Polymorphism identification in goat DGAT1 and STAT5A genes and association with milk production traits

Abstract

Polymorphisms of DGAT1 and STAT5A genes in Xinong Saanen and Guanzhong goat breeds were investigated. PCR-RFLP, SSCP, and DNA sequencing were used to identify three SNPs: DQ380250:g.407_408insC in the DGAT1 gene, AJ237937:g.6798C>T and g.6852C>T in the STAT5A gene. In DGAT1 g.407_408insC locus, the frequencies of C^– allele were 0.79–0.85, and frequencies of C⁺ allele were 0.21–0.15. At STAT5A g.6852C>T locus, frequencies of C allele were 0.70–0.72, and frequencies of T allele were 0.30–0.28. Compared with goats with DGAT1 C^–C^–, those with C^–C⁺ genotype had greater milk fat (P < 0.05). The goats with STAT5A CT had greater milk yield than those with CC genotype (P < 0.05). The results showed that does with C^–C^–CT and C^–C⁺CT yielded more milk than those with C^–C^–CC(P < 0.05). In addition, does with C^–C⁺CT had the highest milk fat in comparison with other combination genotypes (P < 0.05).