Effect of single nucleotide polymorphisms in GH gene promoter region on carcass traits and intramuscular fatty acid compositions in Japanese Black cattle

Previous studies demonstrated that single nucleotide polymorphisms (SNPs) in exon 5 of the bovine growth hormone (GH) gene affected live weight and carcass traits in Japanese Black cattle. The aims of the present study were to identify SNPs in the promoter region of the GH gene and to analyze their effects on carcass traits and intramuscular (i.m.) fatty acid compositions in Japanese Black cattle (511 steers and 252 heifers; 30.5±0.1 months old). SNPs in the promoter region of the GH gene were detected at g.253, g.303, and g.502 and classified into 4 haplotypes, i.e. haplotype P (T-C-C), Q (C-C-C), R (C-C-T), and S (T-T-C). Among genotypes at g.253, genotype TT had the highest carcass weight (CW), rib thickness (RT), and C14:0 and C16:1 contents, but the lowest C18:0 content. The rib eye area (REA) in genotype TT was higher compared with that in genotype CC. Genotype CC had the lowest C16:0 content and higher C18:1 and MUFA contents compared with those in genotype TT. Among genotypes at g.303, genotype CC had the highest C14:0, C16:0, and C16:1 contents, but the lowest C18:1 content. Genotype TT had the lowest CW and RT, but the highest C18:0 content. At both locations, the heterozygous animals showed intermediate values for most traits. Regarding GH promoter diplotypes, diplotype PP had higher CW, C16:0, and C16:1 than diplotype SS and tended to have the lowest C18:0 compared with diplotype QQ and SS. In conclusion, SNPs at g.253 and g.303 in the GH promoter region affects carcass traits in Japanese Black cattle.