par Pays, Etienne 
Référence Annales de parasitologie humaine et comparée, 65 Suppl 1, page (5-10)
Publication Publié, 1990
Référence Annales de parasitologie humaine et comparée, 65 Suppl 1, page (5-10)
Publication Publié, 1990
Article révisé par les pairs
| Résumé : | Although several hundred of different antigen genes exist in the trypanosome genome, only one is usually expressed at a time. This expression occurs in one of several possible telomeric expression sites. Besides being exclusively telomeric, transcription of the antigen gene exhibits other particular characteristics: the RNA polymerase is highly resistant to alpha-amanitin, and the transcription unit comprises several other genes, one of which may encode an adenylate cyclase. Post-transcriptional controls modulate the activity of this transcription unit during the parasite life-cycle. Antigenic variation is achieved through either alternative activation of different expression sites, or gene recombination within a given expression site. These mechanisms ensure a relative programming of antigen expression. |
