The Glossina proteolytic lectin (Gpl) gene is expressed only in members of Glossina species

  • M. W. Burugu
  • B. N. Mbatia
  • E. O. Osir
  • E. U. Kenya
  • L. U. AbubakarEmail author


Differentiation of bloodstream-form trypanosomes into procyclics in tsetse flies (Diptera: Glossinidae) is a crucial step in the establishment of midgut infections. A number of factors have been implicated in the transformation process, including enzymes and lectins or lectin-like molecules. Recently, Glossina proteolytic lectin (Gpl) gene, which encodes a protein with both lectin and trypsin activities has been shown to stimulate transformation of bloodstream-form trypanosomes into procyclics in vitro. Using RT-PCR, we show that the induction of Gpl gene expression by blood meal occurs only in Glossina fuscipes fuscipes Newstead, Glossina austeni Newstead, Glossina pallidipes Austen, and not in the Anopheles gambiae Giles sensu stricto, Phlebotomus duboscqi Neveu-Lemaire, Rhipicephalus appendiculatus Neumann and Stomoxys calcitrans (Linnaeus). The expression means of Gpl mRNA in G. f. fuscipes following a blood meal were significant (P < 0.05) with low expression in teneral flies and reaching a maximum between 48 and 72h (P < 0.05), suggesting time-dependent regulation of the transcription. The expression of the Gpl gene was significantly lower (P < 0.05) in G. f. fuscipes fed on blood meal infected with Trypanosoma brucei brucei as compared with G. f. fuscipes fed on uninfected blood meal. This suggests some form of interaction of T. b. brucei or the parasite products with Gpl within the tsetse midgut leading to down-regulation of the Gpl gene. Additionally, refractory G. f. fuscipes expressed higher (P < 0.05) transcript abundance than the susceptible G. pallidipes.

Key words

Glossina proteolytic lectin gene midgut bloodmeal Glossina species trypanosome 


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  1. Abubakar L. U., Bulimo W. D., Mulaa F. J. and Osir E. O. (2006) Molecular characterization of a tsetse fly midgut proteolytic lectin that mediates differentiation of African trypanosomes. Insect Biochemistry and Molecular Biology 36, 344–352.CrossRefGoogle Scholar
  2. Abubakar L. U., Zimba G., Wells C., Mulaa F. and Osir E. O. (2003) Evidence for the involvement of a tsetse midgut lectin-trypsin complex in differentiation of bloodstream-form trypanosomes. Insect Science and Its Application 23, 197–205.Google Scholar
  3. Acosta-Serrano A., Vassella E., Liniger M., Renggli C. K., Brun R., Roditi I. and Englund P. T. (2001) The surface coat of procyclic Trypanosoma brucei: Programmed expression and proteolytic cleavage of procyclin in the tsetse fly. Proceedings of the National Academy of Sciences of the United States of America 98, 1513–1518.CrossRefGoogle Scholar
  4. Amin D. N., Kamita G. S., Muluvi G. M., Machuka J., Hammock B. D. and Osir E. O. (2006) Glossina proteolytic lectin does not require a carbohydrate moiety for enzymatic or trypanosome-transforming activities. Journal of Medical Entomology 43, 301–308.CrossRefGoogle Scholar
  5. Beach R., Young D. G. and Kiilu G. (1986) New phlebotomine sand fly colonies II. Laboratory colonization of Phlebotomus duboscqi (Diptera: Psychodidae). Journal of Medical Entomology 23, 114–115.CrossRefGoogle Scholar
  6. Bienen E., Hammadi E. and Hill G. C. (1981) Trypanosoma brucei: Biochemical and morphological changes during in vitro transformation of bloodstream to procyclic-trypomastigotes. Experimental Journal of Parasitology 51, 408–417.CrossRefGoogle Scholar
  7. Brun R. and Schonenberger M. (1981) Stimulating effect of citrate and cis-aconitate on the transformation of Trypanosoma brucei bloodstream forms to procyclic forms in vitro. Zeitschrift fur Parasitenkunde 66, 17–24.CrossRefGoogle Scholar
  8. Cross G. and Manning J. (1973) Cultivation of Trypanosoma brucei spp. in semi-defined media. Parasitology 67, 315–331.CrossRefGoogle Scholar
  9. Gooding R. (1974) Digestive processes of haematopha-gous insects: Control of trypsin secretion in Glossina morsitans. Journal of Insect Physiology 20, 957–964.CrossRefGoogle Scholar
  10. Gooding R. (1977) Digestive processes of haematophagous insects: XII Secretion of trypsin and carboxypeptidase B by Glossina morsitans morsitans Westwood (Diptera: Glossinidae). Canadian Journal of Zoology 55, 215–222.CrossRefGoogle Scholar
  11. Han Y. S., Salazar C. E., Reese-Strardy S. R., Cornel A., Gorman M. J., Collins F. H. and Paskewwitz S. M. (1997) Cloning and characterization of a serine protease from human malaria vector, Anopheles gambiae. Insect Molecular Biology 6, 385–395.CrossRefGoogle Scholar
  12. Hao Z., Kasumba I., Lehane M. J., Gibson W. C, Kwon J. and Aksoy S. (2001) Tsetse immune responses and trypanosome transmission: Implications for the development of tsetse-based strategies to reduce trypanosomiasis. Proceedings of the National Academy of Sciences of the United States of America 98, 12648–12653.CrossRefGoogle Scholar
  13. Hunt M., Brun R. and Kohler P. (1994) Studies on compounds promoting the in vitro transformation of Trypanosoma brucei from bloodstream to procyclic forms. Parasitology Research 80, 600–606.CrossRefGoogle Scholar
  14. Ibrahim E. A. R., Ingram G. A. and Moulyneux D. H. (1984) Haemagglutinins and parasite agglutinins in haemolymph and gut of Glossina. Tropical Medicine and Parasitology 35, 151–156.Google Scholar
  15. Imbuga M. O., Osir E. O., Labongo V. L., Darji N. and Otieno L. H. (1992) Studies on tsetse midgut factors that induce differentiation of bloodstream Trypanosoma brucei in vitro. Parasitology Research 78, 10–15.CrossRefGoogle Scholar
  16. Kephart D. (1998) Quantitative RT-PCR: Rapid construction of templates for competitive amplification. Promega Notes 68, 6–7.Google Scholar
  17. Kongoro J. A., Osir E. O., Imbuga M. O. and Oguge N. O. (2002) Comparison of midgut trypsin/lectin activities and trypanosome infection rates in three Glossina species. Insect Science and Its Application 22, 295–301.Google Scholar
  18. Lehane M. J., Aksoy S., Gibson W., Kerhornou A., Berriman M., Halmiton J., Soares M. B., Bonaldo M. F., Lehane S. and Hall N. (2003) Adult midgut expressed sequence tags from the midgut of tsetse fly Glossina morsitans morsitans and expression analysis of putative immune response genes. Genome Biology 4, R63.CrossRefGoogle Scholar
  19. Maudlin I. (1991) Transmission of African trypanosomiasis—interactions among tsetse immune system, symbionts and parasites. A review. Advances in Disease Vector Research 7, 117–148.CrossRefGoogle Scholar
  20. Moffat M., Blakemore D. and Lehane M. (1995) Studies of the synthesis and secretion of digestive trypsin in Stomoxys calcitrans (Insecta: Diptera). Comparative Biochemistry and Physiology 110, 291–300.CrossRefGoogle Scholar
  21. Nebenfuhr A. and Lomax T. (1998) Multiplex titration RT-PCR: Rapid determination of gene expression patterns for a large number of genes. Plant Molecular Biology Reporter 16, 323–339.CrossRefGoogle Scholar
  22. Nguu E. K., Osir E. O., Imbuga M. O. and Olembo N. K. (1996) The effect of host blood in the in vitro transformation of bloodstream trypanosomes by tsetse midgut homogenates. Medical and Veterinary Entomology 110, 317–322.CrossRefGoogle Scholar
  23. Noriega F. G., Pennington J. E., Barillas-Mury C., Wang X. Y. and Wells M. A. (1996) Aedes aegypti midgut early trypsin is post-transcriptionally regulated by blood feeding. Insect Molecular Biology 5, 25–29.CrossRefGoogle Scholar
  24. Noriega F. G., Pennington J. E. and Wells M. (1994) Dietary control of late trypsin gene transcription in Aedes aegypti. Insect Biochemistry and Molecular Biology 24, 627–631.CrossRefGoogle Scholar
  25. Osir E. O., Abubakar L. U. and Imbuga M. O. (1995) Purification and characterization of a midgut lectintrypsin complex from the tsetse fly Glossina longipennis. Parasitology Research 81, 276–281.CrossRefGoogle Scholar
  26. Osir E. O., Imbuga M. O. and Onyango P. (1993) Inhibition of Glossina morsitans midgut trypsin activity by D-glucosamine. Parasitology Research 79, 93–97.CrossRefGoogle Scholar
  27. Roditi I. and Pearson T. W. (1990) The procyclin coat of African trypanosomes (or the not-so-naked trypanosome). Parasitology Today 6, 79–82.CrossRefGoogle Scholar
  28. Rolin S., Honoc-Quertier J., Paturiaux H. F, Nolan D. and Pays E. (1998) Mild acid stress as a differentiation trigger in Trypanosoma brucei. Molecular and Biochemical Parasitology 93, 251–262.CrossRefGoogle Scholar
  29. SAS (1999) SAS/STAT Software. Changes and Enhancement through Release 8.02. Cary, North Carolina.Google Scholar
  30. Seibert P. D. and Larrick J. W. (1992) Competitive PCR. Nature 359, 557–558.CrossRefGoogle Scholar
  31. Van den Abbelle J. and Decleir W. (1992) Study of the vectorial capacity of Glossina sp. related to its digestive physiology and rearing conditions, tsetse control diagnosis and chemotherapy using nuclear techniques, IAEA-TECDOC-634. International Atomic Energy Agency (IAEA), Vienna.Google Scholar
  32. Welburn S. C. and Maudlin I. (1999) Tsetse-trypanosome interactions: Rites of passage. Parasitology Today 15, 399–403.CrossRefGoogle Scholar
  33. Yabu Y. and Takayanagi T. (1988) Trypsin-stimulated transformation of Trypanosoma brucei gambiense bloodstream forms to procylic forms in vitro. Parasitology Research 74, 501–506.CrossRefGoogle Scholar
  34. Yan J., Cheng Q., Li C.-B. and Aksoy S. (2002) Molecular characterization of three gut genes from Glossina morsitans morsitans: Cathepsin B, zinc-metalloprotease and zinc-carboxypeptidase. Insect Molecular Biology 11, 57–65.CrossRefGoogle Scholar

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© ICIPE 2008

Authors and Affiliations

  • M. W. Burugu
    • 1
    • 2
  • B. N. Mbatia
    • 1
    • 3
  • E. O. Osir
    • 1
  • E. U. Kenya
    • 2
  • L. U. Abubakar
    • 3
    • 4
    Email author
  1. 1.Molecular Biology and Biotechnology DepartmentICIPE—African Insect Science for Food and HealthNairobiKenya
  2. 2.Department of BiochemistryKenyatta UniversityNairobiKenya
  3. 3.Department of BiochemistryUniversity of NairobiNairobiKenya
  4. 4.Kenya Marine and Fisheries Research InstituteNairobiKenya

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