Results 1 - 10
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99
Virus-encoded proteinases and proteolytic processing in the Nidovirales
- J. Gen. Virol
, 2000
"... On the basis of similarities in their genome organization and replication strategy, RNA viruses can now be classified into ‘supergroups ’ that often include both animal and plant ..."
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Cited by 105 (29 self)
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On the basis of similarities in their genome organization and replication strategy, RNA viruses can now be classified into ‘supergroups ’ that often include both animal and plant
Detection of porcine reproductive and respiratory syndrome virus and efficient differentiation between Canadian and European strains by reverse transcription and PCR
, 1994
"... multiplex PCR assay. ..."
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Porcine reproductive and respiratory syndrome virus - a persistent infection
- Proc 2nd Int Symp on PRRS
, 1995
"... Like other arteriviruses, porcine reproductive and respiratory syndrome virus (PRRSV) is shed in semen, a feature that is critical for the venereal transmission of this group of viruses. In spite of its epidemiological importance, little is known of the association of PRRSV or other arteriviruses wi ..."
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Cited by 62 (14 self)
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Like other arteriviruses, porcine reproductive and respiratory syndrome virus (PRRSV) is shed in semen, a feature that is critical for the venereal transmission of this group of viruses. In spite of its epidemiological importance, little is known of the association of PRRSV or other arteriviruses with gonadal tissues. We experimentally infected a group of boars with PRRSV 12068-96, a virulent field strain. By combined use of in situ hybridization and immunohistochemistry, we detected infection by PRRSV in the testes of these boars. The PRRSV testicular replication in testis centers on two types of cells: (i) epithelial germ cells of the seminiferous tubules, primarily spermatids and spermatocytes, and (ii) macrophages, which are located in the interstitium of the testis. Histopathologically, hypospermatogenesis, formation of multinucleated giant cells (MGCs), and abundant germ cell depletion and death were observed. We obtained evidence that such germ cell death occurs by apoptosis, as determined by a characteristic histologic pattern and evidence of massive DNA fragmentation detected in situ (TUNEL [terminal deoxynucleotidyltransferase-mediated digoxigenin-UTP nick end labeling] assay). Simultaneously with these testicular alterations, we observed that there is a significant increase in the number of immature sperm cells (mainly MGCs, spermatids, and spermatocytes) in the ejaculates of the PRRSV-inoculated boars and that these cells are infected with PRRSV. Our results indicate that PRRSV may infect target cells other than macrophages, that these infected cells can be primarily responsible for the
The genome organization of the Nidovirales: similarities and differences between arteri-, toro-, and coronaviruses
- Semin Virol
, 1997
"... Viruses in the families Arteriviridae and Coronaviridae have enveloped virions which contain nonseg-mented, positive-stranded RNA, but the constituent genera differ markedly in genetic complexity and virion structure. Nevertheless, there are striking resemblances among the viruses in the organizatio ..."
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Cited by 49 (11 self)
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Viruses in the families Arteriviridae and Coronaviridae have enveloped virions which contain nonseg-mented, positive-stranded RNA, but the constituent genera differ markedly in genetic complexity and virion structure. Nevertheless, there are striking resemblances among the viruses in the organization and expression of their genomes, and sequence conservation among the polymerase polyproteins strongly suggests that they have a common ancestry. On this basis, the International Committee on Taxonomy of Viruses recently established a new order, Nidovirales, to contain the two families. Here, the common traits and distinguishing features of the Nidovirales are reviewed. r 1997 Academic Press KEY WORDS: arterivirus; coronavirus; torovirus; polyprotein processing; RNA recombination.
Porcine reproductive and respiratory syndrome virus comparison: divergent evolution on two continents
- J
, 1999
"... This article cites 64 articles, 31 of which can be accessed free ..."
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Cited by 47 (7 self)
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This article cites 64 articles, 31 of which can be accessed free
Genetic variation in porcine reproductive and respiratory syndrome virus isolates in the midwestern United
, 1996
"... The nucleotide sequence of a 3266 bp region encompassing open reading frames (ORFs) 2 through 7 of the porcine reproductive and respiratory syndrome virus (PRRSV) was determined for 10 isolates recovered from the midwestern United States. Pairwise comparisons showed that genetic distances between is ..."
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Cited by 23 (5 self)
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The nucleotide sequence of a 3266 bp region encompassing open reading frames (ORFs) 2 through 7 of the porcine reproductive and respiratory syndrome virus (PRRSV) was determined for 10 isolates recovered from the midwestern United States. Pairwise comparisons showed that genetic distances between isolates ranged from 2.5 % to 7.9 % (mean 5.8 % + 0.2 %) whereas the Lelystad strain from Europe was, on average, 34-8 % divergent from US clones. Thus, US and European PRRSV isolates represent genetically distinct clusters of the same virus. ORF 5, which encodes the envelope glycoprotein, was the most polymorphic [total nucleotide diversity (re) = 0-097 __+ 0"007] and ORF 6, encoding the viral M protein, was the most conserved (n = 0"038 __ _ 0"003). The substantial differences in nucleotide diversity among ORFs suggests that the virus is evolving by processes other than simple accumulation of random neutral mutations. In support of this hypothesis, statistical analyses of the nucleotide sequence provided strong evidence for intragenic recombination or gene conversion in ORFs 2, 3, 4, 5 and 7, but not in ORF 6. An excess of synonymous (silent) substitutions was observed in all six ORFs, indicating an evolutionary pressure to conserve amino acid sequences. Taken together, the data indicate that despite intragenic recombination among extant PRRSV isolates, purifying selection has acted to maintain the primary structure of individual ORFs.
Equine arteritis virus subgenomic mRNA synthesis: analysis of leader-body junctions and replicative-form RNAs
- J
, 1996
"... and replicative-form RNAs. synthesis: analysis of leader-body junctions Equine arteritis virus subgenomic mRNA ..."
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Cited by 22 (8 self)
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and replicative-form RNAs. synthesis: analysis of leader-body junctions Equine arteritis virus subgenomic mRNA
Identification of a novel structural protein of arteriviruses
- J
, 1999
"... Arteriviruses are positive-stranded RNA viruses with an efficiently organized, polycistronic genome. A short region between the replicase gene and open reading frame (ORF) 2 of the equine arteritis virus (EAV) genome was previously assumed to be untranslated. However, here we report that this segmen ..."
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Cited by 20 (11 self)
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Arteriviruses are positive-stranded RNA viruses with an efficiently organized, polycistronic genome. A short region between the replicase gene and open reading frame (ORF) 2 of the equine arteritis virus (EAV) genome was previously assumed to be untranslated. However, here we report that this segment of the EAV genome contains the 5 * part of a novel gene (ORF 2a) which is conserved in all arteriviruses. The 3 * part of EAV ORF 2a overlaps with the 5 * part of the former ORF 2 (now renamed ORF 2b), which encodes the GS glycoprotein. Both ORF 2a and ORF 2b appear to be expressed from mRNA 2, which thereby constitutes the first proven example of a bicistronic mRNA in arteriviruses. The 67-amino-acid protein encoded by EAV ORF 2a, which we have provisionally named the envelope (E) protein, is very hydrophobic and has a basic C terminus. An E protein-specific antiserum was raised and used to demonstrate the expression of the novel gene in EAV-infected cells. The EAV E protein proved to be very stable, did not form disulfide-linked oligomers, and was not N-glycosylated. Immunofluorescence and immunoelectron microscopy studies showed that the E protein associates with intracellular membranes both in EAV-infected cells and upon independent expression. An analysis of purified EAV particles revealed that the E protein is a structural protein. By using reverse genetics, we demonstrated that both the EAV E and GS proteins are essential for the production of infectious progeny virus. Arteriviruses are enveloped, positive-stranded RNA viruses
Alternative proteolytic processing of the arterivirus replicase ORF1a polyprotein : evidence that NSP2 acts as a cofactor for the NSP4 serine protease
- Journal of Virology
, 1997
"... evidence that NSP2 acts as a cofactor for the ..."
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