Abstract
African trypanosomes evade the host immune response by periodically switching their variant surface glycoprotein (VSG) coat1–3. The resulting, serologically distinct variant antigenic types (VATs) appear in a loosely ordered sequence and those arising early in infections are termed predominant VATs4–8. VAT switching reflects the successive transcriptional activation of single VSG genes from a large repertoire. Activation of some VSG genes is accomplished by duplication of a previously silent basic copy (BC) gene and insertion of this expression linked copy (ELC) near a chromosomal telomere where it is expressed9–16. However, other VSG genes, always located near a telomere, use a non-duplication activation (NDA) mechanism16–19. We report here that the gene encoding the predominant IsTat 1.A VSG can be activated with or without duplication. Four of six independently derived clones activated the 1.A gene without gene duplication or detectable rearrangement. The other two contained an active 1.A ELC, possibly generated by a gene conversion extending to the end of the telomere. The ability to utilize both NDA and ELC mechanisms of gene activation and perhaps an alternative mechanism for gene duplication may account for the fact that VAT l.A is the most predominant VAT of the IsTaR 1 serodeme.
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References
Cross, G. A. M., Holder, A. A., Allen, G. & Boothroyd, J. C. Am. J. trop. Med. Hyg. 29, 1027–1032 (1980).
Borst, P. & Cross, G. A. M. Cell 29, 676–679 (1982).
Marcu, K. B. & Williams, R. O. in Genetic Engineering Vol. 3 (eds Setlow, J. K. & Hollander, A.) T129–T155 (Plenum, New York, 1981).
Gray, A. R. Ann. trop. Med. Parasit. 56, 4–13 (1962).
Van Meirvenne, N., Janssens, P. G. & Magnus, E. Ann. Soc. Belg. Med. trop. 55, 1–23 (1975).
Capbern, A., Giroud, C., Baltz, T. & Mattern, P. Expl Parasit. 42, 6–13 (1977).
Miller, E. N. & Turner, M. J. Parasitology 82, 63–80 (1981).
Hajduk, S. L. & Vickerman, K. Parasitology 83, 609–621 (1981).
Hoeijmakers, J. H. J., Frasch, A. C. C., Bernards, A., Borst, P. & Cross, G. A. M. Nature 284, 78–80 (1980).
Agabian, N., Thomashow, L., Milhausen, M. & Stuart, K. Am. J. trop. Med. Hyg. Suppl. 29, 1043–1049 (1981).
Pays, E., Van Meirvenne, N., Le Ray, D. & Steinert, M. Proc. natn. Acad. Sci. U.S.A. 78, 2673–2677 (1981).
Pays, E., Lhereux, M. & Steinert, M. Nature 292, 265–267 (1981).
Bernards, A. et al. Cell 27, 497–505 (1981).
De Lange, T. & Borst, P. Nature 299, 451–453 (1982).
Milhausen, M. et al. Molec. Biochem. Parasit. 9, 241–254 (1983).
Parsons, M. et al. Molec. Biochem. Parasit. 9, 255–269 (1983).
Williams, R. O., Young, J. R. & Majiwa, P. A. O. Nature 282, 847–849 (1979).
Majiwa, P. A. O., Young, J. R., Englund, P. T., Shapiro, S. Z. & Williams, R. O. Nature 297, 514–516 (1982).
Young, J. R., Donelson, J.E., Majiwa, P. A. O., Shapiro, S. Z. & Williams, R. O. Nucleic Acids Res. 10, 803–819 (1982).
Stuart, K. et al. J. Parasit. (in the press).
Borst, P. in Mobile Genetic Elements (ed. Shapiro, J. A.) 619–656 (Academic, New York, 1983).
Miller, E. N., Williams, R. O. & Turner, M. J. Nature 306, 196–198 (1983).
Myler, P., Allison, J., Agabian, N. & Stuart, K. Cell (submitted).
Longacre, S. et al. Molec. cell Biol. 3, 399–409 (1983).
Laurent, M. et al. Nature 302, 263–266 (1983).
Boothroyd, J. C. & Cross, G. A. M. Gene 20, 281–289 (1982).
Van der Ploeg, L. H. T. et al. Nucleic Acids Res. 10, 3591–3604 (1982).
Nelson, R. G. et al. Cell 34, 901–909 (1983).
DeLange, T. et al. Cell 34, 891–900 (1983).
Parsons, M., Nelson, R. G., Stuart, K. & Agabian, N. Proc. natn. Acad. Sci. U.S.A. 81, 684–688 (1984).
Van der Ploeg, L. H. T., Bernards, A., Rijsewijk, F. A. M. & Borst, P. Nucleic Acids Res. 10, 593–609 (1982).
Pays, E., Lihereux, M. & Steinert, M. Nucleic Acids Res. 10, 3149–3163 (1982).
Raibaud, A. et al. Proc. natn. Acad. Sci. U.S.A. 80, 4306–4310 (1983).
Pays, E. et al. Cell 35, 721–731 (1983).
Southern, E. M. J. molec. Biol. 98, 503–517 (1975).
Smith, G. E. & Summers, M. D. Analyt. Biochem. 109, 123–129 (1980).
Wahl, G. M., Stern, M. & Stark, G. R. Proc. natn. Acad. Sci. U.S.A. 73, 3683–3687 (1979).
Rigby, P. W. J., Dickermann, M., Rhodes, C. & Berg, P. J. molec. Biol. 113, 237–251 (1977).
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Myler, P., Nelson, R., Agabian, N. et al. Two mechanisms of expression of a predominant variant antigen gene of Trypanosoma brucei. Nature 309, 282–284 (1984). https://doi.org/10.1038/309282a0
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DOI: https://doi.org/10.1038/309282a0
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