Circ2388 regulates myogenesis and muscle regeneration.

The formation of skeletal muscle is a complex process that is coordinated by many regulatory factors, such as myogenic factors and noncoding RNAs. Numerous studies have proved that circRNA is an indispensable part of muscle development. However, little is known about circRNAs in bovine myogenesis. In this study, we discovered a novel circRNA, circ2388, formed by reverse splicing of the fourth and fifth exons of the MYL1 gene. The expression of circ2388 was different between fetal and adult cattle muscle. This circRNA is 99% homologous between cattle and buffalo and is localized in the cytoplasm. Thoroughly, we proved that circ2388 had no effect on cattle and buffalo myoblast proliferation but promotes myoblast differentiation and myotube fusion. Furthermore, circ2388 in vivo stimulated skeletal muscle regeneration in mouse muscle injury model. Taken together, our findings suggest that circ2388 promotes myoblast differentiation and promotes the recovery and regeneration of damaged muscles.