Characterization And Potential Role of Myod  On Myogenesis And Muscle Growth In  Shrimp Fenneropenaeus Chinensis

Abstract

The myogenic differentiation factor D (MyoD) plays a pivotal role in regulating myogenesis and adult skeletal muscle growth. This study first characterized and investigated the potential roles of MyoD (FcMyoD) on myogenesis and muscle growth in Fenneropenaeus chinensis that was an economically and nutritionally important shrimp. The full-length cDNA of FcMyoD was 1484 bp in length, encoding 210 amino acids. The expression profiles during five developmental stages revealed that FcMyoD was barely detectable at the gastrula stage but maintained consistently high expression from the nauplius to the post-larval stage along with myogenesis. In addition, FcMyoD was expressed most strongly in muscle and at lower levels in other tissues. Moreover, muscle expression was significantly higher in the larger individuals compared to the small individuals. After 36 days of continuous RNA interference (RNAi), the growth rate of RNAi group with down-regulating FcMyoD decreased significantly. Tissue sections revealed an irregular arrangement of muscle fibers, enlarged intercellular spaces, and a loose structure of RNAi group. These findings suggest the involvement of FcMyoD in myogenesis and muscle growth. The information presented in this study will be valuable for future research aiming to clarify the role of MyoD in myogenesis and muscle growth in shrimp, and provides an important target gene for breeding high-producing shrimp.

Keywords: MyoD, myogenesis, muscle growth, Shrimp