Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In June 2006, 150 wild common carp were sampled from Hamilton Harbour, Lake Ontario, Canada. Tissue pools consisting of kidney, spleen and encephalon were screened for viruses as a condition facilitating the export of live carp to France. Cytopathic effect (CPE), indicative of a viral infection, became evident after 8 days of incubation at 15 degrees C. Eighteen of 30 tissue pools (five fish per pool) eventually demonstrated viral CPE. The viral pathogen was initially cultured and isolated on the epithelioma papulosum cyprini cell line and subsequently shown to produce CPE in the fathead minnow and bluegill fin cell lines. Electron microscopy demonstrated the virus to be a rhabdovirus. Reverse transcriptase-polymerase chain reaction assay and nucleotide sequence analysis identified the isolate as spring viraemia of carp virus (SVCV). Phylogenetic analysis of a 533 bp region of the glycoprotein gene grouped the Canadian isolate in SVCV genogroup Ia together with isolates from Asia and the USA. Sequence comparisons revealed the Hamilton Harbour, Lake Ontario isolate to be most similar to an isolate obtained from common carp in the Calumet Sag Channel in Illinois in 2003 (98.9% nucleotide identity). This is the first report of the detection of SVCV in Canada.
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PMID:First detection and confirmation of spring viraemia of carp virus in common carp, Cyprinus carpio L., from Hamilton Harbour, Lake Ontario, Canada. 1795 10

Reverse genetics system is a powerful tool to study the function of a particular gene. The currently available reverse genetics system for Novirhabdovirus is based on vaccinia-driven T7 RNA polymerase expression. An improved system for the recovery of infectious hematopoietic necrosis virus (IHNV) was developed which utilizes cellular RNA polymerase II machinery for transcription. A full-length cDNA clone of IHNV, flanked by hammerhead ribozyme and hepatitis delta ribozyme sequences, was assembled in an expression plasmid under the control of a cytomegalovirus promoter. Transfection of this full-length plasmid along with the supporting plasmids (N, P, NV and L) into epithelioma papulosum cyprini cells resulted in the recovery of a viable recombinant IHNV (rIHNV). The authenticity of rIHNV was confirmed by the presence of restriction sites introduced artificially in the genome. A recombinant IHNV expressing a foreign gene - enhanced green fluorescent protein - was also recovered. The recovered IHNVs showed similar growth characteristics as the parental IHNV in cell cultures. Challenge of susceptible rainbow trout with wild-type IHNV and rIHNV induced clinical disease signs indistinguishable from the parental strain and produced mortality. Thus, a vaccinia-virus-free reverse genetics system described for IHNV is applicable for the recovery of any Novirhabdovirus, which will facilitate studies on viral pathogenesis and the design of new generation of viral vectored vaccines.
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PMID:A vaccinia-virus-free reverse genetics system for infectious hematopoietic necrosis virus. 2036 10

A recombinant viral hemorrhagic septicemia virus (rVHSV-deltaNV-EGFP) containing the enhanced green fluorescent protein (EGFP) gene instead of the NV gene was produced using the reverse-genetics method. For use as a positive control, another recombinant virus (rVHSV-wild) was also generated, which had an identical nucleotide sequence to the wild-type VHSV genome except for a few artificially replaced nucleotides. The rVHSVs were rescued using a system controlled by T7 RNA polymerase supplied by a retroviral vector. Generation of rVHSV-deltaNV-EGFP and rVHSV-wild was confirmed by sequencing of RT-PCR products, and rescue of infectious rVHSVs was confirmed by observation of plaque formation. Replication efficiency of rVHSV-wild was distinctly lower than that of wild-type VHSV, suggesting that the artificially replaced nucleotides, especially when immediately preceding the G or NV gene start codons, might affect the replication of the virus. Replication of rVHSV-deltaNV-EGFP was slightly lower than that of rVHSV-wild when epithelioma papulosum cyprini cells were infected with multiplicity of infection (MOI) 1.0, but much lower when cells were infected with MOI 0.00001. These results suggest that the NV gene plays an important role in VHSV replication through interactions with host-cell responses, and the lower replication ability of rVHSV-wild compared to wild-type VHSV might be caused by replaced nucleotides just before the NV gene open reading frame (ORF) rather than the G gene ORF. In olive flounder Paralichthys olivaceus, rVHSV-wild produced slower-progressing mortalities than wild-type VHSV, whereas rVHSV-deltaNV-EGFP pathogenesis was highly attenuated. These results suggest that the NV protein of VHSV may play an important role not only in viral replication but also in viral pathogenesis.
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PMID:Generation and characterization of NV gene-knockout recombinant viral hemorrhagic septicemia virus (VHSV) genotype IVa. 2223 92