The Regulatory Role of Myomaker in the Muscle Growth of the Chinese Perch (Siniperca chuatsi)

The fusion of myoblasts is a crucial stage in the growth and development of skeletal muscle. <i>Myomaker</i> is an important myoblast fusion factor that plays a crucial role in regulating myoblast fusion. However, the function of <i>Myomaker</i> in economic fish during posthatching has been poorly studied. In this study, we found that the expression of <i>Myomaker</i> in the fast muscle of Chinese perch (<i>Siniperca chuatsi</i>) was higher than that in other tissues. To determine the function of <i>Myomaker</i> in fast muscle, <i>Myomaker</i>-siRNA was used to knockdown <i>Myomaker</i> in Chinese perch and the effect on muscle growth was determined. The results showed that the growth of Chinese perch was significantly decreased in the <i>Myomaker</i>-siRNA group. Furthermore, both the diameter of muscle fibers and the number of nuclei in single muscle fibers were significantly reduced in the <i>Myomaker</i>-siRNA group, whereas there was no significant difference in the number of BrdU-positive cells (proliferating cells) between the control and the <i>Myomaker</i>-siRNA groups. Together, these findings indicate that <i>Myomaker</i> may regulate growth of fast muscle in Chinese perch juveniles by promoting myoblast fusion rather than proliferation.