Figure 2. Infection of cell monolayers by TgAMA1^KO tachyzoites.

(a) AMA1 immunostaining in RH Δhxgprt, TgAMA1^KO or TgAMA1^FLAG multiplying inside host cells. Scale bar, 5 μm. Plaque assay with HFF cells after 6 days is shown on the right for each strain. Cells are stained with Giemsa. Scale bar, 0.5 mm. (b) Plaque area induced on HFF cells after 7 days infection with WT or TgAMA1^KO tachyzoites. Mean area of ten plaques±s.d. is depicted, *P-value <0.0001 in unpaired Student’s t-test. (c) Pictures of HFF cell monolayers 20 h after co-infection with the ku80::diCre (non-fluorescent) and TgAMA1^KO (green) strains. Scale bar, 10 μm. (d) Quantification of parasites per vacuole after cell infection. (e) Quantification of egressed vacuoles. Data show mean±s.d. of three independent experiments. (f) Analysis of motility patterns. Data represent the mean±s.d. of helical or circular trails associated with parasites counted in 30 fields of view. (b, d–f) The colour codes are shown in panel e. DAPI, 4′,6-diamidino-2-phenylindole; KO, knockout.