The Analysis Between Single Nucleotide Polymorphism Of Melanocortin Receptor 1 (MC1R) Gene And Coat Colour In Partial Chinese Bovine Breeds

In this study,the SNP(single nucleotide polymorphism) of MC1R gene in partial Chinese bovine breeds for the relationship with SNP and coat color were determined.Fresh ear tissue from 32 individuals of six breeds(Tianzhu Yak,Jiulong Yak,Maiwa Yak,Xizang Yak,Fuling Buffalo and Tongjiang cattle) were coolected,extracted DNA and recorded the coat color,under analyzing this data some conclusions were drawn as follow:1.The entire encoding fragments of MC1R gene in 59 individuals from six cattle species/breeds were cloned and sequenced.The lengths of the fragment of amplification were 1045 bp,including 954 bp of the complete CDS sequence,encoded 318 amino acids.The average percent of T,C,A,G were 22.9%(22.7%～23.1%), 35.8%(35.6%～36.0%),15.0%(14.9%～15.2%),26.3%(26.2%～26.4%),respectively. The percent of A+T was 37.9%and G+C was 62.1%,respectively.The content of A+T was slightly lower than that of G+C.2.There were 23 mutation sites in MCIR CDS sequences of the 954 bp length,it was 2.41%of the sequenced length,including 3 transversion(13.04%),19 transitions (82.61%),one deletion(4.35%),among them,six substitutions reside out the known seven transmembrane domains,and all of the seven transmembrane domains have substitutions resided in.The singleton polymorphic and Parsimony-informative sites were 20 and 2,respectively.3.Fourteen haplotype in thirty-two individuals were detected.Twenty-four homozygous and eight heterozygous genotype individuals were determined,respectively.4.An important SNP(Single Nucleotide Polymorphism) at 126 position of the MC1R coding region were found.With the reference sequence accepted,all studied sequences are cytosine on the 126 position.5.As well as the specific substitutions to the determined alleles E~+ and e,we found more new variations.Two new clades significant separated by mutation sites 340,871 and mutation sites 663(defined by allele M2) by phylogenetic analysis,which were tentatively defined by allele M1 and allele M2),respectively.Based on the relation between genotype and coat color,we proposed that the allele M1 is a relatively recessive allele to M2,and the homozygous M1/M1genotype will show uniform white. The allele M2 controls the black or deep grey coat,while allele M2 is also recessive to wild-type allele E~+.