1887

Abstract

The endoparasitic wasp (Ichneumonidae) transmits a polydnavirus (PDV) to its host, , during oviposition. Unlike most other PDVs examined, the virus of (TrPDV) does not appear to play an important role in suppressing the host cellular immune response. However, it inhibits host metamorphosis. In the present study, TrPDV gene expression was examined in parasitized and virus-injected last-instar caterpillars. Northern analysis with viral DNA as a probe revealed only one detectable mRNA, of about 650 bp. The corresponding cDNA, termed TrV1, was cloned and sequenced and found to encode a protein of 103 amino acids which, following cleavage of the putative signal peptide, has a predicted molecular mass of 9·3 kDa. This protein displays limited similarity to the VHv1.4 cysteine-rich protein from the PDV of , mostly within the signal peptide region. By using a TrV1-specific probe, the TrV1 gene was localized to segment G of the TrPDV genome. The cuticle and fat body were identified as the principal sites of TrV1 transcription, with little transcription observed in haemocytes and midgut. Western analysis of proteins extracted from selected tissues of parasitized insects suggested that the TrV1 protein is secreted in the haemolymph. As observed for other PDVs, injection of TrPDV did not suppress transcription of the gene that encodes juvenile hormone esterase, the activity of which is inhibited by the virus. We speculate that the TrV1 protein may play a role in the inhibition of metamorphosis.

Loading

Article metrics loading...

/content/journal/jgv/10.1099/0022-1317-81-7-1871
2000-07-01
2020-01-29
Loading full text...

Full text loading...

/deliver/fulltext/jgv/81/7/0811871a.html?itemId=/content/journal/jgv/10.1099/0022-1317-81-7-1871&mimeType=html&fmt=ahah

References

  1. Altschul, S. F., Madden, T. L., Schaffer, A. A., Zhang, J., Zhang, Z., Miller, W. & Lipman, D. J. ( 1997; ). Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Research 25, 3389-3402.[CrossRef]
    [Google Scholar]
  2. Asgari, S., Hellers, M. & Schmidt, O. ( 1996; ). Host haemocyte inactivation by an insect parasitoid: transient expression of a polydnavirus gene. Journal of General Virology 77, 2653-2662.[CrossRef]
    [Google Scholar]
  3. Asgari, S., Schmidt, O. & Theopold, U. ( 1997; ). A polydnavirus-encoded protein of an endoparasitoid wasp is an immune suppressor. Journal of General Virology 78, 3061-3070.
    [Google Scholar]
  4. Blissard, G. W., Fleming, J. G. W., Vinson, S. B. & Summers, M. D. ( 1986; ). Campoletis sonorensis virus: expression in Heliothis virescens and identification of expressed sequences. Journal of Insect Physiology 32, 351-359.[CrossRef]
    [Google Scholar]
  5. Bucher, P. & Bairoch, A. ( 1994; ). A generalized profile syntax for biomolecular sequences motifs and its function in automatic sequence interpretation. In ISMB-94. Proceedings of the 2nd International Conference on Intelligent Systems for Molecular Biology, pp. 53-61. Edited by R. Altman, D. Brutlag, P. Karp, R. Lathrop & D. Searls. Menlo Park, CA: AAAI Press.
  6. Cui, L. & Webb, B. A. ( 1996; ). Isolation and characterization of a member of the cysteine-rich gene family from Campoletis sonorensis polydnavirus. Journal of General Virology 77, 797-809.[CrossRef]
    [Google Scholar]
  7. Cui, L. & Webb, B. A. ( 1997; ). Homologous sequences in the Campoletis sonorensis polydnavirus genome are implicated in replication and nesting of the W segment family. Journal of Virology 71, 8504-8513.
    [Google Scholar]
  8. Cui, L., Soldevila, A. & Webb, B. A. ( 1997; ). Expression and hemocyte-targeting of a Campoletis sonorensis polydnavirus cysteine-rich gene in Heliothis virescens larvae. Archives of Insect Biochemistry and Physiology 36, 251-271.[CrossRef]
    [Google Scholar]
  9. Cusson, M., Barron, J. R., Goulet, H., Régnière, J. & Doucet, D. ( 1998a; ). Biology and status of Tranosema rostrale rostrale (Hymenoptera: Ichneumonidae), a parasitoid of the eastern spruce budworm (Lepidoptera: Tortricidae). Annals of the Entomological Society of America 91, 87-93.[CrossRef]
    [Google Scholar]
  10. Cusson, M., Lucarotti, C., Stoltz, D., Krell, P. & Doucet, D. ( 1998b; ). A polydnavirus from the spruce budworm parasitoid, Tranosema rostrale (Ichneumonidae). Journal of Invertebrate Pathology 72, 50-56.[CrossRef]
    [Google Scholar]
  11. Cusson, M., Laforge, M., Miller, D., Cloutier, C. & Stoltz, D. ( 2000; ). Functional significance of parasitism-induced suppression of juvenile hormone esterase activity in developmentally delayed Choristoneura fumiferana larvae. General and Comparative Endocrinology 117, 343-354.[CrossRef]
    [Google Scholar]
  12. Dong, K., Zhang, D. & Dahlman, D. L. ( 1996; ). Down-regulation of juvenile hormone esterase and arylphorin production in Heliothis virescens larvae parasitized by Microplitis croceipes. Archives of Insect Biochemistry and Physiology 32, 237-248.[CrossRef]
    [Google Scholar]
  13. Doucet, D. & Cusson, M. ( 1996a; ). Alteration of developmental rate and growth of Choristoneura fumiferana parasitized by Tranosema rostrale: role of the calyx fluid. Entomologia Experimentalis et Applicata 81, 21-30.[CrossRef]
    [Google Scholar]
  14. Doucet, D. & Cusson, M. ( 1996b; ). Role of calyx fluid in alterations of immunity in Choristoneura fumiferana larvae parasitized by Tranosema rostrale. Comparative Biochemistry and Physiology 114A, 311-317.
    [Google Scholar]
  15. Feng, Q. L., Ladd, T. R., Tomkins, B. L., Sundaram, M., Sohi, S. S., Retnakaran, A., Davey, K. G. & Palli, S. R. ( 1999; ). Spruce budworm (Choristoneura fumiferana) juvenile hormone esterase: hormonal regulation, developmental expression and cDNA cloning. Molecular and Cellular Endocrinology 148, 95-108.[CrossRef]
    [Google Scholar]
  16. Hanahan, D. ( 1983; ). Studies on transformation of Escherichia coli with plasmids. Journal of Molecular Biology 166, 557-580.[CrossRef]
    [Google Scholar]
  17. Harlow, E. & Lane, D. (1988). Antibodies: A Laboratory Manual. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory.
  18. Hayakawa, Y., Yazaki, K., Yamanaka, A. & Tanaka, T. ( 1994; ). Expression of polydnavirus genes from the parasitoid wasp Cotesia kariyai in two noctuid hosts. Insect Molecular Biology 3, 97-103.[CrossRef]
    [Google Scholar]
  19. Hofmann, K., Bucher, P., Falquet, L. & Bairoch, A. ( 1999; ). The PROSITE database, its status in 1999. Nucleic Acids Research 27, 215-219.[CrossRef]
    [Google Scholar]
  20. Johner, A., Stettler, P., Gruber, A. & Lanzrein, B. ( 1999; ). Presence of polydnavirus transcripts in an egg–larval parasitoid and its lepidopterous host. Journal of General Virology 80, 1847-1854.
    [Google Scholar]
  21. Khalkhali-Ellis, Z. ( 1995; ). An improved SDS–polyacrylamide gel electrophoresis for resolution of peptides in the range of 3·5–200 kDa. Preparative Biochemistry 25, 1-9.[CrossRef]
    [Google Scholar]
  22. Lawrence, P. O. & Lanzrein, B. ( 1993; ). Hormonal interactions between insect endoparasites and their host insects. In Parasites and Pathogens of Insects, vol. 1, Parasites, pp. 59-86. Edited by N. E. Beckage, S. N. Thompson & B. A. Federici. London: Academic Press.
  23. Li, X. & Webb, B. A. ( 1994; ). Apparent functional role for a cysteine-rich polydnavirus protein in suppression of the insect cellular immune response. Journal of Virology 68, 7482-7489.
    [Google Scholar]
  24. Marck, C. ( 1988; ). ‘DNA Strider’: a ‘C’ program for the fast analysis of DNA and protein sequences on the Apple Macintosh family of computers. Nucleic Acids Research 16, 1829-1836.[CrossRef]
    [Google Scholar]
  25. Nielsen, H., Engelbrecht, J., Brunak, S. & von Heijne, G. ( 1997; ). Identification of prokaryotic and eukaryotic signal peptides and prediction of their cleavage sites. Protein Engineering 10, 1-6.[CrossRef]
    [Google Scholar]
  26. Sambrook, J., Fritsch, E. F. & Maniatis, T. (1989). Molecular Cloning: A Laboratory Manual, 2nd edn. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory.
  27. Sanger, F., Nicklen, S. & Coulson, A. R. ( 1977; ). DNA sequencing with chain-terminating inhibitors. Proceedings of the National Academy of Sciences, USA 74, 5463-5467.[CrossRef]
    [Google Scholar]
  28. Shelby, K. S. & Webb, B. A. ( 1997; ). Polydnavirus infection inhibits translation of specific growth-associated host proteins. Insect Biochemistry and Molecular Biology 27, 263-270.[CrossRef]
    [Google Scholar]
  29. Shelby, K. S. & Webb, B. A. ( 1999; ). Polydnavirus-mediated suppression of insect immunity. Journal of Insect Physiology 45, 507-514.[CrossRef]
    [Google Scholar]
  30. Shelby, K. S., Cui, L. & Webb, B. A. ( 1998; ). Polydnavirus-mediated inhibition of lysozyme gene expression and the antibacterial response. Insect Molecular Biology 7, 265-272.[CrossRef]
    [Google Scholar]
  31. Soldevila, A. I. & Webb, B. A. ( 1996; ). Expression of polydnavirus genes under polydnavirus promoter regulation in insect larvae infected with baculovirus recombinants. Journal of General Virology 77, 1379-1388.[CrossRef]
    [Google Scholar]
  32. Soldevila, A. I., Heuston, S. & Webb, B. A. ( 1997; ). Purification and analysis of a polydnavirus gene product expressed using a poly-histidine baculovirus vector. Insect Biochemistry and Molecular Biology 27, 201-211.[CrossRef]
    [Google Scholar]
  33. Stoltz, D. B. ( 1993; ). The polydnavirus life cycle. In Parasites and Pathogens of Insects, vol. 1, Parasites, pp. 167-187. Edited by N. E. Beckage, S. N. Thompson & B. A. Federici. London: Academic Press.
  34. Stoltz, D. B., Guzo, D. & Cook, D. ( 1986; ). Studies on polydnavirus transmission. Virology 155, 120-131.[CrossRef]
    [Google Scholar]
  35. Strand, M. R. ( 1994; ). Microplitis demolitor polydnavirus infects and expresses in specific morphotypes of Pseudoplusia includens haemocytes. Journal of General Virology 75, 3007-3020.[CrossRef]
    [Google Scholar]
  36. Strand, M. R., McKenzie, D. I., Grassl, V., Dover, B. A. & Aiken, J. M. ( 1992; ). Persistence and expression of Microplitis demolitor polydnavirus in Pseudoplusia includens. Journal of General Virology 73, 1627-1635.[CrossRef]
    [Google Scholar]
  37. Strand, M. R., Witherell, R. A. & Trudeau, D. ( 1997; ). Two Microplitis demolitor polydnavirus mRNAs expressed in hemocytes of Pseudoplusia includens contain a common cysteine-rich domain. Journal of Virology 71, 2146-2156.
    [Google Scholar]
  38. Theilmann, D. A. & Summers, M. D. ( 1988; ). Identification and comparison of Campoletis sonorensis virus transcripts expressed from four genomic segments in the insect hosts Campoletis sonorensis and Heliothis virescens. Virology 167, 329-341.
    [Google Scholar]
  39. Volkoff, A. N., Cerutti, P., Rocher, J., Ohresser, M. C., Devauchelle, G. & Duonor-Cerutti, M. ( 1999; ). Related RNAs in lepidopteran cells after in vitro infection with Hyposoter didymator virus define a new polydnavirus gene family. Virology 263, 349-363.[CrossRef]
    [Google Scholar]
  40. Webb, B. A. ( 1998; ). Polydnavirus biology, genome structure, and evolution. In The Insect Viruses, pp. 105-139. Edited by L. K. Miler & L. A. Ball. New York: Plenum.
  41. Wu, M. M. J., Cassidy, J. R. & Pukkila, P. J. ( 1983; ). Polymorphisms in DNA of Coprinus cinereus. Current Genetics 7, 385-392.[CrossRef]
    [Google Scholar]
  42. Yamanaka, A., Hayakawa, Y., Noda, H., Nakashima, N. & Watanabe, H. ( 1996; ). Characterization of polydnavirus-encoded mRNA in parasitized armyworm larvae. Insect Biochemistry and Molecular Biology 26, 529-536.[CrossRef]
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/jgv/10.1099/0022-1317-81-7-1871
Loading
/content/journal/jgv/10.1099/0022-1317-81-7-1871
Loading

Data & Media loading...

Most cited articles

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error