Plasmodium Protease ROM1 Is Important for Proper Formation of the Parasitophorous Vacuole
Figure 8
Ultrastructural analysis of pyrom1(-) parasites reveals an abnormal parasitophorous vacuole.
(A) Representative electron micrograph images of intracellular parasites developing within a Hepa 1–6 host cell at 4 hours post invasion. Inset shows a close up of the boundary between the parasite and the host cell cytoplasm. Notice the expanded PV space appearing like a halo (*) in the wildtype parasite and a tight fitting PVM with reduced PV space in the R1KO parasite. Scale bars are equal to 0.5 µm. Abbreviations: SPZ-sporozoite, hC- Host cell cytoplasm, hN- Host cell nucleus, PVM- Parasitophorous vacuole membrane, PV-Parasitophorous vacuole space, PPM- Parasite Plasma Membrane, IMC- Inner Membrane Complex. (B)) Quantification of PV space area (halo area) and parasite area was carried out using ImageJ software. The ratio of halo area/parasite area ± SEM for Wildtype parasites (Wt Ctrl) was 0.168±0.017 (N = 38) and for R1KO parasites was 0.094±0.013 (N = 44). Statistics was carried out using One-way ANOVA analysis. (C) The graph shows the distribution of the parasite population as a function of the ratio halo area/parasite area between wildtype (Wt Ctrl) and pyrom1(-) (R1KO). A shift in the R1KO population towards a smaller ratio (>0.00 to 0.05) is observed and is denoted by an asterisk (*).