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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Efeito da adi??o de colesterol e ecdisona na produ??o in vitro do baculov?rus spodoptera frugiperda MNPV

Dantas, Graciana Clecia 02 August 2010 (has links)
Made available in DSpace on 2014-12-17T15:01:23Z (GMT). No. of bitstreams: 1 GracianaCD_DISSERT.pdf: 963468 bytes, checksum: 406e6de21c3be72fd5a9ff01dcdda958 (MD5) Previous issue date: 2010-08-02 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Among the pests that attack corn crop in Brazil, there is Spodoptera frugiperda (JE Smith, 1797) (Lepidoptera: Noctuidae), known as fall armyworm, which is the major corn pest. Due to genetic instability during serial passage of baculoviruses in insect cell culture, the viral bioinseticides in vitro production development is the greatest challenge for mass production of this bioproduct. Successive passages of virus using extracellular viruses (BVs), necessary during viral bioinseticides production scaling up, leads to the appearance of aberrant forms of virus, a process so called as "passage effect ". The main consequence of passage effect is the production of occlusion bodies (OB) decrease, preventing its production using in vitro process. In this study, it was carried out a serial passage of baculovirus Spodoptera frugiperda multiple nucleopolyhedrovirus, isolate 18, using Sf21 cells. A decrease in the production of occlusion bodies from 170 to 92 in the third to fourth passage was observed. A factorial experimental design (22) was employed to verify the influence of two input variables, concentration of the hormone 20 - hydroxyecdysone (CH) and cholesterol (CC) on the values of response variables (volumetric and the specific OB production) of the process, seeking to define the optimum operating ranges trying to reverse or minimize the passage effect. The result indicated a negative influence of the cholesterol addition and positive effect in the hormone supplementation which the optimum range found for the concentrations studied were 8 to 10μg/mL and 5 to 6.5 mg / mL, for cholesterol and hormone concentrations respectively. New experiments were performed with addition of hormone and cholesterol in order to check the influence of these additives on the OB production independently. While the best result obtained from the factorial experiment was 9.4 x 107 OB/mL and 128.4 specific OB/cell, with the addition of only 6μg/mL 20-hydroxyecdysone these concentrations increased to 1.9 x 108 OB/mL and 182.9 OB/cell for volumetric and specific OB production, respectively. This result confirms that the addition of the hormone 20-hydroxyecdysone enhances the SfMNPV in vitro production process performance using Sf21 cells / Dentre as pragas que atacam a cultura do milho no Brasil, destaca-se a Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae), conhecida no est?dio larval como lagarta-do-cartucho, considerada a praga chave da cultura, alimentando-se da planta em todas as suas fases de crescimento, principalmente dos cartuchos de plantas jovens. Para seu controle, tem-se empregado inseticidas qu?micos de amplo espectro, o que tem causado efeitos adversos ao homem e ao meio ambiente. Por essa raz?o, torna-se necess?ria a busca de alternativas mais eficientes, de baixo custo e de f?cil utiliza??o, como o uso de bioinseticidas, especialmente os baculov?rus. Devido ? instabilidade gen?tica durante a passagem seriada de baculov?rus em cultivo de c?lulas de inseto, o desenvolvimento da produ??o in vitro de bioinseticidas virais ? o maior desafio para a sua produ??o massal. Passagens sucessivas de v?rus usando v?rus extracelulares (BVs), necess?rias para o aumento de escala durante a produ??o de bioinseticida viral, leva ao aparecimento de formas aberrantes de v?rus, processo conhecido como efeito de passagem . A principal consequ?ncia do efeito passagem ? a diminui??o da produ??o de corpos de oclus?o (OB), inviabilizando economicamente sua produ??o pelo processo in vitro. Neste trabalho, foi realizada a passagem seriada do isolado 18 do baculov?rus Spodoptera frugiperda multiple nucleopolyhedrovirus em c?lulas Sf21. Foi observada uma queda na produ??o de OB de 170 para 92 da terceira para quarta passagem. Um planejamento experimental fatorial (22) foi empregado para verificar a influ?ncia de duas vari?veis de entrada, concentra??o de horm?nio 20- Hidroxiecdisona (CH) e concentra??o de colesterol (CC), sobre os valores das vari?veis de resposta do processo (produ??o volum?trica e produ??o espec?fica de OB), procurando definir as faixas ?timas de opera??o para reverter ou minimizar o efeito passagem. O resultado deste planejamento indicou influ?ncia negativa da adi??o do colesterol e positiva na adi??o de horm?nio, onde as faixas ?timas encontradas para as concentra??es estudadas foram: 8 a 10μg/mL e 5 a 6,5μg/mL, para as concentra??es de colesterol e horm?nio, respectivamente. Novos experimentos foram realizados com a adi??o individual de horm?nio e colesterol com a finalidade de verificar a influ?ncia destes adjuvantes na produ??o de OB de forma independente. No planejamento experimental obteve-se produ??o volum?trica de 9,4 x 107 OB/mL e espec?fica de 128,4 OB/c?lula. Quando se adicionou 6 μg/mL de 20-Hidroxiecdisona, as concentra??es elevaram-se para 1,9 x 108 OB/mL e 182,9 OB/c?lula, indicando que a adi??o do horm?nio melhorou a efici?ncia da produ??o in vitro de produ??o de SfMNPV em cultivos de c?lulas Sf21
52

Essais de thérapie génique pour la dyskinésie ciliaire primitive / Gene therapy for primary ciliary dyskinesia

Jimenez, Gina Camila 24 November 2016 (has links)
La dyskinésie ciliaire primitive (DCP) est une maladie génétique rare, autosomique récessive, résultant d'un dysfonctionnement des cils de l'épithélium respiratoire. Les patients atteints souffrent d'infections respiratoires chroniques accompagnées de complications évoluant vers l'insuffisance respiratoire, en dépit de traitements antibiotiques et de kinésithérapique à vie. Ils peuvent aussi présenter une hétérotaxie.La première partie de ma thèse a consisté à rechercher des gènes impliqués dans l'hétérotaxie et la DCP. Grâce au séquençage haut-débit, nous avons pu identifier deux nouveaux gènes - MMP21 et RSPH1 - responsables respectivement d'hétérotaxie et de DCP. L'identification de tous les gènes responsables est un préalable indispensable à toute thérapie génique. Dans la deuxième partie, nous avons cherché à développer une thérapie génique in vivo dans le but de restaurer un battement ciliaire normal et ainsi de stopper l'évolution de la maladie. Préalablement, notre laboratoire avait apporté la preuve du concept dans un essai de thérapie génique in vitro impliquant le gène DNAI1. Pour la démonstration in vivo, la lignée Dnahc11iv de souris ayant une mutation du gène Dnahc11 et ayant des cils déficients a été choisie. L'ADNc de DNAH11 (14 kb) a été cloné sous contrôle d'une partie de la séquence du promoteur FOXJ1, suffisante pour limiter l'expression du transgène aux cellules ciliées. Une autre construction a permis de produire des vecteurs dérivés du baculovirus. Un essai de délivrance par voies nasale et trachéale a été réalisé avec succès d'une part avec les vecteurs dérivés du baculovirus et d'autre part avec l'ADNc complexé à des nanoparticules / Primary ciliary dyskinesia (PCD) is a rare autosomal recessive genetic disorder, caused by airway epithelial cilia dysfunction. Patients suffer from chronic respiratory infections along with various organ defects evolving toward respiratory insufficiency, in spite of antibiotic treatment and lifelong physiotherapy. They can also have heterotaxy syndrome. The first part of this work aimed to identify mutations in genes implicated in heterotaxy and PCD. Thanks to next-generation sequencing method, two new genes were identified MMP21 and RSPH1 causing heterotaxy and PCD respectively. The discovery of all causal genes is the base of the development of a PCD therapy system. The second part describes the development and the characterization of tools needed to establish an in vivo gene therapy. The purpose is to restore a normal cilia beating to limit or even stop the disease. First, our laboratory demonstrated the proof-of-concept in an in vitro gene therapy assay for DNAI1. To do so, Dnahc11 deficient mouse model with immotile cilia and PCD symptoms was chosen. Then, to achieve the project, DNAH11 cDNA (14 kb) has been cloned under control of a part of the sequence of the specific promoter (FOXJ1), previously demonstrated as sufficient to limit transgene expression to ciliated cells. Another construction was made to produce baculovirus derived vectors. A cDNA delivery attempt through nasal and tracheal way was done with baculovirus derived vector or DNAH11 cDNA complexed with nanoparticles
53

Analyse de la durabilité de la lutte biologique à l'aide de Baculovirus dans les conditions de protection des cultures. / Analysis of the sustainability of biological control using baculovirus in orchards protection conditions

Graillot, Benoït 17 April 2015 (has links)
La résistance aux agents de biocontrôle est un problème majeur dans les cultures du monde entier. Ainsi, le carpocapse du pommier, Cydia pomonella, a développé des résistances contre des traitements répétés au Cydia pomonella granulovirus (CpGV) dans plusieurs pays d’Europe. Ces résistances posent la question de la durabilité de ce type de lutte contre les ravageurs. Ce travail porte sur l’étude de plusieurs aspects des interactions granulovirus/hôtes : en premier lieu, sur l’étude des différences de sensibilité au CpGV entre des colonies d’insectes de laboratoire afin de mieux cerner les mécanismes d’apparition de résistances. Concernant le virus, le génome complet de cinq isolats viraux utilisés au cours de ces travaux a été séquencé et une analyse des gènes positivement sélectionnés a été conduite afin de découvrir de nouveaux gènes potentiellement importants pour la valeur sélective du virus. L’adaptabilité du CpGV à un hôte C. pomonella résistant ainsi qu’à un hôte d’une espèce proche, Cydia molesta a également été étudiée. Enfin, l’efficacité, sur différentes colonies d’insectes, de populations de génotypes viraux mélangées ainsi que de leurs générations successives ont été analysés. Ces études nous ont permis de mettre en évidence une diversité génétique très étendue chez le CpGV ainsi que des phénomènes de co-infections d’une même cellule et de recombinaison. Ainsi, s’il semble impossible de certifier une méthode de biocontrôle d’une efficacité constante, il apparait que les capacités évolutives des virus permettront de supporter des phénomènes de résistance des hôtes. Un suivi annuel afin de permettre une évolution dirigée du virus sera toutefois obligatoire. / Resistance to biocontrol agents is a critical issue worldwide in orchards. Thereby the codling moth Cydia pomonella developed resistances under repeated treatments with Cydia pomonella granulovirus (CpGV) in several European countries. These resistances raise the issue of the durability of such a pest control. This work aims to investigate various aspects of granulovirus/host interactions: first by studying the susceptibility variations to CpGV infection between different laboratory insect colonies in order to assess the mechanisms of resistances apparition; to investigate the virus diversity, complete genomes of five viral isolates used over this work have been sequenced and an analysis of the positively selected genes has been carried out as to come up with new genes potentially important for the fitness of the virus. The adaptability of CpGV to a resistant C. pomonella host as well as to a related specie, Cydia molesta has also been studied. Finally, the efficiency, on different insect colonies, of mixed populations of viral genotypes as well as their successive offspring have been analyzed. These studies allowed highlighting a wide genetic diversity among CpGVs, together with co-infection within cell and recombination phenomenon. Thus, if it seems impossible to certify a biocontrol method with constant efficacy, it appears that the evolutive capacities of viruses will allow overcoming host resistance phenomenon. However, one will need to keep one step ahead from the virus, which means an annual survey to permit a directed evolution of the virus.
54

The production and purification of functional steroid hormone receptor ligand binding domains towards the development of a biological endocrine disruptor detection system

Tait, Timo 04 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: During the last two and a half decades a large body of research has accumulated indicating the presence of various natural and synthetic chemical compounds within the environment capable of inducing hormone-like responses in humans and animals. Such compounds, termed endocrine disruptors, have been implicated in a variety of developmental, reproductive and physiological abnormalities which have been shown to converge on the endocrine system. Given that endocrine disrupters are comprised of a diverse group of molecules with dissimilar chemical structures, general screening techniques are not feasible for effective environmental monitoring. A primary method of action by which these exogenous molecules affect the homeostatic regulation of the endocrine system is believed to be via the modulation of gene transcription. It is now well established that many endocrine disrupting compounds act upon a principal group of transcription factors, the nuclear receptors, by chance interaction with the ligand binding domains of these proteins. With a view to ultimately design a portable kit for the detection of endocrine disrupting compounds in water based on the bio-specific immobilisation of nuclear receptor ligand binding domains to a stationary membrane matrix, this study specifically describes: 1. The effects on recombinant protein expression by the addition of small molecules to the cultivation media of bacteria. 2. The optimisation of conditions for the lysis of bacterial cells to increase the solubility of heterologously expressed proteins. 3. The purification of recombinant proteins from bacterial cell lysates by means of a two-step chromatographic methodology. 4. The cloning of the genes for the human androgen and estrogen receptors’ ligand binding domains into baculovirus transfer plasmids. 5. Transfer of genetic material from the created baculovirus transfer plasmids to a linearised baculovirus genome for the generation of recombinant viruses. 6. The cultivation, and baculoviral infection, of Spodoptera frugiperda and Trichoplusia ni cell lines. 7. Expression and purification of N-terminal hexahistidine-tagged human nuclear receptor LBDs from insect cell lysates by means of immobilised metal affinity chromatography. / AFRIKAANSE OPSOMMING: Die teenwoordigheid van natuurlike en sintetiese chemiese middels wat oor die vermoë beskik om die aksies van hormone in die mens en dier na te boots het toenemend aftrek gekry in navorsing gedurende die laaste twee en ’n halwe dekades. 'n Verskeidenheid van ontwikkelings-, reproduktiewe- en fisiologiese abnormaliteite ontstaan as gevolg van die aksies van hierdie molekule, genaamd endokriene-ontwrigters, op die natuurlike funksionering van die endokriene-sisteem. Gegewe dat die groep chemiese middels waaruit endokriene-ontwrigters bestaan van diverse oorsprong afkomstig is lei dit daartoe dat algemene analitiese tegnieke nie in alle gevalle geskik is vir effektiewe omgewingsmonitering is nie. Die modulasie van geentranskripsie is een van die metodes wat voorgestel word as ’n metode waarop hierdie eksogene molekule die homeostatiese regulering deur die endokriene-sisteem omverwerp. ’n Algemene metode waarop vele endokrien-ontwrigtende stowwe geentranskripsie beïnvloed, is deur interaksie met die hormoon-bindende gedeeltes van ’n belangrike groep transkripsiefaktore, die nukluêre reseptore. Hierdie studie, met die uiteindelike ontwikkeling van ’n draagbare toetsstelsel vir die opsporing van endokrien-ontwrigtende-stowwe in water, gebasseer op die bio-spesifieke immobilisering van nukluêre reseptor ligand bindingsdomeins op ’n stasionêre membraanmatriks, het ten doel om die volgende te beskryf: 1. Die effek wat die byvoeging van klein molekule tot die groeimedium van bakteriëe het op die uitdrukking van rekombinante proteïene. 2. Die optimisering van bakteriese sel-lisering in terme van verhoging in die oplosbaarheid van heteroloë proteïene. 3. Die suiwering van rekombinante proteïen vanuit bakteriese sellisate deur middel van ’n twee-stap chromatografiese sisteem. 4. Die klonering van die gene vir die menslike androgeen en estrogeen reseptore se ligand bindingsdomeine in bakulovirus oordragplasmiede. 5. Die oordrag van genetiese materiaal vanaf hierdie bakulovirus oordragplasmiede na ’n gelineariseerde bakulovirus genoom deur middel van homoloë rekombinasie vir die produksie van rekombinante virusse. 6. Die groei en infeksie van Spodoptera frugiperda en Trichoplusia ni sellyne wat lei tot die uitdrukking van menssoortgelyke nukluêre reseptor ligandbindingsdomains. 7. Suiwering van N-terminaal heksahistidien-etiket-gekoppelde menslike nukluêre reseptor ligandbindingsdomeins vanuit inseksellisate deur middel van geïmmobiliseerde metaal affiniteitschromatografie.
55

Montagem de um pseudo-hantavírus quimera, contendo a nucleoproteína do vírus Araraquara e as glicoproteínas do vírus Andes, em sistema baculovírus / Assembly of a chimeric hantavirus-like particle, containing the Araraquara nucleoprotein and the Andes glycoproteins, expressed in baculovirus system

Yeda, Fernanda Perez 22 February 2010 (has links)
Os hantavírus, membros da família Bunyaviridae, são os agentes infecciosos responsáveis pela Febre Hemorrágica com Síndrome Renal e pela Síndrome Cardiopulmonar por Hantavírus. São vírus com genoma constituído por três segmentos de RNA fita simples, de polaridade negativa, designados como S, M e L, que codificam, respectivamente, a nucleoproteína, as glicoproteínas G1 e G2 e a RNA polimerase dependente de RNA. Com o objetivo de estudar a montagem de pseudopartículas quiméricas de hantavírus, a proteína N do vírus Araraquara e as glicoproteínas G1 e G2 do vírus Andes foram expressas em sistema baculovírus. A microscopia confocal mostrou a colocalização das proteínas G1 e G2 com a proteína N. Pelos ensaios de imunoprecipitação e de centrifugação em gradiente de sacarose, foi observada a interação entre as proteínas N, G1 e G2. Nas análises por microscopia eletrônica de transmissão foi observada a montagem do pseudo-hantavírus quimera, com morfologia semelhante ao do vírion. O pseudo-hantavírus quimera obtido neste estudo poderá, no futuro, ser utilizado em estudos imunológicos, estruturais e morfológicos. / Hantaviruses, members of the Bunyaviridae family, are the infectious agents responsible for Hemorrhagic Fever with Renal Syndrome and the Hantavirus Cardiopulmonary Syndrome. The viral genome is composed by three segments of single-stranded negative-sense RNA, designated as S, M and L, which encode, respectively, the nucleoprotein, the G1 and G2 glycoproteins, and the RNA-dependent RNA polymerase. In order to study the assembly of a chimeric hantavirus-like particle, the Araraquara nucleoprotein and the Andes glycoproteins were expressed in a baculovirus system. Confocal microscopy showed the colocalization of G1 and G2 proteins with the N protein. Immunoprecipitation assay and sucrose density gradient showed the interaction among N, G1 and G2 proteins. The transmission electron microscopy showed the hantavirus-like particle with the same morphology of the virion. The chimeric hantavirus-like particle produced in this study could be used, in the future, in immunological, structural and morphological studies.
56

Otimização do crescimento de células Sf-9 em biorreator visando à produção de biopesticida. / Optimization of Sf-9 cell growth in bioreactor for the of biopesticide.

Pereira, Guilherme Fabri 24 July 2017 (has links)
Comparadas com células de mamífero, as células de inseto são mais fáceis de cultivar, não acumulam quantidade significativa de sub-produtos tóxicos e apresentam maiores rendimentos na expressão de proteínas heterólogas, porém apresentam uma menor capacidade de realizar modificações pós-traducionais. Células de inseto podem ser empregadas na produção in vitro de baculovírus, usados como pesticidas biológicos. As células Sf-9 estão entre as células de inseto com uso mais difundido. Entender o metabolismo destas células permitirá melhorias nos processos que as empregam, entretanto, ainda há relativamente pouca informação sobre o assunto. Considerando mais especificamente o uso dessas células para produção de baculovírus, também é necessário mais entendimento sobre o processo infectivo e parâmetros que o afetam. Este trabalho teve como objetivo estudar a influência da suplementação do meio de cultivo com diferentes aminoácidos no desenvolvimento das células Sf-9 e determinar a concentração de oxigênio dissolvido ideal para o cultivo destas células, visando elaborar uma metodologia de cultivo em biorreator otimizada e, paralelamente, estudar o processo de infecção de cultivos dessas células com o baculovírus Spodoptera frugiperda (SfMNPV) em diferentes escalas. Para estudar a influência que a adição de aminoácidos ao meio tem sobre o crescimento celular, células Sf-9 foram cultivadas em frascos schotts de 100 e 500 mL, com 20 mL do meio SF900III SFM (serum free medium) suplementados com cisteína, prolina, serina ou asparagina. Os resultados foram comparados com cultivos feitos sem suplementação (controles). A condição que apresentou o melhor resultado em frasco schott foi replicada em biorreator de 1 L de volume útil. Para estudar a influência do oxigênio dissolvido (O.D.) foram testados diferentes setpoints de O.D. em cultivos em biorreator. Em tais ensaios foram testadas as concentrações de O.D de 10%, 30% e 50% da saturação com o ar. Para o estudo do processo de infecção, foram realizadas infecções em frascos schotts de 500 mL, com 20 mL de cultivo, e em biorreator de 1 L. Também foram realizadas infecções em garrafas T-25 como forma de controle de virulência do inóculo viral e do vírus produzido. As principais variáveis analisadas foram µmáx, Xvmáx YX/Glc. Nos ensaios de influencia de O.D., analisou-se também qO2 e qCO2 e, nos ensaios de infecção, a porcentagem de células contendo poliedros. A suplementação com prolina foi prejudicial ao cultivo. A adição de asparagina não teve qualquer influência no desenvolvimento celular. Os resultados das adições de cisteína e serina não foram muito conclusivos, em alguns ensaios houve aumento de Xvmáx, já em outros não foi notado efeito significativo. Nos ensaios em biorreator, todos os valores de O.D. testados apresentaram resultados semelhantes, já a adição de cisteína ao meio em biorreator foi bastante maléfica ao crescimento celular. Os ensaios de infecção mostraram que células Sf-9 são bastante susceptíveis à infecção pelo baculovírus Spodoptera frugiperda e boas produtoras de poliedros virais, e que a vazão gasosa tem efeito negativo na concentração viral na fase líquida dos cultivos em biorreator (título viral). / Compared to mammalian cells, insect cells are easier to culture, do not accumulate significant amounts of toxic byproducts and are capable of higher heterologous protein yields, but have a lower ability to perform post-translational modifications. Insect cells may be employed in the in vitro production of baculoviruses, used as biological pesticides. Sf-9 cells are among the most used insect cell lines. Understanding the metabolism of these cells would allow improvements in the processes that employ them, however, Howeverreports on the metabolism and physiology of Sf-9 cells and insect cells in general are scarce. When considering the use of these cells for baculovirus production, it is also necessary more understanding about the infective process and parameters that can affect it. This work aimed to study the influence that the supplementation of the culture medium with different amino acids have on the development of Sf-9 cells and to determine the ideal dissolved oxygen concentration for the culture of these cells, aiming to elaborate an optimized bioreactor culture methodology and, in parallel, to study the infection process of these cells with the Spodoptera frugiperda baculovirus (SfMNPV) at different scales. To study the influence that the addition of amino acids to the medium has on cell growth, Sf-9 cells were cultured in 100 and 500mL schott flasks with 20mL SF900III SFM (serum free medium) supplemented with cysteine, proline, serine or asparagine. The results were compared with cultures without supplementation (controls). The condition that presented the best result in schott flasks was replicated in a 1L bioreactor. To study the influence of dissolved oxygen (O.D.), experiments with different values of O.D. were conducted at a 1L bioreactor. The O.D. tested were 10%, 30% and 50% of air saturation. To study the infection process, infections were carried out in 500 mL schotted flasks, with 20 mL of culture, and in a 1L bioreactor. Infections were also carried out in 25 cm² T-flasks as a form of virulence control of the viral inoculum and virus produced. The main variables analyzed were µmax, Xvmax YX/Glc. In the O.D. tests, qO2 and qCO2 were also analyzed and, in the infection assays, the percentage of cells containing polyhedra. Proline supplementation was detrimental to the culture. The addition of asparagine had no influence on cellular growth. The results of cysteine and serine additions were not very conclusive, in some studies there was an increase of Xvmax, while in others no significant effect was observed. In the bioreactor trials, all O.D. tested showed similar results and the addition of cysteine to the medium was quite harmful to cell growth. Infection assays showed that Sf-9 cells are quite susceptible to infection by the Spodoptera frugiperda baculovirus and good producers of viral polyhedra, and that the gas flow has a negative effect on the viral concentration in the liquid phase of the bioreactor cultures (viral titer).
57

Interações de folhas de soja e algodão com a atividade do vírus de poliedrose nuclear de Chrysodeixis includens

Baldo, Gizele Rejane 28 February 2018 (has links)
Submitted by Eunice Novais (enovais@uepg.br) on 2018-05-07T19:38:50Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Gizele Baldo.pdf: 5751948 bytes, checksum: df4e7c4c9be199c089c189cbe28764f0 (MD5) / Made available in DSpace on 2018-05-07T19:38:50Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Gizele Baldo.pdf: 5751948 bytes, checksum: df4e7c4c9be199c089c189cbe28764f0 (MD5) Previous issue date: 2018-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os vírus de poliedrose nuclear são importantes agentes de controle microbiano de larvas de lepidópteros. No entanto, sua atividade pode ser comprometida durante a interação com suas plantas hospedeiras. Entender como ocorre a interação do vírus da lagarta Chrysodeixis includens, ChinNPV, com dois de seus hospedeiros, soja e algodão, pode auxiliar a expandir o uso de pesticidas biológicos amenizando suas limitações. A interação planta/vírus foi estudada a fim de verificar a influência da planta sobre o processo de infecção, alterando a forma e o momento em que as larvas se alimentam desses substratos. Os tratamentos foram: disco de folha, incorporação de folha (liofilizada e seca em estufa) em dieta, alimentação com substrato foliar antes da inoculação viral, persistência e exposição do vírus sobre a planta. As avaliações foram realizadas até o 10º ou 12º dias após a inoculação, quando foram determinados o peso e o estágio de desenvolvimento de cada sobrevivente. Os dados de mortalidade foram submetidos à análise de sobrevivência com riscos competitivos e os demais dados à ANOVA. Alterações histopatológicas no intestino médio das lagartas alimentadas com folhas de soja e algodão e inoculadas com o ChinNPV foram analisadas por microscopia de luz. A fixação das partículas virais foi avaliada através da extração da cera epicuticular com cinco solventes, seguida de aplicação, lavagem e contagem do vírus remanescentes. Fixação, morfologia e persistência dos poliedros sobre folhas de soja e algodão, em ambiente controlado e campo, foram avaliadas por MEV em diferentes períodos. A mortalidade das lagartas foi comprometida pelo algodão em quase todos os bioensaios realizados. A inoculação do NPV sobre discos de folha de soja resultou em mortalidades semelhantes à dieta. No entanto, quando tecidos liofilizados foram incorporados à dieta, os folíolos de soja reduziram a mortalidade de C. includens por NPV, com mortalidade análoga à provocada pelo algodão e, quando secos em estufa, a mortalidade larval foi intermediária, entre o apresentado pela dieta artificial e as folhas de algodão. Quando o vírus foi exposto na superfície da soja e posteriormente recuperado, o tempo de contato com a folha (72h) reduziu a atividade do vírus, o mesmo não foi válido para o algodão. A análise histopatológica mostrou desestruturação das células epiteliais no tratamento de alimentação prévia com folha, entretanto este fenômeno não alterou a mortalidade das lagartas. Enquanto em campo, a distribuição dos poliedros foi uniforme no filoplano das duas culturas, no laboratório, os poliedros formaram agregados sobre a superfície da soja. Já quando a cera epicuticular foi removida, a interação da folha com o vírus foi afetada. A atividade do ChinNPV foi comprometida tanto por folhas de soja quanto algodão, sendo que a persistência do vírus começa a reduzir após o terceiro dia de contato com o filoplano. Foi possível observar que a inativação do vírus somente ocorre quando folha de algodão e vírus são fornecidos em conjunto, enquanto na soja, o tempo de contato do vírus com a folha parece influenciar reduzindo a mortalidade das lagartas. Assim, seria interessante estudar formulações e doses para compensar a perda de atividade viral provocada pelos tecidos foliares. / Nucleopolyhedrovirus are important microbial control agents of lepidopteran larvae. However, their activity may be compromised during interaction with their host plants. Understanding the interaction process of the caterpillar virus Chrysodeixis includens, ChinNPV, with two of its hosts, soybean and cotton, may help to expand the use of biological pesticides by alleviating their limitations. The plant/virus interaction was studied in order to verify the influence of the plant on the infection process, changing the form and the moment in which the larvae feed on these substrates. The treatments were: leaf disc, incorporation of leaf (lyophilized and oven-dried) in diet, feeding with leaf substrate before viral inoculation, persistence, and virus exposure on the plant. Evaluations were carried out until the 10th or 12th days after inoculation, when the weight and stage of development of each survivor were determined. Mortality data were submitted to survival analysis with competitive risks and the other data to ANOVA. Histopathological changes in the midgut of caterpillars fed with soybean and cotton leaves and inoculated with ChinNPV were analyzed by light microscopy. Fixation of the virus particles was evaluated by extracting the epicuticular wax with five solvents followed by the application, washing and counting of the remaining virus. Fixation, morphology and persistence of the polyhedra on soybean and cotton leaves, under controlled environment and field, were evaluated by SEM on different periods. The mortality of caterpillars was compromised by cotton in almost all bioassays performed. NPV inoculation on soybean leaf discs resulted in diet-like mortalities. However, when lyophilized tissues were incorporated into the diet, soybean leaflets reduced the mortality of C. includens by NPV, with mortality similar to that caused by cotton, and when drying in oven, the larval mortality was intermediate between that presented by artificial diet and cotton leaves. When the virus was exposed on the soybean surface and later recovered, the time of contact with the leaf (72h) reduced the activity of the virus; the same was not true for cotton. The histopathological analysis showed disruption of epithelial cells in treatments of previous leaf feeding; however, this phenomenon did not change the mortality of caterpillars. While in the field, the polyhedra distribution was uniform on the phylloplane of the two cultures, in the laboratory, the polyhedra formed aggregates on the surface of the soybean. Already when the epicuticular wax was removed, the interaction of the leaf with the virus was affected. The activity of ChinNPV was compromised by both soybean and cotton leaves, and the persistence of the virus begins to decrease after the third day of contact with the phylloplane. It was possible to observe that the inactivation of the virus only occurs when cotton leaf and virus are supplied together, while in soybean, the time of contact of the virus with the leaf seems to influence, reducing the mortality of the caterpillars. Thus, it would be interesting to study formulations and doses to compensate for the loss of viral activity caused by foliar tissues.
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Descrição morfológica do intestino posterior e comportamento diferencial do reto de Bombyx mori frente ao AlfaBV

Silva, Sóstenez Alexandre Vessaro da 17 October 2013 (has links)
Made available in DSpace on 2017-07-10T14:17:03Z (GMT). No. of bitstreams: 1 sostenez.pdf: 5444547 bytes, checksum: 0e57c73e9d81ba62bd8cce82698d43f6 (MD5) Previous issue date: 2013-10-17 / Bombyx mori nucleopolyhedrovirus (BmNPV) is an entomopathogenic and poliorganotrophic virus that infects Bombyx mori. BmNPV consists of a double strand DNA with two distinct phenotypes: the derived polyhedral virus (PDV), responsible for the primary infection in the insect s midgut; and the budded virus (BV), which disperses the infection in the hemocele, causing secondary or systemic infection. It is extremely virulent and when it infects silkworms, causes serious damages to the insect, usually leading to its death or harming the silk production, affecting all the productive chain, leading to economic losses. For a good silk production, a determinant factor is the functioning of the food duct, which is divided in foregut, midgut and hindgut, being the hindgut the place for water and mineral salts absorption and for the end of the digestive process. Several tissues have been established as virus targets, however, others have shown to be resilient to BmNPV. Given the importance of the hindgut, the present paper aimed to verify the susceptibility of its components, ileum, colon and rectum to an geographic isolated of BmNPV in Paraná, Brasil, the BmMNPV. In different post-inoculation days (dpi), the hindgut segment of 5th instar silkworms was dissected and processed for analysis in light microscopy, using conventional dyes and cytochemistry for viral detection and electronic scanning microscopy for the morphological details. The results revealed that the ileum, colon and rectum of the B. mori are constituted by simple epithelium, with alterations in cell morphology, covered by an intima in its luminal side, and that its organization is similar to that of other described insects. The cytological analysis of the ileum, colon and fore rectum revealed that its epithelial cells are not susceptible to BmMNPV in neither of the times analyzed. However, the posterior hindgut or anal duct showed itself to be susceptible to the virus after the 5º dpi, developing all the classic signs described for the infection with AlphaBV, as the presence of viroplasm, nuclear hypertrophy, polyhedra in formation and mature ones. At the end of the infectious cycle, occurs cell lysis with the liberation of viral polyhedra in the intestinal lumen and, consequently, to the external medium, coinciding with the death of the insect. Even with no infection in the other regions of the hindgut, the surrounding tissues have shown infected, affecting the normal functioning of this intestinal region, verified through changes in fecal pellet, which was less compact and changed format. These results will contribute in the establishment of the BmMNPV infectious cycle. Furthermore, the basic knowledge of viral behavior is important for the development of infection control, prevention and previous identification methods of this disease in the field, once it also makes possible the removal of infected silkworms, diminishing the horizontal transmission of the virus in the creation rooms, in a way to reduce the loss of cocoons to be used in the confection of silk yarn / Bombyx mori nucleopolyhedrovirus multiple (BmMNPV) é um vírus entomopatogênico e poliorganotrófico, constituído por DNA fita dupla e apresenta dois fenótipos distintos: o vírus poliédrico derivado, responsável pela infecção primária no intestino médio do inseto; e o vírus broto, que se dispersa na hemocele causando a infecção secundária ou sistêmica. É extremamente virulento e quando infecta lagartas do bicho-da-seda, causa sérios danos ao inseto, geralmente levando-o à morte ou prejudicando a produção da seda, comprometendo toda a sua cadeia produtiva e gerando prejuízos econômicos. Para uma boa produção de seda, um fator determinante é o funcionamento do canal alimentar, que nos insetos é dividido em anterior, médio e posterior, sendo o posterior, local de absorção de água e sais minerais e da finalização do processo digestório. Vários tecidos já foram estabelecidos como alvos do BmMNPV, entretanto outros se mostraram resistentes. Dada a importância do intestino posterior, o presente trabalho objetivou verificar a susceptibilidade de seus componentes, íleo, cólon e reto de lagartas de B. mori do 5° instar ao BmMNPV isolado geográfico do Paraná. Em diferentes dias pós-inoculação (dpi), o intestino posterior foi dissecado e processado para análise em microscopia de luz, utilizando colorações convencionais e citoquímica para detecção viral, e microscopia eletrônica de varredura, para os detalhes morfológicos. Os resultados revelaram que o íleo, cólon e reto de B. mori apresentou morfologia semelhante a de outros lepidópteros. A análise citopatológica do íleo, cólon e o reto anterior revelou que suas células epiteliais não são susceptíveis ao BmMNPV, em nenhum dos tempos analisados. Já o reto posterior ou canal anal, mostrou-se susceptível ao vírus a partir do 5º dpi, desenvolvendo todos os sinais clássicos descritos para a infecção com o AlphaBV, como presença de viroplasma, hipertrofia nuclear, poliedros em formação e maduros. No final do ciclo infeccioso, ocorre a lise celular com a liberação dos poliedros virais para luz intestinal e, consequentemente, para o meio externo, coincidindo com a morte do inseto. Mesmo não havendo infecção nas demais regiões do intestino posterior, os tecidos circunvizinhos se mostraram infectados, o que possivelmente afetou o funcionamento normal desta região, sendo visíveis as modificações na formação do pellet fecal, que se mostrou menos compacto e com alterações no formato. Os resultados obtidos irão contribuir no estabelecimento do ciclo infeccioso deste patógeno. Além disso, o conhecimento básico do comportamento viral é importante para o desenvolvimento de métodos de controle da infecção, prevenção e identificação prévia desta doença no campo, pois, possibilita ainda, a retirada de lagartas infectadas, diminuindo a transmissão horizontal do vírus nos barracões de criação, de forma a reduzir a perda de casulos, a serem utilizados na confecção dos fios de seda
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Analysis of two D1-like dopamine receptors from the honey bee Apis mellifera reveals agonist-independent activity

Blenau, Wolfgang, Mustard, Julie A., Hamilton, Ingrid S., Ward, Vernon K., Ebert, Paul R., Mercer, Alison R. January 2003 (has links)
Dopamine is found in many invertebrate organisms, including insects, however, the mechanisms through which this amine operates remain unclear. We have expressed two dopamine receptors cloned from honey bee (AmDOP1 and AmDOP2) in insect cells (Spodoptera frugiperda), and compared their pharmacology directly using production of cAMP as a functional assay. In each assay, AmDOP1 receptors required lower concentrations of dopamine and 6,7-ADTN for maximal activation than AmDOP2 receptors. Conversely, butaclamol and cis(Z)-flupentixol were more potent at blocking the cAMP response mediated through AmDOP2 than AmDOP1 receptors. Expression of AmDOP1, but not AmDOP2, receptors significantly increased levels of cAMP even in the absence of ligand. This constitutive activity was blocked by cis(Z)-flupentixol. This work provides the first evidence of a constitutively activated dopamine receptor in invertebrates and suggests that although AmDOP1 and AmDOP2 share much less homology than their vertebrate counterparts, they display a number of functional parallels with the mammalian D1-like dopamine receptors.
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Caracterización biológica y molecular de genes involucrados en la virulencia de baculovirus de importancia agronómica

Salvador, Ricardo January 2010 (has links)
Objetivo general de la tesis: Caracterización biológica y molecular de genes involucrados en la virulencia de baculovirus y utilización de los mismos para el mejoramiento genético de virus de importancia agronómica en nuestro país. Objetivos particulares: • Evaluación de la interacción de los virus de EpapGV y AgMNPV en mezclas virales aplicadas sobre larvas de Anticarsia gemmatalis y Epinotia aporema. • Identificación, clonado, secuenciación y estudio funcional de genes de EpapGV relacionados con la virulencia y con posible actividad potenciadora de la infección. • Generación de virus recombinantes (rAcMNPV y AgMNPV) que expresen genes candidatos para el mejoramiento genético de su eficacia insecticida.

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