Identification and Characterization of Follistatin-Related Protein-1 Involved in the Regulation of Chinese Perch Skeletal Muscle Hyperplasia

Follistatin-related protein (FSRP), which belongs to a member of the follistatin family, has been postulated to be a new negative regulator of myostatin (MSTN) and is involved in muscle development. In this study, we cloned the complete cDNA sequence of FSRP-1 from Chinese perch muscle. FSRP-1 mRNA was highly expressed in the fast muscle and brain tissue of adult fish. The expression of FSRP-1 rapidly increased at 90 days post hatching (dph) in the fast muscle of Chinese perch. Furthermore, to investigate the roles of FSRP-1 in muscle growth, we constructed a FSRP- 1 expression vector and isolated FSRP-1 fusion protein. The purified FSRP-1 fusion protein was injected into the muscle tissues of the Chinese perch (90 dph). The results showed that the number of muscle fibers and the satellite cell activation frequency were increased in the FSRP-1 treatment group. In addition, the myostatin (MSTN) expression was significantly decreased upon the FSRP-1 treatment. Collectively, the results suggest a possible mechanism of the FSRP-1 for inhibiting MSTN activity and enhancing muscle growth and renewal in vivo, and it may provide an applicable implication for the defected muscle repairing and regeneration.