A novel selection regime for differentiation defects demonstrates an essential role for the stumpy form in the life cycle of the African trypanosome.
A novel selection scheme has been developed to isolate bloodstream forms of Trypanosoma brucei, which are defective in their ability to differentiate to the procyclic stage. Detailed characterization of one selected cell line (defective in differentiation clone 1 [DiD-1]) has demonstrated that these cells are indistinguishable from the wild-type population in terms of their morphology, cell cycle progression, and biochemical characteristics but are defective in their ability to initiate differentiation to the procyclic form. Although a small proportion of DiD-1 cells remain able to transform, deletion of the genes for glycophosphatidyl inositol-phospholipase C demonstrated that this enzyme was not responsible for this inefficient differentiation. However, the attenuated growth of the Delta-glycophosphatidyl inositol-phospholipase C DiD-1 cells in mice permitted the expression of stumpy characteristics in this previously monomorphic cell line, and concomitantly their ability to differentiate efficiently was restored. Our results indicate that monomorphic cells retain expression of a characteristic of the stumpy form essential for differentiation, and that this is reduced in the defective cells. This approach provides a new route to dissection of the cytological and molecular basis of life cycle progression in the African trypanosome.
Tasker
M
M
School of Biological Sciences, University of Manchester, Manchester M13 9PT, United Kingdom.
Wilson
J
J
Sarkar
M
M
Hendriks
E
E
Matthews
K
K
D000156:Aconitic Acid / Q000494:pharmacology; D000349:Africa; D000818:Animals; D015415:Biomarkers; D001973:Bromodeoxyuridine / Q000378:metabolism; D002454:Cell Differentiation; D008058:Dihydrolipoamide Dehydrogenase / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics; D051379:Mice; D009154:Mutation; D019764:Phosphoenolpyruvate Carboxykinase (ATP) / Q000378:metabolism; D015800:Protozoan Proteins; D012641:Selection, Genetic; D014346:Trypanosoma brucei brucei / Q000187:drug effects / Q000502:physiology*; D010738:Type C Phospholipases / Q000235:genetics / Q000378:metabolism
D015415:Biomarkers; D008562:Membrane Glycoproteins; D015800:Protozoan Proteins; C053277:procyclic acidic repetitive protein, Trypanosoma; D000156:Aconitic Acid; D008058:Dihydrolipoamide Dehydrogenase; D010738:Type C Phospholipases; D019764:Phosphoenolpyruvate Carboxykinase (ATP); D001973:Bromodeoxyuridine