Fig. 1: P. knowlesi as a model to delineate steps of RBC invasion.

a Flow chart shows outcomes of all merozoite-human RBC interactions from 20 schizonts, 0–200 s post egress. ‘Interaction’ = RBC contact lasting ≥2 s. Gliding interaction = forward movement across RBC surface ≥5 s. Events per category indicated in parentheses. b RBC deformation scores for human (left) or macaque (right) interactions based on extent of merozoite indentation/wrapping. 0 = no deformation; 1 = shallow indentation/membrane pinching; 2 = deeper indentation to the side of RBC/intermediate level of host cell membrane pinching around parasite; 3 = full host cell wrapping around merozoite. Bar chart indicates a breakdown of deformation scores for interactions from merozoites which never invade (non), intermediate interactions from merozoites that will invade on subsequent contacts (‘Int’), interactions leading directly to invasion (Inv), and all merozoite-RBC interaction (all). c Supplementary movie 1 stills. Panel 1 shows RBC recovering from deformation and merozoite’s apical end firmly attached to the RBC membrane. White arrow tip indicates merozoite apex. Panels 2-4 show the merozoite pivoting on apical end (white curved arrow), until re-orientation is complete. d Supplementary movie 3 stills. Pk merozoite displays a fluorescent signal between apex and Fluo-4-AM loaded RBC as gliding (red arrows = direction) comes to a pause (panel 4), but before re-orientation begins (panel 6). e Summary schematic depicting order and timings of each step of invasion. For all images, scale bars = 5 μm. Source data for (b) and (e) are provided as a Source Data file.