Genetic variations of ANGPTL6 gene and their associations with growth traits and slaughter traits in Qinchuan cattle.

Angiopoietin-like protein 6 (ANGPTL6), which plays an important role in angiogenesis and energy metabolism as a circulating orphan peptide secreted by liver, could produce a potential effect on growth and development of animals. The objective of this study was to detect genetic variations of ANGPTL6 gene in 732 Qinchuan cattle, as well as to analyze their associations with growth traits and carcass weight. Herein, three novel mutations (T2359C, C2403A and G3258T) were identified in cattle for the first time. Chi-square test showed T2359C and C2403A loci were in Hardy-Weinberg equilibrium except G3258T locus. Haplotype with TCG (wild type) was dominant with frequency of 40.0 % among eight different haplotypes. Statistical analysis showed body height (BH) and hucklebone width (HW) of individuals with genotype CC were significant higher than other genotypes in T2359C locus (P < 0.05). In the C2403A locus, chest girth (CG), chest depth (CD), and chest breadth (CB) of individuals with genotype CA were all extremely significant higher (P < 0.01) while BH was significant higher (P < 0.05) than genotype CC. The association analysis of combined sites showed BH, CG, CB and HW of individuals with combined genotype TC-CA were significant higher than other combined genotypes (P < 0.05) in ScaI-VspI site. BH, CG and CB of individuals with genotype CA-GG were significant higher (P < 0.05) as well as CD was extremely significant higher (P < 0.01) than other genotypes in VspI-RsaI site. For ScaI-VspI-RsaI site, CD and HW of individuals with genotype TC-CA-GG were significant higher (P < 0.05) than those of other combined genotypes. Slaughter test also revealed that the effect of the combined genotypes was extremely significant on the carcass weight. Carcass weight of individuals with genotype TT-CA and TT-CA-GT were extremely significant heavier than other combined genotypes (P < 0.01) in the ScaI-VspI and ScaI-VspI-RsaI sites. And those with genotype TT-GT of ScaI-RsaI were significantly heavy (P < 0.05) as well as the individuals with genotype CA-GT of VspI-RsaI. In conclusion, the present results provided evidence that polymorphisms of ANGPTL6 gene were associated with growth and slaughter traits, and may apply to Qinchuan cattle breeding program as a possible candidate for marker-assisted selection (MAS).