Morphological changes in Trypanosoma congolense after proteolytic removal of the surface coat.

Bloodstream forms of Trypanosoma congolense were exposed to proteases at various concentrations, and the consequences of this treatment were continuously examined by electron microscopy. Unexpectedly, proteolysis did not simply result in the removal of the surface coat, but in dramatic morphological changes characterized by membrane adhesions, subsequently leading to flagella/plasmamembrane and to plasmamembrane/plasmamembrane fusions. The resulting axonemal internalization and rearrangement of cell organelles were followed by profound changes in cell shape. The axonemal motility, however, was maintained.