Figure 4

Both NSC697923 and rapamycin treatment affect parasite growth. (a) Parasite growth over two cycles of intraerythrocytic development for DMSO-, rapamycin- or NSC697923-treated parasites. Synchronised parasite populations (0.2% parasitemia) were treated with either DMSO (control), rapamycin (to induce excision within ubc13) or NSC697923 (to inhibit UBC13), and parasitemia was measured for two cycles by FACS analysis. The data shown are mean ± SEM from triplicate experiments. The parasitemia in both rapamycin and NSC697923-treated parasite culture was significantly lower than that of the control at both cycle 1 and cycle 2. (** p < 0.001) (b) Analysis by microscopy of Giemsa-stained parasites at 24, 44, 49 and 69 h post-invasion. All parasites develop to schizonts but further development of both rapamycin- and NSC697923-treated parasites is delayed: at 49 and 69 h PI control parasites have formed new ring stage and trophozoite stages, whereas both rapamycin and NSC697923-treated parasites are largely schizont and early ring stages at these two time points. Scale bar is 5 µm.