Orientations of filaments used for simulation experiments. A. The plasma membrane (blue) and IMC (yellow) of a slightly flattened sporozoite resting on an EM grid are shown. The arrow indicates the direction of the electron beam. The black box indicates the area enlarged as side and top views in B. B. Cartoons illustrating the orientation of model filaments used for simulation experiments in figures 7 and 8. The red lines and dots represent side and top views of filaments, respectively. The top row shows views along the parasite axis. The bottom row shows views from the plasma membrane onto the IMC. Model I: filaments perpendicular to sporozoite axis and parallel to electron beam direction. Model II: filaments parallel to sporozoite axis and perpendicular to electron beam direction. Model III: filaments perpendicular to sporozoite axis and perpendicular to electron beam direction.