Letteratura scientifica selezionata sul tema "Insect vectors"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Insect vectors".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Articoli di riviste sul tema "Insect vectors"
1
Katili, Moh Zulkifli, Yeni Herdiyeni e Medria Kusuma Dewi Hardhienata. "Leveraging Biotic Interaction Knowledge Graph and Network Analysis to Uncover Insect Vectors of Plant Virus". Journal of Information Systems Engineering and Business Intelligence 10, n. 1 (28 febbraio 2024): 94–109. http://dx.doi.org/10.20473/jisebi.10.1.94-109.
Testo completoAbstract (sommario):
Background: Insect vectors spread 80% of plant viruses, causing major agricultural production losses. Direct insect vector identification is difficult due to a wide range of hosts, limited detection methods, and high PCR costs and expertise. Currently, a biodiversity database named Global Biotic Interaction (GloBI) provides an opportunity to identify virus vectors using its data. Objective: This study aims to build an insect vector search engine that can construct an virus-insect-plant interaction knowledge graph, identify insect vectors using network analysis, and extend knowledge about identified insect vectors. Methods: We leverage GloBI data to construct a graph that shows the complex relationships between insects, viruses, and plants. We identify insect vectors using interaction analysis and taxonomy analysis, then combine them into a final score. In interaction analysis, we propose Targeted Node Centric-Degree Centrality (TNC-DC) which finds insects with many directly and indirectly connections to the virus. Finally, we integrate Wikidata, DBPedia, and NCBIOntology to provide comprehensive information about insect vectors in the knowledge extension stage. Results: The interaction graph for each test virus was created. At the test stage, interaction and taxonomic analysis achieved 0.80 precision. TNC-DC succeeded in overcoming the failure of the original degree centrality which always got bees in the prediction results. During knowledge extension stage, we succeeded in finding the natural enemy of the Bemisia Tabaci (an insect vector of Pepper Yellow Leaf Curl Virus). Furthermore, an insect vector search engine is developed. The search engine provides network analysis insights, insect vector common names, photos, descriptions, natural enemies, other species, and relevant publications about the predicted insect vector. Conclusion: An insect vector search engine correctly identified virus vectors using GloBI data, TNC-DC, and entity embedding. Average precision was 0.80 in precision tests. There is a note that some insects are best in the first-to-five order. Keywords: Knowledge Graph, Network Analysis, Degree Centrality, Entity Embedding, Insect Vector
2
Nie, Danyue, Jiaqiao Li, Qinghua Xie, Lele Ai, Changqiang Zhu, Yifan Wu, Qiyuan Gui, Lingling Zhang e Weilong Tan. "Nanoparticles: A Potential and Effective Method to Control Insect-Borne Diseases". Bioinorganic Chemistry and Applications 2023 (11 maggio 2023): 1–13. http://dx.doi.org/10.1155/2023/5898160.
Testo completoAbstract (sommario):
Insects act as vectors to carry a wide range of bacteria and viruses that can cause multiple vector-borne diseases in humans. Diseases such as dengue fever, epidemic encephalitis B, and epidemic typhus, which pose serious risks to humans, can be transmitted by insects. Due to the absence of effective vaccines for most arbovirus, insect control was the main strategy for vector-borne diseases control. However, the rise of drug resistance in the vectors brings a great challenge to the prevention and control of vector-borne diseases. Therefore, finding an eco-friendly method for vector control is essential to combat vector-borne diseases. Nanomaterials with the ability to resist insects and deliver drugs offer new opportunities to increase agent efficacy compared with traditional agents, and the application of nanoagents has expanded the field of vector-borne disease control. Up to now, the reviews of nanomaterials mainly focus on biomedicines, and the control of insect-borne diseases has always been a neglected field. In this study, we analyzed 425 works of the literature about different nanoparticles applied on vectors in PubMed around keywords, such as“nanoparticles against insect,” “NPs against insect,” and “metal nanoparticles against insect.” Through these articles, we focus on the application and development of nanoparticles (NPs) for vector control, discussing the lethal mechanism of NPs to vectors, which can explore the prospect of applying nanotechnology in the prevention and control of vectors.
3
Chen, Qian, e Taiyun Wei. "Cell Biology During Infection of Plant Viruses in Insect Vectors and Plant Hosts". Molecular Plant-Microbe Interactions® 33, n. 1 (gennaio 2020): 18–25. http://dx.doi.org/10.1094/mpmi-07-19-0184-cr.
Testo completoAbstract (sommario):
Plant viruses typically cause severe pathogenicity in plants, even resulting in the death of plants. Many pathogenic plant viruses are transmitted in a persistent manner via insect vectors. Interestingly, unlike in the plant hosts, persistent viruses are either nonpathogenic or show limited pathogenicity in their insect vectors, while taking advantage of the cellular machinery of insect vectors for completing their life cycles. This review discusses why persistent plant viruses are nonpathogenic or have limited pathogenicity to their insect vectors while being pathogenic to plants hosts. Current advances in cell biology of virus–insect vector interactions are summarized, including virus-induced inclusion bodies, changes of insect cellular ultrastructure, and immune response of insects to the viruses, especially autophagy and apoptosis. The corresponding findings of virus-plant interactions are compared. An integrated view of the balance strategy achieved by the interaction between viral attack and the immune response of insect is presented. Finally, we outline progress gaps between virus-insect and virus-plant interactions, thus highlighting the contributions of cultured cells to the cell biology of virus-insect interactions. Furthermore, future prospects of studying the cell biology of virus-vector interactions are presented.
4
Berasategui, Aileen, Shounak Jagdale e Hassan Salem. "Fusarium phytopathogens as insect mutualists". PLOS Pathogens 19, n. 7 (27 luglio 2023): e1011497. http://dx.doi.org/10.1371/journal.ppat.1011497.
Testo completoAbstract (sommario):
As vectors of numerous plant pathogens, herbivorous insects play a key role in the epidemiology of plant disease. But how phytopathogens impact the metabolism, physiology, and fitness of their insect vectors is often unexplored within these tripartite interactions. Here, we examine the diverse symbioses forged between insects and members of the ascomycete fungal genus Fusarium. While Fusarium features numerous plant pathogens that are causal to diseases such as wilts and rots, many of these microbes also engage in stable mutualisms across several insect clades. Matching a diversity in symbiont localization and transmission routes, we highlight the various roles fusaria fulfill towards their insect hosts, from upgrading their nutritional physiology to providing defense against natural enemies. But as the insect partner is consistently herbivorous, we emphasize the convergent benefit Fusarium derives in exchange: propagation to a novel host plant. Collectively, we point to the synergy arising between a phytopathogen and its insect vector, and the consequences inflicted on their shared plant.
5
Zhao, Wan, Jinting Yu, Feng Jiang, Wei Wang, Le Kang e Feng Cui. "Coordination between terminal variation of the viral genome and insect microRNAs regulates rice stripe virus replication in insect vectors". PLOS Pathogens 17, n. 3 (10 marzo 2021): e1009424. http://dx.doi.org/10.1371/journal.ppat.1009424.
Testo completoAbstract (sommario):
Maintenance of a balance between the levels of viral replication and selective pressure from the immune systems of insect vectors is one of the prerequisites for efficient transmission of insect-borne propagative phytoviruses. The mechanism regulating the adaptation of RNA viruses to insect vectors by genomic variation remains unknown. Our previous study demonstrated an extension of the 3’-untranslated terminal region (UTR) of two genomic segments of rice stripe virus (RSV). In the present study, a reverse genetic system for RSV in human cells and an insect vector, the small brown planthopper Laodelphax striatellus, was used to demonstrate that the 3’-terminal extensions suppressed viral replication in vector insects by inhibiting promoter activity due to structural interference with the panhandle structure formed by viral 3’- and 5’-UTRs. The extension sequence in the viral RNA1 segment was targeted by an endogenous insect microRNA, miR-263a, which decreased the inhibitory effect of the extension sequence on viral promoter activity. Surprisingly, the expression of miR-263a was negatively regulated by RSV infection. This elaborate coordination between terminal variation of the viral genome and endogenous insect microRNAs controls RSV replication in planthopper, thus reflecting a distinct strategy of adaptation of phytoviruses to insect vectors.
6
Labroussaa, Fabien, Adam R. Zeilinger e Rodrigo P. P. Almeida. "Blocking the Transmission of a Noncirculative Vector-Borne Plant Pathogenic Bacterium". Molecular Plant-Microbe Interactions® 29, n. 7 (luglio 2016): 535–44. http://dx.doi.org/10.1094/mpmi-02-16-0032-r.
Testo completoAbstract (sommario):
The successful control of insect-borne plant pathogens is often difficult to achieve due to the ecologically complex interactions among pathogens, vectors, and host plants. Disease management often relies on pesticides and other approaches that have limited long-term sustainability. To add a new tool to control vector-borne diseases, we attempted to block the transmission of a bacterial insect-transmitted pathogen, the bacterium Xylella fastidiosa, by disrupting bacteria–insect vector interactions. X. fastidiosa is known to attach to and colonize the cuticular surface of the mouthparts of vectors; a set of recombinant peptides was generated and the chemical affinities of these peptides to chitin and related carbohydrates was assayed in vitro. Two candidates, the X. fastidiosa hypothetical protein PD1764 and an N-terminal region of the hemagglutinin-like protein B (HxfB) showed affinity for these substrates. These proteins were provided to vectors via an artificial diet system in which insects acquire X. fastidiosa, followed by an inoculation access period on plants under greenhouse conditions. Both PD1764 and HxfAD1-3 significantly blocked transmission. Furthermore, bacterial populations within insects over a 10-day period demonstrated that these peptides inhibited cell adhesion to vectors but not bacterial multiplication, indicating that the mode of action of these peptides is restricted to limiting cell adhesion to insects, likely via competition for adhesion sites. These results open a new venue in the search for sustainable disease-control strategies that are pathogen specific and may have limited nontarget effects.
7
Wu, Xiujuan, e Jian Ye. "Manipulation of Jasmonate Signaling by Plant Viruses and Their Insect Vectors". Viruses 12, n. 2 (27 gennaio 2020): 148. http://dx.doi.org/10.3390/v12020148.
Testo completoAbstract (sommario):
Plant viruses pose serious threats to stable crop yield. The majority of them are transmitted by insects, which cause secondary damage to the plant host from the herbivore-vector’s infestation. What is worse, a successful plant virus evolves multiple strategies to manipulate host defenses to promote the population of the insect vector and thereby furthers the disease pandemic. Jasmonate (JA) and its derivatives (JAs) are lipid-based phytohormones with similar structures to animal prostaglandins, conferring plant defenses against various biotic and abiotic challenges, especially pathogens and herbivores. For survival, plant viruses and herbivores have evolved strategies to convergently target JA signaling. Here, we review the roles of JA signaling in the tripartite interactions among plant, virus, and insect vectors, with a focus on the molecular and biochemical mechanisms that drive vector-borne plant viral diseases. This knowledge is essential for the further design and development of effective strategies to protect viral damages, thereby increasing crop yield and food security.
8
Kaur, Navneet, Daniel K. Hasegawa, Kai-Shu Ling e William M. Wintermantel. "Application of Genomics for Understanding Plant Virus-Insect Vector Interactions and Insect Vector Control". Phytopathology® 106, n. 10 (ottobre 2016): 1213–22. http://dx.doi.org/10.1094/phyto-02-16-0111-fi.
Testo completoAbstract (sommario):
The relationships between plant viruses and their vectors have evolved over the millennia, and yet, studies on viruses began <150 years ago and investigations into the virus and vector interactions even more recently. The advent of next generation sequencing, including rapid genome and transcriptome analysis, methods for evaluation of small RNAs, and the related disciplines of proteomics and metabolomics offer a significant shift in the ability to elucidate molecular mechanisms involved in virus infection and transmission by insect vectors. Genomic technologies offer an unprecedented opportunity to examine the response of insect vectors to the presence of ingested viruses through gene expression changes and altered biochemical pathways. This review focuses on the interactions between viruses and their whitefly or thrips vectors and on potential applications of genomics-driven control of the insect vectors. Recent studies have evaluated gene expression in vectors during feeding on plants infected with begomoviruses, criniviruses, and tospoviruses, which exhibit very different types of virus-vector interactions. These studies demonstrate the advantages of genomics and the potential complementary studies that rapidly advance our understanding of the biology of virus transmission by insect vectors and offer additional opportunities to design novel genetic strategies to manage insect vectors and the viruses they transmit.
9
Zhao, Pingzhi, Xiangmei Yao, Congxi Cai, Ran Li, Jie Du, Yanwei Sun, Mengyu Wang et al. "Viruses mobilize plant immunity to deter nonvector insect herbivores". Science Advances 5, n. 8 (agosto 2019): eaav9801. http://dx.doi.org/10.1126/sciadv.aav9801.
Testo completoAbstract (sommario):
A parasite-infected host may promote performance of associated insect vectors; but possible parasite effects on nonvector insects have been largely unexplored. Here, we show that Begomovirus, the largest genus of plant viruses and transmitted exclusively by whitefly, reprogram plant immunity to promote the fitness of the vector and suppress performance of nonvector insects (i.e., cotton bollworm and aphid). Infected plants accumulated begomoviral βC1 proteins in the phloem where they were bound to the plant transcription factor WRKY20. This viral hijacking of WRKY20 spatiotemporally redeployed plant chemical immunity within the leaf and had the asymmetrical benefiting effects on the begomoviruses and its whitefly vectors while negatively affecting two nonvector competitors. This type of interaction between a parasite and two types of herbivores, i.e., vectors and nonvectors, occurs widely in various natural and agricultural ecosystems; thus, our results have broad implications for the ecological significance of parasite-vector-host tripartite interactions.
10
Zongoma, A. M., D. B. Dangora, M. Sétamou, M. D. Alegbejo e O. J. Alabi. "Identification of mealybugs, soft scale insects and their predators in vineyards across the savannah agro-ecological region of Nigeria". Zoologist (The) 18, n. 1 (8 aprile 2021): 27–32. http://dx.doi.org/10.4314/tzool.v18i1.5.
Testo completoAbstract (sommario):
Insect-vectored viruses are a major threat to grapevine production but there is a dearth of information on the occurrence and distribution of key grapevine pests in Nigeria. The recent detection of grapevine leafroll associated virus-1 (GLRaV-1), a known insect-vectored ampelovirus, in Nigeria elevates the importance of the identification of its potential vectors as a precursor to assessing the risk of grapevine leafroll disease spread. This study was conducted to determine the occurrence and diversity of potential vectors of grapevine viruses and their natural enemies in vineyards across the savannah agro-ecological region of Nigeria. Forty vineyard and nursery locations were surveyed during 2016 and 45 arthropod samples were collected. The samples were first morphologically identified, and DNA barcoding was conducted on a subset of 16 representative samples using universal primers specific to the Mitochondrial Cytochrome Oxidase subunit I (mtCOI) gene of most insects. The results indicated the presence of two species of scale insects (Parasaissetia nigra and Saissetia coffeae) and two mealybug species (Maconellicoccus hirsutus and Ferrisia virgata), some ofwhich are potential grapevine virus vectors, in Nigerian vineyards. In addition, the natural enemies of these insect species were detected which includes three species of parasitoids (Anagyrus kamali, Anagyrus pseudococci and Encarsia inaron) and one predator (Hyperaspidius mimus). While the detection of mealybugs and scale insects underscore the risk of vector-mediated virus spread in Nigerian vineyards, the identification of their natural enemies indicates presence of natural biological control agents to facilitate an integrated management of economically important grapevine virus diseases in the country.
Keywords: Mealybugs; scale insects; parasitoids and predators; insect vectors; grapevine viruses.
Tesi sul tema "Insect vectors"
1
Ivanauskas, Algirdas, e ALGIRDAS IVANAUSKAS. "Phytoplasmas and their insect vectors in Lithuania". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140620_091456-96241.
Testo completoAbstract (sommario):
The aim of the research was to identify the phytoplasmas detected in insects that were found on various phytoplasma-infected plants, and to reveal phytoplasma insect-vectors as well as phytogenetical relationships of identified phytoplasmas.
From previous research, we already know a few mostly widespread phytoplasma groups, subgroups, and many of their host plants in Lithuania. The data on potential vectors of these bacteria are very scarce in Lithuania. The identification and research of insect vectors will help to create more effective strategies and systems to fight with phytoplasmal infections. Identification of phytoplasmas and their vectors will provide important data for research of ecology, distribution, origin, epidemiology, and ways of spreading of these pathogens. Such information is beneficial for plant protection institutions and plant growers in Lithuania and neighbouring countries. It will help to ascertain possible invasive insect species and phytoplasma strains in Lithuania.
During this research for the first time in Lithuania, we determined possible phytoplasma insect vectors using molecular biology methods. Most of the detected phytoplasma subgroups were found in the identified insect species for the first time in Lithuania and worldwide. Our data on new potential insect vector species extend the spectrum of phytoplasma vectors in our region. Phytoplasmas were detected for the first time in five plant species in Lithuania. We identified in this work one... [to full text]Disertacijos darbo tikslas – aptikti ir identifikuoti Lietuvoje paplitusias fitoplazmas vabzdžiuose, surinktuose nuo įvairių augalų su fitoplazminiais simptomais ir nustatyti fitoplazmų vabzdžius pernešėjus bei atskleisti identifikuotų ir kitų fitoplazmų filogenetinius giminingumus. Lietuvoje jau žinomos keletas labiausiai paplitusių fitoplazmų grupių bei pogrupių, taip pat aptikta nemažai jų augalų-šeimininkų. Duomenų apie galimus šių bakterijų pernešėjus Lietuvoje beveik nėra. Pernešėjų identifikavimas ir tyrimas padės kurti veiksmingesnes strategijas bei sistemas kovai su fitoplazminėmis infekcijomis. Fitoplazmų ir jų pernešėjų identifikavimas suteiks svarbių duomenų tiriant šių patogenų ekologiją, paplitimą, kilmę, epidemiologiją, plitimo kelius. Informacija bus naudinga Lietuvos ir kaimyninių šalių augalų apsaugai. Taip pat galės padėti nustatant galimų invazinių vabzdžių rūšių bei fitoplazmų kamienų atsiradimą Lietuvoje dėl klimato kaitos. Šio darbo metu pirmą kartą Lietuvoje molekuliniais metodais buvo išaiškinti fitoplazmų vabzdžiai pernešėjai. Daugelis aptiktų fitoplazmų pogrupių nustatytos identifikotuose vabzdžiuose pirmą kartą, kaip Lietuvoje taip ir pasaulyje. Penkiose augalų rūšyse fitoplazmos aptiktos pirmą kartą Lietuvoje. Darbo metu nustatytas vienas visiškai naujas Lietuvai ir pasauliui ir vienas naujas Lietuvai fitoplazmų pogrupiai bei jų augalai šeimininkai, kas prisideda prie Lietuvoje bei pasaulyje aptinkamų fitoplazmų paplitimo ir bioįvairovės tyrimo... [toliau žr. visą tekstą]
2
Theodorides, Kosmas. "Genetic and systematic studies on Cicadellidae vectors". Thesis, University of East Anglia, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368187.
Testo completo
3
Penaud, Magalie. "Characterization of rAAV vectors packaging in baculovirusinfected insect cells". Thesis, Nantes, 2018. http://www.theses.fr/2018NANT1003.
Testo completoAbstract (sommario):
Les vecteurs dérivés du virus adéno-associé (AAVr) constituent des outils de choix pour le transfert de gène in vivo. Leur innocuité a notamment contribué à leur attractivité et leur utilisation dans des essais cliniques de thérapie génique. Afin d'étendre le champ de leur application au traitement de maladies systémiques, un défi majeur reste à relever : leur production à grande échelle. Le système d'infection de cellules d'insecte par des baculovirus peut répondre à ce challenge, pourtant la biologie de l'AAV dans ces cellules reste méconnue. Ceci se répercute par la présence de particules vides ou par une perte d'infectiosité des vecteurs viraux produits. Le travail présenté dans ce manuscrit a pour objectifs de 1) déterminer l'efficacité et la spécificité d'encapsidation du gène d'intérêt dans les capsides d'AAVr 2) étudier le lien entre ces paramètres et l'expression des protéines Rep et 3) définir le rôle de la protéine AAP (assembly-activating protein) en cellules d'insecte. De façon inédite, nous avons montré que moins de 30% des particules générées contenaient le transgène et que l'ADN baculoviral représentait jusqu'à 2,1% du contenu des capsides d'AAV, avec une prédominance pour les séquences proches des ITR (inverted terminal repeats). Enfin, nous avons démontré que l'AAP était essentielle pour l'assemblage des particules d'AAV2 dans les cellules Sf9. Ce projet participe non seulement à l'élucidation des mécanismes· d'encapsidation des AAV dans les cellules d'insecte mais répond également aux exigences des organismes réglementaires en proposant une technique d' avant-garde d'évaluation des contaminants ADN présents dans les stocks de vecteurs AAVDue to their efficiency and safety, recombinant adenoassociated virus (rAAV) vectors have been widely used for gene therapy. ln the past few years, there have been a large number of positive clinical outputs using AAVbased products spanning broad therapeutic areas. However, the generation of rAAV at sufficient quantity and quality appears as a bottleneck on the path to commercialization. The baculovirus-infected insect cell platform has proven to tackle this challenge, yet, surprisingly, the biology of rAAV in insect cells remains largely unknown. As a result, current vectors suffer from quality problems such as generation of empty particles or reduced infectivity. The objectives of the present work are 1) to determine the rAAV packaging efficiency and specificity in insect cells 2) to investigate the link between packaging and Rep proteins expression, and 3) to decipher the role of the assembly-activating protein (AAP). First, we showed that less than 30% of rAAV particles contained the gene of interest in S19 cells cleared lysate. Second, we found that baculoviral DNA contamination is below 2.1% of encapsidated DNA, with a higher representativity for sequences close to the inverted terminal repeats. Finally, we demonstrated that functional AAP is strictly required for rAAV2 particles assembly in insect cells. Altogether, our data provide novel insights into the biological mechanism of rAAV genome packaging in insect cells and suggest that there is still room for improvement in order to increase vector quality. From a safety perspective, this project has allowed the development of an accurate quality control method to assess DNA contamination in viral vector stocks
4
McCarroll, Lynn. "Characterisation of heterologous gene expression in insect cell lines". Thesis, Oxford Brookes University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389533.
Testo completo
5
Pullen, Janice Gaye. "Development of novel baclovirus expression vectors using the 39K gene promoter". Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260189.
Testo completo
6
Chapple, Susan Dorothy Jane. "Improving baculovirus expression vectors by modulating the synthesis of essential virus protein". Thesis, Oxford Brookes University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264474.
Testo completo
7
Atkinson, Alan Edward. "Expression of neuro-transmitter receptors in insect cells using baculovirus vectors". Thesis, Oxford Brookes University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304651.
Testo completo
8
MOUSSA, ELMAGHAWRY ABDELHAMEED. "SUSTAINABLE INTEGRATED MANAGEMENT OF GRAPEVINE BOIS NOIR AND ITS ASSOCIATED INSECT VECTORS". Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/819771.
Testo completoAbstract (sommario):
Bois Noir (BN) is a disease of the grapevine yellows (GY) complex associated with ‘Candidatus Phytoplasma solani’ (CaPsol) strains, which causes economic crop losses in viticulture worldwide. The epidemiology of BN is very complex due to the involvement of different herbaceous plants and several insect vectors that transmit CaPsol to grapevine. Therefore, the BN containment is very difficult and require massive efforts for possible spread reduction. The heavy application of chemical insecticides was not successful to control the insect vector presence within the vineyard. The thesis work was framed considering the directives provided by the European council 2009/128/EC regarding the promotion of low use of pesticides in sustainable management approaches. In the present thesis dissertation, CaPsol insect vectors and diseased grapevines were the main targets prioritized for successful containment of BN in organically cultivated vineyards in northern Italy. Since H. obsoletus is the widely distributed insect vector in Europe, the management of the leafhopper population was carefully considered. The use of Vitex agnus-castus as trap plant for H. obsoletus as an indirect control strategy was evaluated. Vitex agnus-castus tended to be a preferred host plant for H. obsoletus, but transmission trials demonstrated its ability to harbor CaPsol and indicated the impossibility of using this plant to avoid BN spread. In addition, the efficacy of different entomopathogenic nematodes and fungi as direct control strategy were evaluated against H. obsoletus nymphs and adults. Their application in a laboratory and semi-field conditions showed a promising killing effect that can be implemented for insect vector control in open field. Due to the very low density of H. obsoletus population in heavily BN infected vineyards questions were raised to figure out the other possible presence of alternative insect vectors. Surveys on Auchenorrhyncha coupled with molecular analyses revealed the presence of numerous putative vectors. Some of them, selected on the basis of their abundance, CaPsol-infection rate and CaPsol strains harbored, went through transmission trials. Eight insects were found able to transmit CaPsol to grapevines. Characterization of the bacterial microbiota associated with H. obsoletus and the alternative insect vectors indicated an interesting perspective regarding the microbial signatures associated with xylem- and phloem-feeding insects, and determinants that could be relevant to establish whether an insect species can be a vector or not, opening up new avenues for developing microbial resource management-based approaches. Moreover, grafting of materials collected from recovered grapevines was conducted in field trials with the aim to evaluate its preventive and curative potentials against BN. Results of symptom observation and CaPsol molecular detection on grafted and non-grafted grapevines showed that grafting of recovered shoots can have a curative effect, increasing the natural recovery. Results obtained in this PhD thesis opened new perspectives to develop integrated sustainable strategies for BN management.
9
Warren, Ann. "Transposable genetic elements in the mosquito Aedes aegypti". Thesis, University of Liverpool, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.237672.
Testo completo
10
Ng, Terry Fei Fan. "Discovery of Novel Viruses From Animals, Plants, and Insect Vectors Using Viral Metagenomics". Scholar Commons, 2010. http://scholarcommons.usf.edu/etd/3506.
Testo completoAbstract (sommario):
Understanding emerging viruses is critical for disease monitoring and prediction; however, surveys of novel viruses are hindered by the lack of a universal assay for viruses. Viral metagenomics, consisting of viral particle purification and shotgun sequencing, is a powerful technique for discovering viruses in a wide variety of sample types. However, current protocols are not effective on tissue samples (e.g., lungs, livers and tumors), where they are hindered by the high amount of host nucleic acids which limits the percentage of sequences that originate from viruses. In this dissertation, a modified viral metagenomics protocol was developed and utilized to effectively purify viruses from tissues, enabling the sequencing of novel viruses from animals, plants, and insect vectors.
Viral metagenomics performed directly on tissue samples enabled the discovery of novel vertebrate, plant, insect and bacterial viruses. From a sea turtle fibropapilloma, viral metagenomics revealed a novel tornovirus STTV1, which is only the second single-stranded DNA virus known in reptiles and is extremely different from any previously described viruses. Similarly, from the lung of a sea lion involved in a mortality event, viral metagenomics identified a novel sea lion anellovirus (ZcAV), which is the first anellovirus characterized from a marine animal. The STTV1 and ZcAV genomes were highly divergent from known viruses, to a degree that they could not have been detected by degenerate PCR assays or microarrays, demonstrating viral metagenomics as an effective method for characterizing novel viruses.
In addition to discovery of viruses in individual diseased animals, this dissertation pioneered a technique called vector-enabled metagenomics (VEM) to examine viruses present in insect vectors. VEM combines the power of metagenomics to sequence novel viruses with the ability of insect vectors to integrate viral diversity over space, time, and many host individuals and species. VEM allows for the investigation of viral diversity among the broad range of hosts that the insects feed on, providing an unprecedented snapshot of the viral diversity in natural reservoirs. This dissertation describes the first viral metagenome performed on mosquitoes and whiteflies, providing significant insights to the viral diversity in animal and plant reservoirs. Both animal and plant viruses were represented in the mosquito viromes, which likely originate from animal blood and plant nectar that the mosquitoes feed on. Mosquito viromes contained a diverse range of viruses, including vertebrate, insect, plant, and bacterial viruses, and almost all the viral sequences were novel, suggesting the pan-animal virome is largely uncharacterized. In contrast, only plant viruses were observed in the whitefly viromes because whiteflies feed solely on plants. Whitefly viromes contained known and novel viral sequences infecting crops, novel viral sequences infecting native plants, as well as novel satellites that were the first viral satellites to be documented in North America. Distinct viromes were found amongst the three mosquito samples as well as between the two whitefly samples, demonstrating the diverse and dynamic nature of the viruses in plant and animal reservoirs.
By enabling the discovery of virus in diseased organisms and in insect vectors, viral metagenomics is a powerful technique that will significantly enhance our fundamental scientific understanding of the diversity, transmission, biogeography, and emergence of viruses. The viral metagenomic approach described here has implications for surveillance of emerging viruses, prediction of viral epidemics, and proactive control of diseases.
Libri sul tema "Insect vectors"
1
Service, Mike W. Blood-sucking insects, vectors of disease. London: E. Arnold, 1986.
Cerca il testo completo
2
C, Marquardt William, a cura di. Biology of disease vectors. 2a ed. Boston: Elsevier Academic Press, 2004.
Cerca il testo completo
3
1949-, Clark J. Marshall, American Chemical Society. Division of Agrochemicals., American Chemical Society e Nihon Nōyaku Gakkai, a cura di. Advances in human vector control. Washington, DC: American Chemical Society, 2009.
Cerca il testo completo
4
Crampton, Julian M., C. Ben Beard e Christos Louis, a cura di. The Molecular Biology of Insect Disease Vectors. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-009-1535-0.
Testo completo
5
M, Crampton Julian, Beard C. B. 1957- e Louis C, a cura di. The molecular biology of insect disease vectors: A methods manual. London: Chapman and Hall, 1997.
Cerca il testo completo
6
WHO Study Group on Malaria Vector Control and Personal Protection. Malaria vector control and personal protection: Report of a WHO Study Group. Geneva: World Health Organization, 2006.
Cerca il testo completo
7
Organization, World Health, a cura di. Vector control: Methods for use by individuals and communities. Geneva: World Health Organization, 1997.
Cerca il testo completo
8
Atkinson, Peter W. Vector biology, ecology, and control. Dordrecht: Springer, 2010.
Cerca il testo completo
9
W, Murhammer David, a cura di. Baculovirus and insect cell expression protocols. 2a ed. Totowa, N.J: Humana Press, 2007.
Cerca il testo completo
10
Service, M. W. Medical entomology for students. 4a ed. Cambridge: Cambridge University Press, 2008.
Cerca il testo completoCapitoli di libri sul tema "Insect vectors"
1
Govorushko, Sergey. "Insects as Vectors of Plant Diseases". In Human–Insect Interactions, 248–52. Boca Raton, FL : CRC Press, 2017. | “A science publishers book.”: CRC Press, 2018. http://dx.doi.org/10.1201/9781315119915-16.
Testo completo
2
Possee, Robert D., e Linda A. King. "Baculovirus Transfer Vectors". In Baculovirus and Insect Cell Expression Protocols, 55–75. Totowa, NJ: Humana Press, 2007. http://dx.doi.org/10.1007/978-1-59745-457-5_3.
Testo completo
3
Weintraub, Phyllis, e Jürgen Gross. "Capturing Insect Vectors of Phytoplasmas". In Methods in Molecular Biology, 61–72. Totowa, NJ: Humana Press, 2012. http://dx.doi.org/10.1007/978-1-62703-089-2_6.
Testo completo
4
Tedeschi, Rosemarie, e Assunta Bertaccini. "Transovarial Transmission in Insect Vectors". In Phytoplasmas: Plant Pathogenic Bacteria - II, 115–30. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-2832-9_5.
Testo completo
5
Butter, N. S. "Introduction: Historical Background, Pathogens, Symptoms, and Economic Importance". In Insect Vectors and Plant Pathogens, 1–28. Boca Raton, FL : CRC Press, Taylor & Francis Group, [2018]: CRC Press, 2018. http://dx.doi.org/10.1201/9780429503641-1.
Testo completo
6
Butter, N. S. "Nematodes". In Insect Vectors and Plant Pathogens, 303–18. Boca Raton, FL : CRC Press, Taylor & Francis Group, [2018]: CRC Press, 2018. http://dx.doi.org/10.1201/9780429503641-10.
Testo completo
7
Butter, N. S. "Fungi". In Insect Vectors and Plant Pathogens, 319–30. Boca Raton, FL : CRC Press, Taylor & Francis Group, [2018]: CRC Press, 2018. http://dx.doi.org/10.1201/9780429503641-11.
Testo completo
8
Butter, N. S. "Phytotoxemia". In Insect Vectors and Plant Pathogens, 331–45. Boca Raton, FL : CRC Press, Taylor & Francis Group, [2018]: CRC Press, 2018. http://dx.doi.org/10.1201/9780429503641-12.
Testo completo
9
Butter, N. S. "Plant Pathogens and Electron Microscope". In Insect Vectors and Plant Pathogens, 346–72. Boca Raton, FL : CRC Press, Taylor & Francis Group, [2018]: CRC Press, 2018. http://dx.doi.org/10.1201/9780429503641-13.
Testo completo
10
Butter, N. S. "Pathogen Effects and Ecological Factors". In Insect Vectors and Plant Pathogens, 373–96. Boca Raton, FL : CRC Press, Taylor & Francis Group, [2018]: CRC Press, 2018. http://dx.doi.org/10.1201/9780429503641-14.
Testo completoAtti di convegni sul tema "Insect vectors"
1
Fereres, Alberto. "Behavioral responses of insect vectors of plant disease to climate change". In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.92654.
Testo completo
2
Silva, Diego, e Gustavo Batista. "Signal classification by similarity and feature extraction with application in automatic insect identification". In XXVIII Concurso de Teses e Dissertações da SBC. Sociedade Brasileira de Computação - SBC, 2020. http://dx.doi.org/10.5753/ctd.2015.10006.
Testo completoAbstract (sommario):
Insects have a strong relationship with the human-beings. For example, some species of mosquito transmit diseases that kill millions of people around the world. At the same time, the presence of certain insects is essential for the ecological balance and food production. For this reason, we are developing a novel sensor as a tool to efficiently control disease vectors and agricultural pests without harming other species. In this paper, we demonstrate how we overtook the most important challenge to make this sensor practical: the creation of accurate classification systems. Despite the short duration and the very simple structure of the signal, we managed to successfully identify relevant features using speech and audio analysis techniques. We show that we can achieve an accuracy of 98% in the task of disease vector mosquitoes identification.
3
Trebicki, Piotr. "Future climate: Its effects on insect vectors and spread of plant diseases". In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.112313.
Testo completo
4
Orlovskis, Zigmunds. "Multitasking: How single bacterial virulence proteins modulate plant development and attract insect vectors". In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.105638.
Testo completo
5
Grieve, Bruce, Charles Veys, Jose Dingle, John Colvin e Joachim Nwezeobi. "Portable, in-field, multispectral imaging sensor for real-time detection of insect viral-vectors". In 2017 IEEE SENSORS. IEEE, 2017. http://dx.doi.org/10.1109/icsens.2017.8234206.
Testo completo
6
Campbell, Lindsay. "Climate change effects on rangewide potential distributions and abundances of insect vectors of disease". In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.104997.
Testo completo
7
Hallo, Maria, Danni Brito, Ivan Carrera, Bryan Lema e Miguel Pinto. "Semiautomatic Extraction of Morphological Characters from a Book about Insect Vectors of Chagas Disease". In 2019 IEEE World Conference on Engineering Education (EDUNINE). IEEE, 2019. http://dx.doi.org/10.1109/edunine.2019.8875846.
Testo completo
8
Roslavtseva, S. A., e K. S. Krivonos. "INORGANIC SUBSTANCES AND THEIR EFFECTS ON INSECTS". In V International Scientific Conference CONCEPTUAL AND APPLIED ASPECTS OF INVERTEBRATE SCIENTIFIC RESEARCH AND BIOLOGICAL EDUCATION. Tomsk State University Press, 2020. http://dx.doi.org/10.17223/978-5-94621-931-0-2020-76.
Testo completoAbstract (sommario):
The return of interest in the use of inorganic substances as insecticides is associated with the development of resistance to traditional organic insecticides from the classes of organophosphorus compounds (OPs), carbamates and pyrethroids in populations of insect vectors of pathogens. In this regard, we have developed an insecticide based on a mixture of diatomaceous powder (DP) with silica gel, which is recommended primarily for controlling resistant populations of bed bugs, as well as German cockroaches, fleas, and crickets, and a special insecticide (a mixture of DP with boric acid) for controlling German and black cockroaches and crickets.
9
Zamorzaeva, Irina, e Aighiuni Bahşiev. "Lack of stolbur transmission by seeds in some moldavian tomato and pepper varieties". In International Scientific Symposium "Plant Protection – Achievements and Prospects". Institute of Genetics, Physiology and Plant Protection, Republic of Moldova, 2020. http://dx.doi.org/10.53040/9789975347204.86.
Testo completoAbstract (sommario):
The study of the possibility of stolbur transmission by seeds in some Moldavian tomato and pepper varieties was carried out using molecular diagnostic methods. The lack of the transmission of phytoplasma by seeds was evidenced analysing seedlings growing in the controlled laboratory conditions (thermostat) when the infection by insect vectors was impossible. Moreover, this lack was confirmed by results showing the absence of ‘Ca. P. solani’ infection in plants analyzed in mid-July of 2020 (stages of ‘flowering’ or, mainly, ‘green fruits’) grown in the field or greenhouse.
10
Zamorzaeva, Irina, e Aighiuni Bahsiev. "Phytoplasma testing in sweet pepper in Moldova". In VIIth International Scientific Conference “Genetics, Physiology and Plant Breeding”. Institute of Genetics, Physiology and Plant Protection, Republic of Moldova, 2021. http://dx.doi.org/10.53040/gppb7.2021.29.
Testo completoAbstract (sommario):
Phytoplasma infects a wide variety of crops, causing considerable economic losses. About half of the vegetable crops damaged by phytoplasma belong to the Solanaceae family including tomato, eggplant and pepper which play an important role in the agriculture economics of Moldova. Our previous research confirmed the presence of ‘Candidatus Phytoplasma solani’ (16SrXII-A subgroup) in tomatoes and also identified insect vectors. In this communication, we present for the first time in Moldova the results of molecular diagnosis of association of ‘Ca. P. solani’ in 4% of the analyzed sweet pepper samples. ‘Ca. P. asteris’ group was absent in the pepper field.
Rapporti di organizzazioni sul tema "Insect vectors"
1
Hackett, Kevin, Shlomo Rottem, David L. Williamson e Meir Klein. Spiroplasmas as Biological Control Agents of Insect Pests. United States Department of Agriculture, luglio 1995. http://dx.doi.org/10.32747/1995.7613017.bard.
Testo completoAbstract (sommario):
Toward development of spiroplasmas as novel toxin-delivery systems for biocontrol of beetle pests in the United States (Leptinotarsa decemlineata) and Israel (Maladera matrida), media for cultivating beetle-associated spiroplasmas were improved and surveys of these spiroplasmas were conducted to provide transformable strains. Extensive surveys of spiroplasmas yielded promising extrachromosomal elements for vector constructs. One, plasmid pCT-1, was cloned, characterized, and used as a source of spiroplasma origin of replication in our shuttle vectors. The fibrillin gene was isolated and sequenced and its strong promoter was also used in the constructs. Means for transforming these vectors into spiroplasmas were developed and optimized, with electroporation found to be suitable for most applications. Development and optimization of means for using large unilamellar vesicles (LUVs) in spiroplasma transformation represents a breakthrough that should facilitate insertion of large clusters of virulence genes. With completion of the vector, we should thus be poised to genetically engineer spiroplasmas with genes that will express toxins lethal to our target beetles, thus providing an effective and inexpensive alternative to conventional means of beetle control.
2
Ullman, Diane E., Benjamin Raccah, John Sherwood, Meir Klein, Yehezkiel Antignus e Abed Gera. Tomato Spotted Wilt Tosporvirus and its Thrips Vectors: Epidemiology, Insect/Virus Interactions and Control. United States Department of Agriculture, novembre 1999. http://dx.doi.org/10.32747/1999.7573062.bard.
Testo completoAbstract (sommario):
Objectives. The major aim of the proposed research was to study thrips-TSWV relationships and their role in the epidemiology of the virus with the aim of using this knowledge to reduce crop losses occurring due to epidemics. Our specific objectives were: To determine the major factors involved in virus outbreaks, including: a) identifying the thrips species involved in virus dissemination and their relative role in virus spread; b) determining the virus sources among wild and cultivated plants throughout the season and their role in virus spread, and, c) determining how temperature and molecular variations in isolates impact virus replication in plants and insects and impact the transmission cycle. Background to the topic. Tospoviruses are among the most important emerging plant viruses that impact production of agricultural and ornamental crops. Evolution of tospoviruses and their relationships with thrips vector species have been of great interest because of crop damage caused world wide and the complete absence of suitable methods of control. Tospoviruses threaten crops in Israel and the United States. By understanding the factors contributing to epidemics and the specific relationships between thrips species and particular tospoviruses we hope that new strategies for control can be developed that will benefit agriculture in both Israel and the United States. Major conclusions, solutions, achievements. We determined that at least three tospoviruses were involved in epidemics in Israel and the United States, tomato spotted wilt virus (TSWV), impatiens necrotic spot virus (INSV) and iris yellow spot virus (IYSV). We detected and characterized INSV for the first time in Israel and, through our efforts, IYSV was detected and characterized for the first time in both countries. We demonstrated that many thrips species were present in commercial production areas and trap color influenced thrips catch. Frankliniella occidentalis was the major vector species of INSV and TSWV and populations varied in transmission efficiency. Thrips tabaci is the sole known vector of IYSV and experiments in both countries indicated that F. occidentalis is not a vector of this new tospovirus. Alternate plant hosts were identified for each virus. A new monitoring system combining sticky cards and petunia indicator plants was developed to identify sources of infective thrips. This system has been highly successful in the U.S. and was used to demonstrate to growers that removal of plant sources of infective thrips has a dramatic impact on virus incidence. Finally, a putative thrips receptor mediating acquisition of TSWV was discovered. Implications, scientific and agricultural. Our findings have contributed to new control measures that will benefit agriculture. Identification of a putative thrips receptor for TSWV and our findings relative to thrips/tospovirus specificity have implications for development of innovative new control strategies.
3
Gottlieb, Yuval, e Bradley A. Mullens. Might Bacterial Symbionts Influence Vectorial Capacity of Biting Midges for Ruminant Viruses? United States Department of Agriculture, settembre 2010. http://dx.doi.org/10.32747/2010.7699837.bard.
Testo completoAbstract (sommario):
- Original objectives and revision: The feasibility study performed in the last year was aimed at determining the symbiotic profiles of eight selected Culicoidesspecies in Israel and the USA by: Comparing bacterial communities among geographic populations of primary bluetongue virus (BTV) vectors. Comparing bacterial communities between adults of field-collected, mammal-feeding BTV vectors and non-vectors. Comparing bacterial communities within and between mammal feeders and bird feeders, with special attention to species with unique immature habitats. We made an effort to collect the eight species during the beginning of the project, however, due to the short available collection season, and the significant changes in habitats available for Israeli Culicoides, we initially determined the symbiotic profile of five species: two BTV vectors (C. sonorensis, C. imicola), one mammal feeders with unknown vectoring ability (C. schultzei), one bird feeder (C. crepuscularis), and one unique habitat species (C. cacticola). In addition, upon preliminary symbiont identification we focused our effort on relevant specific symbionts. Background: Biting midges (Culicoides, Diptera: Ceratopogonidae) are vectors of many major viral diseases affecting farm animals, including BT, which is listed among the most damaging by the World Organization for Animal Health (OIE) and has recently emerged in completely unexpected areas (Northern Europe). One of the strategies to reduce the vectorial capacity of insect vectors is by manipulating their specific symbionts either to affect the vector species or to influence performance of the disease agent within it. Despite significant efforts to elucidate the vectorial capacity of certain Culicoidesspecies, and the critical basis of variability in infection, almost no attention has been given to symbiotic interactions between the vector and its bacterial tenants. It is now established that bacterial symbionts have major influences on their host biology, and may interact with disease agents vectored by their hosts. - Major conclusions, solutions, achievements: During the feasibility project we have found two major bacterial symbionts in Israeli and American Culicoides. In Israel we discovered that C. imicola, a known vector of BT, and C. schultzeigp. a suspected vector of BT, carry the symbiotic bacterium Cardinium, a reproductive manipulator symbiont. In C. imicolathe infection rate was close to 50%, and in C. schultzeiit was lower, and restricted to one of two species within Schultzeigroup. In 3 American species (C. sonorensis, C. crepuscularis, C. cacticola) we found the bacterium Burkholderiasp. In all species tested we have also found other bacterial species in diverse quantities and frequencies. - Implications, both scientific and agricultural: Finding specific symbionts in Culicoidesvector species is the first step in developing symbiont based control (SBC) strategies. Both identified symbionts are known from other insects, and Cardiniumis also known as a reproductive manipulator that can cause cytoplasmic incompatibility, an important phenomenon that can be used for spreading desired traits in infected populations. The role of the symbionts in Culicoideshost can be target for manipulation to reduce the vectorial capacity of the host by either changing its fitness so that it is unable to serve as a vector, or by directly changing the symbiont in a way that will affect the performance of the disease agent in its vector. Since Burkholderiaperhaps can be cultured independently of the host, it is a promising candidate for the later option. Thus, we have now opened the door for studying the specific interactions between symbionts and vector species.
4
Gurevitz, Michael, Michael E. Adams e Boaz Shaanan. Structural Elements and Neuropharmacological Features Involved in the Insecticidal Properties of an Alpha Scorpion Neurotoxin: A Multidisciplinary Approach. United States Department of Agriculture, agosto 1995. http://dx.doi.org/10.32747/1995.7573061.bard.
Testo completoAbstract (sommario):
Integrated pest management in modern crop protection requires the use of chemical or biological insecticides in many instances. Nontheless, the use non-selective chemical insecticides poses risks to the environment and livestock and consequently urgent need exists for safer alternatives, which target insects more specifically. Scorpions produce anti-insect selective polypeptide toxins that are biodegradable and not toxic to wam-blooded animals. Therefore, mobilization of these substances into insect pest targets is of major interest. Moreover, clarification of the molecular basis of this selectivity may provide valuable information pertinent to their receptor sites and to the future design of peptidomimetic anti-insect specific substances. These toxins may also be important for reducing the current overuse of chamical insecticides provided they have a synergistic effect with conventional pesticides. All of these objectives were addressed in this research. A direct approach for plant protection was the mobilization of toxins into target pests using baculoviral vectors. The other approach was to develop a suitable system enabling the elucidation of the toxin bioactive site, which would enable design of insecticidal peptidomimetics. In parallel, the mode of action and synergistic effects of scorpion insecticidal toxins, were studied at the sodium channel receptor site. All the above approaches show great promise and clearly indicate that scorpion insecticidal toxins may provide powerful means in insect pest control.
5
Gottlieb, Yuval, Bradley Mullens e Richard Stouthamer. investigation of the role of bacterial symbionts in regulating the biology and vector competence of Culicoides vectors of animal viruses. United States Department of Agriculture, giugno 2015. http://dx.doi.org/10.32747/2015.7699865.bard.
Testo completoAbstract (sommario):
Symbiotic bacteria have been shown to influence host reproduction and defense against biotic and abiotic stressors, and this relates to possible development of a symbiont-based control strategy. This project was based on the hypothesis that symbionts have a significant impact on Culicoides fitness and vector competence for animal viruses. The original objectives in our proposal were: 1. Molecular identification and localization of the newly-discovered symbiotic bacteria within C. imicola and C. schultzei in Israel and C. sonorensis in California. 2. Determination of the prevalence of symbiotic bacteria within different vector Culicoides populations. 3. Documentation of specific symbiont effects on vector reproduction and defense: 3a) test for cytoplasmic incompatibility in Cardinium-infected species; 3b) experimentally evaluate the role of the symbiont on infection or parasitism by key Culicoides natural enemies (iridescent virus and mermithid nematode). 4. Testing the role(s) of the symbionts in possible protection against infection of vector Culicoides by BTV. According to preliminary findings and difficulties in performing experimental procedures performed in other insect symbiosis systems where insect host cultures are easily maintained, we modified the last two objectives as follows: Obj. 3, we tested how symbionts affected general fitness of Israeli Culicoides species, and thoroughly described and evaluated the correlation between American Culicoides and their bacterial communities in the field. We also tried alternative methods to test symbiont-Culicoides interactions and launched studies to characterize low-temperature stress tolerances of the main US vector, which may be related to symbionts. Obj. 4, we tested the correlation between EHDV (instead of BTV) aquisition and Cardinium infection. Culicoides-bornearboviral diseases are emerging or re-emerging worldwide, causing direct and indirect economic losses as well as reduction in animal welfare. One novel strategy to reduce insects’ vectorial capacity is by manipulating specific symbionts to affect vector fitness or performance of the disease agent within. Little was known on the bacterial tenants occupying various Culicoides species, and thus, this project was initiated with the above aims. During this project, we were able to describe the symbiont Cardinium and whole bacterial communities in Israeli and American Culicoides species respectively. We showed that Cardinium infection prevalence is determined by land surface temperature, and this may be important to the larval stage. We also showed no patent significant effect of Cardinium on adult fitness parameters. We showed that the bacterial community in C. sonorensis varies significantly with the host’s developmental stage, but it varies little across multiple wastewater pond environments. This may indicate some specific biological interactions and allowed us to describe a “core microbiome” for C. sonorensis. The final set of analyses that include habitat sample is currently done, in order to separate the more intimately-associated bacteria from those inhabiting the gut contents or cuticle surface (which also could be important). We were also able to carefully study other biological aspects of Culicoides and were able to discriminate two species in C. schultzei group in Israel, and to investigate low temperature tolerances of C. sonorensis that may be related to symbionts. Scientific implications include the establishment of bacterial identification and interactions in Culicoides (our work is cited in other bacteria-Culicoides studies), the development molecular identification of C. schultzei group, and the detailed description of the microbiome of the immature and matched adult stages of C. sonorensis. Agricultural implications include understanding of intrinsic factors that govern Culicoides biology and population regulation, which may be relevant for vector control or reduction in pathogen transmission. Being able to precisely identify Culicoides species is central to understanding Culicoides borne disease epidemiology.
6
Morin, S., L. L. Walling, Peter W. Atkinson, J. Li e B. E. Tabashnik. ets for CRISPR/Cas9-mediated gene drive in Bemisia tabaci. Israel: United States-Israel Binational Agricultural Research and Development Fund, 2021. http://dx.doi.org/10.32747/2021.8134170.bard.
Testo completoAbstract (sommario):
The goal of our BARD proposal was to build both the necessary infrastructure and knowledge for using the CRISPR/Cas9-based gene drive system to control the whitefly Bemisia tabaci. Our research focused on achieving three main goals: (1) establishing a CRISPR/Cas9 gene-editing system for producing genetically-edited B. tabaci; (2) generating and testing CRISPR/Cas9-mediated mutations targeting genes that represent two gene drive strategies: population replacement and population suppression; (3) using computer modeling to optimize strategies for applying CRISPR/Cas9 to control B. tabaci populations in the field. CRISPR gene drive is one of the most promising strategies for diminishing the negative impacts of harmful insects. This technique can introduce mutations into wild populations of pests that reduce their ability to cause damage, reduce their population size, or both. In principle, this can be selfsustaining because mutations carried by relatively few insects can increase in frequency and spread quickly throughout wild populations. Because of this sustainability and the potential benefits to society, agricultural gene-drive systems are most likely to be funded by government agencies, foundations, and grower associations; as with sterile insect releases and most biocontrol programs. Although gene drives have received intensive study in Drosophila and mosquito vectors of human disease, we were one of the first teams pursuing this approach for crop pests. Our project was also one of the first to address CRISPR gene drive in the Hemiptera, an insect order that includes hundreds of pest species. We focused on developing and implementing CRISPR gene drive to reduce the massive damage caused by B. tabaci. This haplodiploid insect is one of the world's most devastating crop pests. Whereas extensive work by others explored CRISPR in diploid species, our project pioneered application of this revolutionary technology to haplodiploids, which have a distinct system of inheritance that presents special challenges and opportunities. Our project has achieved several breakthroughs, including publication of the first paper analyzing CRISPR gene drive in haplodiploids (Li et al. 2020, see next section). Our modeling results from this landmark study demonstrate that CRISPR gene drive can work in haplodiploids, especially if fitness costs associated with the driver allele are low or nil. Our paper was the first to provide a conceptual framework for evaluating and optimizing CRISPR gene drive strategies for managing B. tabaci and other haplodiploid pests. Our breakthroughs in the laboratory have created the infrastructure needed to develop CRISPR for controlling B. tabaci. We established a microinjection system enabling us to introduce CRISPR-derived mutations into B. tabaci embryos. We have used this system to generate and track inherited eye-color mutants of B. tabaci. We have identified and cloned germline promoters, and demonstrated their function in transgenic B. tabaci embryos and other hemipteran insects. We have also developed a tool to easily identify B. tabaci harboring CRISPR-mediated mutations by tagging target genes using a transgenic fluorescent marker. The successful completion of our project provides all the knowledge and infrastructure essential for developing a novel genetic approach for B. tabaci control, which can serve as a non-chemical "green" alternative for managing this global pest. We predict that our discoveries will accelerate the development of the CRISPR gene drive technique for reducing the numbers of this pest and the damage it causes. Still, realization of the benefits of gene-drive technology for pest control will require sustained attention to potential environmental and societal impacts, as well as regulatory and implementation challenges. Given the great promise of this technology and the urgent need for better control methods, we expect that guidance documents and regulations will be in place to allow the scientific community to safely move gene drives for pest control from the laboratory to field trials.
7
Adelberg, Jeff, Halina Skorupska, Bill Rhodes, Yigal Cohen e Rafael Perl-Treves. Interploid Hybridization of Cucumis melo and C. metuliferus. United States Department of Agriculture, dicembre 1999. http://dx.doi.org/10.32747/1999.7580673.bard.
Testo completoAbstract (sommario):
The long-term motivation for this research is to transfer useful traits from a broad based gene pool of wild species into the narrow base of a cultivated crop in Cucumis. Our primary focus was to use polyploid prior to fertilization as a tool to overcome fertility barriers in the cross between C. melo and C. metuliferus. In conducting this research, we explored all combinations of tetraploid and diploid parents, in reciprocal combinations. Pollinations were made in both the field and greenhouse, using emasculated flowers, moneocious females, and open pollination by insect vectors, with morphological selection criteria. After observations of thousands of ovaries, we still have no definitive proof that this hybridization yielded viable embryos. The most promising results came from using tetraploid C. metuliferus, as the maternal parent in the interspecific hybridization, that set fruit were seeds contained small embryos that did not germinate. To obtain fruit set, it was important to rear plants in a cooler sunny greenhouse, as would be found in late winter/early spring. A second interspecific hybrid between wild and cultivated Cucumis, C. hystrix x C. sativus, yielded fertile progeny for the first time, while concomitantly working toward our primary goal. Two distinct treatments were necessary; 1) special plant husbandry was necessary to have the wild species produce fruit in cultivation, and 2) embryo rescue followed by chromosome doubling in vitro was required for fertility restoration. Backcrosses to crop species and resistance to nematodes are compelling areas for further work.
8
Chejanovsky, Nor, e Bruce A. Webb. Potentiation of Pest Control by Insect Immunosuppression. United States Department of Agriculture, gennaio 2010. http://dx.doi.org/10.32747/2010.7592113.bard.
Testo completoAbstract (sommario):
The restricted host range of many baculoviruses, highly pathogenic to Lepidoptera and non-pathogenic to mammals, limits their use to single or few closely related Lepidopteran species and is an obstacle to extending their implementation for pest control. The insect immune response is a major determinant of the ability of an insect pathogen to efficiently multiply and propagate. We have developed an original model system to study the Lepidopteran antiviral immune response based on Spodoptera littoralis resistance to AcMNPV (Autographa californica multiple nucleopolyhedrovirus) infection and the fascinating immunosuppressive activity of polydnaviruses .Our aim is to elucidate the mechanisms through which the immunosuppressive insect polydnaviruses promote replication of pathogenic baculoviruses in lepidopteran hosts that are mildly or non-permissive to virus- replication. In this study we : 1- Assessed the extent to which and the mechanisms whereby the immunosuppressive Campoletis sonorensis polydnavirus (CsV) or its genes enhanced replication of a well-characterized pathogenic baculovirus AcMNPV, in polydnavirus-immunosuppressedH. zea and S. littoralis insects and S. littoralis cells, hosts that are mildly or non-permissive to AcMNPV. 2- Identified CsV genes involved in the above immunosuppression (e.g. inhibiting cellular encapsulation and disrupting humoral immunity). We showed that: 1. S. littoralis larvae mount an immune response against a baculovirus infection. 2. Immunosuppression of an insect pest improves the ability of a viral pathogen, the baculovirus AcMNPV, to infect the pest. 3. For the first time two PDV-specific genes of the vankyrin and cystein rich-motif families involved in immunosuppression of the host, namely Pvank1 and Hv1.1 respectively, enhanced the efficacy of an insect pathogen toward a semipermissive pest. 4. Pvank1 inhibits apoptosis of Spodopteran cells elucidating one functional aspect of PDVvankyrins. 5. That Pvank-1 and Hv1.1 do not show cooperative effect in S. littoralis when co-expressed during AcMNPV infection. Our results pave the way to developing novel means for pest control, including baculoviruses, that rely upon suppressing host immune systems by strategically weakening insect defenses to improve pathogen (i.e. biocontrol agent) infection and virulence. Also, we expect that the above result will help to develop systems for enhanced insect control that may ultimately help to reduce transmission of insect vectored diseases of humans, animals and plants as well as provide mechanisms for suppression of insect populations that damage crop plants by direct feeding.
9
Ghanim, Murad, Joe Cicero, Judith K. Brown e Henryk Czosnek. Dissection of Whitefly-geminivirus Interactions at the Transcriptomic, Proteomic and Cellular Levels. United States Department of Agriculture, febbraio 2010. http://dx.doi.org/10.32747/2010.7592654.bard.
Testo completoAbstract (sommario):
Our project focuses on gene expression and proteomics of the whitefly Bemisia tabaci (Gennadius) species complex in relation to the internal anatomy and localization of expressed genes and virions in the whitefly vector, which poses a major constraint to vegetable and fiber production in Israel and the USA. While many biological parameters are known for begomovirus transmission, nothing is known about vector proteins involved in the specific interactions between begomoviruses and their whitefly vectors. Identifying such proteins is expected to lead to the design of novel control methods that interfere with whitefly-mediated begomovirus transmission. The project objectives were to: 1) Perform gene expression analyses using microarrays to study the response of whiteflies (B, Q and A biotypes) to the acquisition of begomoviruses (Tomato yellow leaf curl (TYLCV) and Squash leaf curl (SLCV). 2) Construct a whitefly proteome from whole whiteflies and dissected organs after begomovirus acquisition. 3) Validate gene expression by q-RTPCR and sub-cellular localization of candidate ESTs identified in microarray and proteomic analyses. 4) Verify functionality of candidate ESTs using an RNAi approach, and to link these datasets to overall functional whitefly anatomical studies. During the first and second years biological experiments with TYLCV and SLCV acquisition and transmission were completed to verify the suitable parameters for sample collection for microarray experiments. The parameters were generally found to be similar to previously published results by our groups and others. Samples from whole whiteflies and midguts of the B, A and Q biotypes that acquired TYLCV and SLCV were collected in both the US and Israel and hybridized to B. tabaci microarray. The data we analyzed, candidate genes that respond to both viruses in the three tested biotypes were identified and their expression that included quantitative real-time PCR and co-localization was verified for HSP70 by the Israeli group. In addition, experiments were undertaken to employ in situ hybridization to localize several candidate genes (in progress) using an oligonucleotide probe to the primary endosymbiont as a positive control. A proteome and corresponding transcriptome to enable more effective protein identification of adult whiteflies was constructed by the US group. Further validation of the transmission route of begomoviruses, mainly SLCV and the involvement of the digestive and salivary systems was investigated (Cicero and Brown). Due to time and budget constraints the RNAi-mediated silencing objective to verify gene function was not accomplished as anticipated. HSP70, a strong candidate protein that showed over-expression after TYLCV and SLCV acquisition and retention by B. tabaci, and co-localization with TYLCV in the midgut, was further studies. Besides this protein, our joint research resulted in the identification of many intriguing candidate genes and proteins that will be followed up by additional experiments during our future research. To identify these proteins it was necessary to increase the number and breadth of whitefly ESTs substantially and so whitefly cDNAs from various libraries made during the project were sequenced (Sanger, 454). As a result, the proteome annotation (ID) was far more successful than in the initial attempt to identify proteins using Uniprot or translated insect ESTs from public databases. The extent of homology shared by insects in different orders was surprisingly low, underscoring the imperative need for genome and transcriptome sequencing of homopteran insects. Having increased the number of EST from the original usable 5500 generated several years ago to >600,000 (this project+NCBI data mining), we have identified about one fifth of the whitefly proteome using these new resources. Also we have created a database that links all identified whitefly proteins to the PAVEdb-ESTs in the database, resulting in a useful dataset to which additional ESTS will be added. We are optimistic about the prospect of linking the proteome ID results to the transcriptome database to enable our own and other labs the opportunity to functionally annotate not only genes and proteins involved in our area of interest (whitefly mediated transmission) but for the plethora of other functionalities that will emerge from mining and functionally annotating other key genes and gene families in whitefly metabolism, development, among others. This joint grant has resulted in the identification of numerous candidate proteins involved in begomovirus transmission by B. tabaci. A next major step will be to capitalize on validated genes/proteins to develop approaches to interfere with the virus transmission.
10
Chejanovsky, Nor, e Bruce A. Webb. Potentiation of pest control by insect immunosuppression. United States Department of Agriculture, luglio 2004. http://dx.doi.org/10.32747/2004.7587236.bard.
Testo completoAbstract (sommario):
Our original aims were to elucidate the mechanisms through which the immunosuppressive insect virus, the Campoletis sonorensis polydnavirus (CsV) promotes replication of a well-characterized pathogenic virus, the Autographa californica multiple nucleopolyhedrovirus (AcMNPV) in hosts that are mildly or non-permissive to virus replication. According to the BARD panels criticism we modified our short-term goals (see below). Thus, in this feasibility study (one-year funding) we aimed to show that: 1. S. littoralis larvae mount an immune response against a baculovirus infection. 2. Immunosuppression of an insect pest improves the ability of a viral pathogen (a baculovirus) to infect the pest. 3. S. littoralis cells constitute an efficient tool to study some aspects of the anti- viral immune response. We achieved the above objectives by: 1. Finding melanized viral foci upon following the baculoviral infection in S . littoralis larvae infected with a polyhedra - positive AcMNPV recombinant that expressed the GFP gene under the control of the Drosophila heat shock promoter. 2. Studying the effect of AcMNPV-infection in S . littoralis immunosuppressed by parasitation with the Braconidae wasp Chelonus inanitus that bears the CiV polydna virus, that resulted in higher susceptibility of S. littoralis to AcMNPV- infection. 3. Proving that S. littoralis hemocytes resist AcMNPV -infection. 4. Defining SL2 as a granulocyte-like cell line and demonstrating that as littoralis hemocytic cell line undergoes apoptosis upon AcMNPV -infection. 5. Showing that some of the recombinant AcMNPV expressing the immuno-suppressive polydna virus CsV- vankyrin genes inhibit baculoviral-induced lysis of SL2 cells. This information paves the way to elucidate the mechanisms through which the immuno- suppressive polydna insect viruses promote replication of pathogenic baculoviruses in lepidopteran hosts that are mildly or non-permissive to virus- replication by: - Assessing the extent to which and the mechanisms whereby the immunosuppressive viruses, CiV and CsV or their genes enhance AcMNPV replication in polydnavirus- immunosuppressed H. zea and S. littoralis insects and S. littoralis cells. - Identifying CiV and CsV genes involved in the above immunosuppression (e.g. inhibiting cellular encapsulation and disrupting humoral immunity). This study will provide insight to the molecular mechanisms of viral pathogenesis and improve our understanding of insect immunity. This knowledge is of fundamental importance to controlling insect vectored diseases of humans, animals and plants and essential to developing novel means for pest control (including baculoviruses) that strategically weaken insect defenses to improve pathogen (i.e. biocontrol agent) infection and virulence.