The penetration of the salivary glands of Rhodnius prolixus by Trypanosoma rangeli.

Ultrastructural studies of the mechanism of penetration of the salivary gland of the reduviid bug Rhodnius prolixus by Trypanosoma rangeli showed that trypanosomes from the haemocoele penetrate the outer "membranes" of the gland flagellum foremost, disrupting the inner layers, to pass between the muscle cells to reach the gland cell basement membrane. This latter is also penetrated flagellum foremost, the parasite invaginating the gland cell plasmalemma beneath, to create a vacuole in which the trypanosome crosses the gland cells to reach the central lumen, often only losing its containing vacuole just before leaving the cell. The structure of the outer "membranes" surrounding the salivary gland appearland cells. These outer "membranes" were found to enclose large numbers of multinucleate "giant form" trypanosomes, whose significance is as yet unknown, but could perhaps represent a stage in the life cycle of the parasite where genetic interchange could take place.