Résumé
This quantitative ultrastructural survery of E. histolytica locomotion in Boyden chambers supports the concept that this parasitis is capable of random, chemokinetic and chemotactic motility. An E. histolytica committed to chemotaxis will flatten over the filter, accumulate smaller vacuoles at the front of the cell, and will also project pseudopods and 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 orientation (chemotaxis). Finally, only on of the 11 features that were analyzed (i.e., number of vacuoles) failed to be distinctly associated with any of the movement forms studied. E. histolytica appears to possess the full repertoire of locomotion modalities observed in free moving eukaryots, and its motility translates into ultrastructural landmarks that could be useful indicators of subcellular events related to locomotion