Trypanosoma brucei: Biochemical and morphological changes during in vitro transformation of bloodstreamto procyclic-trypomastigotes

Trypanosoma brucei brucei in whole rat blood inoculated into a semidefined medium undergoes complete morphological transformation (observed by light microscopy) in 72 hr. This reproducible system permits the biochemical and physiological study of transformation from bloodstream to procyclic trypomastigotes and mitochondrial biogenesis in these organisms. Infectivity for mice is lost after 6 days. Proline stimulates cell growth after transformation. High levels of glucose adversely affect the growth of transforming cells. Respiration during transformation is by an α-glycerophosphate oxidase although a cyanide-sensitive pathway is present after 24–48 hr but does not become fully functional with respect to procyclic trypomastigotes until 20–24 days in culture. The success of this system will permit the biochemical characterization of African trypanosomes as the development of the cytochrome system occurs.