Analysis of genetic diversity of the heat shock protein 70 gene on the basis of abundant sequence polymorphisms in chicken breeds.

This study was designed to detect the sequence variation of the chicken heat shock protein 70 (HSP70) gene. A total of 102 individuals from 8 native Chinese breeds together with Dwarf White Chicken and Red Junglefowl were used to detect sequence variations. The coding regions of the chicken HSP70 gene from 102 individuals were cloned and sequenced. Thirty-six variations were identified, which included 34 single nucleotide polymorphisms and 2 indel mutations. Fifty-seven haplotypes were observed, of which, 43 were breed-specific and 14 were shared. There were 7 Red Junglefowl-specific haplotypes, while Haidong and Silkie only had 2 specific haplotypes. Eleven and 3 haplotypes were shared between and within species, respectively. The variation in nucleotide diversity (Pi) and average number of nucleotide differences (K) among species were consistent. The total Pi of HSP70 was 0.0016, and the total K was 4.1998. The Pi value of Red Junglefowl was the highest (0.0018) and K was 4.8000, while the Pi of Silkie was the lowest (0.0010) and K was 2.5000. These results demonstrated that variation in chicken HSP70 was abundant between and within species.