Possible conversion of axonemal microtubules to pellicular microtubules in Trypanosoma gambiense treated with vinblastine, colchicine plus concanavalin A.

Abstract

The effects of vinblastine alone and in combination with vinblastine, colchicine and concanavalin A on microtubules of Trypanosoma gambiense cultured in vitro were studied ultrastructurally. Trypanosomes treated with vinblastine at 20 micrograms/ml, showed fusion of the extracellular flagellum with the plasma membrane of the parasite. As a result, the axoneme with the paraxial rod in the extracellular flagellum was taken into the cytoplasm. Although the axonemal and pellicular microtubules in T. gambiense differ in function and origin, the axonemal microtubules of the extracellular flagellum that was taken into the cytoplasm could be converted to pellicular microtubules by treatment with a combination of vinblastine (20 micrograms/ml), concanavalin A (10 micrograms/ml) and colchicine (100 micrograms/ml).