Liposome-Encapsulated Rec8 and Dmrt1 Plasmids Induce Red-Spotted Grouper (Epinephelus akaara) Testis Maturation

In fish, the maturity of gonads plays an important role in the development and reproduction of the population, and it also dictates the success of captive breeding. Therefore, finding ways to promote gonadal maturation is an important goal in aquaculture. In this study, we injected recombinant dmrt1 and rec8 overexpression plasmids packaged in liposomes into the immature testis of red-spotted grouper (Epinephelus akaara) and measured the expression of Dmrt1 and Rec8 protein in vivo. Gonadosomatic index (GSI) and gonadal histology analyses showed that the testis developed from the immature to the mature state within 7 days after plasmid injection. Additionally, the spermatozoa concentration and motility in plasmid-injected fish was the same as that of naturally mature fish. These results provided evidence that delivery of dmrt1 and rec8 expression plasmids into the testis via injection induced testis maturation in vivo.