<scp>IGFBP2</scp> : A Factor That Negatively Regulates Muscle Development and Growth

Livestock growth performance is pivotal to meat production and skeletal muscle development. Identifying key genetic variants associated with growth traits can facilitate the selection of superior breeding stock. However, the role of Insulin-like Growth Factor Binding Protein 2 (IGFBP2) in livestock muscle development remains controversial, particularly regarding its genetic regulation in goats. In this study, the whole-genome resequencing of Hainan Black goats (HNBGs) revealed a growth-associated insertion/insertion variant (P1-Del-8-bp) in IGFBP2 3' UTR. Notably, individuals with the DD genotype exhibited significantly impaired growth performance, lower GH levels, and higher IGFBP2 levels compared to other genotypes. Mechanistically, IGFBP2 knockdown significantly enhanced the proliferation and differentiation of goat primary myoblasts (GPMs) by targeting Transforming Growth Factor Beta 2 (TGFβ2). Additionally, reduced IGFBP2 promoted myogenic differentiation by stimulating mitochondrial biogenesis. These findings provide novel insights into the molecular mechanisms governing skeletal muscle development in goats and offer potential genetic targets for livestock molecular breeding strategies aimed at improving meat production efficiency.