Screening of Key Pathways and Key Genes for the Differential Regulation of Subcutaneous and Intramuscular Fat...

The fat mass and obesity-associated gene (FTO) has been shown to play a critical role in fat deposition in both humans and livestock. However, its involvement in subcutaneous and intramuscular fat deposition in chickens remains underexplored. In this study, we investigated the regulatory effects and pathways of FTO on subcutaneous and intramuscular fat deposition in chickens through functional gene verification and bioinformatics analysis. Our results demonstrated that, compared to the control group, exogenous transfection of an FTO lentiviral overexpression vector significantly inhibited cell proliferation and increased lipid accumulation in both subcutaneous and intramuscular adipocytes (p < 0.05). Furthermore, transfection of FTO siRNA markedly increased cell proliferation and reduced lipid accumulation in both subcutaneous and intramuscular adipocytes. A total of 413 and 164 differentially expressed genes were regulated by FTO in subcutaneous and intramuscular adipocytes, respectively. Pathway analysis revealed that the regulation of the actin cytoskeleton was a key process involved in FTO-mediated fat deposition in both subcutaneous and intramuscular adipocytes. Additionally, NRAS and ITGAV (subcutaneous fat), as well as FGF9, PIK3R2, FGF16, and RHOA (intramuscular fat), were identified as key genes enriched in this pathway. In conclusion, FTO differentially regulates fat deposition in chicken subcutaneous and intramuscular adipocytes by targeting distinct functional genes within the actin cytoskeleton pathway.