CRISPR/Cas9 system-based myostatin-targeted disruption promotes somatic growth and adipogenesis in loach, Misgurnus anguillicaudatus

Abstract The mud loach (Misgurnus anguillicaudatus) is one of the most important aquaculture fishes in Asia. The application of the CRISPR/Cas9 system in the cultivation of loach strains with valuable economic traits presents great potential. Myostatin is a candidate factor that can be used for the cultivation of fast-growing loach strains. In this study, the appropriate microinjection dose of the Cas9 protein (600 pg) for genome editing was determined considering both the mutation rate and survival rate of loach embryos. With this microinjection dose of the Cas9 protein, both the exogenous GFP and endogenous myostatin genes were efficiently edited using the CRISPR/Cas9 system. Compared with that in wild-type siblings, the average body weight of the fish in 1-, 2- and 3-month-old myostatin mutant chimeric loaches was significantly increased by 34.9% (P