The Experts below are selected from a list of 651 Experts worldwide ranked by ideXlab platform
Pauline Bernardo - One of the best experts on this subject based on the ideXlab platform.
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Molecular characterization and prevalence of two capulaviruses: Alfalfa leaf curl virus from France and Euphorbia Caput-Medusae latent virus from South Africa
2016Co-Authors: Pauline Bernardo, Emmanuel Fernandez, Brejnev Muhire, Sarah François, Maelle Deshoux, Penelope Hartnady, Kata Farkas, Simona Kraberger, Denis Filloux, Serge GalziAbstract:Little is known about the prevalence, diversity, evolutionary processes, genomic structures and population dynamics of viruses in the divergent geminivirus lineage known as the capulaviruses. We determined and analyzed full genome sequences of 13 Euphorbia Caput-Medusae latent virus (EcmLV) and 26 Alfalfa leaf curl virus (ALCV) isolates, and partial genome sequences of 23 EcmLV and 37 ALCV isolates. While EcmLV was asymptomatic in uncultivated southern African Euphorbia Caput-Medusae, severe alfalfa disease symptoms were associated with ALCV in southern France. The prevalence of both viruses exceeded 10% in their respective hosts. Besides using patterns of detectable negative selection to identify ORFs that are probably functionally expressed, we show that ALCV and EcmLV both display evidence of inter-species recombination and biologically functional genomic secondary structures. Finally, we show that whereas the EcmLV populations likely experience restricted geographical dispersion, ALCV is probably freely moving across the French Mediterranean region.
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identification and characterisation of a highly divergent geminivirus evolutionary and taxonomic implications
2013Co-Authors: Pauline Bernardo, Martine Granier, Michel Peterschmitt, Emmanuel Fernandez, Michael Golden, Mohammad Akram, N Nadarajan, Anthony Rebelo, Darren P Martin, Philippe RoumagnacAbstract:During a large scale "non a priori" survey in 2010 of South African plant-infecting single stranded DNA viruses, a highly divergent geminivirus genome was isolated from a wild spurge, Euphorbia CaputMedusae. In addition to being infectious in E. Caput-Medusae, the cloned viral genome was also infectious in tomato and Nicotiana benthamiana. The virus, named Euphorbia Caput-Medusae latent virus (EcmLV) due to the absence of infection symptoms displayed by its natural host, caused severe symptoms in both tomato and N. benthamiana. The genome organisation of EcmLV is unique amongst geminiviruses and it likely expresses at least two proteins without any detectable homologues within public sequence databases. Although clearly a geminivirus, EcmLV is so divergent that we propose its placement within a new genus that we have tentatively named Capulavirus. Using a set of highly divergent geminiviruses genomes, it is apparent that recombination has likely been a primary process in the genus-level diversification of geminiviruses. It is also demonstrated how this insight, taken together with phylogenetic analyses of predicted coat protein and replication associated protein (Rep) amino acid sequences indicate that the most recent common ancestor of the geminiviruses was likely a dicot-infecting virus that, like modern day mastreviruses and becurtoviruses, expressed its Rep from a spliced complementary strand transcript. (Resume d'auteur)
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molecular characterization of euphorbia Caput Medusae stunt virus evidence for the existence of a new genus within the family geminiviridae
2013Co-Authors: Pauline Bernardo, Martine Granier, Michel Peterschmitt, Emmanuel Fernandez, Michael Golden, Tony A Rebelo, Darren Patrick Martin, Philippe RoumagnacAbstract:Studies focusing on phytoviruses isolated from the wild are rare. Nevertheless, even if those studies remain scarce, it is increasingly accepted that viruses coming from wild plants might play a role on disease emergence and in the functioning of ecosystems. Geminivirus are a major cause of disease on plants of agronomic interest. We hypothesize that strengthening our knowledge of the geminivirus diversity coming from the wild could help reconstructing the evolutionary history of the Geminiviridae family but also could help us understanding and predicting future epidemics. Over the past two decades, rolling circle amplification (RCA) has been more and more employed for the detection of small circular single-stranded DNA viruses, including geminivirus coming from the wild 1. We have used this method for detecting the presence of ssDNA from 236 plants collected in the South African fynbos. We have obtained amplified DNAs from 36% of the plants (85 out of 236 plants). Using classical cloning and sequencing methods, we have obtained ten sequences of which one was identified as a plant virus. This viral sequence corresponds to a new geminivirus, which infects a wild spurge (Euphorbia Caput-Medusae). This geminivirus is highly divergent from the current known members of the family Geminiviridae and is likely to represent a new previously unknown genus of this agriculturally highly relevant family of viruses. The virus, which we have named Euphorbia Caput-Medusae stunt virus (EcmSV) is not obviously a recombinant of viruses in the known geminivirus genera, has features most similar to viruses in the genus Mastrevirus (the presence of a repA gene and the production transcripts that are almost certainly spliced), but it also has unique features among geminiviruses (potential product of spliced V2-V3 ORFs). Besides EcmSV providing new information on the evolutionary history of geminiviruses, its discovery stresses the need to better assess viral diversity at the interface between wild and cultivated areas (by in situ sampling) and to study viruses isolated from wild hosts for their potential to infect crop species and vice-versa (by in vitro experimentation). 1. Varsani,A. et al. A highly divergent South African geminivirus species (Texte integral)
Serge Galzi - One of the best experts on this subject based on the ideXlab platform.
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Molecular characterization and prevalence of two capulaviruses: Alfalfa leaf curl virus from France and Euphorbia Caput-Medusae latent virus from South Africa
2016Co-Authors: Pauline Bernardo, Emmanuel Fernandez, Brejnev Muhire, Sarah François, Maelle Deshoux, Penelope Hartnady, Kata Farkas, Simona Kraberger, Denis Filloux, Serge GalziAbstract:Little is known about the prevalence, diversity, evolutionary processes, genomic structures and population dynamics of viruses in the divergent geminivirus lineage known as the capulaviruses. We determined and analyzed full genome sequences of 13 Euphorbia Caput-Medusae latent virus (EcmLV) and 26 Alfalfa leaf curl virus (ALCV) isolates, and partial genome sequences of 23 EcmLV and 37 ALCV isolates. While EcmLV was asymptomatic in uncultivated southern African Euphorbia Caput-Medusae, severe alfalfa disease symptoms were associated with ALCV in southern France. The prevalence of both viruses exceeded 10% in their respective hosts. Besides using patterns of detectable negative selection to identify ORFs that are probably functionally expressed, we show that ALCV and EcmLV both display evidence of inter-species recombination and biologically functional genomic secondary structures. Finally, we show that whereas the EcmLV populations likely experience restricted geographical dispersion, ALCV is probably freely moving across the French Mediterranean region.
Emmanuel Fernandez - One of the best experts on this subject based on the ideXlab platform.
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Molecular characterization and prevalence of two capulaviruses: Alfalfa leaf curl virus from France and Euphorbia Caput-Medusae latent virus from South Africa
2016Co-Authors: Pauline Bernardo, Emmanuel Fernandez, Brejnev Muhire, Sarah François, Maelle Deshoux, Penelope Hartnady, Kata Farkas, Simona Kraberger, Denis Filloux, Serge GalziAbstract:Little is known about the prevalence, diversity, evolutionary processes, genomic structures and population dynamics of viruses in the divergent geminivirus lineage known as the capulaviruses. We determined and analyzed full genome sequences of 13 Euphorbia Caput-Medusae latent virus (EcmLV) and 26 Alfalfa leaf curl virus (ALCV) isolates, and partial genome sequences of 23 EcmLV and 37 ALCV isolates. While EcmLV was asymptomatic in uncultivated southern African Euphorbia Caput-Medusae, severe alfalfa disease symptoms were associated with ALCV in southern France. The prevalence of both viruses exceeded 10% in their respective hosts. Besides using patterns of detectable negative selection to identify ORFs that are probably functionally expressed, we show that ALCV and EcmLV both display evidence of inter-species recombination and biologically functional genomic secondary structures. Finally, we show that whereas the EcmLV populations likely experience restricted geographical dispersion, ALCV is probably freely moving across the French Mediterranean region.
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identification and characterisation of a highly divergent geminivirus evolutionary and taxonomic implications
2013Co-Authors: Pauline Bernardo, Martine Granier, Michel Peterschmitt, Emmanuel Fernandez, Michael Golden, Mohammad Akram, N Nadarajan, Anthony Rebelo, Darren P Martin, Philippe RoumagnacAbstract:During a large scale "non a priori" survey in 2010 of South African plant-infecting single stranded DNA viruses, a highly divergent geminivirus genome was isolated from a wild spurge, Euphorbia CaputMedusae. In addition to being infectious in E. Caput-Medusae, the cloned viral genome was also infectious in tomato and Nicotiana benthamiana. The virus, named Euphorbia Caput-Medusae latent virus (EcmLV) due to the absence of infection symptoms displayed by its natural host, caused severe symptoms in both tomato and N. benthamiana. The genome organisation of EcmLV is unique amongst geminiviruses and it likely expresses at least two proteins without any detectable homologues within public sequence databases. Although clearly a geminivirus, EcmLV is so divergent that we propose its placement within a new genus that we have tentatively named Capulavirus. Using a set of highly divergent geminiviruses genomes, it is apparent that recombination has likely been a primary process in the genus-level diversification of geminiviruses. It is also demonstrated how this insight, taken together with phylogenetic analyses of predicted coat protein and replication associated protein (Rep) amino acid sequences indicate that the most recent common ancestor of the geminiviruses was likely a dicot-infecting virus that, like modern day mastreviruses and becurtoviruses, expressed its Rep from a spliced complementary strand transcript. (Resume d'auteur)
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molecular characterization of euphorbia Caput Medusae stunt virus evidence for the existence of a new genus within the family geminiviridae
2013Co-Authors: Pauline Bernardo, Martine Granier, Michel Peterschmitt, Emmanuel Fernandez, Michael Golden, Tony A Rebelo, Darren Patrick Martin, Philippe RoumagnacAbstract:Studies focusing on phytoviruses isolated from the wild are rare. Nevertheless, even if those studies remain scarce, it is increasingly accepted that viruses coming from wild plants might play a role on disease emergence and in the functioning of ecosystems. Geminivirus are a major cause of disease on plants of agronomic interest. We hypothesize that strengthening our knowledge of the geminivirus diversity coming from the wild could help reconstructing the evolutionary history of the Geminiviridae family but also could help us understanding and predicting future epidemics. Over the past two decades, rolling circle amplification (RCA) has been more and more employed for the detection of small circular single-stranded DNA viruses, including geminivirus coming from the wild 1. We have used this method for detecting the presence of ssDNA from 236 plants collected in the South African fynbos. We have obtained amplified DNAs from 36% of the plants (85 out of 236 plants). Using classical cloning and sequencing methods, we have obtained ten sequences of which one was identified as a plant virus. This viral sequence corresponds to a new geminivirus, which infects a wild spurge (Euphorbia Caput-Medusae). This geminivirus is highly divergent from the current known members of the family Geminiviridae and is likely to represent a new previously unknown genus of this agriculturally highly relevant family of viruses. The virus, which we have named Euphorbia Caput-Medusae stunt virus (EcmSV) is not obviously a recombinant of viruses in the known geminivirus genera, has features most similar to viruses in the genus Mastrevirus (the presence of a repA gene and the production transcripts that are almost certainly spliced), but it also has unique features among geminiviruses (potential product of spliced V2-V3 ORFs). Besides EcmSV providing new information on the evolutionary history of geminiviruses, its discovery stresses the need to better assess viral diversity at the interface between wild and cultivated areas (by in situ sampling) and to study viruses isolated from wild hosts for their potential to infect crop species and vice-versa (by in vitro experimentation). 1. Varsani,A. et al. A highly divergent South African geminivirus species (Texte integral)
Denis Filloux - One of the best experts on this subject based on the ideXlab platform.
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Molecular characterization and prevalence of two capulaviruses: Alfalfa leaf curl virus from France and Euphorbia Caput-Medusae latent virus from South Africa
2016Co-Authors: Pauline Bernardo, Emmanuel Fernandez, Brejnev Muhire, Sarah François, Maelle Deshoux, Penelope Hartnady, Kata Farkas, Simona Kraberger, Denis Filloux, Serge GalziAbstract:Little is known about the prevalence, diversity, evolutionary processes, genomic structures and population dynamics of viruses in the divergent geminivirus lineage known as the capulaviruses. We determined and analyzed full genome sequences of 13 Euphorbia Caput-Medusae latent virus (EcmLV) and 26 Alfalfa leaf curl virus (ALCV) isolates, and partial genome sequences of 23 EcmLV and 37 ALCV isolates. While EcmLV was asymptomatic in uncultivated southern African Euphorbia Caput-Medusae, severe alfalfa disease symptoms were associated with ALCV in southern France. The prevalence of both viruses exceeded 10% in their respective hosts. Besides using patterns of detectable negative selection to identify ORFs that are probably functionally expressed, we show that ALCV and EcmLV both display evidence of inter-species recombination and biologically functional genomic secondary structures. Finally, we show that whereas the EcmLV populations likely experience restricted geographical dispersion, ALCV is probably freely moving across the French Mediterranean region.
Simona Kraberger - One of the best experts on this subject based on the ideXlab platform.
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Molecular characterization and prevalence of two capulaviruses: Alfalfa leaf curl virus from France and Euphorbia Caput-Medusae latent virus from South Africa
2016Co-Authors: Pauline Bernardo, Emmanuel Fernandez, Brejnev Muhire, Sarah François, Maelle Deshoux, Penelope Hartnady, Kata Farkas, Simona Kraberger, Denis Filloux, Serge GalziAbstract:Little is known about the prevalence, diversity, evolutionary processes, genomic structures and population dynamics of viruses in the divergent geminivirus lineage known as the capulaviruses. We determined and analyzed full genome sequences of 13 Euphorbia Caput-Medusae latent virus (EcmLV) and 26 Alfalfa leaf curl virus (ALCV) isolates, and partial genome sequences of 23 EcmLV and 37 ALCV isolates. While EcmLV was asymptomatic in uncultivated southern African Euphorbia Caput-Medusae, severe alfalfa disease symptoms were associated with ALCV in southern France. The prevalence of both viruses exceeded 10% in their respective hosts. Besides using patterns of detectable negative selection to identify ORFs that are probably functionally expressed, we show that ALCV and EcmLV both display evidence of inter-species recombination and biologically functional genomic secondary structures. Finally, we show that whereas the EcmLV populations likely experience restricted geographical dispersion, ALCV is probably freely moving across the French Mediterranean region.