The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Houssam Attoui - One of the best experts on this subject based on the ideXlab platform.
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full genome sequencing and genetic characterization of eubenangee viruses identify pata virus as a distinct species within the genus orbivirus
PLOS ONE, 2012Co-Authors: Manjunatha N Belaganahalli, Houssam Attoui, Ross A Lunt, Ian Pritchard, Sushila Maan, Narender S. Maan, Kyriaki Nomikou, P D Kirkland, Joe BrownlieAbstract:Eubenangee virus has previously been identified as the cause of Tammar sudden death syndrome (TSDS). Eubenangee virus (EUBV), Tilligery virus (TILV), Pata virus (PATAV) and Ngoupe virus (NGOV) are currently all classified within the Eubenangee virus species of the genus Orbivirus, family Reoviridae. Full genome sequencing confirmed that EUBV and TILV (both of which are from Australia) show high levels of aa sequence identity (>92%) in the conserved polymerase VP1(Pol), sub-core VP3(T2) and outer core VP7(T13) proteins, and are therefore appropriately classified within the same virus species. However, they show much lower amino acid (aa) identity levels in their larger outer-capsid protein VP2 (<53%), consistent with membership of two different serotypes - EUBV-1 and EUBV-2 (respectively). In contrast PATAV showed significantly lower levels of aa sequence identity with either EUBV or TILV (with <71% in VP1(Pol) and VP3(T2), and <57% aa identity in VP7(T13)) consistent with membership of a distinct virus species. A proposal has therefore been sent to the Reoviridae Study Group of ICTV to recognise ‘Pata virus’ as a new Orbivirus species, with the PATAV isolate as serotype 1 (PATAV-1). Amongst the other orbiviruses, PATAV shows closest relationships to Epizootic Haemorrhagic Disease virus (EHDV), with 80.7%, 72.4% and 66.9% aa identity in VP3(T2), VP1(Pol), and VP7(T13) respectively. Although Ngoupe virus was not available for these studies, like PATAV it was isolated in Central Africa, and therefore seems likely to also belong to the new species, possibly as a distinct ‘type’. The data presented will facilitate diagnostic assay design and the identification of additional isolates of these viruses.
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micromonas pusilla reovirus a new member of the family Reoviridae assigned to a novel proposed genus mimoreovirus
Journal of General Virology, 2006Co-Authors: Houssam Attoui, Philippe De Micco, Fauziah Mohd Jaafar, Mourad Belhouchet, Xavier De Lamballerie, Corina P. D. BrussaardAbstract:Micromonas pusilla reovirus (MpRV) is an 11-segmented, double-stranded RNA virus isolated from the marine protist Micromonas pusilla. Sequence analysis (including conserved termini and presence of core motifs of reovirus polymerase), morphology and physicochemical properties confirmed the status of MpRV as a member of the family Reoviridae. Electron microscopy showed that intact virus particles are unusually larger (90–95 nm) than the known size of particles of viruses belonging to the family Reoviridae. Particles that were purified on caesium chloride gradients had a mean size of 75 nm (a size similar to the size of intact particles of members of the family Reoviridae), indicating that they lost outer-coat components. The subcore particles had a mean size of 50 nm and a smooth surface, indicating that MpRV belongs to the non-turreted Reoviridae. The maximum amino acid identity with other reovirus proteins was 21 %, which is compatible with values existing between distinct genera. Based on morphological and sequence findings, this virus should be classified as the representative of a novel genus within the family Reoviridae, designated Mimoreovirus (from Micromonas pusilla reovirus). The topology of the phylogenetic tree built with putative polymerase sequences of the family Reoviridae suggested that the branch of MpRV could be ancestral. Further analysis showed that segment 1 of MpRV was much longer (5792 bp) than any other reovirus segment and encoded a protein of 200 kDa (VP1). This protein exhibited significant similarities to O-glycosylated proteins, including viral envelope proteins, and is likely to represent the additional outer coat of MpRV.
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expansion of family Reoviridae to include nine segmented dsrna viruses isolation and characterization of a new virus designated aedes pseudoscutellaris reovirus assigned to a proposed genus dinovernavirus
Virology, 2005Co-Authors: Houssam Attoui, Philippe De Micco, Fauziah Mohd Jaafar, Mourad Belhouchet, Philippe Biagini, Jean-françois Cantaloube, Xavier De LamballerieAbstract:Family Reoviridae is known, by definition, to contain dsRNA viruses with 10-12 genome segments. We report here the characterization of the first member of this family with a nine-segmented genome. This virus was isolated from Aedes pseudoscutellaris mosquito cells and designated aedes pseudoscutellaris reovirus (APRV). Virions are single-shelled with turrets but are non-occluded by contrast to cypoviruses. APRV replicates in various mosquito cell lines, but not in mice or mammalian cells. Complete sequence analysis showed that APRV is phylogenetically related to cypoviruses, fijiviruses and oryzaviruses. The maximum amino acid identities with cypoviruses, oryzaviruses or fijiviruses in the polymerase, are compatible with values observed between these genera and lower than values within a given genus. This suggests that APRV should be classified within a new genus that we designated Dinovernavirus (sigla from D: Double-stranded, i: insect, nove: nine from the latin "novem", rna: RNA, virus) in family Reoviridae.
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common evolutionary origin of aquareoviruses and orthoreoviruses revealed by genome characterization of golden shiner reovirus grass carp reovirus striped bass reovirus and golden ide reovirus genus aquareovirus family Reoviridae
Journal of General Virology, 2002Co-Authors: Houssam Attoui, Philippe De Micco, Fauziah Mohd Jaafar, Qin Fang, Philippe Biagini, Jean-françois Cantaloube, Xavier De LamballerieAbstract:Full-length and partial genome sequences of four members of the genus Aquareovirus, family Reoviridae (Golden shiner reovirus, Grass carp reovirus, Striped bass reovirus and golden ide reovirus) were characterized. Based on sequence comparison, the unclassified Grass carp reovirus was shown to be a member of the species Aquareovirus C. The status of golden ide reovirus, another unclassified aquareovirus, was also examined. Sequence analysis showed that it did not belong to the species Aquareovirus A or C, but assessment of its relationship to the species Aquareovirus B, D, E and F was hampered by the absence of genetic data from these species. In agreement with previous reports of ultrastructural resemblance between aquareoviruses and orthoreoviruses, genetic analysis revealed homology in the genes of the two groups. This homology concerned eight of the 11 segments of the aquareovirus genome (amino acid identity 17–42%), and similar genetic organization was observed in two other segments. The conserved terminal sequences in the genomes of members of the two groups were also similar. These data are undoubtedly an indication of the common evolutionary origin of these viruses. This clear genetic relatedness between members of distinct genera is unique within the family Reoviridae. Such a genetic relationship is usually observed between members of a single genus. However, the current taxonomic classification of aquareoviruses and orthoreoviruses in two different genera is supported by a number of characteristics, including their distinct G+C contents, unequal numbers of genome segments, absence of an antigenic relationship, different cytopathic effects and specific econiches.
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Genus Coltivirus (family Reoviridae): genomic and morphologic characterization of Old World and New World viruses.
Archives of Virology, 2002Co-Authors: Houssam Attoui, Philippe Biagini, Jean-françois Cantaloube, P. De Micco, F. A. Murphy, F. Mohd Jaafar, X. De LamballerieAbstract:We report a genomic and morphologic study of the European Eyach (EYA) virus (genus Coltivirus, family Reoviridae) and a comparative analysis with the American Colorado tick fever (CTF) virus (the type species of the genus). The previously established, but distant, antigenic relationship between these viruses was strengthened by genetic findings (presence of cognate genes, amino acid identity between 55 and 88%, similar conserved terminal motifs, suspected read-through phenomenon in segment 9 of both viruses) and by indistinguishable ultramicroscopic morphologies. Moreover, putative constitutive modifying enzyme activities were suspected to be carried out by homologous viral proteins (RNA-dependent RNA polymerase, methyl/guanylyl transferase, NTPase).
Guohui Zhou - One of the best experts on this subject based on the ideXlab platform.
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synergism between southern rice black streaked dwarf virus and rice ragged stunt virus enhances their insect vector acquisition
Phytopathology, 2014Co-Authors: Han Wang, Guohui ZhouAbstract:Southern rice black-streaked dwarf virus (SRBSDV), a tentative species in the genus Fijivirus, family Reoviridae, is a novel rice virus transmitted by the white-backed planthopper (Sogatella furcifera). Since its discovery in 2001, SRBSDV has spread rapidly throughout eastern and southeastern Asia and caused large rice losses in China and Vietnam. Rice ragged stunt virus (RRSV) (genus Oryzavirus, family Reoviridae) is a common rice virus vectored by the brown planthopper (Nilaparvata lugens). RRSV is also widely distributed in eastern and southeastern Asia but has not previously caused serious problems in China owing to its low incidence. With SRBSDV's spread, however, RRSV has become increasingly common in China, and is frequently found in co-infection with SRBSDV. In this study, we show that SRBSDV and RRSV interact synergistically, the first example of synergism between plant viruses in the family Reoviridae. Rice plants co-infected with both viruses displayed enhanced stunting, earlier symptoms, and higher virus titers compared with singly infected plants. Furthermore, white-backed and brown planthoppers acquired SRBSDV and RRSV, respectively, from co-infected plants at higher rates. We propose that increased RRSV incidence in Chinese fields is partly due to synergism between SRBSDV and RRSV.
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southern rice black streaked dwarf virus alters insect vectors host orientation preferences to enhance spread and increase rice ragged stunt virus co infection
Phytopathology, 2014Co-Authors: Han Wang, Donglin Xu, Lingling Pu, Guohui ZhouAbstract:In recent years, Southern rice black-streaked dwarf virus (SRBSDV), a tentative species in the genus Fijivirus (family Reoviridae), has spread rapidly and caused serious rice losses in eastern and southeastern Asia. With this virus spread, Rice ragged stunt virus (RRSV, genus Oryzavirus, family Reoviridae) became more common in southern China, usually in co-infection with the former. SRBSDV and RRSV are transmitted by two different species of planthoppers, white-backed planthopper (WBPH, Sogatella furcifera) and brown planthopper (BPH, Nilaparvata lugens), respectively, in a persistent, circulative, propagative manner. In this study, using a Y-shape olfactometer-based device, we tested the host preference of three types of macropterous WBPH adults for healthy or SRBSDV-infected rice plants. The results showed that virus-free WBPHs significantly preferred infected rice plants to healthy plants, whereas both the viruliferous and nonviruliferous WBPHs preferred healthy plants to infected plants. In additional tests, we found that the BPHs significantly preferred healthy plants when they were virus free, whereas RRSV-carrying BPHs preferred SRBSDV-infected rice plants. From these findings, we propose that plant viruses may alter host selection preference of vectors to enhance their spread and that of insects vectoring another virus to result in co-infection with more than one virus.
Piet A Van Rijn - One of the best experts on this subject based on the ideXlab platform.
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structural protein vp2 of african horse sickness virus is not essential for virus replication in vitro
Journal of Virology, 2017Co-Authors: Rene G P Van Gennip, Piet A Van Rijn, Sandra G P Van De Water, Christiaan A PotgieterAbstract:The Reoviridae family consists of nonenveloped multilayered viruses with a double-stranded RNA genome consisting of 9 to 12 genome segments. The Orbivirus genus of the Reoviridae family contains African horse sickness virus (AHSV), bluetongue virus, and epizootic hemorrhagic disease virus, which cause notifiable diseases and are spread by biting Culicoides species. Here, we used reverse genetics for AHSV to study the role of outer capsid protein VP2, encoded by genome segment 2 (Seg-2). Expansion of a previously found deletion in Seg-2 indicates that structural protein VP2 of AHSV is not essential for virus replication in vitro. In addition, inframe replacement of RNA sequences in Seg-2 by that of green fluorescence protein (GFP) resulted in AHSV expressing GFP, which further confirmed that VP2 is not essential for virus replication. In contrast to virus replication without VP2 expression in mammalian cells, virus replication in insect cells was strongly reduced, and virus release from insect cells was completely abolished. Further, the other outer capsid protein, VP5, was not copurified with virions for virus mutants without VP2 expression. AHSV without VP5 expression, however, could not be recovered, indicating that outer capsid protein VP5 is essential for virus replication in vitro. Our results demonstrate for the first time that a structural viral protein is not essential for orbivirus replication in vitro, which opens new possibilities for research on other members of the Reoviridae family.
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requirements and comparative analysis of reverse genetics for bluetongue virus btv and african horse sickness virus ahsv
Virology Journal, 2016Co-Authors: Piet A Van Rijn, Sandra G P Van De Water, Femke Feenstra, Rene G P Van GennipAbstract:Background Bluetongue virus (BTV) and African horse sickness virus (AHSV) are distinct arthropod borne virus species in the genus Orbivirus (Reoviridae family), causing the notifiable diseases Bluetongue and African horse sickness of ruminants and equids, respectively. Reverse genetics systems for these orbiviruses with their ten-segmented genome of double stranded RNA have been developed. Initially, two subsequent transfections of in vitro synthesized capped run-off RNA transcripts resulted in the recovery of BTV. Reverse genetics has been improved by transfection of expression plasmids followed by transfection of ten RNA transcripts. Recovery of AHSV was further improved by use of expression plasmids containing optimized open reading frames.
X. De Lamballerie - One of the best experts on this subject based on the ideXlab platform.
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Genus Coltivirus (family Reoviridae): genomic and morphologic characterization of Old World and New World viruses.
Archives of Virology, 2002Co-Authors: Houssam Attoui, Philippe Biagini, Jean-françois Cantaloube, P. De Micco, F. A. Murphy, F. Mohd Jaafar, X. De LamballerieAbstract:We report a genomic and morphologic study of the European Eyach (EYA) virus (genus Coltivirus, family Reoviridae) and a comparative analysis with the American Colorado tick fever (CTF) virus (the type species of the genus). The previously established, but distant, antigenic relationship between these viruses was strengthened by genetic findings (presence of cognate genes, amino acid identity between 55 and 88%, similar conserved terminal motifs, suspected read-through phenomenon in segment 9 of both viruses) and by indistinguishable ultramicroscopic morphologies. Moreover, putative constitutive modifying enzyme activities were suspected to be carried out by homologous viral proteins (RNA-dependent RNA polymerase, methyl/guanylyl transferase, NTPase).
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Sequence determination and analysis of the full-length genome of colorado tick fever virus, the type species of genus Coltivirus (Family Reoviridae).
Biochemical and Biophysical Research Communications, 2000Co-Authors: Houssam Attoui, Philippe De Micco, Frederique Billoir, Philippe Biagini, Jean-françois Cantaloube, Reine De Chesse, X. De LamballerieAbstract:The Colorado tick fever virus (CTFV) is the type species of genus Coltivirus, family Reoviridae. Its genome consisting of 12 segments of dsRNA was completely sequenced. It was found to be 29,174 nucleotides long (the longest of all Reoviridae genomes characterized to date). Conserved sequences at the 5' end (SACUUUUGY) and at the 3' end (WUGCAGUS) of the 12 segments were identified. The analysis of the putative proteins deduced from the nucleotide sequences permitted to identify functional motifs. In particular, the VP1 was identified unambiguously as the viral RNA dependent RNA pylmerase (RDRP) (VP1pol), with a GDD located at a similar position to Reoviridae RDRPs. In other genes, RGD cell-binding, NTPAse, single strand binding protein and kinase motifs were identified. Comparison with Reoviridae proteins showed significant similarities to RDRPs (CTFV-VP1) and sigma C protein of orthoreovirus (CTFV-VP6). Similarities to nonviral enzymatic proteins, such as methyltransferases, NTPAses, RNA replication factors, were also identified.
Han Wang - One of the best experts on this subject based on the ideXlab platform.
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synergism between southern rice black streaked dwarf virus and rice ragged stunt virus enhances their insect vector acquisition
Phytopathology, 2014Co-Authors: Han Wang, Guohui ZhouAbstract:Southern rice black-streaked dwarf virus (SRBSDV), a tentative species in the genus Fijivirus, family Reoviridae, is a novel rice virus transmitted by the white-backed planthopper (Sogatella furcifera). Since its discovery in 2001, SRBSDV has spread rapidly throughout eastern and southeastern Asia and caused large rice losses in China and Vietnam. Rice ragged stunt virus (RRSV) (genus Oryzavirus, family Reoviridae) is a common rice virus vectored by the brown planthopper (Nilaparvata lugens). RRSV is also widely distributed in eastern and southeastern Asia but has not previously caused serious problems in China owing to its low incidence. With SRBSDV's spread, however, RRSV has become increasingly common in China, and is frequently found in co-infection with SRBSDV. In this study, we show that SRBSDV and RRSV interact synergistically, the first example of synergism between plant viruses in the family Reoviridae. Rice plants co-infected with both viruses displayed enhanced stunting, earlier symptoms, and higher virus titers compared with singly infected plants. Furthermore, white-backed and brown planthoppers acquired SRBSDV and RRSV, respectively, from co-infected plants at higher rates. We propose that increased RRSV incidence in Chinese fields is partly due to synergism between SRBSDV and RRSV.
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southern rice black streaked dwarf virus alters insect vectors host orientation preferences to enhance spread and increase rice ragged stunt virus co infection
Phytopathology, 2014Co-Authors: Han Wang, Donglin Xu, Lingling Pu, Guohui ZhouAbstract:In recent years, Southern rice black-streaked dwarf virus (SRBSDV), a tentative species in the genus Fijivirus (family Reoviridae), has spread rapidly and caused serious rice losses in eastern and southeastern Asia. With this virus spread, Rice ragged stunt virus (RRSV, genus Oryzavirus, family Reoviridae) became more common in southern China, usually in co-infection with the former. SRBSDV and RRSV are transmitted by two different species of planthoppers, white-backed planthopper (WBPH, Sogatella furcifera) and brown planthopper (BPH, Nilaparvata lugens), respectively, in a persistent, circulative, propagative manner. In this study, using a Y-shape olfactometer-based device, we tested the host preference of three types of macropterous WBPH adults for healthy or SRBSDV-infected rice plants. The results showed that virus-free WBPHs significantly preferred infected rice plants to healthy plants, whereas both the viruliferous and nonviruliferous WBPHs preferred healthy plants to infected plants. In additional tests, we found that the BPHs significantly preferred healthy plants when they were virus free, whereas RRSV-carrying BPHs preferred SRBSDV-infected rice plants. From these findings, we propose that plant viruses may alter host selection preference of vectors to enhance their spread and that of insects vectoring another virus to result in co-infection with more than one virus.
