Abstract
African trypanosomes evade clearance in immune-competent hosts by periodically replacing their major surface glycoprotein with an antigenically different glycoprotein1–4. Expression of many of these variant surface glycoproteins (VSGs) is associated with the duplication and transposition of silent basic copy genes (BCs) into unlinked genomic expression sites5–10. The new expression-linked VSG gene copies (ELCs) are oriented with their 3′ ends proximal to chromosome telomeres11–14. Other VSG genes are activated without the production of an ELC10,15–18.The 3′ ends of these VSG genes are near chromosome telomeres both when they are active and when they are inactive. Recently, we have shown that activation of the VSG-1 gene in the BoTaR (Bordeaux trypanozoon antigen repertoire) serodeme of Trypanosoma equiperdum involves the duplication and transposition of a telomeric BC gene into one of at least three unlinked telomeric sites9. Here we show that the VSG-1 ELC is inactivated but not eliminated in some antigenic variants derived from a VSG-1 expressor. In addition, a subsequent variant that again expresses VSG-1 has not reactivated the residual VSG-1 ELC (R-ELC), but instead contains a new, active VSG-1 ELC in an unlinked telomeric site. These results show that the simple presence of an ELC in a potential expression site is not sufficient for its expression.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Vickerman, K. Nature 273, 613–617 (1978).
Cross, G. A. M. Proc. R. Soc. B202, 55–72 (1978).
Englund, P. T., Hajduk, S. L. & Marini, J. C. A. Rev. Biochem. 51, 695–726 (1982).
Capbern, A., Giroud, C., Baltz, T. & Mattern, P. Expl Parasit. 42, 6–13 (1977).
Hoeijmakers, J. H. J., Frash, A. C. C., Bernards, A., Borst, P. & Cross, G. A. M. Nature 284, 78–80 (1980).
Pays, E., Van Meirvenne, N., LeRay, D. & Steinert, M. Proc. natn. Acad. Sci. U.S.A. 78, 2673–2677 (1981).
Pays, E., Lheureux, M. & Steinert, M. Nature 292, 265–267 (1981).
Majiwa, P. A. O., Young, J. R., England, P. T., Shapiro, S. Z. & Williams, R. O. Nature 297, 514–516 (1982).
Longacre, S. et al. Molec. cell. Biol. 3, 399–409 (1983).
Borst, P. & Cross, G. A. M. Cell 29, 291–303 (1982).
Williams, R. O., Young, J. R. & Majiwa, P. A. O. Nature 299, 417–421 (1982).
De Lange, T. & Borst, P. Nature 299, 451–453 (1982).
Pays, E., Lheureux, 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).
Williams, R. O., Young, J. R. & Majiwa, P. A. O. Nature 282, 847–849 (1979).
Young, J. R., Shah, J. S., Matthyssens, G. & Williams, R. O. Cell 32, 1149–1159 (1983).
Young, J. R., Donelson, J. E., Majiwa, P. A. O., Shapiro, S. Z. & Williams, R. O. Nucleic Acids Res. 10, 803–819 (1982).
Donelson, J. E., Young, J. R., Dorfman, D., Majiwa, P. A. O. & Williams, R. O. Nucleic Acids Res. 10, 6581–6595 (1982).
Michels, P. A. M., Bernards, A., Van Der Ploeg, L. H. T. & Borst, P. Nucleic Acids Res. 10, 2353–2366 (1982).
Borst, P. et al. in Proc. Cetus-UCLA Meet. on Molec. Biol. of Host Parasite Interactions, Park City, Utah (eds Agabian, N. & Eisen, H.) (in the press).
Michels, P. A. M. et al. J. molec. Biol. (in the press).
Laurent, M. et al. Nature 302, 262–266 (1983).
Longacre, S. et al. Molec. cell. Biol. 3, 410–414 (1983).
Young, J. R., Turner, M. J. & Williams, R. O. in Proc. Cetus-UCLA Meet, on Molec. Biol. of Host Parasite Interactions, Park City, Utah (eds Agabian, N. & Eisen, H.) (in the press).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Buck, G., Longacre, S., Raibaud, A. et al. Stability of expression-linked surface antigen gene in Trypanosoma equiperdum. Nature 307, 563–566 (1984). https://doi.org/10.1038/307563a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/307563a0
- Springer Nature Limited