Dynamic profiling of myogenesis in developing ovine skeletal muscle

Understanding the mechanisms of embryonic and fetal myogenesis in farm animals is pivotal as muscle fiber characteristics are crucial for meat production. Herein, histocytology and transcriptome analyses of ovine skeletal muscle were performed at 11 time points spanning from early embryo to the stage before birth to identify the characteristics of ovine myoblast and myofiber formation at different developmental stages. Two waves of myogenesis corresponding to primary and secondary myofiber generation, myogenesis transition, and residence of satellite cells (SCs) were detected. Temporal histocytology analysis revealed the developmental hierarchies of myogenesis, including myogenic determination, primary and secondary myofiber formation, myofiber growth and maturation, and the onset of SC generation. Transcriptomic profiling delineated gene expression patterns during fetal muscle development, revealed the gene clusters involved in distinct developmental phases. The findings of this study collectively provide substantial evidence for and insights into the mechanism of programming myogenesis of ovine skeletal muscle.