1887

Abstract

The endoparasitic wasp injects a symbiotic polydnavirus into its host . Viral gene expression protects the wasp egg and larva from encapsulation by host haemocytes. Three related polydnavirus (CsPDV) genes, which are expressed in parasitized , have been previously isolated and grouped into a cysteine-rich gene family. In this report, a CsPDV gene encoding an abundant 1.4 kb mRNA expressed in parasitized insects was isolated and mapped to viral segment V (15.2 kb) by Southern blotting and PCR. The VHv1.4 cDNA is 1338 bp long and has an ORF that encodes 322 amino acids with two complete and one partial cysteine motifs. Similar to other characterized CsPDV cysteine motifs, the VHv1.4 motifs are also characterized by six cysteines at conserved positions and variable inter-cysteine amino acids. DNA sequence analyses show that the VHv1.4 gene shares regions of significant identity (73–97%) with the VHv1.1 gene, a member of the cysteine-rich gene family. The VHv1.4 and the VHv1.1 proteins are 62% identical overall; at the N termini including the signal peptide and the N-terminal cysteine motif the identity is greater (90%). Unlike other CsPDV cysteinerich genes, the VHv1.4 cDNA has two conserved domains (77% identical in nucleotides, 55% identical in amino acids) that presumably result from the duplication of a portion of the gene. The VHv1.4 gene has four introns with splicing sites located at positions similar to VHv1.1 introns. Introns 2 and 3, located in the first and second domains respectively, have greater identity (97%) than the flanking exon sequences (77%). We propose, based on the evidence presented in this paper, that the VHv1.4 gene is a new member of the cysteinerich polydnavirus gene family.

Loading

Article metrics loading...

/content/journal/jgv/10.1099/0022-1317-77-4-797
1996-04-01
2022-01-21
Loading full text...

Full text loading...

/deliver/fulltext/jgv/77/4/JV0770040797.html?itemId=/content/journal/jgv/10.1099/0022-1317-77-4-797&mimeType=html&fmt=ahah

References

  1. Blissard G. W., Fleming J. G. W., Vinson S. B., Summers M. D. 1986a; Campoletis sonorensis virus: expression in Heliothis virescens and identification of expressed sequences. Journal of Insect Physiology 32:351–359
    [Google Scholar]
  2. Blissard G. W., Vinson S. B., Summers M. D. 1986b; Identification, mapping, and in vitro translation of Campoletis sonorensis virus mRNAs from parasitized Heliothis virescens larvae. Journal of Virology 57:318–327
    [Google Scholar]
  3. Blissard G. W., Smith O. P., Summers M. D. 1987; Two related viral genes are located on a single superhelical DNA segment of the multipartite Campoletis sonorensis virus genome. Virologv 160:120–134
    [Google Scholar]
  4. Blissard G. W., Theilmann D. A., Summers M. D. 1989; Segment W of the Campoletis sonorensis virus: expression, gene products, and organization. Virology 169:78–79
    [Google Scholar]
  5. Chomczynski P., Sacchi N. 1987; Single step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Analytical Biochemistry 161:156–159
    [Google Scholar]
  6. Dib-Hajj S. D., Webb B. A., Summers M. D. 1993; Structure and evolutionary implications of a ‘cysteine-rich’ Campoletis sonorensis polydnavirus gene family. Proceedings of the National Academy of Sciences, USA 90:3765–3769
    [Google Scholar]
  7. Edson K. M., Vinson S. B., Stoltz D. B., Summers M. D. 1981; Virus in a parasitoid wasp: suppression of the cellular immune response in the parasitoid’s host. Science 211:582–583
    [Google Scholar]
  8. Eldridge R., Li Y., Miller L. K. 1992; Characterization of a baculovirus gene encoding a small conotoxinlike polypeptide. Journal of Virology 66:6563–6571
    [Google Scholar]
  9. Fleming J. G. W., Summers M. D. 1991; Polydnavirus DNA is integrated in the DNA of its parasitoid wasp host. Proceedings of the National Academy of Sciences, USA 88:9770–9774
    [Google Scholar]
  10. Fleming J. G. W., Blissard G. W., Summers M. D., Vinson S. B. 1983; Expression of Campoletis sonorensis virus in the parasitized host, Heliothis virescens . Journal of Virology 48:74–78
    [Google Scholar]
  11. Frohman M. A. 1990; RACE: rapid amplification of cDNA ends. In PCR Protocols. A Guide to Methods and Applications pp 28–38 Edited by Innis M. A., Gelfand D. H., Sninsky J. J., White T. J. San Diego: Academic Press;
    [Google Scholar]
  12. Kozak M. 1983; Comparison of initiation of protein synthesis in procaryotes, eucaryotes, and organelles. Microbiology Review 47:1–45
    [Google Scholar]
  13. Krell P. J., Summers M. D., Vinson S. B. 1982; Virus with a multipartite superhelical DNA genome from the ichneumonid parasitoid Campoletis sonorensis . Journal of Virology 43:859–870
    [Google Scholar]
  14. 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]
  15. Luckhart S., Webb B. A. 1996; Interaction of a wasp ovarian protein and polydnavirus in host immune suppression. Developmental and Comparative Immunology (in press)
    [Google Scholar]
  16. Nouri H., Ishida I., Miyashita E., Sato M., Urano A., Deguchi T. 1987; Cloning and sequence analysis of cDNAs for neurohypophysial hormones vasotocin and mesotocin for the hypothalamus of toad, Bufo japonicus . Proceedings of the National Academy of Sciences, USA 84:3043–3046
    [Google Scholar]
  17. Norton W. N., Vinson S. B. 1983; Correlating the initiation of virus replication with a specific pupal developmental phase of an ichneumonid parasitoid. Cell and Tissue Research 231:387–389
    [Google Scholar]
  18. Olivera B. M., River J., Clark C., Ramilo C. A., Corpuz G. P., Abogadie F. C., Mena E. E., Woodward S. R., Hillyard D. R., Lourdes J. C. 1990; Diversity of Conus neuropeptides. Science 249:257–263
    [Google Scholar]
  19. Olivera B. M., Rivers J., Scott J. K., Hillyard D. R., Cruz L. J. 1991; Conotoxins. Journal of Biological Chemistry 266:22067–22070
    [Google Scholar]
  20. Sambrook J., Fritsch E. F., Maniatis T. 1989 Molecular Cloning: A Laboratory Manual 2nd edn New York: Cold Spring Harbor Laboratory;
    [Google Scholar]
  21. 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
    [Google Scholar]
  22. Shelby K. S., Webb B. A. 1994; Polydnavirus infection inhibits synthesis of an insect plasma protein, arylphorin. Journal of General Virology 75:2285–2292
    [Google Scholar]
  23. Stoltz D. B., Beckage N. E., Blissard G. W., Fleming J. G. W., Krell P. J., Theilmann D. A., Summers M. D., Webb B. A. 1995; Polydnaviridae. In Virus Taxonomy. Sixth Report of the International Committee on Taxonomy of Viruses pp 143–147 Edited by A F., Murphy C., Fauquet M., Bishop D. H. L., Ghabrial S. A., Jarvis A. W., Martelli G. P., Mayo M. A., Summers M. D. Vienna & New York: Springer-Verlag;
    [Google Scholar]
  24. Stoltz D. B., Whitfield J. B. 1992; Viruses and virus-like entities in the parasitic hymenoptera. Journal of Hymenoptera Research 1:125–139
    [Google Scholar]
  25. Stoltz D. B., Krell P. J., Summers M. D., Vinson S. B. 1984; Polydnaviridae - a proposed family of insect viruses with segmented, double-stranded, circular DNA genomes. Intervirology 21:1–4
    [Google Scholar]
  26. Theilmann D. A., Summers M. D. 1986; Molecular analysis of Campoletis sonorensis virus DNA in the lepidopteran host Heliothis virescens . Journal of General Virology 67:1961–1969
    [Google Scholar]
  27. Theilmann D. A., Summers M. D. 1987; Physical analysis of the Campoletis sonorensis virus multipartite genome and identification of a family of tandemly repeated elements. Journal of Virology 61:2589–2598
    [Google Scholar]
  28. 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]
  29. Tung J. S.-S., Daugherty B. L., O’Neill L., Law S. W., Han J., Mark G. E. 1989; PCR amplification of specific sequences from a cDNA library. In PCR Technology: Principles and Applications for DNA Amplification pp 99–104 Edited by Erlich H. A. New York: Stockton;
    [Google Scholar]
  30. Von Heune G. 1986; A new method for predicting signal sequence cleavage sites. Nucleic Acids Research 14:4683–4690
    [Google Scholar]
  31. Webb B. A., Luckhart S. 1994; Evidence for an early immunosuppressive role for related Campoletis sonorensis venom and ovarian proteins in Heliothis virescens . Archives of Insect Biochemistry and Physiology 26:147–163
    [Google Scholar]
  32. Webb B. A., Luckhart S. 1996; Factors mediating short- and long-term immune suppression in a parasitized insect. Journal of Insect Physiology 42:33–40
    [Google Scholar]
  33. Webb B. A., Summers M. D. 1990; Venom and viral expression products of the endoparasitic wasp Campoletis sonorensis share epitopes and related sequences. Proceedings of the National Academy of Sciences, USA 87:4961–4965
    [Google Scholar]
  34. Webb B. A., Summers M. D. 1992; Stimulation of polydnavirus replication by 20-hydroxyecdysone. Experientia 48:1018–1022
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/jgv/10.1099/0022-1317-77-4-797
Loading
/content/journal/jgv/10.1099/0022-1317-77-4-797
Loading

Data & Media loading...

Most cited this month Most Cited RSS feed

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