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Auswahl der wissenschaftlichen Literatur zum Thema „Transmission du symbiote“
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Zeitschriftenartikel zum Thema "Transmission du symbiote"
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Kaltenpoth, Martin, und Laura V. Flórez. „Versatile and Dynamic Symbioses Between Insects and Burkholderia Bacteria“. Annual Review of Entomology 65, Nr. 1 (07.01.2020): 145–70. http://dx.doi.org/10.1146/annurev-ento-011019-025025.
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Symbiotic associations with microorganisms represent major sources of ecological and evolutionary innovations in insects. Multiple insect taxa engage in symbioses with bacteria of the genus Burkholderia, a diverse group that is widespread across different environments and whose members can be mutualistic or pathogenic to plants, fungi, and animals. Burkholderia symbionts provide nutritional benefits and resistance against insecticides to stinkbugs, defend Lagria beetle eggs against pathogenic fungi, and may be involved in nitrogen metabolism in ants. In contrast to many other insect symbioses, the known associations with Burkholderia are characterized by environmental symbiont acquisition or mixed-mode transmission, resulting in interesting ecological and evolutionary dynamics of symbiont strain composition. Insect– Burkholderia symbioses present valuable model systems from which to derive insights into general principles governing symbiotic interactions because they are often experimentally and genetically tractable and span a large fraction of the diversity of functions, localizations, and transmission routes represented in insect symbioses.
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Stoy, Kayla S., Joselyne Chavez, Valeria De Las Casas, Venkat Talla, Aileen Berasategui, Levi T. Morran und Nicole M. Gerardo. „Evaluating coevolution in a horizontally transmitted mutualism“. Evolution 77, Nr. 1 (08.12.2022): 166–85. http://dx.doi.org/10.1093/evolut/qpac009.
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Abstract Many interspecific interactions are shaped by coevolution. Transmission mode is thought to influence opportunities for coevolution within symbiotic interactions. Vertical transmission maintains partner fidelity, increasing opportunities for coevolution, but horizontal transmission may disrupt partner fidelity, potentially reducing opportunities for coevolution. Despite these predictions, the role of coevolution in the maintenance of horizontally transmitted symbioses is unclear. Leveraging a tractable insect–bacteria symbiosis, we tested for signatures of pairwise coevolution by assessing patterns of host–symbiont specialization. If pairwise coevolution defines the interaction, we expected to observe evidence of reciprocal specialization between hosts and their local symbionts. We found no evidence for local adaptation between sympatric lineages of Anasa tristis squash bugs and Caballeronia spp. symbionts across their native geographic range. We also found no evidence for specialization between three co-localized Anasa host species and their native Caballeronia symbionts. Our results demonstrate generalist dynamics underlie the interaction between Anasa insect hosts and their Caballeronia symbionts. We predict that selection from multiple host species may favor generalist symbiont traits through diffuse coevolution. Alternatively, selection for generalist traits may be a consequence of selection by hosts for fixed cooperative symbiont traits without coevolution.
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Gundel, Pedro E., Prudence Sun, Nikki D. Charlton, Carolyn A. Young, Tom E. X. Miller und Jennifer A. Rudgers. „Simulated folivory increases vertical transmission of fungal endophytes that deter herbivores and alter tolerance to herbivory in Poa autumnalis“. Annals of Botany 125, Nr. 6 (03.02.2020): 981–91. http://dx.doi.org/10.1093/aob/mcaa021.
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Abstract Background and Aims The processes that maintain variation in the prevalence of symbioses within host populations are not well understood. While the fitness benefits of symbiosis have clearly been shown to drive changes in symbiont prevalence, the rate of transmission has been less well studied. Many grasses host symbiotic fungi (Epichloë spp.), which can be transmitted vertically to seeds or horizontally via spores. These symbionts may protect plants against herbivores by producing alkaloids or by increasing tolerance to damage. Therefore, herbivory may be a key ecological factor that alters symbiont prevalence within host populations by affecting either symbiont benefits to host fitness or the symbiont transmission rate. Here, we addressed the following questions: Does symbiont presence modulate plant tolerance to herbivory? Does folivory increase symbiont vertical transmission to seeds or hyphal density in seedlings? Do plants with symbiont horizontal transmission have lower rates of vertical transmission than plants lacking horizontal transmission? Methods We studied the grass Poa autumnalis and its symbiotic fungi in the genus Epichloë. We measured plant fitness (survival, growth, reproduction) and symbiont transmission to seeds following simulated folivory in a 3-year common garden experiment and surveyed natural populations that varied in mode of symbiont transmission. Key Results Poa autumnalis hosted two Epichloë taxa, an undescribed vertically transmitted Epichloë sp. PauTG-1 and E. typhina subsp. poae with both vertical and horizontal transmission. Simulated folivory reduced plant survival, but endophyte presence increased tolerance to damage and boosted fitness. Folivory increased vertical transmission and hyphal density within seedlings, suggesting induced protection for progeny of damaged plants. Across natural populations, the prevalence of vertical transmission did not correlate with symbiont prevalence or differ with mode of transmission. Conclusions Herbivory not only mediated the reproductive fitness benefits of symbiosis, but also promoted symbiosis prevalence by increasing vertical transmission of the fungus to the next generation. Our results reveal a new mechanism by which herbivores could influence the prevalence of microbial symbionts in host populations.
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Ferrari, Julia, und Fabrice Vavre. „Bacterial symbionts in insects or the story of communities affecting communities“. Philosophical Transactions of the Royal Society B: Biological Sciences 366, Nr. 1569 (12.05.2011): 1389–400. http://dx.doi.org/10.1098/rstb.2010.0226.
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Bacterial symbionts are widespread in insects and other animals. Most of them are predominantly vertically transmitted, along with their hosts' genes, and thus extend the heritable genetic variation present in one species. These passengers have a variety of repercussions on the host's phenotypes: besides the cost imposed on the host for maintaining the symbiont population, they can provide fitness advantages to the host or manipulate the host's reproduction. We argue that insect symbioses are ideal model systems for community genetics. First, bacterial symbionts directly or indirectly affect the interactions with other species within a community. Examples include their involvement in modifying the use of host plants by phytophagous insects, in providing resistance to natural enemies, but also in reducing the global genetic diversity or gene flow between populations within some species. Second, one emerging picture in insect symbioses is that many species are simultaneously infected with more than one symbiont, which permits studying the factors that shape bacterial communities; for example, horizontal transmission, interactions between host genotype, symbiont genotype and the environment and interactions among symbionts. One conclusion is that insects' symbiotic complements are dynamic communities that affect and are affected by the communities in which they are embedded.
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Cheng, D. J., und R. F. Hou. „Histological observations on transovarial transmission of a yeast-like symbiote in Nilaparvata lugens Stal (Homoptera, Delphacidae)“. Tissue and Cell 33, Nr. 3 (Juni 2001): 273–79. http://dx.doi.org/10.1054/tice.2001.0173.
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Acar, Tessa, Sandra Moreau, Marie-Françoise Jardinaud, Gabriella Houdinet, Felicia Maviane-Macia, Frédéric De Meyer, Bart Hoste et al. „The association between Dioscorea sansibarensis and Orrella dioscoreae as a model for hereditary leaf symbiosis“. PLOS ONE 19, Nr. 4 (22.04.2024): e0302377. http://dx.doi.org/10.1371/journal.pone.0302377.
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Hereditary, or vertically-transmitted, symbioses affect a large number of animal species and some plants. The precise mechanisms underlying transmission of functions of these associations are often difficult to describe, due to the difficulty in separating the symbiotic partners. This is especially the case for plant-bacteria hereditary symbioses, which lack experimentally tractable model systems. Here, we demonstrate the potential of the leaf symbiosis between the wild yam Dioscorea sansibarensis and the bacterium Orrella dioscoreae (O. dioscoreae) as a model system for hereditary symbiosis. O. dioscoreae is easy to grow and genetically manipulate, which is unusual for hereditary symbionts. These properties allowed us to design an effective antimicrobial treatment to rid plants of bacteria and generate whole aposymbiotic plants, which can later be re-inoculated with bacterial cultures. Aposymbiotic plants did not differ morphologically from symbiotic plants and the leaf forerunner tip containing the symbiotic glands formed normally even in the absence of bacteria, but microscopic differences between symbiotic and aposymbiotic glands highlight the influence of bacteria on the development of trichomes and secretion of mucilage. This is to our knowledge the first leaf symbiosis where both host and symbiont can be grown separately and where the symbiont can be genetically altered and reintroduced to the host.
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Salem, Hassan, Laura Florez, Nicole Gerardo und Martin Kaltenpoth. „An out-of-body experience: the extracellular dimension for the transmission of mutualistic bacteria in insects“. Proceedings of the Royal Society B: Biological Sciences 282, Nr. 1804 (07.04.2015): 20142957. http://dx.doi.org/10.1098/rspb.2014.2957.
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Across animals and plants, numerous metabolic and defensive adaptations are a direct consequence of symbiotic associations with beneficial microbes. Explaining how these partnerships are maintained through evolutionary time remains one of the central challenges within the field of symbiosis research. While genome erosion and co-cladogenesis with the host are well-established features of symbionts exhibiting intracellular localization and transmission, the ecological and evolutionary consequences of an extracellular lifestyle have received little attention, despite a demonstrated prevalence and functional importance across many host taxa. Using insect–bacteria symbioses as a model, we highlight the diverse routes of extracellular symbiont transfer. Extracellular transmission routes are unified by the common ability of the bacterial partners to survive outside their hosts, thereby imposing different genomic, metabolic and morphological constraints than would be expected from a strictly intracellular lifestyle. We emphasize that the evolutionary implications of symbiont transmission routes (intracellular versus extracellular) do not necessarily correspond to those of the transmission mode (vertical versus horizontal), a distinction of vital significance when addressing the genomic and physiological consequences for both host and symbiont.
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Boyd, Bret M., Julie M. Allen, Ryuichi Koga, Takema Fukatsu, Andrew D. Sweet, Kevin P. Johnson und David L. Reed. „Two Bacterial Genera, Sodalis and Rickettsia, Associated with the Seal Louse Proechinophthirus fluctus (Phthiraptera: Anoplura)“. Applied and Environmental Microbiology 82, Nr. 11 (18.03.2016): 3185–97. http://dx.doi.org/10.1128/aem.00282-16.
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ABSTRACTRoughly 10% to 15% of insect species host heritable symbiotic bacteria known as endosymbionts. The lice parasitizing mammals rely on endosymbionts to provide essential vitamins absent in their blood meals. Here, we describe two bacterial associates from a louse,Proechinophthirus fluctus, which is an obligate ectoparasite of a marine mammal. One of these is a heritable endosymbiont that is not closely related to endosymbionts of other mammalian lice. Rather, it is more closely related to endosymbionts of the genusSodalisassociated with spittlebugs and feather-chewing bird lice. Localization and vertical transmission of this endosymbiont are also more similar to those of bird lice than to those of other mammalian lice. The endosymbiont genome appears to be degrading in symbiosis; however, it is considerably larger than the genomes of other mammalian louse endosymbionts. These patterns suggest the possibility that thisSodalisendosymbiont might be recently acquired, replacing a now-extinct, ancient endosymbiont. From the same lice, we also identified an abundant bacterium belonging to the genusRickettsiathat is closely related toRickettsia ricketsii, a human pathogen vectored by ticks. No obvious masses of theRickettsiabacterium were observed in louse tissues, nor did we find any evidence of vertical transmission, so the nature of its association remains unclear.IMPORTANCEMany insects are host to heritable symbiotic bacteria. These heritable bacteria have been identified from numerous species of parasitic lice. It appears that novel symbioses have formed between lice and bacteria many times, with new bacterial symbionts potentially replacing existing ones. However, little was known about the symbionts of lice parasitizing marine mammals. Here, we identified a heritable bacterial symbiont in lice parasitizing northern fur seals. This bacterial symbiont appears to have been recently acquired by the lice. The findings reported here provide insights into how new symbioses form and how this lifestyle is shaping the symbiont genome.
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Russell, S. L., E. McCartney und C. M. Cavanaugh. „Transmission strategies in a chemosynthetic symbiosis: detection and quantification of symbionts in host tissues and their environment“. Proceedings of the Royal Society B: Biological Sciences 285, Nr. 1890 (31.10.2018): 20182157. http://dx.doi.org/10.1098/rspb.2018.2157.
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Transmission of bacteria vertically through host tissues ensures offspring acquire symbionts; however, horizontal transmission is an effective strategy for many associations and plays a role in some vertically transmitted symbioses. The bivalve Solemya velum and its gammaproteobacterial chemosynthetic symbionts exhibit evolutionary evidence of both transmission modes, but the dominant strategy on an ecological time scale is unknown. To address this, a specific primer set was developed and validated for the S. velum symbiont using a novel workflow called specific marker design (SMD). Symbionts were quantified in spawned eggs and sediment and seawater samples from S. velum habitats with qPCR. Each egg was estimated to contain 50–100 symbiont genomes. By contrast, symbiont DNA was found at low abundance/occurrence in sediment and seawater, often co-occurring with host mitochondrial DNA, obscuring its origin. To ascertain when eggs become infected, histological sections of S. velum tissues were labelled for symbiont 16S rRNA via in situ hybridization. This revealed symbionts in the ovary walls and mature oocytes, suggesting association in late oogenesis. These data support the hypothesis that S. velum symbionts are vertically transmitted every host generation, thus genetic signatures of horizontal transmission are driven by ecologically infrequent events. This knowledge furthers our understanding of vertical and horizontal mode integration and provides insights across animal–bacterial chemosynthetic symbioses.
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Ciche, Todd A., Kwi-suk Kim, Bettina Kaufmann-Daszczuk, Ken C. Q. Nguyen und David H. Hall. „Cell Invasion and Matricide during Photorhabdus luminescens Transmission by Heterorhabditis bacteriophora Nematodes“. Applied and Environmental Microbiology 74, Nr. 8 (15.02.2008): 2275–87. http://dx.doi.org/10.1128/aem.02646-07.
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ABSTRACT Many animals and plants have symbiotic relationships with beneficial bacteria. Experimentally tractable models are necessary to understand the processes involved in the selective transmission of symbiotic bacteria. One such model is the transmission of the insect-pathogenic bacterial symbionts Photorhabdus spp. by Heterorhabditis bacteriophora infective juvenile (IJ)-stage nematodes. By observing egg-laying behavior and IJ development, it was determined that IJs develop exclusively via intrauterine hatching and matricide (i.e., endotokia matricida). By transiently exposing nematodes to fluorescently labeled symbionts, it was determined that symbionts infect the maternal intestine as a biofilm and then invade and breach the rectal gland epithelium, becoming available to the IJ offspring developing in the pseudocoelom. Cell- and stage-specific infection occurs again in the pre-IJ pharyngeal intestinal valve cells, which helps symbionts to persist as IJs develop and move to a new host. Synchronous with nematode development are changes in symbiont and host behavior (e.g., adherence versus invasion). Thus, Photorhabdus symbionts are maternally transmitted by an elaborate infectious process involving multiple selective steps in order to achieve symbiont-specific transmission.
Dissertationen zum Thema "Transmission du symbiote"
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Szafranski, Kamil. „Cycles de vie des symbiontes chez les bivalves des environnements à base chimiosynthétique de l'océan profond“. Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066454/document.
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De nombreuses bactéries entrent en symbiose avec les métazoaires colonisant les habitats à base chimiosynthétique dans l'océan profond. Les hôtes auxquels elles apportent le carbone organique deviennent ainsi dépendants des bactéries sulfo-oxydantes et/ou méthanotrophes. Pour assurer la continuité de ces associations et la colonisation de nouveaux sites, des stratégies diverses de dispersion ont été développées par les animaux. Deux types de transmission des bactéries symbiotiques existent : la transmission verticale où elles sont transmises via les gamètes, et la transmission horizontale où elles sont acquises à partir de l¿environnement, depuis des populations de bactéries libres ou relarguées par d'autres hôtes. Cette thèse vise à répondre à des questions concernant les cycles de vie des symbiontes. La diversité et la distribution des formes libres de symbiontes et des bactéries apparentées dans plusieurs habitats réduits ont été étudiées par l¿analyse des séquences de l'ARNr 16S des bactéries colonisant des substrats organiques déployés dans l'Atlantique et la Méditerranée. La transmission maternelle des symbiontes chez le bivalve vésicomyidé Isorropodon bigoti du golfe de Guinée a été confirmée par l'observation et l'identification des symbiontes dans les ovocytes et dans les stades post-larvaires. Enfin, l'effet des stress chimique, thermique et de la remontée sur la dynamique des populations de symbiontes sulfo-oxydants et méthanotrophes chez la moule Bathymodiolus azoricus a été analysé par les techniques de FISH 3D et de pyroséquençage. Cette thèse a permis de mieux comprendre des cycles de vie des bactéries symbiotiques dans et en dehors de leur hôtes animauxMetazoans colonizing deep-sea reducing habitats often employ chemosymbiotic bacterial associations. Hosts become dependent upon their sulfur-oxidizing and/or methanotrophic symbionts, which provide organic carbon compounds. Various larval dispersal strategies have evolved in the hosts, ensuring the colonization of new sites. The continuity of the symbiotic association is maintained by symbiont transmission. Symbionts may pass directly to the host’s progeny via gametes (vertical transmission) or may be acquired from the environment as free-living forms or as those released from other hosts (horizontal transmission). This work answers several questions about the lifecycles of symbionts regarding the diversity of symbiont-related bacteria in environmental bacterial communities; the localization and dynamics of symbionts in host tissues depending on their transmission mode; or after abiotic stresses applied to the holobiont.The diversity and the distribution of free-living symbionts and their close relatives from several chemosynthesis-based habitats has been analysed by 454 pyrosequencing of the 16S rRNA of bacteria colonizing plant-derived substrates in the Northern Atlantic and Mediterranean. The trans-ovarial transmission has been detailed in the clam Isorropodon bigoti by the identification of symbionts within oocytes and in the forming gills of their post-larvae. Finally, the influence of several abiotic stresses in Bathymodiolus azoricus mussels on the dynamics of their symbionts has been investigated by FISH and pyrosequencing. This PhD presents new data regarding various aspects of the life cycle of chemosynthetic symbionts inside and outside their metazoan hosts
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Michaud, Caroline. „Dynamique des symbioses mutualistes hôtes-microbiotes : mode et efficacité de transmission des symbiotes dans les populations du termite xylophage Reticulitermes grassei“. Thesis, Tours, 2019. http://www.theses.fr/2019TOUR4027.
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Les symbioses mutualistes sont ubiquistes et jouent un rôle majeur dans le fonctionnement des écosystèmes. Chez les insectes, il est souvent décrit que la spécificité et la stabilité évolutive de ces symbioses mutualistes est due à une transmission verticale stricte des symbiotes des parents à la descendance. Pour tester le rôle de la transmission verticale dans le maintien évolutif des symbioses mutualiste, son exclusivité et son efficacité doivent être étudiées à une échelle évolutive (d’une lignée hôte à une autre) ainsi qu’à une échelle écologique (d’une génération à la suivante). Ce projet de thèse a pour but d’étudier la transmission verticale comme mécanisme de stabilisation évolutive dans les associations nutritionnelles entre les termites souterrains du genre Reticulitermes et leurs symbiotes mutualistes intestinaux. Pour cela, des outils de biologie moléculaire ont été développés afin d’étudier la diversité et la composition de la communauté microbienne intestinale totale des termites (approche de méta-code barre), mais également en se focalisant sur les protistes du genre Trichonympha qui jouent un rôle essentiel dans la dégradation de la lignocellulose (approches de barcoding ADN et de PCR quantitative). Le premier axe de cette thèse vise à étudier les patterns de transmission des symbiotes à l’échelle évolutive du genre Reticulitermes en testant l’hypothèse que la phylogénie de l’hôte est un facteur majeur expliquant la composition du microbiote intestinal des termites. L’étude menée sur les Trichonympha de termites a permis de montrer que la diversification de ces associations n’est pas uniquement expliquée par des événements de co-spéciation, mais que des événements de changement d’hôte et de perte de symbiotes ont eu lieu. L’étude menée sur l’ensemble du microbiote intestinal des termites permettra de déterminer ces patterns de diversification sur l’ensemble des taxa microbiens. Le second axe de cette thèse est d’évaluer le niveau de fidélité entre partenaires à une échelle intergénérationnelle en testant l’hypothèse que la transmission verticale des symbiotes est stricte d’une génération à une autre. L’efficacité de la transmission verticale a été mesurée en deux étapes : (i) en comparant les symbiotes présents dans les ouvriers de la colonie avec ceux portés par les reproducteurs primaires (i.e. les alates) lorsqu’ils quittent leur colonie natale pour en fonder une nouvelle, et (ii) en comparant les symbiotes présents dans les ouvriers des deux colonies parentales avec ceux portés par la nouvelle colonie fondée. Les résultats préliminaires de l’étude sur les deux Trichonympha présents chez R. grassei semblent indiquer qu’ils sont co-transmis dans les alates. L’étude sur l’ensemble du microbiote intestinal permettra de déterminer si tous les taxa microbiens sont co-transmis ou si une transmission aléatoire des symbiotes a lieu dans les alates. Une troisième étude sur l’ensemble du microbiote permettra de déterminer si tous les taxa microbiens sont transmis par les parents à la descendance. Ensemble, ces différentes études permettront de tester la transmission verticale comme mécanisme induisant une fidélité entre partenaires dans les systèmes termitesmicrobiote intestinal. A l’échelle des protistes du genre Trichonympha, ce mécanisme ne semble pas le seul impliqué dans la stabilité évolutive de ces associationsMany animals including humans live in symbiotic interaction with gut microorganisms contributing to essential functions (nutrition, immunity). The ‘vertical’ way of transmission of symbionts (i.e., from parents to offspring) must stabilise these symbioses, notably by strengthening partner fidelity. However, the efficiency of vertical transmission has rarely been studied, especially in the case where hosts harbour a complex microbial community (or ‘microbiota’) composed by many microbial taxa interacting between them and with the host.The objective of this work was to study the mode and efficiency of transmission of gut microorganisms (protists and bacteria) helping the wood-feeding termite Reticulitermes grassei to digest ingested wood (lignocellulose fibres). Our results revealed contrasted situations between microorganisms. While protists are efficiently vertically transmitted, the majority of bacterial taxa is not only vertically transmitted but seems to be acquired by the environment
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Gros, Olivier. „Symbiose bactérienne et transmission des symbiontes chez des mollusques bivalves tropicaux de la famille des Lucinidae inféodés aux herbiers et à la mangrove“. Lyon 1, 1997. http://www.theses.fr/1997LYO10087.
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Six especes de bivalves tropicaux de la famille des lucinidae (codakia orbicularis, c. Orbiculata, c. Pectinella, linga pensylvanica, lucina nassula et l. Pectinata) hebergeant des bacteries endosymbiotiques sulfo-oxydantes dans des cellules specialisees des branchies ont ete etudiees. L'etude ultrastructurale des filaments branchiaux a mis en evidence des particularites propres a chacune des especes pouvant soit intervenir dans les relations avec leurs symbiontes, soit constituer des adaptations au milieu. L'etude phylogenetique des endosymbiontes, effectuee par sequencage de l'adnr 16s, a notamment montre que les symbiontes de c. Orbicularis, c. Orbiculata, c. Pectinella et l. Pensylvanica appartiennent a la meme espece. A l'oppose, le symbionte de l. Pectinata semble representer la lignee la plus eloignee des bacteries symbiotiques des membres de la superfamille des lucinacea. L'hypothese de la transmission verticale des symbiontes chez les especes etudiees a pu etre rejetee. Cependant, le mode environnemental n'a ete demontre que pour c. Orbicularis, seule espece dont le developpement est maitrise. Le symbionte de c. Orbicularis est transmis aux nouvelles generations d'hote par l'intermediaire d'une forme libre associee au sediment, qui penetrerait par endocytose au niveau du pole apical des cellules indifferenciees de la zone laterale des filaments branchiaux de juveniles aposymbiotiques, qui se differencient alors en bacteriocytes. Le developpement larvaire de c. Orbicularis est de type planctotrophe facultatif; la metamorphose se deroule en deux etapes, avec un blocage a la fin du stade plantigrade qui peut etre letal en l'absence de substrat adequat. Le developpement de juveniles aposymbiotiques obtenu en presence de sable sterile montre que la symbiose n'est indispensable ni au developpement larvaire ni a la metamorphose de c. Orbicularis. Les cellules indifferenciees de la zone laterale des juveniles aposymbiotiques gardent leur capacite de differenciation de nombreux mois apres la metamorphose. De plus, l'infestation des branchies par les bacteries de l'environnement n'est pas limitee a une periode determinee du developpement ni a un stade determine de differenciation des filaments branchiaux.
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Gibson, Cara. „Heritable Microbial Endosymbionts in Insects: Insights from the Study of a Parasitic Wasp and its Cockroach Host“. Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/195875.
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Endosymbiosis is a pervasive phenomenon that has been a powerful force in insect evolution. In many well studied insect-bacterial associations, the bacteria can serve as reproductive manipulators, nutritional mutualists or defenders of their hosts. Fungi are also frequently associated with insects, and initial estimates suggest that these fungi are hyperdiverse. Saving a handful of examples, however, the functions of these fungi within insect hosts are largely unknown. This dissertation begins with a review that lays the conceptual groundwork for understanding bacterial and fungal endosymbiosis in insects. I make predictions about why one versus the other microbe might serve the insect, given any unique physiological, ecological or evolutionary conditions. I then aim to derive insights about microbial symbiosis by focusing on a particular system, that of brownbanded cockroaches, Supella longipalpa (Blattaria: Blattellidae) and their specialist wasp parasitoids, Comperia merceti (Hymenoptera: Encyrtidae). Here, I identify the symbiotic community of these two insects by using both culture-dependent and independent methods to characterize the vertically transmitted bacterial and fungal associates. Finally, I show that a heritable fungus in C. merceti, long presumed to be a mutualist, is parasitic under laboratory conditions: infected wasps incur fitness costs for housing the fungal symbiont relative to uninfected wasps. Additionally, although the fungus is not horizontally transmitted sexually, it is readily horizontally transmitted from the offspring of infected females to those of uninfected females that are using the same host.
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Russell, Shelbi Lianne. „Mode and Fidelity of Bacterial Symbiont Transmission and Its Impact on Symbiont Genome Evolution“. Thesis, Harvard University, 2016. http://nrs.harvard.edu/urn-3:HUL.InstRepos:33493576.
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Mutualistic symbioses have enabled the colonization of novel habitats and niches in a large array of eukaryotic and bacterial taxa. Reliable mechanisms of symbiont transmission between host generations are necessary to stabilize these associations over evolutionary time. Historically, symbionts have been categorized as either vertically transmitted from the parents to offspring or horizontally transmitted through the environment. The route between hosts influences how symbiont populations are connected between hosts and between geographic localities. Over evolutionary time vertical transmission leads to gene loss and genome erosion. Growing evidence from diverse associations suggests that modes utilizing both horizontal and vertical strategies exist, raising the question of how these “mixed modes” influence symbiont genome evolution. The overarching goal of my dissertation was to determine whether the mode of symbiont transmission in an obligate mutualism is consistent over evolutionary time and what impact transmission mode fidelity has on symbiont genome evolution. To test these questions, I used the chemosynthetic symbiosis between the marine bivalve Solemya velum and its gammaproteobacterial symbionts, which has been reported to transmit its symbionts vertically through the ovary, but bears none of the genomic hallmarks of strict vertical transmission.
In this work, I used population genomics of S. velum subpopulations sampled from five localities along the New England coast, from Massachusetts to North Carolina, to test for evidence of horizontal transmission in the evolutionary history of this species. These analyses revealed that symbionts and mitochondria do not exhibit concordant genealogies, divergent symbiont lineages have come into contact and recombined, and symbiont genomes have experienced large-scale structural changes mediated by mobile elements and horizontal gene transfer. In total, these lines of evidence indicate that a substantial amount of horizontal transmission has occurred in the recent history of this association. The vertical transmission route through host tissues was characterized via in situ hybridization to symbiont 16S rRNA in adult host tissues and by qPCR of the rhlE gene in spawned eggs. These data showed that symbionts are present at low abundance in the ovary, associated with the supportive cells and mature oocytes, and each spawned egg contains approximately 50-100 copies of the symbiont genome. Lastly, I tested for evidence of mixed transmission modes in symbiont populations contained within host tissues (each host gill contains more than a billion symbiont cells), by deep-coverage whole genome sequencing. Using a novel variant-calling procedure, I detected low amounts of genetic variation among symbiont genomes within a host relative to between hosts. However, the variant sites that were present were correlated in position along the genome, present on the same chromosome, and segregating in the symbiont population at large, suggesting that these variants arose via recombination with a variant symbiont genotype introduced by horizontal transmission.
In total, this work supports the existence of mixed transmission modes in symbiotic associations and indicates they have distinct consequences for symbiont evolution. Mixed modes may provide a best-of-both-worlds strategy to ensure that hosts acquire symbionts every generation while maintaining opportunities for recombination and acquisition of novel genetic elements. These results are relevant to understanding the impact of symbiont transmission mode on genome evolution in associations ranging from mutualisms to pathogenic infections.Biology, Organismic and Evolutionary
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Wooding, Amy Lorraine. „Sex determination and symbiont transmission in the Sirex-Amylostereum mutualism“. Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/79213.
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Interactions among living organisms fall along the mutualism-parasitism continuum; where mutualistic interactions benefit one or both organisms and parasitic interactions harm them. Mutualisms are a particularly interesting form of interaction as their evolutionary stability is constantly at risk of destabilisation by cheaters which take greater advantage of their partners than other symbionts in the population. This has resulted in organisms involved in mutualistic interactions have evolved many mechanisms to prevent destabilisation by cheaters. Insects are involved in mutualistic interactions with a myriad of organisms, in particular micro-organisms. Some of the most well documented insect–micro–organism interactions are those of the fungus–farming insects; Attine ants, termites and ambrosia beetles, and the obligate mutualistic fungi they cultivate. These mutualisms have remained stable over millions of years. Another, less well studied, apparently stable, obligate insect-fungus mutualism is the interaction between Sirex woodwasps and Amylostereum fungi. In this review we examine the evolution of mutualisms from initial interaction, through to maintenance of a stable obligate interaction, and explore the mechanisms that act to stabilise them. We explore the evolutionary and ecological factors necessary for the maintenance of the Sirex–Amylostereum mutualism in the context of work that has been done on the evolution of other more extensively studied insect-fungus mutualisms.Dissertation (MSc)--University of Pretoria, 2014.
Genetics
MSc
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Salerno, Jennifer L. „Transmission and Nutritional Contribution of Dual Bacterial Symbionts in Deep-Sea Mussels“. W&M ScholarWorks, 2003. https://scholarworks.wm.edu/etd/1539626398.
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Boilard, Aurélie. „Ontogenèse du microbiote chez le poisson vivipare Brachyistius frenatus : transmission verticale de symbiotes microbiens pionniers?“ Master's thesis, Université Laval, 2021. http://hdl.handle.net/20.500.11794/69498.
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Chez les Mammifères, le recrutement du microbiote débute in utero, ce qui restait à démontrer chez d'autres classes de Vertébrés. L’objectif général du projet était de tester si un tel recrutement se produit chez un Vertébré non Mammifère. Nous avons testé, chez le Poisson vivipare Brachyistius frenatus, l'hypothèse selon laquelle la poche utérine est colonisée par un microbiote transmissible aux alevins, conférant à leur propre microbiote une ontogenèse semblable à celle des Mammifères. Le projet visait l’atteinte des objectifs suivant: i) caractériser le mode de transmission du microbiote, ii) établir la composition, la diversité et les relations des communautés bactériennes du microbiote des femelles, des juvéniles et de leur environnement et iii) déterminer l’ontogenèse du microbiote chez B. frenatus. Ce projet a permis de caractériser le mode de transmission du microbiote, sa séquence de recrutement, ainsi que la contribution respective de différentes communautés sources en caractérisant la diversité bactérienne du microbiote des femelles, des juvéniles et de leur environnement avec une approche métagénomique de type code barre. La région V4 du gène de l'ARNr 16S a été ciblée comme marqueur taxonomique bactérien pour identifier les taxons des différents échantillons.Cette étude nous a permis d’identifier le premier cas d’une transmission verticale du microbiote in utero chez un vivipare non Mammifère et les résultats sous-entendent que B. frenatus est peut-être un tout nouveau modèle d’ontogenèse du microbiote. Cette étude a permis l’acquisition des connaissances sur la transmission du microbiote et, dans le contexte de convergence évolutive de la viviparité, elle ouvre à de nouvelles perspectives quant aux avantages évolutifs d'une telle transmission de symbiotes microbiens.In Mammals microbial recruitment starts in utero, something that had not been shown in any other Vertebrate class. The main goal of this project was to test whether this type of recruitment happens in a non-mammalian Vertebrate. We tested in the viviparous fish Brachyistius frenatus the hypothesis under which the uterine pouch is colonized by a microbiome transmissible to the juveniles, conferring them an ontogeny similar to Mammals. This project also aimed to i) characterize the mode of transmission of the microbiota, ii) establish the composition, diversity and relationships between the microbial communities of pregnant females, juveniles and their environment and iii) determine the ontogeny of the microbiota in B. frenatus. We characterized the mode of transmission of the microbiome, explored its recruitment and the contribution of different source communities with a metagenomic approach (bar coding). We targeted the hyper variable region V4 of the small subunit (16S) rRNA gene to determine the presence of a vertical transmission of the microbiome In this study, we confirmed the presence of a vertically transmissible microbiome in the viviparous fish B. frenatus. We documented for the first time an in utero transmission of themicrobiota in a non-mammalian viviparous species. Our results also hint that B. frenatus might be a new model of microbiota ontogeny. This study contributes to the acquisition of knowledge on microbiome transmission and, in the context of evolutionary convergence of viviparity, allows the formulation of hypotheses concerning the evolutionary advantages of in utero microbiome transmission.
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Cameira, Rita Maria Santos. „Gastrointestinal symbionts of wild chimpanzees and sympatric colobus monkeys living in close proximity of humans in Liberia and Uganda“. Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2018. http://hdl.handle.net/10400.5/15151.
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Dissertação de Mestrado Integrado em Medicina VeterináriaEsta dissertação teve como objetivo principal caracterizar a fauna de simbiontes de chimpanzés (Pan troglodytes), e colobos pretos e brancos (Colobus sp.) de diferentes localidades Africanas (Parque Nacional de Sapo, na Libéria e em Bulindi, no Uganda), comparar resultados entre eles e estudos prévios e teorizar sobre as possíveis implicações zoonóticas dos simbiontes encontrados. Recorrendo a técnicas de coprologia como sedimentação MIF modificada e a flutuação de Sheather, e um teste de imunofluorescência direta para deteção de oocistos de Crypstosporidium e cistos de Giardia, 47 amostras fecais preservadas de chimpanzé e 15 de colobos pretos e brancos foram examinadas. Os protozoários detetados incluíram Troglodytella abrassarti, Entamoeba spp., Blastocystis sp. e Iodamoeba buetschlii; e nematodes, Trichuris sp, Colobenterobius sp., strongylideos e várias larvas de nematodes. Todas as amostras foram negativas no teste de imunofluorescência directa. Em geral, o espectro de simbiontes encontrado no presente estudo está de acordo com o que é regularmente descrito em estudos que abordam chimpanzés e colobos pretos e brancos de vida selvagem. Contudo, pequenos microrganismos aquáticos denominados Rotifera ou rotíferos foram observados pela primeira vez em amostras fecais de chimpanzé e colobos pretos e brancos. Considerando o contato próximo entre os primatas estudados e seres humanos, é importante realizar futuras pesquisas recorrendo a técnicas moleculares nos simbiontes assinalados por este trabalho e avaliar o seu real potencial zoonótico.
ABSTRACT - Gastrointestinal symbionts of wild chimpanzees and sympatric colobus monkeys living in close proximity of humans in Liberia and Uganda - This dissertation aimed to characterize the symbiont fauna of chimpanzees (Pan troglodytes) and black and white colobus (Colobus sp.) from different African localities, (Sapo National Park in Liberia and Bulindi in Uganda), compare results between them and previous studies, and theorize about possible zoonotic implications of the found symbionts. Using coprologic techniques as modified MIF sedimentation and Sheather’s flotation, and a direct immunofluorescence teste for detection of Crypstosporidium oocysts and Giardia cysts, 47 chimpanzee and 15 black and white colobus preserved fecal samples were examined. Detected protozoans included Troglodytella abrassarti, Entamoeba spp., Blastocystis sp. and Iodamoeba buetschlii; and nematodes, Trichuris sp., Colobenterobius sp., strongylids and various nematodes larvae. All samples were negative for the direct immunofluorescence test. Overall, the spectrum of symbionts found in the present study is in accordance with what is regularly described in studies addressing the free ranging chimpanzees and black and white colobus. However, small aquatic microorganisms denominated Rotifera or rotifers were observed for the first time in chimpanzee and in black and white colobus faecal samples. Considering the close contact between the studied primates and humans, it is important to conduct further research using molecular techniques in the found symbionts to assess the real zoonotic potential.
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Zug, Roman. „The Wolbachia pandemic among arthropods: interspecies transmission and mutualistic effects“. Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/18866.
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Wolbachien sind weitverbreitete bakterielle Symbionten von Arthropoden. Sie werden überwiegend durch maternale Vererbung übertragen, können aber auch horizontal von Art zu Art übertragen werden. Wolbachien sind berüchtigt dafür, die Wirtsreproduktion zu manipulieren, können aber auch Mutualismen mit ihren Wirten evolvieren. In dieser Arbeit untersuche ich, welche Rolle horizontale Transmission und mutualistische Effekte bei der Wolbachien-Pandemie unter Arthropoden spielen. Zunächst schätze ich, dass Millionen Arthropodenarten mit Wolbachien infiziert sind. Um diese erstaunliche Verbreitung zu verstehen, entwickele ich ein Modell zur horizontalen zwischenartlichen Transmission von Wolbachien, das auf epidemiologischer und Netzwerk-Theorie aufbaut. Die Ergebnisse weisen auf die Bedeutung von horizontaler Transmission über große phylogenetische Distanzen hin. Da eine erfolgreiche Transmission wahrscheinlich durch symbionteninduzierte Wirtsvorteile begünstigt wird, betrachte ich dann umfassend und kritisch Wolbachien-Arthropoden-Mutualismen und finde diese in vielfältigen Kontexten, aber nur begrenzt Hinweise auf Wolbachien-induzierten Wirtsschutz. Mithilfe eines populationsgenetischen Modells untersuche ich dann den Einfluss von Wirtsvorteilen auf die Infektionsdynamik von Wolbachien. Erstmalig leite ich Invasionsbedingungen und Gleichgewichtsfrequenzen für Wolbachien-Doppelinfektionen her. Die Ergebnisse bestätigen, dass Wirtsvorteile die Invasion von Wolbachien in neue Wirte erheblich erleichtern. Schließlich untersuche ich die Wechselwirkungen zwischen einer Wolbachien-Infektion und dem Immunsystem des Wirtes, wobei ein Schwerpunkt auf reaktiven Sauerstoffspezies liegt. Ich schlage eine Hypothese vor, die unterschiedliche Immunantworten in neuen und ko-evolvierten Assoziationen erklärt. Insgesamt sprechen die Ergebnisse dieser Arbeit für einen wesentlichen Anteil von horizontaler Transmission und mutualistischen Effekten an der Wolbachien-Pandemie in Arthropoden.Wolbachia are widespread bacterial symbionts of arthropods. They are transmitted predominantly via maternal inheritance, but are also able to move between different species (horizontal transmission). Wolbachia are notorious for selfishly interfering with host reproduction, but they can also evolve mutualistic associations with their hosts. In this thesis, we analyze the role of horizontal transmission and mutualistic effects in the Wolbachia pandemic among arthropods. First, we derive an estimate of the number of Wolbachia-infected arthropod species and find that millions of species are infected. In order to explain this striking distribution, we develop a model of Wolbachia horizontal transmission between species, building on epidemiological theory and network theory. Our findings point to the importance of transmission over large phylogenetic distances. Given that successful horizontal transmission is likely to be facilitated by symbiont-induced host benefits, we then perform a comprehensive review of Wolbachia-arthropod mutualisms and find that these occur in diverse contexts, although the evidence of Wolbachia-induced host protection in nature is limited so far. By means of a population genetic model, we then analyze the influence of host benefits on the infection dynamics of Wolbachia. For the first time, we derive invasion conditions and equilibrium frequencies for Wolbachia double infections. Our results corroborate that host benefits substantially facilitate invasion of Wolbachia into novel hosts. Finally, we examine the interactions between Wolbachia infection and the host immune system, with a focus on reactive oxygen species. We propose a hypothesis that explains differential immune responses in novel and coevolved associations. Taken together, the findings presented in this thesis argue for a significant involvement of horizontal transmission and mutualistic effects in the Wolbachia pandemic among arthropods.
Bücher zum Thema "Transmission du symbiote"
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Mavingui, Patrick, Claire Valiente Mor und Pablo Tortosa. Exploiting symbiotic interactions for vector/disease control. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198789833.003.0011.
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Arthropods transmit a variety of diseases to humans and animals, including arboviruses, bacteria and parasites. No efficient treatments or control methods are available for many vector-borne diseases, especially for emerging diseases. Therefore, the development of alternative strategies aiming at controlling disease transmission is encouraged worldwide. Although transmission phenomenon is a result of complex interactions involving several actors evolving in a changing environment, the biotic relationship between pathogens and their vectors represents a key step in successful disease transmission. Recent studies highlighted a strong impact of microbiomes on the life-history traits of arthropod hosts. This chapter emphasizes those biotic interactions having an impact on adaptive traits influencing disease transmission. Evidence in behavioral alterations of vector populations/individuals with relevance to vector-pathogen transmission mitigation is reviewed. Opportunities to take advantage of such biotic processes in the control of vector-borne diseases in different epidemiological, entomological and environmental settings are explored.
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Tennant, Neil. Transmission of Truthmakers. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198777892.003.0009.
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We begin by introducing the formal genus ‘conditional M-relative construct’, of which M-relative truthmakers and falsitymakers, and core proofs, are species. Fortunately they can stand in symbiotic relations, even though they cannot hybridize. We aim to generalize the earlier method we used in order to prove Cut-Elimination, so that the inputs P for the binary operation [P,P′] can be truthmakers (whereas P′ remains a core proof); and so that the reduct itself, when it is finally determined by recursive application of all the transformations called for, is a truthmaker for the conclusion of P′. This result can be understood as revealing that formal semantics can be carried out in a kind of infinitary proof-theory. Core proof transmits truth courtesy of normalization.
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Strohm, Paul, Hrsg. Middle English. Oxford University Press, 2007. http://dx.doi.org/10.1093/oxfordhb/9780199287666.001.0001.
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This title is part of the the Oxford Twenty-First Century Approaches to Literature series, edited by Paul Strohm. This book evaluates different approaches to Middle English literature, with special emphasis on the new, promising, and previously unexplored. It focuses on works of “major authors” such as Geoffrey Chaucer and William Langland, but also on many little-known and neglected texts. It looks at general conditions of textual production and reception, and explores how medieval processes of textual transmission have affected the reception and interpretation of medieval literature. It also discusses the relationship, both symbiotic and challenging, between medieval manuscripts and the modern canon, covering such subjects as multilinguality, the role of audience, translation, transmission, and periodization itself in considering the literature of previous eras. The book is organized into four sections: Conditions and Contexts, Vantage Points, Textual Kinds and Categories, and Writing and the World. Each essay focuses on a theme ranging through such matters as authority, form, imaginative theory, liturgy, drama, incarnational (auto)biography, vernacular theology, heresy, gossip, authorship, and humanism. Contributors tackle topics such as form, genre, the movement from script to print, the orality and aurality of medieval culture, and relationships between beauty, aesthetics, and literary genre.
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Jeffs, Kathleen. Rehearsal and Translation. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198819349.003.0003.
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This chapter discusses the degree to which the texts in the RSC’s Spanish Golden Age season accomplished Boswell’s goal for these to be ‘accurate translations’ and ‘not adaptations’. Despite both theoretical and practical problems presented by using a ‘literal’ translation as part of the translation process of the comedia, it is a valuable step in translating plays of the Golden Age for English audiences. The wider purpose of this chapter is to develop a vocabulary and a vision of how the literal-to-performance-text transmission process might be improved. This allows for a more symbiotic relationship between the work of scholars, critics, and translators on the one hand, and that of theatre professionals on the other, in order to create a more robust comedia performance tradition and a model which will be useful for other foreign translations.
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Nettleton, Claire Correo, Ellen K. Levy, Molly Duggins, Jane Prophet, Marie-Pier Boucher, Louise Mackenzie, Charissa N. Terranova et al., Hrsg. Art and Biotechnology. Bloomsbury Publishing Plc, 2024. http://dx.doi.org/10.5040/9781350376069.
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This interdisciplinary anthology examines the relationship between developments in biotechnology and both artistic and literary innovation, focussing in particular on how newfound molecular technologies and knowledge regimes, such as CRISPR gene editing, alter conceptions of what it means to be human. The book presents 21 essays, split across five parts, from a coterie of artists, scientists, and theorists, which examine the symbiotic relationship between humans, animals, and viruses as well as the impossibility of germ-free existence. The essays in this volume are urgent in their topicality, embodying the exhilarating yet alarming zeitgeist of contemporary nonhuman-to-human viral transmission and gene editing technologies. Ultimately, Art and Biotechnology reveals how art has influenced biotechnological innovation and has shaped the discussion around gene editing and the socio-cultural aspects of the Covid-19 pandemic. It is essential reading for students and researchers focussing on science and art, environmental humanities, and ethics. In the age of biotechnology, is it possible to conceive of microbes as our new paintbrush, DNA as our typewriter and organic tissue as our new clay? Through an interdisciplinary approach, we examine how newfound molecular technologies and knowledge regimes, such as CRISPR-Cas9 genome editing and the recent COVID-19 pandemic, alter understandings of the human experience. We ask: Where do the arts, which have been at the forefront of technological innovation, sit in relation to our ongoing viral and biomedical entanglement? How have the arts shaped discussion and ethical considerations around genome editing and COVID-19? How have the pandemic and biotechnological innovation—from CRISPR to vaccines with messenger RNA (mRNA)—transformed what it means to be human? To answer these inquiries, we assembled interdisciplinary artists and scholars with a keen interest or background in biology to examine interconnections between artistic and literary and biotechnological innovation. Whether studies, reflections, or artistic practice engaging with biotechnology or COVID-19, the chapters draw inspiration from one another and the practices of fellow artists, scientists, humanists and from the non-humans inside and around us. Their narratives complement research by the medical community—especially those who documented personal experiences with COVID-19 or engaged directly with the virus in their creative work. Artists are particularly suited to making the seemingly imperceptible visible, including microscopic entities, thus contributing to our collective understanding of public health. Manipulating genetic sequences has had a transformative impact on both scientific and artistic narratives. The humanities are a method of thinking critically and ethically about emerging biotechnologies, especially in the realms of genetics and disease control and their societal impact at a time of rapid acceleration. In an era of mass extinction and global heating, biotechnological arts offer hope for ecological restoration while cautioning against the technological dominance of the planet. Art can also aid us in processing the vast racial and economic disparities surrounding the pandemic and the profound loss of millions of lives. This anthology is urgent in its topicality, epitomizing the zeitgeist of contemporary nonhuman-to-human viral transmission and genome editing technologies.
Buchteile zum Thema "Transmission du symbiote"
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Phillips, D. A., F. D. Dakora, E. Sande, C. M. Joseph und J. Zoń. „Synthesis, release, and transmission of alfalfa signals to rhizobial symbionts“. In Symbiotic Nitrogen Fixation, 69–80. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-1088-4_7.
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Szklarzewicz, Teresa, und Anna Michalik. „Transovarial Transmission of Symbionts in Insects“. In Results and Problems in Cell Differentiation, 43–67. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-60855-6_3.
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Deckert, Ron J., Catherine A. Gehring und Adair Patterson. „Pine Seeds Carry Symbionts: Endophyte Transmission Re-examined“. In Seed Endophytes, 335–61. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-10504-4_16.
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Bulgheresi, Silvia. „Microbial Symbiont Transmission: Basic Principles and Dark Sides“. In Beneficial Microorganisms in Multicellular Life Forms, 299–311. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-21680-0_22.
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Becker, Miriam. „The female organs of symbiont transmission in the Eumolpinae“. In Novel aspects of the biology of Chrysomelidae, 363–70. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-1781-4_30.
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Gorovits, Rena, und Henryk Czosnek. „Insect Symbiotic Bacterial GroEL (Chaperonin 60) and Plant Virus Transmission“. In Heat Shock Proteins, 173–87. Dordrecht: Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-6787-4_11.
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Maudlin, Ian. „Transmission of African Trypanosomiasis: Interactions Among Tsetse Immune System, Symbionts, and Parasites“. In Advances in Disease Vector Research, 117–48. New York, NY: Springer New York, 1991. http://dx.doi.org/10.1007/978-1-4613-9044-2_6.
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Douglas, A. E. „How Symbioses Are Formed“. In Symbiotic Interactions, 78–99. Oxford University PressOxford, 1994. http://dx.doi.org/10.1093/oso/9780198542865.003.0005.
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Abstract Research on the formation of symbioses includes four topics. 1. Identification of the source of the partner. A host may acquire its symbionts either from the environment or directly from another host. In many associations, the symbionts are transferred directly from a hostparent to its offspring, and this process is known as vertical transmission. 2. Establishment of the symbiosis. It is usual to consider the development of an association as a series of stages, each stage dependent on the successful completion of the previous stage. As a hypothetical example, an association between an animal host and microbial symbiont may include contact, internalization of the microorganism, and initiation of nutrient transfer. 3. Specificity of the association. This refers to the taxonomic range of partners with which an organism can form a symbiosis. Specificity is a consequence of both the degree of specialization of an organism for its partner, and its capacity to select and discriminate between alternative potential partners.
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Boomsma, Jacobus J. „Inclusive fitness as driver of cooperation for mutual benefit“. In Domains and Major Transitions of Social Evolution, 105–29. Oxford University PressOxford, 2022. http://dx.doi.org/10.1093/oso/9780198746171.003.0005.
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Abstract Mutual aid cannot evolve unless it offers compensating direct benefits for an actor or indirect benefits for her relatives. This phrase is a gene’s eye version of Darwin’s statement that no adaptation can arise for the exclusive good of another species. Such thinking has inspired studies that explored how Hamilton’s rule can explain adaptation in symbiotic mutualisms. When studies tracked genetics, they converged on the conclusion that interspecific “altruism” is always driven by clonal or family altruism within the partner species, which confirmed Darwin’s insight and earlier conclusions that “altruism between species” is a misnomer. I review the dynamics of cooperation and conflict in symbioses where unicellular partners associate with a multicellular host either by voluntarily horizontal acquisition or in a coerced setting of vertical transmission. I then consider symmetry and redundancy of partnerships and their degree of genetic closure, showing that hosts either maintain societies of symbionts or have a lifetime non-redundant partnerships with a single symbiont. This suggests that the egalitarian MTE origin of LECA can be understood by the same non-redundant closure principle that I used in Chapter 4 to explain the recurrent MTEs towards organismal multicellularity and colonial superorganismality. This explanation includes the origin of meiotic sex and can likely be extended to the origin of the first prokaryote cell. In general, the arguments in this and the previous chapter imply the conjectures that (1) higher grades of organismality did not emerge, they were naturally selected adaptive syndromes (2) their ancestral properties had nothing to do with being relatively big or complex; and (3) non-redundant partnership was essential to suppress conflict over resource acquisition, while reproductive allocation conflicts appear to have been unimportant at MTE origins.
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Boomsma, Jacobus J. „Adaptation, control information, and the human condition“. In Domains and Major Transitions of Social Evolution, 194–222. Oxford University PressOxford, 2022. http://dx.doi.org/10.1093/oso/9780198746171.003.0008.
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Abstract Following the inductive logic of Hume’s fork, this book has partitioned Hamilton’s rule so that it offers a general necessary and concrete sufficiency condition for the origins of major transitions in evolution (MTEs). My conjecture could in principle have been formulated decades ago, but several forms of confusion have compromised its development. First, Darwinism was “environmentalized” throughout the 20th century, becoming a branch of ecology and allowing researchers to avoid asking questions about adaptive design. This problem disappears only when adhering to a strict definition of what an environment really is, as George Williams did in 1966 and Helena Cronin updated in 2005. Second, many have failed to appreciate that the gene’s eye view of adaptive evolution is a concept of genetic information and phenotypic agency rather than of genetic reductionism. Making that perspective explicit helps to connect inclusive fitness theory to Shannon’s information theory, because both are about the use of information for prediction and control. It then emerges that inclusive fitness theory, captured by Price equation logic of selection and transmission, is the only biological theory that might ultimately be reconciled with theoretical physics via quantum Darwinism. Third, anthropomorphic bias has been rampant in biology, particularly in conceptualizing the human MTE. Our own transition is exceptional in not having originated via a new level of lifetime commitment and obligate reproductive division of labor, but from an already complex society that became domesticated by cumulative culture—an endosymbiosis between individual brains and sets of self-organizing algorithmic symbionts. Under that assumption, a dual Price equation framework may be the best unbiased tool for unraveling the extent of cooperation and conflicts between our genetic endowment and the reproductive interests of our Lamarckian brain symbionts. Dual host–symbiont agency appears to make anthropomorphic concepts such as “self-domestication” and “self-deception” moot, and to shed intriguing light on patterns of MTE symmetry over time.
Konferenzberichte zum Thema "Transmission du symbiote"
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Zhou, Hu, Qianqian Zhang und Ying-Chang Liang. „Assistance-Transmission Tradeoff for RIS-Assisted Symbiotic Radios“. In ICC 2023 - IEEE International Conference on Communications. IEEE, 2023. http://dx.doi.org/10.1109/icc45041.2023.10279231.
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Elsayed, Mohamed, Ahmed Samir, Ahmad A. Aziz El-Banna, Khaled Rabie, Xingwang Li und Basem M. ElHalawany. „Symbiotic Ambient Backscatter IoT Transmission over NOMA-Enabled Network“. In ICC 2022 - IEEE International Conference on Communications. IEEE, 2022. http://dx.doi.org/10.1109/icc45855.2022.9838941.
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Gile, Gillian. „Evolution and transmission of cockroach and termite hindgut symbiotic protozoa“. In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.117402.
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Wang, Sibao. „Blocking malaria transmission with genetically engineered symbiotic bacteria from vector mosquitoes“. In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.94051.
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Liu, Yanyan, Pinyi Ren und Qinghe Du. „Symbiotic Communication: Concurrent Transmission for Multi-Users Based on Backscatter Communication“. In 2020 International Conference on Wireless Communications and Signal Processing (WCSP). IEEE, 2020. http://dx.doi.org/10.1109/wcsp49889.2020.9299793.
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Chen, Hao, Ruizhe Long und Ying-Chang Liang. „Transmission Protocol and Beamforming Design for RIS-Assisted Symbiotic Radio over OFDM Carriers“. In GLOBECOM 2023 - 2023 IEEE Global Communications Conference. IEEE, 2023. http://dx.doi.org/10.1109/globecom54140.2023.10437023.
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Liu, Yin-Quan. „Diversity, distribution, and horizontal transmission to a parasitoid of symbionts in theBemisia tabaciwhitefly complex“. In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.113197.
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Russell, Jacob. „Strong community structuring of defensive heritable symbionts is shaped by context-dependent transmission rates“. In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.115395.
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Wang, Zhaowei, Zhisheng Yin, Xiucheng Wang, Nan Cheng, Yunchao Song und Tom H. Luan. „CNN-Based Synergetic Beamforming for Symbiotic Secure Transmissions in Integrated Satellite-Terrestrial Network“. In 2023 IEEE 23rd International Conference on Communication Technology (ICCT). IEEE, 2023. http://dx.doi.org/10.1109/icct59356.2023.10419711.
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Mason, Charles. „Transmission and function of the major fungal symbiont of the Asian longhorned beetle (Anoplophora glabripennis)“. In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.89395.
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Gottlieb, Yuval, Bradley Mullens und 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, Juni 2015. http://dx.doi.org/10.32747/2015.7699865.bard.
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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.
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Zchori-Fein, Einat, Judith K. Brown und Nurit Katzir. Biocomplexity and Selective modulation of whitefly symbiotic composition. United States Department of Agriculture, Juni 2006. http://dx.doi.org/10.32747/2006.7591733.bard.
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Whiteflies are sap-sucking insects that harbor obligatory symbiotic bacteria to fulfill their dietary needs, as well as a facultative microbial community with diverse bacterial species. The sweetpotato whitefly Bemisia tabaci (Gennadius) is a severe agricultural pest in many parts of the world. This speciesconsists of several biotypes that have been distinguished largely on the basis of biochemical or molecular diagnostics, but whose biological significance is still unclear. The original objectives of the project were (i) to identify the specific complement of prokaryotic endosymbionts associated with select, well-studied, biologically and phylogeographically representative biotypes of B. tabaci, and (ii) to attempt to 'cure’ select biotypes of certain symbionts to permit assessment of the affect of curing on whitefly fitness, gene flow, host plant preference, and virus transmission competency.To identify the diversity of bacterial community associated with a suite of phylogeographically-diverseB. tabaci, a total of 107 populations were screened using general Bacteria primers for the 16S rRNA encoding gene in a PCR. Sequence comparisons with the available databases revealed the presence of bacteria classified in the: Proteobacteria (66%), Firmicutes (25.70%), Actinobacteria (3.7%), Chlamydiae (2.75%) and Bacteroidetes (<1%). Among previously identified bacteria, such as the primary symbiont Portiera aleyrodidarum, and the secondary symbionts Hamiltonella, Cardinium and Wolbachia, a Rickettsia sp. was detected for the first time in this insect family. The distribution, transmission, and localization of the Rickettsia were studied using PCR and fluorescence in situ hybridization (FISH). Rickettsia was found in all 20 Israeli B. tabaci populations screened as well as some populations screened in the Arizona laboratory, but not in all individuals within each population. FISH analysis of B. tabaci eggs, nymphs and adults, revealed a unique concentration of Rickettsia around the gut and follicle cells as well as its random distribution in the haemolymph, but absence from the primary symbiont housing cells, the bacteriocytes. Rickettsia vertical transmission on the one hand and its partial within-population infection on the other suggest a phenotype that is advantageous under certain conditions but may be deleterious enough to prevent fixation under others.To test for the possible involvement of Wolbachia and Cardiniumin the reproductive isolation of different B. tabacibiotypes, reciprocal crosses were preformed among populations of the Cardinium-infected, Wolbachia-infected and uninfected populations. The crosses results demonstrated that phylogeographically divergent B. tabaci are reproductively competent and that cytoplasmic incompatibility inducer-bacteria (Wolbachia and Cardinium) both interfered with, and/or rescued CI induced by one another, effectively facilitating bidirectional female offspring production in the latter scenario.This knowledge has implications to multitrophic interactions, gene flow, speciation, fitness, natural enemy interactions, and possibly, host preference and virus transmission. Although extensive and creative attempts undertaken in both laboratories to cure whiteflies of non-primary symbionts have failed, our finding of naturally uninfected individuals have permitted the establishment of Rickettsia-, Wolbachia- and Cardinium-freeB. tabaci lines, which are been employed to address various biological questions, including determining the role of these bacteria in whitefly host biology.
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Hunter, Martha S., und Einat Zchori-Fein. Rickettsia in the whitefly Bemisia tabaci: Phenotypic variants and fitness effects. United States Department of Agriculture, September 2014. http://dx.doi.org/10.32747/2014.7594394.bard.
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The sweet potato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) is a major pest of vegetables, field crops, and ornamentals worldwide. This species harbors a diverse assembly of facultative, “secondary” bacterial symbionts, the roles of which are largely unknown. We documented a spectacular sweep of one of these, Rickettsia, in the Southwestern United States in the B biotype (=MEAM1) of B. tabaci, from 1% to 97% over 6 years, as well as a dramatic fitness benefit associated with it in Arizona but not in Israel. Because it is critical to understand the circumstances in which a symbiont invasion can cause such a large change in pest life history, the following objectives were set: 1) Determine the frequency of Rickettsia in B. tabaci in cotton across the United States and Israel. 2) Characterize Rickettsia and B. tabaci genotypes in order to test the hypothesis that genetic variation in either partner is responsible for differences in phenotypes seen in the two countries. 3) Determine the comparative fitness effects of Rickettsia phenotypes in B. tabaci in Israel and the United States. For Obj. 1, a survey of B. tabaci B samples revealed the distribution of Rickettsia across the cotton-growing regions of 13 sites from Israel and 22 sites from the USA. Across the USA, Rickettsia frequencies were heterogeneous among regions, but were generally at frequencies higher than 75% and close to fixation in some areas, whereas in Israel the infection rates were lower and declining. The distinct outcomes of Rickettsia infection in these two countries conform to previouslyreported phenotypic differences. Intermediate frequencies in some areas in both countries may indicate a cost to infection in certain environments or that the frequencies are in flux. This suggests underlying geographic differences in the interactions between bacterial symbionts and the pest. Obj. 2, Sequences of several Rickettsia genes in both locations, including a hypervariableintergenic spacer gene, suggested that the Rickettsia genotype is identical in both countries. Experiments in the US showed that differences in whitefly nuclear genotype had a strong influence on Rickettsia phenotype. Obj. 3. Experiments designed to test for possible horizontal transmission of Rickettsia, showed that these bacteria are transferred from B. tabaci to a plant, moved inside the phloem, and could be acquired by other whiteflies. Plants can serve as a reservoir for horizontal transmission of Rickettsia, a mechanism that may explain the occurrence of phylogenetically-similarsymbionts among unrelated phytophagous insect species. This plant-mediated transmission route may also exist in other insect-symbiont systems, and since symbionts may play a critical role in the ecology and evolution of their hosts, serve as an immediate and powerful tool for accelerated evolution. However, no such horizontal transmission of Rickettsia could be detected in the USA, underlining the difference between the interaction in both countries, or between B. tabaci and the banded wing whitefly on cotton in the USA (Trialeurodes sp. nr. abutiloneus) and the omnivorous bug Nesidiocoristenuis. Additionally, a series of experiments excluded the possibility that Rickettsia is frequently transmitted between B. tabaci and its parasitoid wasps Eretmocerusmundus and Encarsiapergandiella. Lastly, ecological studies on Rickettsia effects on free flight of whiteflies showed no significant influence of symbiont infection on flight. In contrast, a field study of the effects of Rickettsia on whitefly performance on caged cotton in the USA showed strong fitness benefits of infection, and rapid increases in Rickettsia frequency in competition population cages. This result confirmed the benefits to whiteflies of Rickettsia infection in a field setting.
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Ullman, Diane, James Moyer, Benjamin Raccah, Abed Gera, Meir Klein und Jacob Cohen. Tospoviruses Infecting Bulb Crops: Evolution, Diversity, Vector Specificity and Control. United States Department of Agriculture, September 2002. http://dx.doi.org/10.32747/2002.7695847.bard.
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Objectives. The overall goal of the proposed research was to develop a mechanistic understanding of tospovirus evolution, diversity and vector specificity that could be applied to development of novel methods for limiting virus establishment and spread. Our specific objectives were: 1) To characterize newly intercepted tospoviruses in onion, Hippeastrum and other bulb crops and compare them with the known tomato spotted wilt virus (TSWV) and its isolates; 2) To characterize intra- and interspecific variation in the virus transmission by thrips of the new and distinct tospoviruses. and, 3) To determine the basis of vector specificity using biological, cellular and molecular approaches. Background. New tospoviruses infecting bulb crops were detected in Israel and the US in the mid-90s. Their plant host ranges and relationships with thrips vectors showed they differed from the type member of the Tospovirus genus, tomato spotted wilt virus (TSWV). Outbreaks of these new viruses caused serious crop losses in both countries, and in agricultural and ornamental crops elsewhere. In the realm of plant infecting viruses, the tospoviruses (genus: Tospovirus , family: Bunyaviridae ) are among the most aggressive emerging viruses. Tospoviruses are transmitted by several species of thrips in a persistent, propagative fashion and the relationships between the viruses and their thrips vectors are often specific. With the emergence of new tospoviruses, new thrips vector/tospovirus relationships have also arisen and vector specificities have changed. There is known specificity between thrips vector species and particular tospoviruses, although the cellular and molecular bases for this specificity have been elusive. Major conclusions, solutions and achievements. We demonstrated that a new tospovirus, iris yellow spot virus (IYSV) caused "straw bleaching" in onion (Allium cepa) and lisianthus necrosis in lisianthus (Eustoma russellianum). Characterization of virus isolates revealed genetic diversity among US, Brazilian, Dutch and Israeli isolates. IYSV was not seed transmitted, and in Israel, was not located in bulbs of infected plants. In the US, infected plants were generated from infected bulbs. The relationship between IYSV and Thrips tabaci was shown to be specific. Frankliniella occidentalis, the primary vector of many other tospoviruses, did not transmit IYSV isolates in Israel or the US. Furthermore, 1': tabaci populations varied in their transmission ability. Transmission was correlated to IYSV presence in thrips salivary glands. In Israel, surveys in onion fields revealed that the onion thrips, Thrips tabaci Lindeman was the predominant species and that its incidence was strongly related to that of IYSV infection. In contrast, in the U.S., T. tabaci and F. occidentalis were present in high numbers during the times sampled. In Israel, insecticides reduced onion thrips population and caused a significant yield increase. In the US, a genetic marker system that differentiates non-thrips transmissible isolates from thrips transmissible isolate demonstrated the importance of the M RNA to thrips transmission of tospoviruses. In addition, a symbiotic Erwinia was discovered in thrips and was shown to cause significant artifacts in certain types of virus binding experiments. Implications, scientific and agricultural. Rapid emergence of distinct tospoviruses and new vector relationships is profoundly important to global agriculture. We advanced the understanding of IYSV in bulb crops and its relationships with thrips vector species. The knowledge gained provided growers with new strategies for control and new tools for studying the importance of particular viral proteins in thrips specificity and transmission efficiency.