title: Synchronous expression of individual metacyclic variant surface glycoprotein genes in Trypanosoma brucei.
abstract: One distinctive feature of the Trypanosoma brucei life cycle is the presence of two discrete populations that are based on differential expression of variant surface glycoproteins (VSGs). Both are adapted to the environmental pressures they face and more importantly, both contribute directly to transmission. Metacyclics in the tsetse fly enable transmission to a new mammalian host, whereas bloodstream trypanosomes must avoid immune destruction to the extent that sufficient numbers are available for transmission, when the insect vector takes a blood meal. At present, there are few investigations on the molecular aspects of parasite biology in the tsetse vector and specifically about the activation of metacyclic VSG gene expression. Here we used an established in vitro differentiation system based on the overexpression of the RNA-binding protein 6 (RBP6), to monitor two metacyclic VSGs (VSG 397 and VSG 653) during development from procyclics to infectious metacyclic forms. We observed that activation of these two mVSGs was simultaneous both at the transcript and protein level, and manifested by the appearance of only one of the mVSGs in individual cells.
authors.affiliation: Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06536, USA.
authors.forename: Kiantra
authors.initials: K
authors.lastname: Ramey-Butler
authors.affiliation: Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06536, USA; Department of Cell Biology, Yale School of Medicine, New Haven, CT 06536, USA.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Ullu
authors.affiliation: Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06536, USA. Electronic address: nikolay.kolev@yale.edu.
authors.forename: Nikolay G
authors.initials: NG
authors.lastname: Kolev
authors.affiliation: Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT 06536, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Tschudi
mesh_terms: D005786:Gene Expression Regulation; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008018:Life Cycle Stages; D011401:Promoter Regions, Genetic; D014346:Trypanosoma brucei brucei / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D014353:Trypanosomiasis, African / Q000469:parasitology*; D014643:Variant Surface Glycoproteins, Trypanosoma / Q000235:genetics* / Q000378:metabolism
chemical_list: D014643:Variant Surface Glycoproteins, Trypanosoma
keywords: Gene activation; Gene expression; Metacyclics; Surface coat; Trypanosoma brucei; VSG