Expression profiles of the p38 MAPK signaling pathway from Chinese shrimp I Fenneropenaeus chinensis in response to viral and bacterial infections

Mitogen-activated protein kinase (MAPK) signaling pathway plays an important role in cellular response to inflammatory cytokines, environmental stress and pathogenic infection, However, compared with mammals and insects, the potential function of p38 MAPK from Chinese shrimp (Fenneropenaeus chinensis) in response to viruses and bacterial infection is limited. In the study, the immune responses of four genes MKK3, MKK4, p38 and ATF-2 from F. chinensis were investigated in defending against white spot syndrome virus (WSSV), Vibrio anguillarum (V. anguillarum) and Staphylococcus aureus (S. aureus) infection. Results demonstrated that the expression levels of these four genes were apparently modulated in hemocytes and gills when shrimp were stimulated by WSSV or bacteria, particularly at 3-24 h after infection. MKK3, p38 and ATF-2 were most sensitive to V. anguillarum (Gram-negative bacteria), followed by WSSV and S. aureus (Gram-positive bacteria), while MKK4 gene was most sensitive to S. aureus, followed by WSSV and V. anguillarum. Knockdown of Fcp38 by RNA interference (RNAi) resulted in a reduction in the expression of FcMKK3 and FcATF-2. The results indicate that p38MAPK signaling pathway plays a role in defending against viral and bacterial infections in F. chinensis.