Genetic diversity and breed origin of Wuhua Yellow chicken inferred from mitochondrial DNA D-loop sequences

For depicting genetic diversity and phylogeny of Wuhua Yellow chicken，one hundred and twenty samples were used to directly sequence using PCR products of mitochondrial DNA D-loop. The results showed that the Wuhua Yellow chicken obtained high levels of genetic diversity，with nucleotide diversity，average number of nucleotide differences and haplotype diversity for 0.01298 ± 0.00051，6.750 and 0.913 ± 0.012，respectively. The content of C++G（ 42.5%） was lower than T+A（ 57.5%）. A total of 33 mutation sites were detected，including 23 T to C and 10 A to G transitions，accounted for 6.35% of the analyzed sequences. Thirty-two haplotypes were defined，with 19 exclusive haplotypes and 13 shared haloptypes. The haplotype diversity and genetic distance were 0.913±0.012 and 0.013±0.003，respectively. These haplotypes were mainly distributed in clades A，B，C and E， and B was the dominated haplogroup. Phylogenetic analysis and geographical distribution indicated that there were four maternal origins to Wuhua Yellow chicken，which was influenced to some extent，by the gene flow of domestic chicken from northern China.