THE ULTRASTRUCTURE OF ENTAMOEBA-HISTOLYTICA LOCOMOTION

This quantitative ultrastructural survey of E. histolytica locomotion in Boyden chambers supports the concept that this parasite is capable of random, chemokinetic and chemotactic motility. An E. histolytica co mmitted to chemotaxis will flatten over the filter, accumulate smaller vacuoles at the front of the cell, and will also project pseudopods a nd its polarized body towards and alongside the chemoattractant axis, respectively. Other cell features such as cell polarization, membrane ruffling, hyaline, total number of pseudopods and caudal displacement of the nucleus appear to be associated with the locomotion efforts as such, perhaps reflecting speed (chemokinesis) but irrespective of orie ntation (chemotaxis). Finally, only one of the 11 features that were a nalyzed (i.e., number of vacuoles) failed to be distinctly associated with any of the movement forms studied. E. histolytica appears to poss ess the full repertoire of locomotion modalities observed in free movi ng eukaryots, and its motility translates into ultrastructural landmar ks that could be useful indicators of subcellular events related to lo comotion.