Study On The Association Between Single Nucleotide Polymorphisms Of Melanogenic TYR Gene And MITF Gene And The Plumage Color Traits Of Goose

The coat color of domestic and wild animals was determined mainly by the content and distribution of two melanin, eumelanin and phaeomelanin, which is produced by specialized pigment cells known as melanocytes. The plumage color straits of poultry are not only an important economic trait, but is the genetic markers of breed or strain selection. The genetic variation of the MITF (Microphthalmia-associated transcription factor) gene and the TYR (tyrosinase) gene were associated with the coat color of animals, and they have been proposed to be an important candidate gene in coat color genesis. In this study, the single nucleotide polymorphisms (SNPs) of TYR gene and MITF gene were detected and analyzed based on the method of PCR product direct sequencing and the samples of three goose breeds with different plumage colors, the white plumage Zhe dong white goose (pure white), the grey plumage Lands, the spotted plumage Lands, which aimed for studying the association between the genetic variation of TYR gene and MITF gene and the plumage color traits of goose.We sequenced588bp fragment of exon1in TYR gene and1397bp fragment of the whole coding regions in MITF gene. Bioinformatics analysis showed that the nucleotide homology of TYR gene and MITF gene the between obtained sequence of goose and the sequence of the red jungle fowl were as high as90%and93%, respectively.By screening single nucleotide polymorphism sites in all individuals, we found four SNPs sites, c.138G>A、c.280T>C、c.345G>A and c.369G>A, in exon1of TYR gene, among which, the c.138G>A was the rare mutation. One SNP site, C.1109C>T, was also found in partial of the coding region of MITF gene, which contained two alleles, resulting in three genotypes of CC, CT and TT. After translating for nucleotide sequence of TYR gene, we found that the mutation c.280T>C could cause the amino acid changes (Tyr92His), and the other mutations were synonymous mutations. Haplotype analysis results demonstrated that H3(T-G-G) and H3H3were predominant diplotypes and predominant diplotypes combinations, respectively. Association analysis demonstrated that diplotypes H1and H5were highly significantly associated with white plumage of Zhe dong white goose (p<0.01) and H2and H3were highly significantly associated with all three different plumage color (p<0.01). At the site c.1109C>T of MITF, the TT genotype was the predominant allele and significantly associated with white plumage of Zhe dong white goose (p<0.05). Accordingly, there was a certain correlation between the genetic variation of TYR gene and MITF gene and the plumage color traits of goose, and the two genes were the candidate gene for goose plumage color traits.