1887

Abstract

The baculovirus nuclear polyhedrosis virus interferes with insect larval development by altering the host’s hormonal system. The level of haemolymph ecdysteroids, the insect moulting hormone, was found to be higher in virus-infected larvae than in uninfected controls. This was consistently observed in both fourth instars and day 5-infected fifth instars. The rate of hormone synthesis was examined by incubation of the prothoracic gland. Gland activity in virus-infected larvae was higher than controls and continued until the late stages of virus infection, even during the time that controls had ceased to secrete ecdysone after moulting. During virus replication. The prothoracic gland was observed to maintain morphological and ultrastructural characteristics indicative of ecdysone biosynthetic activities. Therefore, it is likely that the insects are no longer under the control of the normal hormonal system after virus infection. It is felt that the alteration of hormone titre and the rate of ecdysone synthesis is the result of the activity of ecdysteroid UDP-glucosyl transferase (EGT), a virus-encoded enzyme which is thought to inactivate ecdysteroids by sugar conjugation.

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1996-03-01
2024-03-29
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References

  1. Bell R. A., Owens C. D., Shapiro M., Tardif J. R. 1981; Mass rearing and virus production. In The Gypsy Moth: Research Toward Integrated Pest Management pp 599–655 Forest Service Technical Bulletin 1584; Washington. DC: USDA:
    [Google Scholar]
  2. Bollenbacher W. E., Vedeckis W. V., Gilbert L. I., O’Conner J. D. 1975; Ecdysone titers and prothoracic gland activity during the larval-pupal development of Manduca sexta . Developmental Biology 44:46–53
    [Google Scholar]
  3. Bollenbacher W. E., Agui N., Granger N. A., Gilbert L. I. 1979; In vitro activation of insect prothoracic glands by the prothoracicotropic hormone. Proceedings of the National Academy of Sciences, USA 76:5148–5152
    [Google Scholar]
  4. Burand J. P., Park E. J. 1992; Effect of nuclear polyhedrosis virus infection on development and pupation of gypsy moth larvae. Journal of Invertebrate Pathology 60:171–175
    [Google Scholar]
  5. Chino H., Sakurai S., Ohtaki T., Ikekawa T., Miyazaki H., Ishibashi M., Abuki H. 1974; Biosynthesis of a-ecdysone by prothoracic gland in vitro . Science 183:529–530
    [Google Scholar]
  6. Dougherty E. M., Kelly T. J., Rochford R., Forney J. A., Adams J. R. 1987; Effects of infection with a granulosis virus on larval growth, development and ecdysteroid production in the cabbage looper, Trichophisia ni . Physiological Entomology 12:23–30
    [Google Scholar]
  7. Granados R. R., Williams K. A. 1986; In vivo infection and replication of baculoviruses. In The Biology of Baculoviruses pp 89–108 Edited by Granados R. R., Federici B. A. Boca Raton: CRC Press;
    [Google Scholar]
  8. Hanton W. K., Douglas R. D., Bollenbacher W. E. 1993; Ultrastructure of prothoracic glands during larval–pupal development of the tobacco hornworm, Manduca sexta: a reappraisal. Journal of Morphology 216:95–112
    [Google Scholar]
  9. Herman W. S. 1967; The ecdysial glands of arthropods. International Review of Cytology 22:269–347
    [Google Scholar]
  10. Kelly T. J., Masler E. P., Thyagaraja B. S., Bell R. A., Imberski R. B. 1992; Development of an in vitro assay for prothoracicotropic hormone of the gypsy moth, Lymantria dispar (L.) following studies on the identification, titers and synthesis of ecdysteroids in last-instar females. Journal of Comparative Physiology B 162:581–587
    [Google Scholar]
  11. King D. S., Bollenbacher W. E., Borst D. W., Vedeckis W. V., O’Conner J. D., Ittycheriah P. I., Gilbert L. I. 1974; The secretion of α-ecdysone by the prothoracic glands of Manduca sexta in vitro . Proceedings of the National Academy of Sciences, USA 71:793–796
    [Google Scholar]
  12. Lafont R., Beydon P., Blais C., Garcia M., Lachaise F., Riera F., Somme G., Girault J. P. 1986; Ecdysteroid metabolism: a comparative study. Insect Biochemistry 16:11–16
    [Google Scholar]
  13. O’Reilly D. R., Miller L. K. 1989; A baculovirus blocks insect molting by producing ecdysteroid UDP-glucosyl transferase. Science 245:1110–1112
    [Google Scholar]
  14. O’Reilly D. R., Miller L. K. 1990; Regulation of expression of a baculovirus ecdysteroid UDP-glucosyl transferase gene. Journal of Virology 64:1321–1328
    [Google Scholar]
  15. O’Reilly D. R., Howarth O. W., Rees H. H., Miller L. K. 1991; Structure of the ecdysone glucoside formed by a baculovirus ecdysteroid UDP-glucosyl transferase. Insect Biochemistry 21:795–801
    [Google Scholar]
  16. O’Reilly D. R., Brown M. R., Miller L. K. 1992; Alteration of ecdysteroid metabolism due to baculovirus infection of the fall armyworm Spodoptera frugiperda: host ecdysteroids are conjugated with galactose. Insect Biochemistry and Molecular Biology 22:313–320
    [Google Scholar]
  17. Park E. J., Burand J. P., Yin C.-M. 1993; The effect of baculovirus infection on ecdysteroid titer in gypsy moth larvae. Journal of Insect Physiology 39:791–796
    [Google Scholar]
  18. Sedlak B. J., Marchione L., Devorkin B., David R. 1983; Correlations between endocrine gland ultrastructure and hormone titers in the fifth larval instar of Manduca sexta . General and Comparative Endocrinology 52:291–310
    [Google Scholar]
  19. Smith S. L. 1985; Regulation of ecdysteroid titer: synthesis. In Comprehensive Insect Physiology Biochemistry and Pharmacology vol 7 pp 295–341 Edited by Kerkut G. A., Gilbert L. I. Oxford: Pergamon Press;
    [Google Scholar]
  20. Spurr A. R. 1969; A low-viscosity epoxy resin embedding medium for electron microscopy. Journal of Ultrastructure Research 26:31–3
    [Google Scholar]
  21. Steel C. G. H., Vafopoulou X. 1989; Ecdysteroid titer profiles during growth and development of arthropods. In Ecdysone: From Chemistry to Mode of Action pp 221–231 Edited by Koolman J. New York: Thieme Medical Publishers;
    [Google Scholar]
  22. Volkman L. E., Keddie B. A. 1990; Nuclear polyhedrosis virus pathogenesis. Seminars in Virology 1:249–256
    [Google Scholar]
  23. Weevers R. D. 1966; A lepidopteran saline: effects of inorganic cation concentrations on sensory, reflex and motor responses in a herbivorous insect. Journal of Experimental Biology 44:163–184
    [Google Scholar]
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