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Enzyme variation in Trypanosoma brucei spp. I. Evidence for the sub-speciation of Trypanosoma brucei gambiense

  • A. Tait (a1), Eldirdiri A. Babiker (a1) and D. Le Ray (a1)


Three groups of stocks of Trypanosoma brucei ssp, defined by the criteria of host, human serum resistance and place of isolation as T. b. gambiense, T. b. brucei (Nigeria) and T. b. brucei/rhodesiense (non-gambiense, Uganda) were screened for electrophoretic variation at 20 enzyme loci. One enzyme (Peptidase C) was found to differentiate all T. b. gambiense stocks from the other T. brucei stocks and, taken together with specific variants of 5 other enzymes, could be used to unambiguously define T. b. gambiense stocks. Using a population genetics approach, the frequencies of the different variants in the three groups of stocks were estimated and from them the average similarity and difference between groups were measured using the statistics of genetic identity (I) and genetic distance (D). These results show firstly, that T. b. gambiense is more different from the other two groups than they are from each other and, secondly, that the values of I and D obtained are consistent with T. b. gambiense constituting a sub- or sibling species of T. brucei. Three domestic animal isolates from Zaire and Cameroun were also screened for enzyme variation and two of these identified as T. b. gambiense, thereby establishing the existence of an animal reservoir host. In parallel, these stocks were tested for human serum resistance resulting in the same identification. Studies of the antigen repertoires and antigen gene structure were carried out by other workers on all the T. b. gambiense stocks reported here and the same conclusions reached as to the identification and ability to discriminate this subspecies from other groups of T. brucei stocks. The results presented here are discussed in relation to other published data on enzyme variation in T. brucei.



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Apted, F. I. C. (1970). The epidemiology of Rhodesian sleeping sickness. In The African Trypanosomiases (ed. Mulligan, H. W.), pp, 645660. London: Allen & Unwin.
Ayala, F. J., Tracy, M. L., Hedgecock, D. & Richmond, R. C. (1974). Genetic differentiation during the speciation process in Drosophila. Evolution 28, 576–92.
Borst, P., Van der Ploeg, M., Van Hoek, J. F. M., Tas, J. & James, J. (1982). On the DNA content and ploidy of trypanosomes. Molecular and Biochemical Parasitology 6, 1323.
Eldirdiri, A. B. & Le Ray, D. (1981). Adaptation of low virulence stocks of T. b. gambiense to rat and mouse. Annales de la Société belge de médecine tropicale 61, 51–9.
Ferguson, A. (1980). Biochemical Systematics and Evolution. Glasgow and London: Blackie.
Gibson, W., Marshall, T. F. De C. & Godfrey, D. G. (1980). Numerical analysis of enzyme polymorphism: a new approach to the epidemiology and taxonomy of trypanosomes of the subgenus Trypanozoon. Advances in Parasitology 18, 175246.
Gibson, W., Mehlitz, D., Lanham, S. M. & Godfrey, D. G. (1978). The identification of T. brucei gambiense in Liberian pigs and dogs by isoenzymes and resistance to human plasma. Tropenmedizin und Parasitologie 29, 335–45.
Godfrey, D. G. & Kilgour, V. (1976). Enzyme electrophoresis in characterising the causative organism of Gambian trypanosomiasis. Transactions of the Royal Society of Tropical Medicine and Hygiene 70, 219–24.
Harris, H. & Hopkinson, D. A. (1976). Handbook of Enzyme Electrophoresis in Human Genetics. Amsterdam: North Holland Publishing Company.
Hawking, F. (1976). The resistance to human plasma of Trypanosoma brucei, T. rhodesiense and T. gambiense. II. Survey of strains from East Africa and Nigeria. Transactions of the Royal Society of Tropical Medicine and Hygiene 70, 513–20.
Heisch, R. B., McMahon, J. P. & Manson-Baht, P. E. C. (1958). The isolation of T. rhodesiense from a bushbuck. British Medical Journal 2, 1203–4.
Hoare, C. A. (1972). The Trypanosomes of Mammals. Oxford: Blackwell Scientific Publications.
Lanham, S. M. & Godfrey, D. G. (1970). Isolation of salivarian trypanosomes from man and other animals using DEAE-cellulose. Experimental Parasitology 28, 521–34.
Mayr, E. (1953). Concepts of classification and nomenclature in higher organisms and micro-organisms. Annals of the New York Academy of Sciences 56, 391–7.
Mehlitz, D., Zillman, U., Scott, G. M. & Godfrey, D. G. (1982). Epidemiological studies on the animal reservoir of Gambiense sleeping sickness. III. Characterization of Trypanosoon stocks by isoenzymes and sensitivity to human serum. Tropenmedizin und Parasitologie 33, 113–18.
Miles, M. A., Lanham, S. M., De Souza, A. A. & Pova, M. (1980). Further enzymic characters of T. cruzi and their evaluation for strain identification. Transactions of the Royal Society of Tropical Medicine and Hygiene 74, 221–37.
Nei, M. (1972). Genetic distance between populations. American Naturalist 106, 283–92.
Pays, E., Dekerck, P., Van Assel, S., Sternert, M., Le Ray, D. & Van Meirvenne, N. (1983). Comparative analysis of a T. b. gambiense antigen gene family and its potential use in epidemiology of sleeping sickness. Molecular and Biochemical Parasitology 7, 6374.
Rickman, L. R. & Robson, J. (1970). The testing of proven Trypanosoma brucei and T. rhodesiense strains by the blood infectivity test. Bulletin of the World Health Organization 42, 911–16.
Tait, A. (1970). Enzyme variation between syngens in Paramedium aurelia. Biochemical Genetics 4, 461–70.
Tait, A. (1980). Diploidy and mating in trypanosomes. Nature, London 287, 536–8.
Tait, A. (1984). The biochemical characterisation of T. brucei ssp. by enzyme electrophoresis. World Health Organization Symposium on Application of Biochemical and Molecular Biology Techniques to Problems of Parasite and Vector Identification.Geneva: (in the Press).
Tibayrenc, M., Cariou, M. L. & Solignac, M. (1981). Interpretation genetiques des zymogrammes de Flagelle's des genres Trypanosoma et Leishmania. Comptes rendus, Académie des sciences, Paris 292, 623–5.
Tibayrenc, M. & Miles, M. A. (1983). A genetic comparison between Brazilian and Bolivian zymodemes of T. cruzi. Transactions of the Royal Society of Tropical Medicine and Hygiene 77, 7683.
Van Meirvenne, N., Janssens, P. G. & Magnus, E. (1973). Further studies on the lytic and neutralising action of human serum on T. brucei. Annales de la Société belge de médecine tropicale 53, 4956.
Van Meirivenne, N., Janssens, P. G. & Magnus, E. (1975). Antigenic variation in syringe passaged populations of Trypanosoma brucei. 1. Rationalisation of the experimental approach. Annales de la Société belge de médecine tropicale 55, 123.
Zimmermann, E. G., Kilpatrick, C. W. & Hart, B. J. (1978). The genetics of speciation in the rodent genus Peromyscus. Evolution 32, 565–79.

Enzyme variation in Trypanosoma brucei spp. I. Evidence for the sub-speciation of Trypanosoma brucei gambiense

  • A. Tait (a1), Eldirdiri A. Babiker (a1) and D. Le Ray (a1)


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