Polymorphism in GHRH gene and its association with growth traits in Chinese native cattle.

Growth hormone-releasing hormone (GHRH) is secreted by the hypothalamus and stimulates growth hormone (GH) released from the pituitary. Mutations detected in GHRH gene showed associations with animal production traits. The purpose of this study was to investigate the association of the GHRH gene with growth traits in Chinese native cattle. PCR-SSCP and sequencing were used to detect mutations of the GHRH gene in this study. One novel mutation 4251nt (C>T) was found and the frequencies of C allele were 0.8778 and 0.8476 for Qinchuan and Nanyang cattle, respectively. Body weight with the CT genotype was significantly higher (P<0.05 or P<0.01) than those with CC genotype for different growth periods (6, 12, 18, and 24 months old) in Nanyang cattle. Our findings suggested that polymorphism in bovine GHRH might be one of the important genetic factors to influence body weight.