title: Amoeboid locomotion of Acanthamoeba castellanii with special reference to cell-substratum interactions.
abstract: The amoeboid locomotion of Acanthamoeba castellanii has been studied by observation of individual cells moving on a planar glass substratum. Cell-substratum interactions involved in traction have been observed by reflexion interference microscopy. A variable part of the ventral surface of A. castellanii formed a protean platform, the 'associated contact', from which filopodia were subtended; these established stable, focal adhesions (approximately 0.4 micron diameter) on the substratum beneath. Surprisingly, acanthopodia, a prominent feature of this protozoon, did not play an obvious role in traction. The dimensions of the cell-substratum gap in the associated contact could be modulated by the concentration of ambient electrolyte. Dilution of electrolyte from 50 mM-KC1 to 2mM resulted in (i) an increase in the cell-substratum gap, (ii) a marked decrease in cell motility, (iii) reduced cell adhesion to glass.
mesh_terms: D000268:Adhesiveness; D000656:Amoeba / Q000166:cytology / Q000502:physiology*; D000818:Animals; D002465:Cell Movement / Q000187:drug effects; D004573:Electrolytes / Q000494:pharmacology; D008124:Locomotion; D008857:Microscopy, Interference; D008858:Microscopy, Phase-Contrast; D014741:Video Recording
chemical_list: D004573:Electrolytes