Switching trypanosome coats: what's in the wardrobe?
The African trypanosome Trypanosoma brucei is best known for its extraordinarily sophisticated antigenic variation of a protective variant surface glycoprotein (VSG) coat. T. brucei has >1000 VSG genes and pseudogenes, of which one is transcribed at a time from one of multiple telomeric VSG expression sites. Switching the active VSG gene can involve DNA rearrangements replacing the old VSG with a new one, or alternatively transcriptional control. The astonishing revelation from the T. brucei genome sequence is that <7% of the sequenced VSGs seem to have fully functional coding regions. This preponderance of pseudogenes in the VSG gene repertoire will necessitate a rethink of how antigenic variation in African trypanosomes operates.
Taylor
Jesse E
JE
Peter Medawar Building for Pathogen Research, University of Oxford, South Parks Road, Oxford OX1 3SY, UK.
Rudenko
Gloria
G
D000818:Animals; D000940:Antigenic Variation; D005786:Gene Expression Regulation; D018503:Genome, Protozoan; D011544:Pseudogenes; D014158:Transcription, Genetic; D014346:Trypanosoma brucei brucei / Q000235:genetics* / Q000276:immunology; D014643:Variant Surface Glycoproteins, Trypanosoma / Q000235:genetics* / Q000276:immunology
D014643:Variant Surface Glycoproteins, Trypanosoma