RESUMEN
Transmission of plant viruses by insect vectors is facilitated by unequivocal tri-partite interactions among host plants, viruses, and associated vectors. The advent of next-generation sequencing including whole genome sequencing, RNA/small RNA sequencing, proteomics, and metabolomics aided in elucidating the molecular mechanisms involved in virus transmission by insect vectors and infection in host plants.
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Insectos Vectores , Metabolómica , Enfermedades de las Plantas , Virus de Plantas , Proteómica , Virus de Plantas/genética , Virus de Plantas/fisiología , Insectos Vectores/virología , Insectos Vectores/genética , Enfermedades de las Plantas/virología , Enfermedades de las Plantas/genética , Animales , Metabolómica/métodos , Proteómica/métodos , Plantas/virología , Plantas/metabolismo , Plantas/genética , Genómica/métodos , Interacciones Huésped-Patógeno/genética , Secuenciación de Nucleótidos de Alto RendimientoRESUMEN
Orthotospovirus tomatomaculae (tomato spotted wilt virus, TSWV) is transmitted by the western flower thrips, Frankliniella occidentalis. Epoxyoctadecamonoenoic acids (EpOMEs) function as immune-suppressive factors, particularly in insects infected by viral pathogens. These oxylipins are produced by cytochrome P450 monooxygenases (CYPs) and are degraded by soluble epoxide hydrolase (sEH). In this study, we tested the hypothesis that TSWV modulates the EpOME level in the thrips to suppress antiviral responses and enhance its replication. TSWV infection significantly elevated both 9,10-EpOME and 12,13-EpOME levels. Following TSWV infection, the larvae displayed apoptosis in the midgut along with the upregulated expression of four caspase genes. However, the addition of EpOME to the viral treatment notably reduced apoptosis and downregulated caspase gene expressions, which led to a marked increase in TSWV titers. The CYP and sEH genes of F. occidentalis were identified, and their expression manipulation using RNA interference (RNAi) treatments led to significant alternations in the insect's immune responses and TSWV viral titers. To ascertain which viral factor influences the host EpOME levels, specialized RNAi treatments targeting genes encoded by TSWV were administered to larvae infected with TSWV. These treatments demonstrated that NSS expression is pivotal in manipulating the genes involved in EpOME metabolism. These results indicate that NSs of TSWV are crucially linked with the elevation of host insect EpOME levels and play a key role in suppressing the antiviral responses of F. occidentalis.
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Oxilipinas , Thysanoptera , Tospovirus , Animales , Tospovirus/fisiología , Oxilipinas/metabolismo , Thysanoptera/virología , Insectos Vectores/virología , Insectos Vectores/inmunología , Factores de Virulencia/genética , Factores de Virulencia/metabolismo , Proteínas no Estructurales Virales/metabolismo , Proteínas no Estructurales Virales/genética , Larva/virología , Larva/inmunología , Apoptosis/efectos de los fármacos , Sistema Enzimático del Citocromo P-450/metabolismo , Sistema Enzimático del Citocromo P-450/genética , Epóxido Hidrolasas/metabolismo , Epóxido Hidrolasas/genéticaRESUMEN
Epizootic hemorrhagic disease virus (EHDV) is transmitted by Culicoides biting midges. Studies aiming to predict the likely spread of EHDV require an understanding of the viral infection and replication kinetics within these insects, including the proportion of the insect population that are able to support virus transmission. Here, we describe methods for the infection of Culicoides with EHDV in the laboratory via oral infection using an artificial membrane system or a cotton pledget and intrathoracic (IT) inoculation. Each method can be used to explore determinants of vector competence of Culicoides species and populations for EHDV.
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Ceratopogonidae , Virus de la Enfermedad Hemorrágica Epizoótica , Insectos Vectores , Infecciones por Reoviridae , Animales , Ceratopogonidae/virología , Virus de la Enfermedad Hemorrágica Epizoótica/fisiología , Insectos Vectores/virología , Infecciones por Reoviridae/transmisión , Infecciones por Reoviridae/virología , Infecciones por Reoviridae/veterinariaRESUMEN
Arboviruses can be paternally transmitted by male insects to offspring for long-term persistence, but the mechanism remains largely unknown. Here, we use a model system of a destructive rice reovirus and its leafhopper vector to find that insect ribosome-rescuer Pelo-Hbs1 complex expressed on the sperm surface mediates paternal arbovirus transmission. This occurs through targeting virus-containing tubules constituted by viral nonstructural protein Pns11 to sperm surface via Pns11-Pelo interaction. Tubule assembly is dependent on Hsp70 activity, while Pelo-Hbs1 complex inhibits tubule assembly via suppressing Hsp70 activity. However, virus-activated ubiquitin ligase E3 mediates Pelo ubiquitinated degradation, synergistically causing Hbs1 degradation. Importantly, Pns11 effectively competes with Pelo for binding to E3, thus antagonizing E3-mediated Pelo-Hbs1 degradation. These processes cause a slight reduction of Pelo-Hbs1 complex in infected testes, promoting effective tubule assembly. Our findings provide insight into how insect sperm-specific Pelo-Hbs1 complex is modulated to promote paternal virus transmission without disrupting sperm function.
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Hemípteros , Proteínas de Insectos , Espermatozoides , Animales , Masculino , Espermatozoides/metabolismo , Espermatozoides/virología , Hemípteros/virología , Hemípteros/metabolismo , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Arbovirus , Proteínas HSP70 de Choque Térmico/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Reoviridae/fisiología , Insectos Vectores/virología , Insectos Vectores/metabolismo , Ribosomas/metabolismo , Infecciones por Arbovirus/transmisión , Infecciones por Arbovirus/metabolismo , Infecciones por Arbovirus/virologíaRESUMEN
Systemic viral infection of insects typically begins with the primary infection of midgut epithelial cells (enterocytes) and subsequent transit of the progeny virus in an apical-to-basal orientation into the hemocoel. For insect-vectored viruses, an oppositely oriented process (basal-to-apical transit) occurs upon secondary infection of salivary glands and is necessary for virus transmission to non-insect hosts. To examine this inversely oriented virus transit in these polarized tissues, we assessed the intracellular trafficking of two model viral envelope proteins (baculovirus GP64 and vesicular stomatitis virus G) in the midgut and salivary gland cells of the model insect, Drosophila melanogaster. Using fly lines that inducibly express either GP64 or VSV G, we found that each protein, expressed alone, was trafficked basally in midgut enterocytes. In salivary gland cells, VSV G was trafficked apically in most but not all cells, whereas GP64 was consistently trafficked basally. We demonstrated that a YxxØ motif present in both proteins was critical for basal trafficking in midgut enterocytes but dispensable for trafficking in salivary gland cells. Using RNAi, we found that clathrin adaptor protein complexes AP-1 and AP-3, as well as seven Rab GTPases, were involved in polarized VSV G trafficking in midgut enterocytes. Our results indicate that these viral envelope proteins encode the requisite information and require no other viral factors for appropriately polarized trafficking. In addition, they exploit tissue-specific differences in protein trafficking pathways to facilitate virus egress in the appropriate orientation for establishing systemic infections and vectoring infection to other hosts. IMPORTANCE: Viruses that use insects as hosts must navigate specific routes through different insect tissues to complete their life cycles. The routes may differ substantially depending on the life cycle of the virus. Both insect pathogenic viruses and insect-vectored viruses must navigate through the polarized cells of the midgut epithelium to establish a systemic infection. In addition, insect-vectored viruses must also navigate through the polarized salivary gland epithelium for transmission. Thus, insect-vectored viruses appear to traffic in opposite directions in these two tissues. In this study, we asked whether two viral envelope proteins (VSV G and baculovirus GP64) alone encode the signals necessary for the polarized trafficking associated with their respective life cycles. Using Drosophila as a model to examine tissue-specific polarized trafficking of these viral envelope proteins, we identified one of the virus-encoded signals and several host proteins associated with regulating the polarized trafficking in the midgut epithelium.
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Drosophila melanogaster , Transporte de Proteínas , Glándulas Salivales , Proteínas del Envoltorio Viral , Animales , Glándulas Salivales/virología , Glándulas Salivales/metabolismo , Proteínas del Envoltorio Viral/metabolismo , Proteínas del Envoltorio Viral/genética , Drosophila melanogaster/virología , Drosophila melanogaster/metabolismo , Insectos Vectores/virología , Insectos Vectores/metabolismo , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Enterocitos/virología , Enterocitos/metabolismo , Tracto Gastrointestinal/virología , Tracto Gastrointestinal/metabolismoRESUMEN
Bluetongue virus (BT) is a vector-borne virus that causes a disease, called bluetongue, which results in significant economic loss and morbidity in sheep, cattle, goats and wild ungulates across all continents of the world except Antarctica. Despite the geographical breadth of its impact, most BT epidemiological models are informed by parameters derived from the 2006-2009 BTV-8 European outbreak. The aim of this study was to develop a highly adaptable model for BT which could be used elsewhere in the world, as well as to identify the parameters which most influence outbreak dynamics, so that policy makers can be properly informed with the most current information to aid in disease planning. To provide a framework for future outbreak modelling and an updated parameterisation that reflects natural variation in infections, a newly developed and parameterised two-host, two-vector species ordinary differential equation model was formulated and analysed. The model was designed to be adaptable to be implemented in any region of the world and able to model both epidemic and endemic scenarios. It was parameterised using a systematic literature review of host-to-vector and vector-to-host transmission rates, host latent periods, host infectious periods, and vaccine protection factors. The model was demonstrated using the updated parameters, with South Africa as a setting based on the Western Cape's known cattle and sheep populations, local environmental parameters, and Culicoides spp. presence data. The sensitivity analysis identified that the duration of the infectious period for sheep and cows had the greatest impact on the outbreak length and number of animals infected at the peak of the outbreak. Transmission rates from cows and sheep to C. imicola midges greatly influenced the day on which the peak of the outbreak occurred, along with the duration of incubation period, and infectious period for cows. Finally, the protection factor of the vaccine had the greatest influence on the total number of animals infected. This knowledge could aid in the development of control measures. Due to gradual climate and anthropological change resulting in alterations in vector habitat suitability, BT outbreaks are likely to continue to increase in range and frequency. Therefore, this research provides an updated BT modelling framework for future outbreaks around the world to explore transmission, outbreak dynamics and control measures.
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Virus de la Lengua Azul , Lengua Azul , Enfermedades de los Bovinos , Brotes de Enfermedades , Animales , Lengua Azul/epidemiología , Lengua Azul/transmisión , Lengua Azul/virología , Lengua Azul/prevención & control , Ovinos , Bovinos , Brotes de Enfermedades/veterinaria , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/virología , Enfermedades de los Bovinos/transmisión , Ceratopogonidae/virología , Sudáfrica/epidemiología , Modelos Teóricos , Insectos Vectores/virología , Modelos Biológicos , CabrasRESUMEN
BACKGROUND: Culicoides biting midges exhibit a global spatial distribution and are the main vectors of several viruses of veterinary importance, including bluetongue (BT) and African horse sickness (AHS). Many environmental and anthropological factors contribute to their ability to live in a variety of habitats, which have the potential to change over the years as the climate changes. Therefore, as new habitats emerge, the risk for new introductions of these diseases of interest to occur increases. The aim of this study was to model distributions for two primary vectors for BT and AHS (Culicoides imicola and Culicoides bolitinos) using random forest (RF) machine learning and explore the relative importance of environmental and anthropological factors in a region of South Africa with frequent AHS and BT outbreaks. METHODS: Culicoides capture data were collected between 1996 and 2022 across 171 different capture locations in the Western Cape. Predictor variables included climate-related variables (temperature, precipitation, humidity), environment-related variables (normalised difference vegetation index-NDVI, soil moisture) and farm-related variables (livestock densities). Random forest (RF) models were developed to explore the spatial distributions of C. imicola, C. bolitinos and a merged species map, where both competent vectors were combined. The maps were then compared to interpolation maps using the same capture data as well as historical locations of BT and AHS outbreaks. RESULTS: Overall, the RF models performed well with 75.02%, 61.6% and 74.01% variance explained for C. imicola, C. bolitinos and merged species models respectively. Cattle density was the most important predictor for C. imicola and water vapour pressure the most important for C. bolitinos. Compared to interpolation maps, the RF models had higher predictive power throughout most of the year when species were modelled individually; however, when merged, the interpolation maps performed better in all seasons except winter. Finally, midge densities did not show any conclusive correlation with BT or AHS outbreaks. CONCLUSION: This study yielded novel insight into the spatial abundance and drivers of abundance of competent vectors of BT and AHS. It also provided valuable data to inform mathematical models exploring disease outbreaks so that Culicoides-transmitted diseases in South Africa can be further analysed.
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Enfermedad Equina Africana , Lengua Azul , Ceratopogonidae , Insectos Vectores , Aprendizaje Automático , Animales , Bovinos , Enfermedad Equina Africana/epidemiología , Enfermedad Equina Africana/transmisión , Enfermedad Equina Africana/virología , Lengua Azul/epidemiología , Lengua Azul/transmisión , Lengua Azul/virología , Virus de la Lengua Azul , Ceratopogonidae/virología , Clima , Brotes de Enfermedades , Ecosistema , Caballos , Insectos Vectores/virología , Bosques Aleatorios , Sudáfrica/epidemiología , OvinosRESUMEN
Most mathematical models that assess the vectorial capacity of disease-transmitting insects typically focus on the influence of climatic factors to predict variations across different times and locations, or examine the impact of vector control interventions to forecast their potential effectiveness. We combine features of existing models to develop a novel model for vectorial capacity that considers both climate and vector control. This model considers how vector control tools affect vectors at each stage of their feeding cycle, and incorporates host availability and preference. Applying this model to arboviruses of veterinary importance in Europe, we show that African horse sickness virus (AHSV) has a higher peak predicted vectorial capacity than bluetongue virus (BTV), Schmallenberg virus (SBV), and epizootic haemorrhagic disease virus (EHDV). However, AHSV has a shorter average infectious period due to high mortality; therefore, the overall basic reproduction number of AHSV is similar to BTV. A comparable relationship exists between SBV and EHDV, with both viruses showing similar basic reproduction numbers. Focusing on AHSV transmission in the UK, insecticide-treated stable netting is shown to significantly reduce vectorial capacity of Culicoides, even at low coverage levels. However, untreated stable netting is likely to have limited impact. Overall, this model can be used to consider both climate and vector control interventions either currently utilised or for potential use in an outbreak, and could help guide policy makers seeking to mitigate the impact of climate change on disease control.
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Infecciones por Arbovirus , Arbovirus , Ceratopogonidae , Clima , Insectos Vectores , Animales , Infecciones por Arbovirus/transmisión , Infecciones por Arbovirus/prevención & control , Arbovirus/fisiología , Insectos Vectores/virología , Insectos Vectores/fisiología , Ceratopogonidae/virología , Ceratopogonidae/fisiología , Modelos Teóricos , Europa (Continente)/epidemiología , Número Básico de Reproducción , Virus de la Lengua Azul/fisiologíaRESUMEN
The potato leafhopper (Empoasca fabae, PLH) is a serious pest that feeds on a wide range of agricultural crops and is found throughout the United States but is not known to be a vector for plant-infecting viruses. We probed the diversity of virus sequences in field populations of PLH collected from four Midwestern states: Illinois, Indiana, Iowa, and Minnesota. High-throughput sequencing data from total RNAs extracted from PLH were used to assemble sequences of fifteen positive-stranded RNA viruses, two negative-stranded RNA viruses, and one DNA virus. These sequences included ten previously described plant viruses and eight putative insect-infecting viruses. All but one of the insect-specific viruses were novel and included three solemoviruses, one iflavirus, one phenuivirus, one lispivirus, and one ambidensovirus. Detailed analyses of the novel genome sequences and their evolutionary relationships with related family members were conducted. Our study revealed a diverse group of plant viruses circulating in the PLH population and discovered novel insect viruses, expanding knowledge on the untapped virus diversity in economically important crop pests. Our findings also highlight the importance of monitoring the emergence and circulation of plant-infecting viruses in agriculturally important arthropod pests.
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Genoma Viral , Hemípteros , Filogenia , Virus de Plantas , Animales , Hemípteros/virología , Virus de Plantas/genética , Virus de Plantas/clasificación , Virus de Plantas/aislamiento & purificación , Enfermedades de las Plantas/virología , Enfermedades de las Plantas/parasitología , Productos Agrícolas/virología , Virus de Insectos/genética , Virus de Insectos/clasificación , Virus de Insectos/aislamiento & purificación , Solanum tuberosum/virología , Solanum tuberosum/parasitología , Secuenciación de Nucleótidos de Alto Rendimiento , Virus ADN/genética , Virus ADN/clasificación , Virus ADN/aislamiento & purificación , Virus ARN/genética , Virus ARN/clasificación , Virus ARN/aislamiento & purificación , Variación Genética , Insectos Vectores/virologíaRESUMEN
Vesicular stomatitis (VS) is a vector-borne livestock disease caused by the vesicular stomatitis New Jersey virus (VSNJV). This study presents the first application of an SEIR-SEI compartmental model to analyze VSNJV transmission dynamics. Focusing on the 2014-2015 outbreak in the United States, the model integrates vertebrate hosts and insect vector demographics while accounting for heterogeneous competency within the populations and observation bias in documented disease cases. Key epidemiological parameters were estimated using Bayesian inference and Markov chain Monte Carlo (MCMC) methods, including the force of infection, effective reproduction number (Rt), and incubation periods. The model revealed significant underreporting, with only 10-24% of infections documented, 23% of which presented with clinical symptoms. These findings underscore the importance of including competence and imperfect detection in disease models to depict outbreak dynamics and inform effective control strategies accurately. As a baseline model, this SEIR-SEI implementation is intended to serve as a foundation for future refinements and expansions to improve our understanding of VS dynamics. Enhanced surveillance and targeted interventions are recommended to manage future VS outbreaks.
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Brotes de Enfermedades , Estomatitis Vesicular , Estados Unidos/epidemiología , Estomatitis Vesicular/epidemiología , Estomatitis Vesicular/virología , Animales , Virus de la Estomatitis Vesicular New Jersey/genética , Teorema de Bayes , Bovinos , Insectos Vectores/virología , Ganado/virologíaRESUMEN
INTRODUCTION: Culicoides Latreille biting midges are vectors of high concern as they can transmit serious veterinary diseases such as bluetongue virus or epizootic haemorrhagic disease virus, among others. Little is known about these vectors in Galicia, so a comprehensive literature review and an intensive monitoring were carried out in the region. MATERIAL AND METHODS: The Autonomous Community of Galicia was sampled through three different vector surveillance projects between 2004 and 2023. A total of 239 sampling points were deployed alongside the Galician territory. In addition, a literature review of Culicoides in Galicia related content was made by consulting several digital repositories. RESULTS: A total of 33 species of Culicoides belonging to 8 subgenera were identified. Among them, 15 are considered or suspected to be potential vectors of several pathogens of medical and/or veterinary interest. In addition, 20 of them are reported for the first time in the region. Updated distribution maps of the Culicoides biting midges of Galicia were provided, including several notes regarding their ecology and relevance for both public health and animal welfare. CONCLUSIONS: The present work is one of the most complete works made at regional level in Spain to date. As Galicia's economy relies heavily on livestock farming, this work will provide a solid baseline in order to develop new research lines in the future regarding prevention to vector-borne diseases.
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Ceratopogonidae , Insectos Vectores , Ceratopogonidae/fisiología , Ceratopogonidae/virología , Animales , España , Insectos Vectores/virología , Insectos Vectores/fisiología , Distribución Animal , BiodiversidadRESUMEN
The West Nile virus (WNV), primarily transmitted by mosquitoes, is one of the most widespread flaviviruses globally, with past outbreaks occurring in the USA and Europe. Recent studies in parts of Africa, including Kenya, have identified the West Nile virus Koutango lineage (WN-KOUTV) among phlebotomine sandfly populations, however, our understanding of this virus remains limited. This study aimed to characterize WN-KOUTV from phlebotomine sandflies. Sandflies were sampled between 12th -16th March 2021 and 16th -20th March 2023 from six villages each in Baringo and Isiolo Counties, using CDC light traps. Female sandflies were taxonomically identified and pooled based on genus and site of collection. Virus isolation was performed in Vero cells. Viral genomes were determined using next-generation sequencing. Phylogenetic and molecular clock analyses were done to decipher the virus's evolutionary relationships. Comparative analyses of amino acid sequences were performed to determine variations. Protein modeling in Pymol was conducted to elucidate variations in key protein regions. Evolutionary pressure analysis investigated the selection pressures on the virus. In vitro experiments were done to investigate the virus growth kinetics in mammalian Vero E6 and mosquito C6/36 cells. We report the isolation of WN-KOUTV from Salabani in Baringo and Aremet in Isiolo, Kenya. The isolated WN-KOUTVs clustered with previously identified WN-KOUTV strains. Comparative analysis revealed a unique amino acid at NS5 653. The WN-KOUTV lineage as a whole is under purifying selective pressure, with diversifying pressure acting at site NS3 267. The current WN-KOUTV replicated in Vero E6 and C6/36 cells comparable to West Nile virus Lineage 1a, isolated from mosquitoes. Subsequent isolations of WN-KOUTV in phlebotomine sandflies suggest potential vectors, however, vector competence studies would confirm this. Replication in mammalian and insect cell lines suggests there may exist a vector/host relationship. We speculate the close genetic relationship of WN-KOUTV strains from East and West Africa may potentially be enabled by bird migratory routes between the two regions. If proven, this could point to a potential future pandemic pathway for this virus.
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Filogenia , Psychodidae , Virus del Nilo Occidental , Animales , Kenia , Virus del Nilo Occidental/genética , Virus del Nilo Occidental/aislamiento & purificación , Chlorocebus aethiops , Psychodidae/virología , Células Vero , Genoma Viral , Femenino , Insectos Vectores/virología , Fiebre del Nilo Occidental/virología , Fiebre del Nilo Occidental/transmisión , Fiebre del Nilo Occidental/epidemiologíaRESUMEN
Background: The Rift Valley Fever (RVF) is an arbovirus disease responsible of regular epizootics and epidemics in sub-Saharan Africa and Arabian Peninsula. In 2016, Niger experienced its first outbreak of RVF in Tahoua region, which resulted in high consequences in animal and human health. The aim of this study was to investigate on the RVFV circulation among potential vectors of the disease. Methods: This was a cross-sectional survey carried out in Tahoua and Agadez regions in August 2021. Adult mosquitoes were collected by using the morning spray in human dwellings and the CDC light trap methods. After morphological identification, viral RNA was extracted. The RNA was extracted by using QIAamp Viral RNA Mini Kit (Qiagen). The RVFV detection was performed by using the qRT-PCR method. Results: A total of 2487 insects (1978 mosquitoes, 509 sandflies and 251 biting midges) were identified and divided into three families (Culicidae, Psychodidae and Ceratopogonidae). The Culicidae family composed of the Culex genus being the most abundant with a predominance of Cx.pipiens (31.88%; n = 793) followed by Mansonia sp (21.51%; n = 535), Anophelesgambiae s.l. (8.44%; n = 210), An. pharoensis (0.72%; n = 18), An. rufipes (0.48%; n = 12), Cx. quinquefasciatus (6.39%; n = 159), the Psychodidae with sandflies (20.46%; n = 509), and the Ceratopogonidae with Culicoides genus (10.09%; n = 251). The qRT-PCR carried out on a sample of mosquitoes (N = 96) highlighted that one individual of Cx.pipiens was found positive to RVFV. This specimen was from Tassara locality (Tahoua) and collected by CDC Light Trap method. Conclusion: This study reveals for the first time the circulation of RVFV among Cx.pipiens in Niger and highlights the possible vectorial role of this vector in the disease transmission. Further investigations should be carried out to identify the biological and ecological determinants that support the maintenance of the virus in this area in order to guide control interventions.
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Culex , Fiebre del Valle del Rift , Virus de la Fiebre del Valle del Rift , Animales , Virus de la Fiebre del Valle del Rift/aislamiento & purificación , Virus de la Fiebre del Valle del Rift/genética , Culex/virología , Estudios Transversales , Fiebre del Valle del Rift/epidemiología , Fiebre del Valle del Rift/transmisión , Fiebre del Valle del Rift/virología , Niger/epidemiología , Mosquitos Vectores/virología , Humanos , Insectos Vectores/virologíaRESUMEN
Salivary proteins of insect herbivores can suppress plant defenses, but the roles of many remain elusive. One such protein is glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from the saliva of the Recilia dorsalis (RdGAPDH) leafhopper, which is known to transmit rice gall dwarf virus (RGDV). Here we show that RdGAPDH was loaded into exosomes and released from salivary glands into the rice phloem through an exosomal pathway as R. dorsalis fed. In infected salivary glands of R. dorsalis, the virus upregulated the accumulation and subsequent release of exosomal RdGAPDH into the phloem. Once released, RdGAPDH consumed H2O2 in rice plants owing to its -SH groups reacting with H2O2. This reduction in H2O2 of rice plant facilitated R. dorsalis feeding and consequently promoted RGDV transmission. However, overoxidation of RdGAPDH could cause potential irreversible cytotoxicity to rice plants. In response, rice launched emergency defense by utilizing glutathione to S-glutathionylate the oxidization products of RdGAPDH. This process counteracts the potential cellular damage from RdGAPDH overoxidation, helping plant to maintain a normal phenotype. Additionally, salivary GAPDHs from other hemipterans vectors similarly suppressed H2O2 burst in plants. We propose a strategy by which plant viruses exploit insect salivary proteins to modulate plant defenses, thus enabling sustainable insect feeding and facilitating viral transmission.
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Hemípteros , Peróxido de Hidrógeno , Oryza , Enfermedades de las Plantas , Saliva , Animales , Hemípteros/virología , Peróxido de Hidrógeno/metabolismo , Oryza/virología , Oryza/metabolismo , Enfermedades de las Plantas/virología , Saliva/metabolismo , Saliva/virología , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Glándulas Salivales/virología , Glándulas Salivales/metabolismo , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Insectos Vectores/virología , Floema/virología , Floema/metabolismo , Reoviridae/fisiología , Glutatión/metabolismo , Proteínas y Péptidos Salivales/metabolismo , Virus de Plantas/fisiología , Defensa de la Planta contra la HerbivoriaRESUMEN
Bluetongue disease is an infectious disease transmitted by Culicoides as vectors, mainly infecting ruminants. Because ruminants play an important role in animal husbandry in China, the outbreak of bluetongue disease can cause serious economic losses. Maxent model was applied to predict the distribution of bluetongue in China based on the data derived from domestic and foreign academic literature databases including CNKI, Wanfang Database, PubMed, Web of Science and Google Scholar. The results showed that annual mean temperature (BIO1), precipitation in driest month (BIO14), sheep density (SD) and altitude (Elev) were the relevant variables of bioclimatic suitable zones for bluetongue disease. Precipitation in wettest month (BIO13), BIO1, BIO14, Elev were the main variables affecting the habitat of the bluetongue vector Culicoides. The most suitable climate for bluetongue infection occurs in southern China, central China and parts of Xinjiang. The suitable living areas of Culicoides are mainly located in southern, central and eastern China, and the overlap of the two suitable areas is high. The study suggested that southern, central, and eastern China are high-risk areas for bluetongue due to the significant overlap of suitable habitats for both the disease and its vector. Implementing effective surveillance and targeted control strategies in these regions is crucial for mitigating the impact of bluetongue disease.
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Lengua Azul , Ceratopogonidae , Lengua Azul/transmisión , Lengua Azul/epidemiología , Animales , China/epidemiología , Ceratopogonidae/virología , Ovinos , Insectos Vectores/virología , Virus de la Lengua Azul/fisiología , ClimaRESUMEN
To describe the transmission dynamics of maize streak virus infection, in the paper, we first formulate a stochastic maize streak virus infection model, in which the stochastic fluctuations are depicted by a logarithmic Ornstein-Uhlenbeck process. This approach is reasonable to simulate the random impacts of main parameters both from the biological significance and the mathematical perspective. Then we investigate the detailed dynamics of the stochastic system, including the existence and uniqueness of the global solution, the existence of a stationary distribution, the exponential extinction of the infected maize and infected leafhopper vector. Especially, by solving the five-dimensional algebraic equations corresponding to the stochastic system, we obtain the specific expression of the probability density function near the quasi-endemic equilibrium of the stochastic system, which provides valuable insights into the stationary distribution. Finally, the model is discretized using the Milstein higher-order numerical method to illustrate our theoretical results numerically. Our findings provide a groundwork for better methods of preventing the spread of this type of virus.
Asunto(s)
Virus de la Veta de Maíz , Conceptos Matemáticos , Modelos Biológicos , Enfermedades de las Plantas , Procesos Estocásticos , Zea mays , Enfermedades de las Plantas/virología , Enfermedades de las Plantas/estadística & datos numéricos , Zea mays/virología , Animales , Virus de la Veta de Maíz/fisiología , Simulación por Computador , Insectos Vectores/virología , Epidemias/estadística & datos numéricos , Hemípteros/virologíaRESUMEN
Catalase (CAT) is the main reactive oxygen species (ROS)-scavenging enzyme in plants and insects. However, it remains elusive whether and how insect saliva CAT suppresses ROS-mediated plant defense, thereby promoting initial virus transmission by insect vectors. Here, we investigated how leafhopper Recilia dorsalis catalase (RdCAT) was secreted from insect salivary glands into rice phloem, and how it was perceived by rice chaperone NO CATALASE ACTIVITY1 (OsNCA1) to scavenge excessive H2O2 during insect-to-plant virus transmission. We found that the interaction of OsNCA1 with RdCAT activated its enzymatic activity to decompose H2O2 in rice plants during leafhopper feeding. However, initial insect feeding did not significantly change rice CATs transcripts. Knockout of OsNCA1 in transgenic lines decreased leafhopper feeding-activated CAT activity and caused higher H2O2 accumulation. A devastating rice reovirus activated RdCAT expression and promoted the cosecretion of virions and RdCAT into leafhopper salivary cavities and ultimately into the phloem. Virus-mediated increase of RdCAT secretion suppressed excessive H2O2, thereby promoting host attractiveness to insect vectors and initial virus transmission. Our findings provide insights into how insect saliva CAT is secreted and perceived by plant chaperones to suppress the early H2O2 burst during insect feeding, thereby facilitating viral transmission.
Asunto(s)
Catalasa , Hemípteros , Peróxido de Hidrógeno , Insectos Vectores , Oryza , Saliva , Animales , Peróxido de Hidrógeno/metabolismo , Hemípteros/virología , Hemípteros/fisiología , Saliva/virología , Saliva/enzimología , Catalasa/metabolismo , Catalasa/genética , Insectos Vectores/virología , Oryza/virología , Oryza/genética , Oryza/enzimología , Reoviridae/fisiología , Enfermedades de las Plantas/virología , Floema/virologíaRESUMEN
Multiple species within the order Hemiptera cause severe agricultural losses on a global scale. Aphids and whiteflies are of particular importance due to their role as vectors for hundreds of plant viruses, many of which enter the insect via the gut. To facilitate the identification of novel targets for disruption of plant virus transmission, we compared the relative abundance and composition of the gut plasma membrane proteomes of adult Bemisia tabaci (Hemiptera: Aleyrodidae) and Myzus persicae (Hemiptera: Aphididae), representing the first study comparing the gut plasma membrane proteomes of two different insect species. Brush border membrane vesicles were prepared from dissected guts, and proteins extracted, identified and quantified from triplicate samples via timsTOF mass spectrometry. A total of 1699 B. tabaci and 1175 M. persicae proteins were identified. Following bioinformatics analysis and manual curation, 151 B. tabaci and 115 M. persicae proteins were predicted to localize to the plasma membrane of the gut microvilli. These proteins were further categorized based on molecular function and biological process according to Gene Ontology terms. The most abundant gut plasma membrane proteins were identified. The ten plasma membrane proteins that differed in abundance between the two insect species were associated with the terms "protein binding" and "viral processes." In addition to providing insight into the gut physiology of hemipteran insects, these gut plasma membrane proteomes provide context for appropriate identification of plant virus receptors based on a combination of bioinformatic prediction and protein localization on the surface of the insect gut.
Asunto(s)
Áfidos , Tracto Gastrointestinal , Proteínas de Insectos , Insectos Vectores , Virus de Plantas , Animales , Proteínas de Insectos/metabolismo , Insectos Vectores/virología , Insectos Vectores/metabolismo , Áfidos/virología , Áfidos/metabolismo , Tracto Gastrointestinal/virología , Tracto Gastrointestinal/metabolismo , Proteínas de la Membrana/metabolismo , Hemípteros/virología , Hemípteros/metabolismo , Proteoma , Membrana Celular/metabolismoRESUMEN
Curly top disease, caused by beet curly top virus (BCTV), is among the most serious viral diseases affecting sugar beets in western USA. The virus is exclusively transmitted by the beet leafhopper (BLH, Circulifer tenellus) in a circulative and non-propagative manner. Despite the growing knowledge on virus-vector interactions, our understanding of the molecular interactions between BCTV and BLH is hampered by limited information regarding the virus impact on the vector and the lack of genomic and transcriptomic resources for BLH. This study unveils the significant impact of BCTV on both the performance and transcriptome response of BLHs. Viruliferous BLHs had higher fecundity than non-viruliferous counterparts, which was evident by upregulation of differentially expressed transcripts (DETs) associated with development, viability and fertility of germline and embryos in viruliferous insects. Conversely, most DETs associated with muscle movement and locomotor activities were downregulated in viruliferous insects, implying potential behavioural modifications by BCTV. Additionally, a great proportion of DETs related to innate immunity and detoxification were upregulated in viruliferous insects. Viral infection also induced notable alterations in primary metabolisms, including energy metabolism, namely glucosidases, lipid digestion and transport, and protein degradation, along with other cellular functions, particularly in chromatin remodelling and DNA repair. This study represents the first comprehensive transcriptome analysis for BLH. The presented findings provide new insights into the multifaceted effects of viral infection on various biological processes in BLH, offering a foundation for future investigations into the complex virus-vector relationship and potential management strategies for curly top disease.
Asunto(s)
Beta vulgaris , Perfilación de la Expresión Génica , Hemípteros , Insectos Vectores , Enfermedades de las Plantas , Animales , Hemípteros/virología , Hemípteros/genética , Enfermedades de las Plantas/virología , Enfermedades de las Plantas/genética , Insectos Vectores/virología , Insectos Vectores/genética , Beta vulgaris/virología , Transcriptoma , Geminiviridae/genética , Geminiviridae/fisiología , Fertilidad/genéticaRESUMEN
Rice black-streaked dwarf virus (RBSDV) is an etiological agent of a destructive disease infecting some economically important crops from the Gramineae family in Asia. While RBSDV causes high yield losses, genetic characteristics of replicative viral populations have not been investigated within different host plants and insect vectors. Herein, eleven publicly available RNA-Seq datasets from Chinese RBSDV-infected rice, maize, and viruliferous planthopper (Laodelphax striatellus) were obtained from the NCBI database. The patterns of SNP and RNA expression profiles of expected RBSDV populations were analyzed by CLC Workbench 20 and Geneious Prime software. These analyses discovered 2,646 mutations with codon changes in RBSDV whole transcriptome and forty-seven co-mutated hotspots with high variant frequency within the crucial regions of S5-1, S5-2, S6, S7-1, S7-2, S9, and S10 open reading frames (ORFs) which are responsible for some virulence and host range functions. Moreover, three joint mutations are located on the three-dimensional protein of P9-1. The infected RBSDV-susceptible rice cultivar KTWYJ3 and indigenous planthopper datasets showed more co-mutated hotspot numbers than others. Our analyses showed the expression patterns of viral genomic fragments varied depending on the host type. Unlike planthopper, S5-1, S2, S6, and S9-1 ORFs, respectively had the greatest read numbers in host plants; and S5-2, S9-2, and S7-2 were expressed in the lowest level. These findings underscore virus/host complexes are effective in the genetic variations and gene expression profiles of plant viruses. Our analysis revealed no evidence of recombination events. Interestingly, the negative selection was observed at 12 RBSDV ORFs, except for position 1015 in the P1 protein, where a positive selection was detected. The research highlights the potential of SRA datasets for analysis of the virus cycle and enhances our understanding of RBSDV's genetic diversity and host specificity.