The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Nor Chejanovsky - One of the best experts on this subject based on the ideXlab platform.
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replication of varroa destructor Virus 1 vdv 1 and a varroa destructor Virus 1 deformed wing Virus Recombinant vdv 1 dwv in the head of the honey bee
Virology, 2011Co-Authors: Naama Zioni, Victoria Soroker, Nor ChejanovskyAbstract:Abstract A country-wide screen for viral pathogens in Israeli apiaries revealed significant incidence of deformed wing Virus (DWV) and Varroa destructor -1 Virus (VDV-1). To understand these Viruses' possible involvement in deformed wing syndrome of honey bees, we studied their replication in symptomatically and asymptomatically infected bees qualitatively and quantitatively, using RT-PCR, quantitative real-time RT-PCR, and immunodetection of the major viral capsid protein VP1. We found, for the first time, replication of VDV-1 and/or a VDV-1–DWV Recombinant Virus in the heads of recently emerged symptomatic bees. These Viruses replicated to high copy numbers, yielding the major viral capsid VP1 processed for subsequent assembly of viral particles. Our results clearly distinguished between symptomatic and asymptomatic bees infected with VDV-1 and VDV-1–DWV and suggest the hypothesis that VDV-1, in addition to DWV, may be involved in inducing the deformed wing pathology. Thus VDV-1–DWV recombination may yield virulent strains able to cause overt infections in Varroa -infested bee colonies.
Naama Zioni - One of the best experts on this subject based on the ideXlab platform.
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replication of varroa destructor Virus 1 vdv 1 and a varroa destructor Virus 1 deformed wing Virus Recombinant vdv 1 dwv in the head of the honey bee
Virology, 2011Co-Authors: Naama Zioni, Victoria Soroker, Nor ChejanovskyAbstract:Abstract A country-wide screen for viral pathogens in Israeli apiaries revealed significant incidence of deformed wing Virus (DWV) and Varroa destructor -1 Virus (VDV-1). To understand these Viruses' possible involvement in deformed wing syndrome of honey bees, we studied their replication in symptomatically and asymptomatically infected bees qualitatively and quantitatively, using RT-PCR, quantitative real-time RT-PCR, and immunodetection of the major viral capsid protein VP1. We found, for the first time, replication of VDV-1 and/or a VDV-1–DWV Recombinant Virus in the heads of recently emerged symptomatic bees. These Viruses replicated to high copy numbers, yielding the major viral capsid VP1 processed for subsequent assembly of viral particles. Our results clearly distinguished between symptomatic and asymptomatic bees infected with VDV-1 and VDV-1–DWV and suggest the hypothesis that VDV-1, in addition to DWV, may be involved in inducing the deformed wing pathology. Thus VDV-1–DWV recombination may yield virulent strains able to cause overt infections in Varroa -infested bee colonies.
Victoria Soroker - One of the best experts on this subject based on the ideXlab platform.
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replication of varroa destructor Virus 1 vdv 1 and a varroa destructor Virus 1 deformed wing Virus Recombinant vdv 1 dwv in the head of the honey bee
Virology, 2011Co-Authors: Naama Zioni, Victoria Soroker, Nor ChejanovskyAbstract:Abstract A country-wide screen for viral pathogens in Israeli apiaries revealed significant incidence of deformed wing Virus (DWV) and Varroa destructor -1 Virus (VDV-1). To understand these Viruses' possible involvement in deformed wing syndrome of honey bees, we studied their replication in symptomatically and asymptomatically infected bees qualitatively and quantitatively, using RT-PCR, quantitative real-time RT-PCR, and immunodetection of the major viral capsid protein VP1. We found, for the first time, replication of VDV-1 and/or a VDV-1–DWV Recombinant Virus in the heads of recently emerged symptomatic bees. These Viruses replicated to high copy numbers, yielding the major viral capsid VP1 processed for subsequent assembly of viral particles. Our results clearly distinguished between symptomatic and asymptomatic bees infected with VDV-1 and VDV-1–DWV and suggest the hypothesis that VDV-1, in addition to DWV, may be involved in inducing the deformed wing pathology. Thus VDV-1–DWV recombination may yield virulent strains able to cause overt infections in Varroa -infested bee colonies.
Michel L Bunning - One of the best experts on this subject based on the ideXlab platform.
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west nile Virus Recombinant dna vaccine protects mouse and horse from Virus challenge and expresses in vitro a noninfectious Recombinant antigen that can be used in enzyme linked immunosorbent assays
Journal of Virology, 2001Co-Authors: Brent S Davis, Gwongjen J Chang, Bruce C Cropp, John T Roehrig, Denise A Martin, Carl J Mitchell, Richard A Bowen, Michel L BunningAbstract:Introduction of West Nile (WN) Virus into the United States in 1999 created major human and animal health concerns. Currently, no human or veterinary vaccine is available to prevent WN viral infection, and mosquito control is the only practical strategy to combat the spread of disease. Starting with a previously designed eukaryotic expression vector, we constructed a Recombinant plasmid (pCBWN) that expressed the WN Virus prM and E proteins. A single intramuscular injection of pCBWN DNA induced protective immunity, preventing WN Virus infection in mice and horses. Recombinant plasmid-transformed COS-1 cells expressed and secreted high levels of WN Virus prM and E proteins into the culture medium. The medium was treated with polyethylene glycol to concentrate proteins. The resultant, containing high-titered Recombinant WN Virus antigen, proved to be an excellent alternative to the more traditional suckling-mouse brain WN Virus antigen used in the immunoglobulin M (IgM) antibody-capture and indirect IgG enzyme-linked immunosorbent assays. This Recombinant antigen has great potential to become the antigen of choice and will facilitate the standardization of reagents and implementation of WN Virus surveillance in the United States and elsewhere.
Cica Urbino - One of the best experts on this subject based on the ideXlab platform.
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the selection driven emergence of an unusual tomato yellow leaf curl Virus Recombinant that displaced its parental Viruses
2016Co-Authors: Zineb Belabess, Cica Urbino, Martine Granier, Abdessalem Tahiri, Abdelali Blenzar, Michel PeterschmittAbstract:TYLCV-IS76 (IS76) is a Recombinant from Morocco generated between representatives of the Israel strain of Tomato yellow leaf curl Virus (TYLCV-IL) and the Spanish strain of Tomato yellow leaf curl Sardinia Virus (TYLCSV-ES). Unlike the previously reported TYLCV/TYLCSV Recombinants, IS76 has a non-canonical recombination profile and has replaced its parental Viruses in Southern Morocco (Belabess et al. 2015, Virology 486, 291-306). As its emergence coincided with the deployment of Ty-1-tolerant tomato cultivars, it was thought that IS76 may have a selective advantage in tolerant plants. This prediction was tested by comparing the fitness of agro-infectious clones of IS76 and representatives of its parental Viruses in tomato plants harboring or not the Ty-1 gene. IS76 DNA accumulation was significantly higher than that of TYLCV-IL and TYLCSV-ES in the plants of the tolerant cultivar. The fitness advantage did not incur any accumulation cost in the susceptible plants. Interestingly, the IS76 selective advantage was associated with a dramatic negative impact of IS76 on TYLCV-IL accumulation which was shown to be determined by the Recombinant nature of IS76. As the fitness results are consistent with the selection of IS76 by tolerant tomato plants, it was intriguing that IS76 has emerged only in Morocco and not in other countries where Ty-1-tolerant tomato cultivars were similarly deployed. It was hypothesized that the emergence of IS76 requires an extremely rare combination of circumstances which occurred by chance in Morocco. The monitoring of the population of TYLCV/TYLCSV Recombinants generated in 10 Ty-1-tolerant and 10 nearly isogenic susceptible plants co-infected with parental Viruses, confirmed this hypothesis. Indeed, although 100% of the coinfected plants were positive for TYLCV-IL/TYLCSV-ES Recombinants from 60 days post inoculation (dpi), IS76-type Recombinants were generated in only 5 susceptible and 1 tolerant plants and they remained among the rarest Recombinants even at 365 dpi. (Texte integral)
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agroecological and evolutionary factors driving the success emergence of a non canonical tomato yellow leaf curl Virus Recombinant
Building bridges between disciplines for sustainable management of plant virus diseases, 2016Co-Authors: Zineb Belabess, Martine Granier, Abdessalem Tahiri, Abdelali Blenzar, Michel Peterschmitt, Cica UrbinoAbstract:BACKGROUND and OBJECTIVES Recombination is one of the driving forces for viral evolution, and particularly for the Tomato yellow leaf curl (Tylc) associated begomoViruses (family Geminiviridae). TYLCV-IS76 (IS76) is a peculiar Recombinant from Morocco generated between representatives of the Israel strain of Tomato yellow leaf curl Virus (TYLCV-IL) and the Spanish strain of Tomato yellow leaf curl Sardinia Virus (TYLCSV-ES). Unlike the previously reported TYLCV/TYLCSV Recombinants, IS76 has a non-canonical recombination profile and has entirely displaced its parental Viruses, possibly because of its positive selection by tomato cultivars bearing the Ty-1 tolerant gene (see the sister communication of Belabess et al.(1)). This prediction was tested by comparing the fitness of IS76 to those of representatives of parental Viruses, in tomato plants harboring or not the Ty-1 gene. As the fitness results were consistent with the selective hypothesis, a second question had to be addressed: as all the Mediterranean used tomato cultivar tolerant to Tylc associated Viruses are bearing the Ty-1 gene, why has such Recombinant not been reported elsewhere? MATERIAL and METHODS The fitness of IS76 was estimated in a Ty-1 tolerant cultivar, and in a susceptible nearly isogenic line, in single or mixed infections with parental Viruses TYLCV-IL and TYLCSV-ES. Viral DNA intra plant accumulation was measured with real time PCR (qPCR) and used as a proxy of fitness. An artificial TYLCV-IS76 Recombinant (IS76') was constructed by site-directed mutagenesis to analyze the molecular determinant of the potential fitness advantage. The probability of emergence of IS76 type Recombinants was estimated in 10 Ty-1 tolerant and 10 nearly isogenic susceptible plants co-infected with parental Viruses, by monitoring the generated recombination patterns over time up to 240 days post inoculation (dpi). RESULTS IS76 DNA accumulation was significantly higher than that of TYLCV-IL and TYLCSV-ES in the tolerant cultivar, both in single or mixed infections. The fitness advantage of IS76 in the tolerant plants did not pay any accumulation cost in the susceptible plants in which IS76 accumulation was similar or higher than that of both parental Viruses. Interestingly the IS76 selective advantage was associated with a dramatic negative impact on TYLCV-IL accumulation, which was shown to be determined by the recombination nature of IS76. Indeed, the TYLCV-IL parent dropped below the qPCR detection level at 120 dpi and the whitefly transmissibility level from 60 dpi. Recombinants exhibiting the typical IS76 recombination breakpoint were generated in plants of both cultivars co-inoculated with the parental Viruses but very unexpectedly they remained at an extremely low frequency even up to one year after infection. CONCLUSIONS Our results support the positive selection of IS76 by the Ty-1 gene and validate the selective hypothesis to explain its emergence and the entire displacement of its parents in the Souss. It is expected that the fitness advantage of IS76 may involve gene silencing because the Ty-1 gene codes for an RdRp (2) and because the short TYLCSV derived region of IS76 is located in a region which has been reported for two begomoViruses to be one of the favored target of siRNA and methylation(3). The fact that IS76 type Recombinants did not dominate in co-inoculated plants in which they were generated may suggest that their emergence may need a highly improbable combination of circumstance which may have occurred by chance in the Souss. (Resume d'auteur ers cannot use pesticides due to their prohibitive price and because their usage is banned or more and more restricted. Thus, it is crucial to develop and study new biological control approaches. In fact, Crop protection is a challenging domain of research, even for mathematicians. Many experiments have been or are conducted around the world to test different innovative Bioagressors control tools or strategies. However, these experiments are often located in one place, they are expansive, difficult to conduct and to reproduce, and, according to some crops (perennial crops), may take several years.... Mathematical Modelling and Simulations can be of great help to study these (complex) systems in close connexion with the experiments. In this talk I will present different examples, based on ongoing works, where Mathematics can be helpfull and bring new insights about Plant-Bioagressors interactions. In particular modelling plant epidemiology or/and plant-insect interactions may lead to novel and challenging mathematical problems, from the theoretical and numerical point of view... with, in addition, pratical applications. (Resume d'auteur)
