Abstract
Some variable surface glycoprotein (VSG) genes of Trypanosoma brucei undergo duplication and transposition when they are expressed. We report here the cloning of cDNAs coding for two VSGs from the ILtar 1 repertoire. Analysis of the genomes of trypanosomes expressing these and other antigens shows that there is no additional copy of the sequences coding for eight VSG in expressing clones of trypanosomes, and reveals rearrangements analogous to those previously described for the gene for another VSG from this antigen repertoire. The data indicate that duplication does not accompany the expression of these VSG genes. Transposition to a specific expression site cannot be excluded, but would have to involve either a much larger segment of DNA, or movement to a region of much greater homology with the previous flanking sequences, than is observed for VSG genes that are duplicated when expressed. It is reasoned that the control of expression by coupled duplication and transposition is not sufficient to account for the selection of a single VSG gene for expression.
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- Agabian N., Thomashow L., Milhausen M., Stuart K. Structural analysis of variant and invariant genes in trypanosomes. Am J Trop Med Hyg. 1980 Sep;29(5 Suppl):1043–1049. doi: 10.4269/ajtmh.1980.29.1043. [DOI] [PubMed] [Google Scholar]
- Borst P., Frasch A. C., Bernards A., Hoeijmakers J. H., Van der Ploeg L. H., Cross G. A. The genes for variant antigens in trypanosomes. Am J Trop Med Hyg. 1980 Sep;29(5 Suppl):1033–1036. doi: 10.4269/ajtmh.1980.29.1033. [DOI] [PubMed] [Google Scholar]
- Buell G. N., Wickens M. P., Payvar F., Schimke R. T. Synthesis of full length cDNAs from four partially purified oviduct mRNAs. J Biol Chem. 1978 Apr 10;253(7):2471–2482. [PubMed] [Google Scholar]
- Cross G. A. Antigenic variation in trypanosomes. Proc R Soc Lond B Biol Sci. 1978 Jun 5;202(1146):55–72. doi: 10.1098/rspb.1978.0057. [DOI] [PubMed] [Google Scholar]
- Cross G. A. Immunochemical aspects of antigenic variation on trypanosomes. The third Fleming Lecture. J Gen Microbiol. 1979 Jul;113(1):1–11. doi: 10.1099/00221287-113-1-1. [DOI] [PubMed] [Google Scholar]
- Doyle J. J., Behin R., Mauel J., Rowe D. S. Antibody-induced movement of protozoan surface membrane antigens. Ann N Y Acad Sci. 1975 Jun 30;254:315–325. doi: 10.1111/j.1749-6632.1975.tb29181.x. [DOI] [PubMed] [Google Scholar]
- Grunstein M., Hogness D. S. Colony hybridization: a method for the isolation of cloned DNAs that contain a specific gene. Proc Natl Acad Sci U S A. 1975 Oct;72(10):3961–3965. doi: 10.1073/pnas.72.10.3961. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gubbins E. J., Maurer R. A., Hartley J. L., Donelson J. E. Construction and analysis of recombinant DNAs containing a structural gene for rat prolactin. Nucleic Acids Res. 1979 Mar;6(3):915–930. doi: 10.1093/nar/6.3.915. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hoeijmakers J. H., Frasch A. C., Bernards A., Borst P., Cross G. A. Novel expression-linked copies of the genes for variant surface antigens in trypanosomes. Nature. 1980 Mar 6;284(5751):78–80. doi: 10.1038/284078a0. [DOI] [PubMed] [Google Scholar]
- Paterson B. M., Roberts B. E., Kuff E. L. Structural gene identification and mapping by DNA-mRNA hybrid-arrested cell-free translation. Proc Natl Acad Sci U S A. 1977 Oct;74(10):4370–4374. doi: 10.1073/pnas.74.10.4370. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pays E., Lheureux M., Steinert M. Analysis of the DNA and RNA changes associated with the expression of isotypic variant-specific antigens of trypanosomes. Nucleic Acids Res. 1981 Sep 11;9(17):4225–4238. doi: 10.1093/nar/9.17.4225. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pays E., Lheureux M., Steinert M. The expression-linked copy of a surface antigen gene in Trypanosoma is probably the one transcribed. Nature. 1981 Jul 16;292(5820):265–267. doi: 10.1038/292265a0. [DOI] [PubMed] [Google Scholar]
- Pays E., Van Meirvenne N., Le Ray D., Steinert M. Gene duplication and transposition linked to antigenic variation in Trypanosoma brucei. Proc Natl Acad Sci U S A. 1981 May;78(5):2673–2677. doi: 10.1073/pnas.78.5.2673. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rougeon F., Kourilsky P., Mach B. Insertion of a rabbit beta-globin gene sequence into an E. coli plasmid. Nucleic Acids Res. 1975 Dec;2(12):2365–2378. doi: 10.1093/nar/2.12.2365. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sakano H., Hüppi K., Heinrich G., Tonegawa S. Sequences at the somatic recombination sites of immunoglobulin light-chain genes. Nature. 1979 Jul 26;280(5720):288–294. doi: 10.1038/280288a0. [DOI] [PubMed] [Google Scholar]
- Shapiro S. Z., Young J. R. An immunochemical method for mRNA purification. Application to messenger RNA encoding trypanosome variable surface antigen. J Biol Chem. 1981 Feb 25;256(4):1495–1498. [PubMed] [Google Scholar]
- Vickerman K. Antigenic variation in trypanosomes. Nature. 1978 Jun 22;273(5664):613–617. doi: 10.1038/273613a0. [DOI] [PubMed] [Google Scholar]
- Wickens M. P., Buell G. N., Schimke R. T. Synthesis of double-stranded DNA complementary to lysozyme, ovomucoid, and ovalbumin mRNAs. Optimization for full length second strand synthesis by Escherichia coli DNA polymerase I. J Biol Chem. 1978 Apr 10;253(7):2483–2495. [PubMed] [Google Scholar]
- Williams R. O., Marcu K. B., Young J. R., Rovis L., Williams S. C. A characterization of mRNA activites and their sequence complexities in Trypanosoma brucei: partial purification and properties of the VSSA mRNA. Nucleic Acids Res. 1978 Sep;5(9):3171–3182. doi: 10.1093/nar/5.9.3171. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Williams R. O., Young J. R., Majiwa P. A., Doyle J. J., Shapiro S. Z. Analyses of variable antigen gene rearrangements in Trypanosoma brucei. Am J Trop Med Hyg. 1980 Sep;29(5 Suppl):1037–1042. doi: 10.4269/ajtmh.1980.29.1037. [DOI] [PubMed] [Google Scholar]
- Williams R. O., Young J. R., Majiwa P. A., Doyle J. J., Shapiro S. Z. Contextural genomic rearrangements of variable-antigen genes in Trypanosoma brucei. Cold Spring Harb Symp Quant Biol. 1981;45(Pt 2):945–949. doi: 10.1101/sqb.1981.045.01.111. [DOI] [PubMed] [Google Scholar]