Figure 6.

Induction of cell apoptosis and bioassays against different fly strains. (a) Annexin V-FITC staining assay. The S2 cells were incubated with or without MrM35-4 for 1 h and then harvested in PBS buffer by staining with the FITC-conjugated annexin V and PI (propidium iodide) for 30 min in dark. The dying cells could bind annexin V-FITC showing green staining, and those cells that lost membrane integrity could be stained by PI in red. (b) Trypan blue staining. The S2 cells were incubated with or without MrM35-4 for 3 h and then stained with trypan blue for 10 min. (c) Comparison of apoptotic cells between mock control and MrM35-4 treatments. Apoptotic cells were counted after trypan blue staining. **, t-test, P = 0.0011. (d) Survival of the wild-type, PPO1^∆, PPO2^∆, and PPO1^∆PPO2^∆ mutants of D. melanogaster after topical infection with the WT and different mutants of M. robertsii.