Branched Electron Transport Chain in Trypanosoma mega

THE life cycle of certain pathogenic African trypanosomes is characterized by a striking change in the mechanism of oxidative reactions on which the aerobic metabolism of the organism depends. Vertebrate bloodstream forms of Trypanosoma brucei group trypanosomes apparently depend on a non-mitochondrial, cyanide-insensitive α-glycerophosphate oxidase system¹. Cells which become established when trypanosomes are grown in culture resemble those found in the insect vector. Early reports on the metabolism of these culture forms described a cyanide-sensitive terminal respiration², associated with the presence of a complex mitochondrial network^3,4 and cytochrome pigments^2,5,6. The only reports of cyanide-insensitive respiration in culture forms have been for recently transformed Trypanosoma brucei^7,8 and Trypanosoma mega⁹.