Abstract
Ascoviruses (AVs) belong to a family of double-stranded DNA viruses that infect Lepidoptera insects and cause the unique pathology of forming virion-containing vesicles in the hemolymph of infected hosts. Virions of AVs are large and contain more than 12 polypeptides. A gene, TnAV-CP, encoding the major structural protein of the Trichoplusia ni ascovirus 2a (TnAV-2a) was cloned by immunoscreening an expression library with antibodies against total TnAV virion proteins. TnAV-CP is an intronless gene with an open reading frame encoding a protein of 455 amino acids. Southern blot showed that it is a single copy gene. A 3.8 kb BamHI fragment containing the complete TnAV-CP gene was cloned and sequenced. Northern analysis detected the transcription of the 1.4 kb TnAV-CP mRNA from 24 h after infection. The predicted TnAV-CP protein was expressed in bacterial expression system and purified to homogeneity. The recombinant protein was used to affinity-purify specific antibodies from the antiserum. The purified antibodies reacted strongly with a single protein of ∼52 kDa from the total TnAV virion proteins in a Western blot. This protein corresponds to the most abundant structural protein present in the virions of several AVs. Sequence comparison showed that TnAV-CP is most homologous to the putative capsid proteins from AVs infecting noctuid insects, less homologous to that of Diadromus pulchellus ascovirus 4a (DpAV-4a), further supporting the distinction of two subgroups within the family Ascoviridae. Phylogenetic analysis using the putative capsid protein suggested that AVs were closely related to members of Iridoviridae, which corroborated the result based on DNA polymerase δ sequences. The apparent differences between Ascoviridae and Iridoviridae in host range, virion morphology, and genome configuration, and the similarities in genes and methylation of genomic DNA were discussed.
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References
Federici B.A., Proc Natl Acad Sci USA 80, 7664-7668, 1983.
Federici B.A., Bigot Y., Granados R.R., Hamm J.J., Miller L.K., and Vlak J.M., in Van Regenmortel M.H.V., Fauquet C.M., Bishop D.H.L., Carstens E.B., Estes M.K., Lemon S.M., Maniloff J., Mayo M.A., McGeoch D.J., Pringle C.R., and Wickner R.B. (eds), Virus Taxonomy, Seventh Report of the International Committee on Taxonomy of Viruses. Academic Press, London, 2000.
Cheng X.W., Carner G.R., and Brown T.M., J Gen Virol 80, 1537-1540, 1999.
Bigot Y., Stasiak K., Rouleux-Bonnin F., and Federici B.A., J Gen Virol 81, 3073-3082, 2000.
Pellock B.J., Lu A., Meagher R.B., Weise M.J., and Miller L.K., Virology 216, 146-157, 1996.
Stasiak K., Demattei M.V., Federici B.A., and Bigot Y., J Gen Virol 81, 3059-3072, 2000.
Federici B.A., J Invertebr Pathol 40, 41-54, 1982.
Browning H.W., Federici B.A., and Oatman E.R., Environ Entomol 11, 550-554, 1982.
Carner G.R. and Hudson J.S., J Invertebr Pathol 41, 238-249, 1983.
Hamm J.J., Pair S.D., and Marti O.G., Florida Entomol 69, 524-531, 1986.
Cheng X.W., Carner G.R., and Arif B.M., J Gen Virol 81, 3083-3092, 2000.
Bigot Y., Rabouille A., Doury G., Sizaret P.Y., Delbost F., Hamelin M.H., and Periquet G., J Gen Virol 78, 1149-1163, 1997.
Bigot Y., Rabouille A., Sizaret P.Y., Hamelin M.H., and Periquet G., J Gen Virol 78, 1139-1147, 1997.
Federici B.A. and Govindarajan R., J Invertebr Pathol 56, 300-311, 1990.
Hamm J.J., Styer E.L., and Federici B.A., J Invertebr Pathol 72, 138-146, 1998.
Govindarajan R., and Federici B.A., J Invertebr Pathol 56, 291-299, 1990.
Federici B.A., Vlak J.M., and Hamm J.J., J Gen Virol 71, 1661-1668, 1990.
Sambrook J., Fritsch E.F., and Maniatis T., Molecular Cloning: A Laboratory Manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, 1989.
Cui L., Luckhart S., and Rosenberg R., Insect Mol Bio 9, 127-137, 2000.
Frohman M.A., in Innis M.A., Gelfand D.H., Sninsky J.J., and White T.J. (eds), PCR Protocols: A Guide to Methods and Application. Academic Press, San Diego, 1990, pp. 28-38.
Cui L., Soldevila A., and Webb B.A., Arch Insect Physiol Biochem 36, 251-271, 1997.
Harlow E. and Lane D., Using Antibodies: A Laboratory Manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 1999.
Cameron I.R., Virology 178, 35-42, 1990.
Williams T., Adv Virus Res 46, 345-412, 1996.
Delius H., Darai G., and Flugel R.M.J., Virol 49, 609-614, 1984.
Schnitzler P., Soltai J.B., Fischer M., Reisner H., Scholz J., Delius H., and Darai G., Virology 160, 66-74, 1987.
Tidona C.A., Schnitzler P., Kehm R., and Darai G., Virus Genes 16, 59-66, 1998.
Tidona C.A. and Darai G., Virology 230, 207-216, 1997.
Jakob N.J., Muller K., Bahr U., and Darai G., Virology 286, 182-196, 2001.
He J.G., Deng M., Weng S.P., Li Z., Zhou S.Y., Long Q.X., Wang X.Z., and Chan S.M., Virology 291, 126-139, 2001.
He J.G., Lu L., Deng M., He H.H., Weng S.P., Wang X.H., Zhou S.Y., Long Q.X., Wang X.Z., and Chan S.M., Virology 292, 185-197, 2002.
Hamm J.J., Nordlund D.A., and Marti O.G., Environ Entomol 14, 258-261, 1985.
Webb B.A., in Ball A. and Miller L.K., (eds), The Insect Viruses. Plenum Press, New York, 1998, pp. 105-139.
Whitfield J.B., Proc Natl Acad Sci USA 99, 7508-7513, 2002.
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Zhao, K., Cui, L. Molecular Characterization of the Major Virion Protein Gene from the Trichoplusia ni Ascovirus. Virus Genes 27, 93–102 (2003). https://doi.org/10.1023/A:1025132720885
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DOI: https://doi.org/10.1023/A:1025132720885