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The effects of Onchocerca lienalis infection on vitellogenesis in the British blackfly, Simulium ornatum

Published online by Cambridge University Press:  06 April 2009

M. Renshaw  and
H. Hurd
M. Renshaw
Affiliation:
Centre for Applied Entomology and Parasitology, Department of Biological Science, Keele University, Staffs ST5 5BG, UK
H. Hurd
Affiliation:
Centre for Applied Entomology and Parasitology, Department of Biological Science, Keele University, Staffs ST5 5BG, UK
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Summary

We have previously described the major yolk protein, vitellin, in the British blackfly Simulium ornatum Meigen. Here we demonstrate that vitellogenin, synthesized in the fat body and secreted into the haemolymph, is composed of subunits with the same approximate molecular weight as vitellin, namely 200 and 68 kDa. Simulium ornatum is the natural vector for the cattle filarial nematode Onchocerca lienalis Stiles, which induces host fecundity depletion. A significant reduction in ovarian vitellin content was associated with infection by intrathoracic injection of 20 O. lienalis microfilariae immediately after blood-feeding. Fat body synthesis of vitellogenin was significantly reduced as early as 8 h post-infection in comparison with sham-injected flies. When total haemolymph protein from infected and sham injected flies was compared, titres were significantly depressed 6 h post-infection. However, later in the infection, titres were elevated by 30%, the major component being vitellogenin. The injection of dead microfilariae had no effect. An infection burden of a single parasite caused a significant reduction in ovarian protein content in comparison with shams, but no further significant decrease was observed as the parasite burden was increased from 5 to 20. Possible mechanisms underlying the disturbance of Simulium reproductive physiology are proposed.

Keywords

Simulium ornatumOnchocerca lienalisvitellogeninvitellogenesisfecundity depletion
Type
Research Article
Information
Parasitology , Volume 109 , Issue 3 , September 1994 , pp. 337 - 343
Copyright
Copyright © Cambridge University Press 1994

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References

REFERENCES

Bianco, A. E., Ham, P. J., El Sinnary, K. & Nelson, G. S. (1980). Large scale recovery of Onchocerca microfilariae from naturally infected cattle and horses. Transactions of the Royal Society of Tropical Medicine and Hygiene 74, 109.Google Scholar
Cheke, R. A., Garms, R. & Kerner, M. (1982). The fecundity of Simulium damnosum s.l. in northern Togo and infections with Onchocerca spp. Annals of Tropical Medicine and Parasitology 54, 561–8.CrossRefGoogle Scholar
Clements, A. N. (1992). The Biology of Mosquitoes, Vol. 1. London: Chapman and Hall.Google Scholar
Hacker, C. S. (1971). The differential effect of Plasmodium gallinaceum on the fecundity of several strains of Aedes aegypti. Journal of Invertebrate Pathology 18, 373–7.CrossRefGoogle ScholarPubMed
Ham, P. J. (1992). Immunity in haematophagous insect vectors of parasitic infection. Advances in Disease Vector Research 9, 101–49.CrossRefGoogle Scholar
Ham, P. J. & Banya, A. J. (1984). The effect of experimental Onchocerca infections on the fecundity and oviposition of laboratory reared Simulium spp. (Diptera: Simuliidae). Tropenmedizin und Parasitologie 35, 61–6.Google Scholar
Ham, P. J. & Gale, C. L. (1984). Bloodmeal enhanced Onchocerca development and its correlation with fecundity in laboratory reared blackflies (Diptera: Simuliidae). Tropenmedizin und Parasitologie 35, 212–16.Google Scholar
Ham, P. J., Townson, S., James, E. R. & Bianco, A. E. (1981). An improved technique for the cryopreservation of Onchocerca microfilariae. Parasitology 83, 139–46.CrossRefGoogle ScholarPubMed
Harlow, E. & Lane, D. P. (1988). Antibodies: A Laboratory Manual. Cold Spring Harbor, New York: Cold Spring Harbor Laboratory.Google Scholar
Hays, A. R. & Raikhel, A. S. (1990). A novel protein produced by the vitellogenic fat body and accumulated in mosquito oocytes. Roux's Archives of Developmental Biology 199, 114–21.CrossRefGoogle ScholarPubMed
Hurd, H. (1990). Physiological and behavioural interactions between parasites and invertebrate hosts. Advances in Parasitology, Vol. 29 (ed. Baker, J. R. & Muller, R.), pp. 272–318. London: Academic Press.Google Scholar
Hurd, H. (1993). Reproductive disturbances induced by parasites and pathogens in insects. In Parasites and Pathogens of Insects (ed. Beckage, N. E., Thompson, S. N. & Federici, B. A.), pp. 87–105. Orlando: Academic Press.CrossRefGoogle Scholar
Hurd, H. & Arme, C. (1986). Hymenolepis diminuta: influence of metacestodes on synthesis and secretion of fat body protein and its ovarian sequestration in the intermediate host, Tenebrio molitor. Parasitology 93, 111–20.CrossRefGoogle ScholarPubMed
Hurd, H. & Arme, C. (1987). Hymenolepis diminuta: effect of infection upon the patency of the follicular epithelium in the intermediate host, Tenebrio molitor. Journal of Invertebrate Pathology 49, 227–34.CrossRefGoogle ScholarPubMed
Javadian, E. & Macdonald, W. W. (1974). The effect of infection with Brugia pahangi and Dirofilaria repens on the egg production of Aedes aegypti. Annals of Tropical Medicine and Parasitology 68, 477–81.CrossRefGoogle ScholarPubMed
Raikhel, A. S. (1992). Vitellogenesis in mosquitoes. Advances in Disease Vector Research 9, 1–39. New York: Springer-Verlag.CrossRefGoogle Scholar
Renshaw, M. & Hurd, H. (1994). Vitellogenin sequestration by Simulium oocytes: the effect of Onchocerca infection. Physiological Entomology 19, 70–4.CrossRefGoogle Scholar