Fig. 3

Depletion of PPKL caused strong defects in parasite growth in vitro and in vivo. A, B The lytic cycle was examined by plaque formation assay. Tachyzoites (150 parasites/well) were tested on HFF host cell monolayers and allowed to grow in the absence or presence of auxin for 7 days (A). Plaque areas were scored for the TIR1, PPKL-AID, and the complementation line (B). Three independent experiments were performed in triplicate. Scale bar = 0.5 cm. C Parasite replication was assayed for three of the parasite lines. Parasites were allowed to grow in the absence or presence of auxin for 24 h, followed by IFA for scoring of vacuoles containing different numbers of individual parasites. Data were analyzed by two-way ANOVA with Tukey’s multiple comparisons. ****P < 0.0001 for different numbers of parasites/vacuoles. D Examples of the PPKL-AID parasites grown in auxin. Parasites exhibited deformed morphology with enlarged bodies and multiple nuclei. Scale bars = 2 μm. E, F Survival of mice infected with TIR1, PPKL-AID, and the complementation line (PPKL-COMP) in the absence and presence of auxin. Each mouse was infected with 100 tachyzoites, and five mice per cage were randomly grouped and supplied with either the vehicle or auxin. Six-week-old female BALB/c mice were used in the assay, and body weight and health were monitored daily. Three experiments were performed, and an example of the experiments is shown