1985 Fiscal Year Final Research Report Summary
Basic studies on production of useful foreign gene products in the silkworm, Bombyx mori, using insect virus vectors
Project/Area Number |
58440014
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Research Category |
Grant-in-Aid for General Scientific Research (A)
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Allocation Type | Single-year Grants |
Research Field |
蚕糸学
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Research Institution | Tottori University |
Principal Investigator |
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Project Period (FY) |
1983 – 1985
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Keywords | Insect virus / protein / silkworm / vector / gene expression / polyhedrosis virus / 多角体病ウイルス / 樹立細胞株 |
Research Abstract |
Many wild isolates of insect viruses and established cell lines were screened for the studies of insect viral replication. Extensive searching showed that Bombyx mori nuclear polyhedrosis virus (SlNPV) can replicate in BmN cells, and Spodoptera litura NPV can replicate in CLS79, SF21AE, and TN368. More than two hundred viral isolates of Spodoptera litura nuclear polyhedrosis virus were plaque purified on established cell lines. These viral clones were classified into four groups concerning in vitro host range. Viral DNAs, polypeptides, polyhedral proteins were purified and compared. Biochemical characters of the viruses between host range groups were rellativelly different, however, there were a few changes in biochemical characters within the same host range group. These results indicate that wild isolates of SlNPV are a mixture of different viral clones. DNA fragments containing polyhedrin gene in BmNPV were cloned into pUC19 plasmid using cDNA as a probe. The cDNA was made from mRNA isolated from infected fat bodies at the late stage of infection. Nucleotide sequences of polyhedral coding region and its 5' and 3' regions were determined by the dideoxy sequencing method described by Sanger. A complete gene library of BmNPV was made using pUC9, PUC19, pBR322 plasmids as vectors. A physical map of BmNPV was also constructed. Transfection of viral DNA purified from viral particles of BmNPV produced intact viral particles in the cell fluids, indicating that recombinant NPV can be produced by cotransfection of a recombinant plasmid and viral DNA. Heat stability and viral growth of a recombinant virus with insertion of an E2 protein of BPV-2 were not different from that of T3 wild isolate of BmNPV.
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Research Products
(10 results)