Polymorphisms of the Growth Hormone Releasing Hormone Receptor Gene Affect Body Conformation Traits in Chinese Dabieshan Cattle

SIMPLE SUMMARY: Increasing growth traits can impact the economic benefit of livestock. Polymorphisms can offer us potential molecular markers for the growth traits of cattle, and provide a reference for cultivating an improved cattle population according to the markers in the future. In this study, the growth hormone-releasing hormone receptor gene polymorphism is significantly associated with the body conformation traits of Chinese Dabieshan cattle, and it could be used as a candidate genetic marker for body conformation trait selection in cattle. This study further verified that the GHRHR gene plays a vital role in Chinese cattle, and provides a data basis for the research and improvement of cattle breeding programs in China. ABSTRACT: This study was performed to expose the polymorphisms of the growth hormone-releasing hormone receptor gene in Chinese Dabieshan cattle, evaluate its effect on body conformation traits, and find potential molecular markers in Chinese cattle. The GHRHR structure and the phylogenetic tree were analyzed using bioinformatics software. The polymorphism of the GHRHR gene in 486 female cattle was genotyped by PCR-RFLP and DNA sequencing, and the association between SNPs and body conformation traits of Chinese Dabieshan cattle was analyzed by one-way ANOVA in SPSS software. GHRHR was often conserved in nine species, and its sequence of cattle was closest to sheep and goats. Six polymorphic SNPs were identified, g.10667A > C and g.10670A > C were missense mutation. The association analysis indicated that the six SNPs significantly influenced the body conformation traits of Chinese Dabieshan cattle (p < 0.05). Six haplotypes were identified and Hap1 (-CAACGA-) had the highest frequency (36.10%). The Hap3/5 (-GCCCCCGGAAGG-) exhibited a significantly greater wither height (WH), hip height (HH), heart girth (HG), and hip width (HW) (p < 0.05). Overall, the polymorphisms of GHRHR affected the body conformation traits of Chinese Dabieshan cattle, and the GHRHR gene could be used as a molecular marker in Dabieshan cattle breeding programs.