Transcriptomic Insights Reveal PRTFDC1 as a Novel Regulator of Myogenic Differentiation in Sujiang Pig Satellite Cells

Sujiang pigs, a high-quality local Chinese breed, represent a valuable model for investigating muscle development and improving meat production through genetic selection. Skeletal muscle satellite cells (MuSCs) are essential regulators of muscle growth, with differentiation tightly controlled by specific genes and signaling pathways. In this study, MuSCs were isolated from the gastrocnemius muscle and subjected to mRNA sequencing during proliferation (GM) and differentiation stages (DM1, DM2, and DM4, collectively referred to as DM). A total of 2790 differentially expressed genes (DEGs) were identified, including 1551 upregulated and 1239 downregulated genes. Time-series analysis revealed 16 significant expression patterns. These DEGs were primarily associated with muscle development and differentiation and were enriched in Wnt, PI3K-Akt, JAK-STAT, p53, Hippo, and Apelin signaling pathways. Among them, phosphoribosyl transferase domain containing 1 (PRTFDC1) exhibited pronounced downregulation during differentiation. Functional validation demonstrated that PRTFDC1 overexpression promoted myotube formation and upregulated <i>MYOD1</i>, <i>MYOG</i>, and <i>MYH1</i> expression, whereas knockdown significantly inhibited differentiation. Furthermore, PRTFDC1 enhanced phosphorylation of key proteins in the cGAS-STING signaling pathway. Collectively, this study elucidates the temporal transcriptional regulation of MuSC differentiation in Sujiang pigs and identifies PRTFDC1 as a novel regulatory factor, providing a molecular foundation for breeding strategies and meat quality improvement.