Figure 2

The interaction between viral miRNA and host STAT gene.

(A) The predicted target gene of WSSV-miR-22. The 3′UTR of the STAT gene could be targeted by WSSV-miR-22. (B) The direct interaction between viral miRNA and host gene. The synthesized WSSV-miR-22 mimic and the plasmid consisting of EGFP and shrimp STAT 3′UTR were co-transfected into insect High Five cells. The mutant of STAT 3′UTR (EGFP-∆STAT) was included in the co-transfection as a control. At 48 h after cotransfection, the fluorescence of cells was examined. The seed sequence targeted by WSSV-miR-22 was underlined. (C) Effects of WSSV-miR22 on the STAT gene expression. The relative fluorescence intensity of cells was determined. (D) The influence of WSSV-miR-22 overexpression on the expression of shrimp STAT gene in vivo. WSSV and WSSV-miR-22- mimic were co-injected into shrimp. As a control, WSSV only was included in the injections. At different time post-infection, the expression of STAT was examined with quantitative real-time PCR. (E) The effect of WSSV-miR-22 silencing on the STAT expression in vivo. AMO-WSSV-miR-22 was injected into WSSV-infected shrimp to knock down the WSSV-miR-22 expression. WSSV only was used as a control. At different time post-infection, the expression of STAT was detected with quantitative real-time PCR. Statistically significant differences between treatments were indicated by asterisks (**p < 0.01).