Growth hormone receptor gene expression in the skeletal muscle of normal and double-muscled bovines during foetal development

Abstract

-The expression of the growth hormone receptor (GHR) gene was investigated in semitendinosus muscle during bovine foetal development in both normal and double-muscled Charolais foetuses which differ with respect to muscle development. Northern-blot analysis of foetal muscle RNA preparations with a GHR cDNA probe identified the 4.5 kb GHR mRNA as early as 130 days post-conception. In double-muscled animals, the expression of GHR mRNA increased from 130 to 210 days of gestation while it stayed stable in normal ones. It was significantly higher (P < 0.05) in double-muscled foetuses compared to normal ones from the second third of gestation. Northern-blot analysis of foetal muscle RNA preparations from both genotypes with a β-actin cDNA probe, revealed lower β-actin gene expression in double-muscled foetuses than in normal ones, suggesting a delay in the differentiation of muscle cells. In situ hybridisation revealed the localisation of specific GHR mRNA in muscle cells at all gestation stages analysed (130, 170, 210 days postconception) but not in connective tissue surrounding the muscle cells. At the adult stage, the hybridisation signal was also very high and observed in muscle cells only. These results show the ontogeny of GHR mRNA in bovine muscle and demonstrate a difference between normal and doublemuscled animals. muscle / bovine / receptor / growth hormone / in situ hybridisation

Prenatal developmental changes in glucose transporters, intermediary metabolism and hormonal receptors related to the IGF/insulin-glucose axis in the heart and adipose tissue of bovines

“…This might have important implications for both farm animals and human beings. In doublemuscled cattle (which are characterised by muscle hypertrophy and lower fat depots), an enhanced insulin action on glucose transport rate in calves [59], a higher expression of the growth hormone receptor (which regulates IGF I and IGF II expression) [60] and a higher level of a specific IGF-II transcript in skeletal muscles at the end of gestation were observed compared to normal animals. In humans, insulin resistance in subjects born with intrauterine growth retardation is associated with impaired GLUT4 expression at the mRNA level in muscle and adipose tissue [61].…”

Association of a Novel Single Nucleotide Polymorphism in Growth Hormone Receptor Gene with Production Traits in Bali Cattle

“…The growth hormone exerts its effects on growth and metabolism by interacting with a growth hormone receptor (GHR) on the surface of the target cells (Listrat et al, 2005). Mutation of GHR gene might affect its binding capacity and signaling pathway, thereby altering the GH activity in the target tissues (Di Stasio et al, 2005).…”