Quantitative analysis of Plasmodium ookinete motion in three dimensions suggests a critical role for cell shape in the biomechanics of malaria parasite gliding motility

摘要: Motility is a fundamental part of cellular life and survival, including for Plasmodium parasites--single-celled protozoan pathogens responsible human malaria. The motile cycle forms achieve motility, called gliding, via the activity an internal actomyosin motor. Although gliding based on well-studied system actin myosin, its core biomechanics are not completely understood. Currently accepted models suggest it results from specifically organized motor that produces rearward directional force. When linked to surface-bound adhesins, this force passaged cell posterior, propelling parasite forwards. Gliding motility observed in all three stages Plasmodium: sporozoites, merozoites ookinetes. However, only ookinetes--formed inside midgut infected mosquitoes--that display continuous without necessity host entry. This makes them ideal candidates invasion-free biomechanical analysis. Here we apply plate-based imaging approach study ookinete motion three-dimensional (3D) space understand how movement facilitates colonization. Using single-cell tracking numerical analysis 3D, our demonstrates ookinetes move with conserved left-handed helical trajectory. Investigation morphology suggests trajectory may be subpellicular cytoskeleton, complementary whole subcellular electron microscopy showing that, like their paths, share corkscrew shape underlying twisted microtubular architecture. Through comparisons 3D between wild-type cytoskeleton-knockout mutant demonstrate perturbation changes broadly linear. Therefore, while precise linkages architecture organization remain unknown, molecular basis may, addition force, key adaptive strategy malaria dissemination and, as such, transmission.