The Identification of SNPs in BCDO2 Gene for Skin Color in Chinese Indigenous Chicken

Abstract

ABSTRACT A complete linkage disequilibrium between the SNP (SNP B) in BCDO2 gene and the yellow skin phenotype in European domestic chicken has been reported. Here, we genotyped the reported SNPs (SNP A, SNP B, and SNP C) of the BCDO2 gene in 183 Chinese Indigenous chickens from 11 breeds/populations, including 57 yellow, 17 white, and 109 black skin chickens. The frequency of all three SNPs were significantly different between yellow and white skin chickens (p<0.01). In black skin chickens, a high frequency of the heterozygous genotype (AG) in SNP A (0.51) and SNP B (0.48) was observed. A total of three haplotypes (AAA, AGA, and GAA) from these three SNPs were obtained. Frequencies of the proposed yellow skin-associated haplotype AGA in yellow skin, white skin, and black skin chickens were 0.81, 0.35, and 0.56, respectively. The results showed that the yellow skin phenotype of the evaluated birds has not been under selection, and that the BCDO2 gene in black skin chickens, evolutionally may undergo a transition phase from yellow to white skin chicken. We concluded that, the SNPs of BCDO2 gene not only can be used to determine whether the chicken was subjected to selection, but may also be used as a marker when selecting for the preferred skin color in chicken breeding programs.

Keywords

• b-carotene dioxygenase (BCDO2)
• Chinese indigenous chickens
• SNPs
• skin color