MSG is involved in sperm gelatinolytic activity in the prawn, Macrobrachium rosenbergii

Proteases in male reproductive tract are considered to play key roles in fertilization processes. In contrast to mammals, there are limited data concerning crustacean sperm proteases. We previously identified a novel sperm gelatinase (MSG) from Macrobrachium rosenbergii that was inhibited by a male reproduction-related Kazal-type protease inhibitor (MRPINK) specifically. In the present study, MSG was found to be distributed on the vas deferens and terminal ampullae by Western blot. Immunohistochemical analyses revealed that MSG was expressed in secretory epithelial cells and sperm distributed mainly at the base zone. RNA interference (RNAi) mediated knock-down of MSG resulted in a marked loss of sperm gelatinolytic activity. Taken together, the results show that MSG is closely linked to and probably involved in the fertilization process.