Expression Patterns and Correlation Analyses of Myogenesis-Related Genes in Sheep Fetal Semitendinosus and...

This study explored the expression patterns and interrelationships of myogenesis-related genes in the Semitendinosus and Longissimus dorsi of sheep foetuses at different developmental stages. Haematoxylin and eosin (H&E) staining was used to observe the microstructure of both tissues. The expression and localization of MyoD, MyoG, Myomaker, and Glucocorticoid Receptor (GR) proteins were detected by immunohistochemistry. Quantitative real-time PCR and Western blotting were respectively used to detect the mRNA and protein expression of myogenesis-related genes (MyoD, MyoG, Myf5, Myf6, Pax3, Pax7, Myomaker, Myostatin, and GR) at different developmental stages. The correlations among myogenesis-related genes were analysed by the Pearson correlation coefficient. Finally, the regulatory elements and transcription factor binding sites in the 5' regulatory region of sheep myogenesis-related genes were predicted by bioinformatics analysis. Our results showed that the number and cross-sectional area of muscle fibres in Semitendinosus were lower than those in Longissimus dorsi. The expression patterns and correlations of myogenesis-related genes at the protein and/or mRNA levels were not entirely consistent between the two muscle groups, indicating the complexity of spatiotemporal regulation. The regulatory element analyses suggested that the potential self-, mutual, and cooperative transcriptional regulation relationships, either direct or indirect, existed among the myogenesis-related genes. The study provides a foundation for further exploring the gene regulatory mechanisms and molecular breeding strategies in sheep.