Transgenic red carp (Cyprinus carpio) with LcMSTN1 propeptide: Enhanced growth and unchanged muscle fat content

Growth and meat quality are concerned issues in aquaculture. The inhibition of MSTN can lead to significant muscle proliferation in mammals, as well as a decrease in muscle fat content. In fish, the effect of MSTN inhibition on muscle fat content is ambiguous. In this study, we constructed transgenic red carp with Larimichthys crocea MSTN1 propeptide (LcMSTN1 propeptide) to study how the inhibition of MSTN1 affects the growth and muscle fat content in fish. Southern Blotting showed that LcMSTN1 propeptide was integrated into the red carp genome. In muscle tissue, the expression of MSTN1 propeptide in transgenic red carp was significantly higher than that of non-transgenic red carp (P < 0.001). The mRNA levels of growth-related genes, MyoD, MyoG and MyHC, in the muscle tissue of transgenic red carp were also significantly higher than those in non-transgenic red carp (P < 0.01). However, there was no significant difference in both muscle fat content and the mRNA levels of lipid metabolism-related genes FAS and LPL between transgenic and non-transgenic red carps. Microscopical observation showed that the muscle fiber diameter in transgenic red carp was significantly larger than that of nontransgenic red carp, implying hypertrophy of muscle fibers. These results indicate that LcMSTN1 propeptide can promote the muscle growth, and does not affect muscle fat content in transgenic red carp, which is different from mammals.

Automated summary

The inhibition of MSTN1 in transgenic red carp promoted muscle growth without affecting muscle fat content, which differs from mammals. The study found that the expression of MSTN1 propeptide and growth-related genes were significantly higher in transgenic red carp, indicating muscle hypertrophy.