A new aspect of the morphological transformation of Trypanosoma cruzi brought about by environmental variation.

The development of Trypanosoma cruzi has been described both in vertebrate and invertebrate hosts, and the morphological transformations of the parasite have been studied in both cell-free cultures and tissue cultures. The investigators who studied this topic have emphasized the fact that the morphogenesis of T. cruzi may be associated with a series of factors. In the present study, we noted that when bloodstream trypomastigotes leave a vertebrate host reaching the digestive tract of triatomines through the blood sucking action of these vectors, specific culture by blood plating or maintenance of blood in physiological saline at different temperatures shows a phenomenon of trypanosome joining, with intensive movement of internal organelles (nucleus and kinetoplast) and junction at the kinetoplast level. Different situations may occur after this phenomenon, such as flagellate separation, passage of kinetoplast content from one individual to another, transformation into rounded elements that approach the pairs of agglomerate, or the formation of spherical elements similar to cyst-like bodies. When observed by light or phase-contrast microscopy, these bodies appear to be static and show inner structures moving in circles or in disorderly manner. On the basis of the molecular studies carried out by other authors, who observed that not all proteins synthetized from DNA are of immediate usefulness in the cell, but need to undergo activation by the action of another protein or of environmental variation, we may infer that T. cruzi, under adverse conditions, i.e. a change in habitat, may undergo transformations, taking on different forms for the exchange of genetic information for adaptation to the environment and for possible continuity of the evolutionary cycle.