Integrated gene co-expression network analysis and experimental validation identified integrin beta 1 as a candidate gene affecting milk production in dairy cattle.

Identification of functional genes associated with milk production is essential for establishing effective breeding programs in dairy cattle. To date, the specific functional genes involved in milk production in dairy cows remain to be identified. In this study, we used public RNA-seq data from dairy cows and employed gene co-expression network analysis to identify the integrin beta 1 (ITGB1) as a potential candidate gene related to lactation. In vitro assays demonstrated that ITGB1 knockdown in bovine mammary epithelial cells (MAC-T) inhibited cell proliferation, increased apoptosis, and reduced triglyceride levels. Transcriptomic analysis further revealed that ITGB1 knockdown resulted in differential expression of 503 genes, which were significantly enriched in the FoxO, IL-17, and HIF-1 signaling pathways. Moreover, ITGB1 knockdown caused a reduction in the phosphorylation of both AKT and FoxO1. Conversely, SC79-mediated activation of AKT promoted the phosphorylation and nuclear export of FoxO1, which in turn inhibited the expression of pro-apoptotic factors such as BIM and BAX, thereby attenuating the pro-apoptotic effects induced by ITGB1 knockdown in MAC-T cells. Our findings indicate that ITGB1 is a functional gene regulating milk production and a promising candidate gene for selective breeding in dairy cattle.