Figure 3. Morphological comparisons of parasites with mutations in pfcrt compared with their parental controls.

(a) Parasites were synchronized by sorbitol lysis and areas of FVs and parasites (approximately 38 h post-invasion) were measured and expressed as ratios (A_FV/A_Parasite). 3D7, FCB and Dd2^Dd2 (open bars; n = 72, 31 and 42, respectively) and 3D7^L272F, FCB^C101F and Dd2^{Dd2 L272F} (closed bars; n = 84, 58 and 88, respectively) parasites were analyzed and significant enlargement of the FV was confirmed in 3D7^L272F, FCB^C101F and Dd2^{Dd2 L272F} parasites relative to 3D7, FCB and Dd2^Dd2, respectively (*p < 0.0001: two-tailed, unpaired, Student’s t-test). (b,c) Transmission electron micrographs of 3D7 and 3D7^L272F parasites, respectively, showing the food vacuole (FV) and nucleus (N). Note the enlarged electron lucent FV in 3D7^L272F (suggesting changes in the process of hemoglobin degradation and formation of hemozoin crystals). RBCs infected with 3D7^L272F displayed approximately 7.5-fold more knobs (arrowheads) on the host surface than 3D7-infected RBCs, although this is likely due to sub-population selection rather than a direct link to the mutation in pfcrt. (insert) Detail of a knob. Bars represent 1 μm (b,c) and 100 nm (insert).