Open AccessDNA rearrangements and antigenic variation in Trypanosoma equiperdum: multiple expression-linked sites in independent isolates of trypanosomes expressing the same antigen.
Author(s) -
Shirley Longacre,
Urszula Hibner,
A Raibaud,
Harvey Eisen,
Théo Baltz,
Christian Giroud,
D Baltz
Publication year - 1983
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.3.3.399
Subject(s) - biology , antigenic variation , gene , gene duplication , genetics , trypanosoma , complementary dna , trypanosoma brucei , antigen , microbiology and biotechnology , dna , genomic dna
African trypanosomes resist the immune response of their mammalian hosts by varying the surface glycoprotein which constitutes their antigenic identity. The molecular mechanism of this antigenic variation involves the successive activation of a series of genes which code for different variant surface glycoproteins (VSGs). We have studied the expression of two VSG genes (those of VSG-1 and VSG-28) in Trypanosoma equiperdum, and we report the following findings. (i) The expression of both VSG genes is associated with the duplication and transposition of corresponding basic copy genes. (ii) The duplicated transposed copy appears to be the expressed copy. (iii) Although there are multiple genes which cross-hybridize with the VSG-1 cDNA probe, only one of these appears to be used as a template for the expression-linked copy in four independent BoTat-1 clones. (iv) Analysis of the genomic environments of the expressed VSG-1 genes from each of four independently derived BoTat-1 trypanosome clones revealed that there are at least three different sites into which the expression-linked copy can be inserted.