Correlation analysis between three novel SNPs of the Src gene in bovine and milk production traits

As an essential signaling modulator, Src gene appears to be necessary for increased expression of the prolactin receptor, normal downstream signaling, and alveolar cell organization. In this study, we detected the polymorphism of Src gene by polymerase chain reaction-restriction fragment length polymorphism assay (PCR-RFLP) and DNA sequencing methods in 985 individuals from three Chinese cattle breeds. Three novel single nucleotide polymorphisms (SNPs) (g.14062C > T ss161151834, g.17302G > A ss161151835, g.18107T > C ss161151836) were detected. Least squares analysis showed that cows with g.14062C > T-CC genotypes and g.18107T > C-TT genotypes had the highest protein rate, while the cows with g.17302G > A-GG genotype had higher 305 d milk yield (p < 0.05), fat yield (p < 0.01) and protein yield (p < 0.01) than the ones with genotypes g.17302G > A-GA. These results revealed the statistical significant effects of three SNPs of the Src gene on the milk production traits in Chinese Holstein. In addition, based on the nine genotypes constructed from 27 combined haplotypes, the association analysis between combined haplotypes and milk production traits was carried out. Statistic results showed that the cows with combined haplotypes H2H4(CCGATT) had the highest fat rate and the highest protein rate and the cows with combined haplotypes H1H8(TCGATC) and H3H7(TCGGCC) had greater 305 d mild yield than H1H2(CCAATC)(P < 0.05). Our finding demonstrated that the Src gene possibly contributed to conducting association analysis and can be recognized as genetic marker in milk production traits and other performance for animal breeding and genetics.