Effects of substitution of fp25K genes on in vivo infection phenotypes. (A) Postmortem host degradation of BmNPV-infected larvae. B. mori larvae were subcutaneously injected with BVs from T3 or recombinant BmNPVs. Host degradation was assessed visually, and infected larvae were photographed at 7 dpi. (B) V-CATH secretion into the hemolymph of BmNPV-infected larvae. B. mori larvae were injected with BVs from T3 or recombinant BmNPVs, and hemolymph samples were collected at 4 dpi. Western blot analysis of the hemolymph samples was performed with anti-V-CATH antibody. The molecular masses of protein standards are indicated to the left. P, pro-V-CATH; M, mature form of V-CATH. (C) V-CATH activities of hemolymph samples from virus-infected larvae. Hemolymph samples from T3- or recombinant BmNPV-infected larvae at 4 dpi were assayed for V-CATH activity in the presence (black bars) or absence (white bars) of E64, a cysteine protease inhibitor. Data shown are means ± SD (n = 10). *, P < 0.05 by one-way ANOVA and Dunnett's posttests using T3 as a control. (D) Quantification of OB release into the hemolymph of BmNPV-infected larvae at 4 dpi. Data shown are means ± SD (n = 10). *, P < 0.05 by one-way ANOVA and Dunnett's posttests using T3 as a control.