FIG 1.

Electron microscopic characterization of trophozoite-stage P. falciparum reveals three distinct HCs in IRBC. (A) Representative electron micrograph of an untreated trophozoite. The nucleus (Nuc), digestive vacuole (DV), mitochondria (Mito), and cytostome (Cyto) are indicated. (B to D) Typical 3D reconstructions of untreated trophozoites showing the parasite surface (dark blue), nucleus (light blue), DV (yellow), mitochondria (orange), hemoglobin-containing structures (red), and cytostomal collars (green). (B) 3D model of a parasite containing two cytostomes with collars (black arrowheads) (C) 3D model of a parasite with one cytostome and one phagotroph (black arrowhead) that contains hemoglobin but lacks a collar. (D) 3D model of a parasite with two cytostomes and an HCv (black arrowhead). (E) Bar graph illustrating the average number of various hemoglobin structures per parasite. Parasites have, on average, 2.65 cytostomes, 0.34 phagotrophs, and 0.25 hemoglobin vesicles. n = 15. (F) Graph comparing the percentages of single sections containing hemoglobin bodies in untreated parasites and permeabilized parasites that have been treated with SLO. HCv contain approximately 7% of the hemoglobin within a trophozoite. n = 600 sections. ***, P < 0.005. Scale bars, 500 nm.