Abstract
Skeletal muscle development is crucial for livestock production, and understanding the molecular mechanisms involved is essential for enhancing muscle growth in sheep. This study aimed to investigate the role of Nfix, a member of the nuclear factor I (NFI) family, in regulating muscle development in sheep, filling a significant gap in the current understanding of Nfix deficiency and its impact on skeletal muscle growth, as no similar studies have been reported in this species. Bioinformatic analysis, including temporal analysis of transcriptome data, identified Nfix as a potential target gene for muscle growth regulation. The effects of Nfix overexpression and knockout on the proliferation and differentiation of sheep skeletal muscle cells were investigated. Changes in the expression of associated marker genes were assessed to explore the regulatory link between Nfix and the myostatin (MSTN) gene. Additionally, target miRNAs for Nfix and MSTN were predicted using online databases such as miRWalk, resulting in the construction of an Nfix-miRNA-MSTN interactive regulatory network. The findings revealed that Nfix promotes the proliferation and differentiation of sheep skeletal muscle cells, with further analysis indicating that Nfix may regulate muscle cell development by modulating MSTN expression. This study provides preliminary insights into the function of Nfix in sheep skeletal muscle development and its regulatory interactions, addressing a critical knowledge gap regarding Nfix deficiency and its implications for muscle growth. These findings contribute to a better understanding of muscle biology in sheep and provide a theoretical foundation for future research into the regulatory mechanisms governing muscle development.