 1 receptor (MC1R) genes have been accepted as major genes involved in the plumage pigmentation of chickens. The co-segregation of plumage coloration and sequence polymorphism in TYR and MC1R genes were investigated using an intercross between black and white plumage color types of the Dongxiang blue-shelled chicken. Profiles of plumage color changing and genes expression levels of TYR and MC1R were observed from hatch to 112 d of age using quantitative real-time reverse transcription-PCR. Intercrossed offspring were classified by phenotypes of plumage colors. The phenotypes of black and amber chicks with genotypes of E_C_ exhibited a black feather pattern, whereas white, gray, and buff chicks with genotypes of E_cc and eecc belonged to the white feather pattern. Although TYR in cooperation with MC1R determined the coloration feather patterns, the different phenotypes did not correspond completely with the genotypes. During the period studied, plumage phenotype changed dramatically, and the buff and gray down were gradually replaced by whiteness feathers. Real-time reverse transcription-PCR studies showed that 1) expression levels of TYR declined dramatically with age, and expression at hatch was highest (P<0.01) during the ages studied; 2) expression level of MC1R was higher at 28 d than at younger and older ages; and 3) expression of TYR in chickens carrying E/E and E/e alleles on MC1R loci were higher than those carrying e/e alleles from hatch to 28 d.

Genome-Wide Analyses Identifies Known and New Markers Responsible of Chicken Plumage Color

“…One of the most significant markers (SNP AX-75379450) was located within the TYR gene, while a total of 10 significant SNPs were concentrated in a very small interval of 0.27 Mb within the GRM5 gene. TYR codes for a key enzyme in melanin biosynthesis and it has been accepted as a major gene involved in plumage color in chickens [22][23][24]. A previous study reported that TYR showed the greatest level of differential expression in the skin of black versus white chickens [24].…”

Analysis of skin color change and related gene expression after crossing of Dongxiang black chicken and ISA layer

“…In addition, Liu et al (2010) studied Dongxiang black chicken from hatching to 112 days, and found that MC1R expression in skin peaked at 28 d and decreased thereafter. Dorshorst et al (2011) found that EDNRB2 expression was significantly different between adult black and non-black chicken, although the difference in EDNRB was non-significant.…”

Mutations of &lt;i&gt;TYR&lt;/i&gt; and &lt;i&gt;MITF&lt;/i&gt; Genes are Associated with Plumage Colour Phenotypes in Geese

“…After the report of (Oetting et al, 1985) that the C locus is the structural locus for tyrosinase in the fowl, the TYR gene was first cloned from chicken (Mochii et al, 1992). Previous studies have shown that mutations of the TYR gene are associated with albinism phenotype in many vertebrates, such as human (Fukai et al, 1995; Oetting, 2000), mouse (Yokoyama et al, 1990), rat (Blaszczyk et al, 2005), cat (Imes et al, 2006), rabbits (Aigner et al, 2000), cattle (Schmutz et al, 2004), chicken (Tobita-Teramoto et al, 2000; Sato et al, 2007; Liu et al, 2010). …”