Fig. 5

Zebrafish larvae treated with MLN4924 are more sensitive to SVCV infection. (A)Representative images of zebrafish larvae (3 dpf), both uninfected and infected with SVCV for 24 h, after treatment with the vehicle (DMSO; the control) or MLN4924 (1 μM). Dead larvae (indicated with red arrows) were characterized by a lack of movement, absence of blood circulation, and bodily degeneration. (B) Survival ratios indicated that zebrafish larvae treated with MLN4924 were more sensitive to SVCV infection than were larvae treated with vehicle (DMSO). Zebrafish larvae (3 dpf; n = 90 in total) were infected with SVCV (2 × 10⁸ TCID₅₀/ml) after pretreatment with either vehicle (DMSO) or MLN4924 (1 μM); this experiment was repeated three times (n = 30 for each). We counted the numbers of dead larvae at 8, 16, 24, 32, 40, and 48 h post-infection. (C–E) Viral replication was much greater in SVCV-infected zebrafish larvae treated with MLN4924 (1 μM), as compared with the control. Zebrafish larvae were infected with SVCV after pretreatment with either vehicle (DMSO; the control) or MLN4924 (1 μM). After incubation for 24 h, we used qRT-PCR assays to determine the expression levels of the SVCV genes P (C), G (D), and N genes (E). Data are shown as mean ± SEM of three independent experiments, each performed in triplicate; the statistical analysis was performed using GraphPad Prism 5 (unpaired t-test).