Дисертації з теми "Pathogenicity genes"
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Reitmann, Anandi. "Identification of pathogenicity genes in Phytophthora cinnamomi." Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/79179.
Повний текст джерелаNishiyama, Yukihiro. "Herpesvirus Genes: Molecular Basis of Viral Replication and Pathogenicity." 名古屋大学医学部, 1996. http://hdl.handle.net/2237/6180.
Повний текст джерелаHolman, Holly A. "Investigation of ICP34.5 and its role in HSV pathogenicity." Thesis, University of Glasgow, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321914.
Повний текст джерелаFulton, Ciaran Eugene. "The isolation of virulence genes from the ubiquitous plant pathogen, Colletotrichum gloeosporioides." Thesis, Queen's University Belfast, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337296.
Повний текст джерелаJackson, Robert Wilson. "Plasmids and virulence in Pseudomonas syringae pv. phaseolicola." Thesis, University of the West of England, Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389510.
Повний текст джерелаLiddle, Shona. "Strategies for studying pathogenicity genes of Xanthomanas campestris pv. campestris." Thesis, University of East Anglia, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306113.
Повний текст джерелаBesi, Maria. "Identification of novel pathogenicity-related genes in the rice blast fungus, Magnaporthe oryzae." Thesis, University of East Anglia, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.539361.
Повний текст джерелаCouchman, Edward C., Hilary P. Browne, Matt Dunn, Trevor D. Lawley, J. Glenn Songer, Val Hall, Liljana Petrovska, et al. "Clostridium sordellii genome analysis reveals plasmid localized toxin genes encoded within pathogenicity loci." BioMed Central Ltd, 2015. http://hdl.handle.net/10150/610282.
Повний текст джерелаAmmouneh, Hassan. "Molecular characterisation of virulence genes on a pathogenicity island in Pseudomonas savastanoi pv. phaseolicola." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405032.
Повний текст джерелаGamieldien, Junaid. "Novel genomic approaches for the identification of virulence genes and drug targets in pathogenic bacteria." Thesis, University of the Western Cape, 2001. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_4400_1185438906.
Повний текст джерелаWhile the many completely sequenced genomes of bacterial pathogens contain all the determinants of the host-pathogen interaction, and also every possible drug target and recombinant vaccine candidate, computational tools for selecting suitable candidates for further experimental analyses are limited to date. The overall objective of my PhD project was to attempt to design reusable systems that employ the two most important features of bacterial evolution, horizontal gene transfer and adaptive mutation, for the identification of potentially novel virulence-associated factors and possible drug targets. In this dissertation, I report the development of two novel technologies that uncover novel virulence-associated factors and mechanisms employed by bacterial pathogens to effectively inhabit the host niche. More importantly, I illustrate that these technologies may present a reliable starting point for the development of screens for novel drug targets and vaccine candidates, significantly reducing the time for the development of novel therapeutic strategies. Our initial analyses of proteins predicted from the preliminary genomic sequences released by the Sanger Center indicated that a significant number appeared to be more similar to eukaryotic proteins than to their bacterial orthologs. In order determine whether acquisition of genetic material from eukaryotes has played a role in the evolution of pathogenic bacteria, we developed a system that detects genes in a bacterial genome that have been acquired by interkingdom horizontal gene transfer.. Initially, 19 eukaryotic genes were identified in the genome of Mycobacterium tuberculosis of which 2 were later found in the genome of Pseudomonas aeruginosa, along with two novel eukaryotic genes.
Surprisingly, six of the M. tuberculosis genes and all four eukaryotic genes in P. aeruginosa may be involved in modulating the host immune response through altering the steroid balance and the production of pro-inflammatory lipids. We also compared the genome of the H37Rv M. tuberculosis strain to that of the CDC- 1551 strain that was sequenced by TIGR and found that the organisms were virtually identical with respect to their gene content, and hypothesized that the differences in virulence may be due to evolved differences in shared genes, rather than the absence/presence of unique genes. Using this observation as rationale, we developed a system that compares the orthologous gene complements of two strains of a bacterial species and mines for genes that have undergone adaptive evolution as a means to identify possibly novel virulence &ndash
associated genes. By applying this system to the genome sequences of two strains of Helicobacter pylori and Neisseria meningitidis, we identified 41 and 44 genes that are under positive selection in these organisms, respectively. As approximately 50% of the genes encode known or potential virulence factors, the remaining genes may also be implicated in virulence or pathoadaptation. Furthermore, 21 H. pylori genes, none of which are classic virulence factors or associated with a pathogenicity island, were tested for a role in colonization by gene knockout experiments. Of these, 61% were found to be either essential, or involved in effective stomach colonization in a mouse infection model. A significant amount of strong circumstantial and empirical evidence is thus presented that finding genes under positive selection is a reliable method of identifying novel virulence-associated genes and promising leads for drug targets.
Kim, Kwang Hyung. "Functional Analysis of Secondary Metabolite Biosynthesis-Related Genes in Alternaria brassicicola." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/39452.
Повний текст джерелаPh. D.
Kgaladi, Joe. "Pathogenicity and immunogenicity of recombinant rabies viruses expressing the Lagos bat virus matrix and glycoprotein genes." Thesis, University of Pretoria, 2015. http://hdl.handle.net/2263/79257.
Повний текст джерелаThesis (PhD)--University of Pretoria, 2015.
Microbiology and Plant pathology
PhD
Unrestricted
Oliveira, Aline Luísa de. "Relação entre genes plasmidiais e virulência e análise do sistema de secreção tipo 6 em isolados de Escherichia coli patogênica aviária (APEC)." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/119612.
Повний текст джерелаAvian pathogenic Escherichia coli (APEC) causes extraintestinal infections in birds, which can be localized or systemic, known as colibacillosis. The APEC pathotype is still undefined, but several virulence genes are associated with these strains, as the plasmid-linked genes iroN, ompT, hlyF, iss and iutA, proposed in 2008 as APEC virulence predictors. Besides the known virulence genes, other factors may be associated with bacterial pathogenicity, such as the protein secretion machineries called Secretion Systems. Described in 2006, Type 6 Secretion System (T6SS) has been associated with virulence of APEC strains. This work is divided in two parts: the first aimed to evaluate the frequency of iroN, ompT, hlyF, iss and iutA genes in 401 avian strains of E. coli and its relationship with in vivo pathogenicity of these strains. The second part aimed to verify the frequency of T6SS genes (clpV, vgrG, icmF and dotU) in a collection of 187 APEC strains; and verify, in some positive strains, the expression of a phenotype related to the system, as well as the gene expression of effector vgrG and ATPase clpV2, besides the secretion of proteins into the culture medium and during contact with eukaryotic cells. The results of the first part of this study indicate that isolates harboring two or more of the genes analyzed were most likely to be pathogenic than strains harboring only one or none of the genes. The results of the second part show that several strains harbored two copies of at least one of the genes tested, and some of them were resistant to predation by D. discoideum. No differences were found between the expression of genes vgrG (1 and 2) and clpV2 in pure culture or in contact with eukaryotic cells. This work presents the screening of plasmidial genes in a large collection of Escherichia coli isolates, and the first screening of T6SS genes in a collection of APEC isolates.
Islam, Kazi Tariqul. "IDENTIFICATION AND CHARACTERIZATIONS OF PATHOGENICITY GENES IN FUSARIUM VIRGULIFORME, THE CAUSAL AGENT OF SOYBEAN SUDDEN DEATH SYNDROME (SDS)." OpenSIUC, 2015. https://opensiuc.lib.siu.edu/dissertations/1103.
Повний текст джерелаAndersson, Robert. "Characterisation of regulatory genes involved in the control of virulence determinants in Erwinia carotovora subsp. carotovora /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5732-7.pdf.
Повний текст джерелаBetts, Melania Figueroa. "Identification of New Pathogenicity Genes in Magnaporthe Oryzae through the Construction of an Agrobacterium Tumefacines-Mediated Insertion Mutant Library." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/194453.
Повний текст джерелаMansouri, Saara. "IDENTIFICATIN AND CHARACTERIZATION OF PATHOGENICITY GENES IN FUSARIUM VIRGULIFORME, THE CAUSAL AGENET OF SUDDEN DEATH SYNDROME (SDS) IN SOYBEAN." OpenSIUC, 2012. https://opensiuc.lib.siu.edu/dissertations/573.
Повний текст джерелаRojas, Thaís Cabrera Galvão 1980. "Detecção de genes sob seleção positiva em linhagens de Escherichia coli patogênicas para aves (APEC) e para humanos." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317369.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: A bactéria Escherichia coli coloniza o trato intestinal de aves e humanos, de maneira comensal sem causar processos infecciosos. No entanto alguns clones adquiriram fatores de virulência específicos, permitindo o desenvolvimento de diferentes doenças como infecção do trato urinário, diarréia e meningite em humanos e colibacilose em aves. As linhagens que causam doença em aves são tipicamente denominadas APEC (Avian Pathogenic Escherichia coli). Neste trabalho foram sequenciados e anotados os genomas de quatro linhagens APECs (SCI-07, SEPT362, S17 e O8)que, juntamente com mais nove genomas referentes a linhagens de Escherichia coli patogênicas para aves e patogênicas para humanos foram utilizados para a busca de genes sob seleção positiva. Os genes homólogos foram agrupados,e posteriormente submetidos ao alinhamento de códons e das sequencias protéicas correspondentes. Uma árvore filogenética foi gerada para cada grupo de proteínas homólogas. Testes estatísticos determinaram qual entre os modelos de seleção neutra ou seleção positiva melhor explicou os dados existentes (alinhamentos de códons e árvores filogenéticas). Essas análises detectaram duzentas e cinquenta e quatro grupos de genes homólogos com evidência de seleção positiva. Para cada grupo foi realizado um teste de recombinação para verificar se o aumento na variação das sequencias não era devido à conversão gênica, resultando em cento e dezesseis grupos de genes homólogos sob seleção positiva. A proteína correspondente a um gene de cada grupo de genes homólogos foi identificada, por meio da ferramenta Blast. Diversos fatores de virulência, já conhecidos, e proteínas regulatórias puderem ser detectados. Os genes sob seleção positiva, também foram submetidos à anotação considerando o termo GO (Gene Ontology),apenas da categoria processo biológico. Dos cento e dezesseis genes apenas cinquenta e sete puderam ser identificados por meio dessa metodologia. O resultado da classificação dos genes dentro da classe GO, considerando o terceiro nível hierárquico,mostrou que a maioria dos genes anotados (31) tinha relação com o metabolismo primário.As proteínas cuja identificação, por meio do blast, não foi possível (proteínas hipotéticas)foram submetidas à análise de predição de localização subcelular e de peptídeo sinal. Essas análises revelaram que três proteínas desconhecidas (hypothetical proteinECIAI39_1028, hypothetical proteinZ0639e hypothetical proteinEC042_3791) são potenciais alvos para estudos que visam à busca de novos fatores de virulência de Escherichia coli patogênicas
Abstract: The bacterium Escherichia coli colonizesthe intestinal tract of birds and humans, in a commensal relationship without causing infection. However, some clones have acquired specific virulence factors allowing the development of various diseases such as urinary tract infection, diarrhea and meningitis in humans and colibacillosis in poultry. The strains that cause disease in birds are typically named APEC (Avian Pathogenic Escherichia coli). In this study we sequenced and annotated the genomes of four APECs strains (SCI-07, SEPT362, S17 and O8). These genomes and nine others avian pathogenic Escherichia coli and humans pathogenic strains genomes were used for studying genes under positive selection. The homologous genes were grouped and then subjected to codons and corresponding protein sequences alignment. A phylogenetic tree was generated for each group of homologous proteins. Statistical tests determined which among neutral or positive selection models best explains the existing data (codon alignments and phylogenetic trees). This analyzes detected two hundred fifty-four groups of homologous genes with positive selection evidence. For each group a recombination test was conducted to verify if the variation increase in the sequences was not due to gene conversion, resulting in one hundred and sixteen groups of homologous genes under positive selection. The protein corresponding to a gene of each group of homologous genes under positive selection was identified through Blast tool. Genes under positive selection were annotated considering the GO term (Gene Ontology), just for the biological process category. Only fifty-seven genes could be identified using this methodology. The gene classification within the GO classes, considering only the third hierarchical level showed that most of the annotated genes (31) were related with the primary metabolism. Proteins which blast identification was not possible (hypothetical proteins) were subjected to sub cellular localization and signal peptide prediction analyzes. These analyzes revealed that three unknown proteins (hypothetical protein ECIAI39_1028, hypothetical protein Z0639e hypothetical protein EC042_3791) are potential targets for studies, in order to search for new virulence factors of pathogenic Escherichia coli
Doutorado
Microbiologia
Doutora em Genética e Biologia Molecular
Guilhabert, Magalie. "Development of molecular genetic systems for identifying pathogenicity genes in Xylella fastidiosa, the bacterial pathogen causing Pierce's disease of grapevines /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.
Повний текст джерелаMain-Hester, Kara L. "Counter-silencing of laterally acquired genes, including Salmonella Pathogenicity Island 4, by three DNA binding proteins, HilA, HilD, and SlyA /." Thesis, Connect to this title online; UW restricted, 2008. http://hdl.handle.net/1773/11498.
Повний текст джерелаFunnell, Deanna Lillian. "The inheritance of pathogenicity genes in Nectria haematococca mating population VI and the association of virulence of pea with dispensable chromosomes." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/288699.
Повний текст джерелаBarbosa, Fernanda de Oliveira [UNESP]. "Importância dos genes fliC e motB de Salmonella enterica subsp. enterica sorovar Enteritidis na colonização intestinal e invasão sistêmica em aves (Gallus gallus domesticus)." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/137909.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Salmonella Enteritidis (SE) causa o paratifo aviário em aves e frequentemente está relacionada aos surtos de infecção alimentar em seres humanos. A contribuição do flagelo versus motilidade na interação patógenohospedeiro requer estudos mais aprofundados. Para melhor entendimento da contribuição individual desses fatores de virulência em aves, pintinhos de um dia de vida foram desafiados oralmente com estirpe selvagem de SE, uma mutante não-móvel mas flagelada (SE ΔmotB) e outra mutante aflagelada (SE ΔfliC). Excreção fecal e colonização de fígado, baço e conteúdo cecal pelas estirpes de SE foram avaliadas. Além disso, também foi realizada a avaliação das alterações macroscópicas e microscópicas. Nos estágios iniciais da infecção, ambos mutantes mostraram menor capacidade de colonizar o ceco, além de menor recuperação no baço por SE ΔfliC comparando a estirpe selvagem SE. Após 7 dpi não havia diferenças na contagem das três estirpes em conteúdo cecal, fígado e baço. Análises histopatológicas demonstraram que estirpes flageladas (SE ΔmotB e SE) induziram reatividade linfóide em inglúvio, ceco, íleo e fígado. No entanto, nos estágios iniciais da infecção a estirpe SE ΔfliC não estimulou a reatividade linfóide em lâmina própria de ceco e íleo mas induziu discretos focos necróticos em fígado. Portanto, neste estudo a presença de estrutura flagelar e motilidade parece exercer um papel nos estágios iniciais da colonização intestinal e infecção sistêmica por SE nas aves.
Salmonella Enteritidis (SE) causes fowl paratyphoid in poultry often related to outbreaks of food-borne diseases in humans. The contribution of flagella and motility in host pathogen interaction require further investigation. To better understand the individual contribution of these virulence factors in poultry, one day old chickens were challenged orally with wildtype strain of SE, a nonmotile but fully flagellated (SE ΔmotB) and aflagellated mutant (SE ΔfliC). Faecal excretion and colonization of liver, spleen and cecal contents by the SE strains were assessed. Additionally, the assessment of gross and microscopic alterations was also performed. At the early stages of infection both mutants showed lower capacity to colonize the ceca, besides the lower recovering in spleen of SE ΔfliC comparing to the wild type of SE. After 7 dpi there were no differences among the counts of the three strains in ceca, liver and spleen. Histopathological analyses demonstrated that flagellated strains (wild type SE and SE ΔmotB) induced lymphoid reactivity in crop, ceca, ileum and liver. On the other hand, in the early stages of infection, SE ΔfliC strain did not stimulate lymphoid reactivity in lamina propria of ceca and ileum but induced discrete necrotic foci in liver. Thus in the present study the flagellar structure and motility seemed to play a role at the early stages of the intestinal colonization and systemic infection by SE in the chicken.
FAPESP: 2014/02014-1
Pace, Fernanda de 1981. "Estudo de genes do Sistema de Secreção tipo VI em uma linhagem de Escherichia coli patogênica para aves (APEC)." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317391.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Linhagens de Escherichia coli patogênica para aves (APEC) causam infecções extraintestinais e são responsáveis por significativas perdas econômicas na indústria avícola mundial. Recentemente, foram descritos isolados de APEC geneticamente relacionados a diversas outras E.coli extraintestinais (ExPEC) de origem humana, indicando a possibilidade das mesmas constituírem risco zoonótico para humanos. Alguns dos conhecidos fatores de virulência de APEC incluem adesinas, sistema de aquisição de ferro, citotoxinas, entre outros. Nesse trabalho, demonstramos que a linhagem de APEC SEPT 362, isolada do fígado de uma ave apresentando sinais clínicos de septicemia, expressa o Sistema de Secreção Tipo VI (SST6), causa rearranjo do citoesqueleto de células epiteliais cultivadas in vitro, é capaz de aderir e invadir células HeLa e é viável dentro de macrófagos. Para estudar o envolvimento do SST6 na patogênese da linhagem SEPT362, foram deletados três genes desse sistema: hcp, que codifica para uma proteína estrutural e secretada, clpV, que codifica para uma ATPase e icmF (intracellular multiplication factor), gerando três mutantes, respectivamente. Todos os mutantes demonstraram uma diminuição nos processos de adesão e invasão a células HeLa, formação de biofilme e virulência in vivo. Estudos de transcriptoma mostraram que a expressão da fímbria tipo 1 encontra-se diminuída nesses mutantes, o que poderia ser responsável pela diminuição do processo de adesão e invasão às células epiteliais. Nesse trabalho, demonstramos que o SST6 é importante para o processo de patogenicidade, visto que todos os mutantes tiveram sua virulência atenuada em experimentos realizados in vivo com uma significativa diminuição de características relacionadas à patogenicidade in vitro. Esses resultados demonstram que os genes estudados do SST6 influenciam a expressão da fímbria tipo 1 e contribuem para a patogênese desta linhagem APEC
Abstract: Avian pathogenic Escherichia coli (APEC) strains frequently cause extraintestinal infections and are responsible for significant economic losses in the poultry industry worldwide. APEC isolates are closely related to human extraintestinal pathogenic E. coli (ExPEC) strains and may also act as pathogens for humans. Known APEC virulence factors include adhesins such as type 1 fimbriae and curli, iron acquisition systems, and cytotoxins, among others. Here we demonstrated that APEC strain SEPT362, isolated from a septicemic hen, expresses a type VI secretion system (T6SS), causes cytoskeleton rearrangements, invades epithelial cells, replicates within macrophages, and causes lethal disease in chicks. To assess the contribution of the T6SS to SEPT362 pathogenesis, we generated three mutants, ?hcp (which encodes a protein suggessed to be both secreted and a structural component of the T6SS), ?clpV (encoding the T6SS ATPase) and ?icmF (intracellular multiplication factor). All mutants showed decreased adherence and invasion to HeLa cells and decrease in several other pathogenicity related characteristics. Transcriptome studies showed that the level of expression of type 1 fimbriae was decreased in these mutants, which may account for the diminished adhesion and invasion of epithelial cells. The T6SS seems to be important for the disease process, given that both mutants (?hcp and ?clpV) were attenuated in an infection model in chicks. These results suggest that the T6SS influences the expression of type 1 fimbriae and contributes to the pathogenesis of this APEC strain pathogenesis
Doutorado
Genetica de Microorganismos
Doutor em Genetica e Biologia Molecular
Hoppenau, Clara Elisabeth [Verfasser], Gerhard [Akademischer Betreuer] Braus, and Ursula [Akademischer Betreuer] Kües. "Characterization of the pathogenicity relevant genes THI4 and PA14_2 in Verticillium dahliae / Clara Elisabeth Hoppenau. Gutachter: Gerhard Braus ; Ursula Kües. Betreuer: Gerhard Braus." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2014. http://d-nb.info/1047706857/34.
Повний текст джерелаScarpari, Leandra Maria. "Modulação da expressão de genes de patogenicidade putativos em Xylella fastidiosa sob condições de baixa e alta densidade celular." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/11/11138/tde-18062002-093603/.
Повний текст джерелаXylella fastidiosa (Xf) is the causal agent of several economically important plant diseases. Recently, Xf has been identified as the causal agent of citrus variegated chlorosis (CVC), a disease that represents a major economic problem for citrus growers in the São Paulo State. Xf is a gram-negative, fastidious and xylem-limited bacterium. Based on the fact that plants may show disease symptoms a long time after infection in Xf-citrus interaction, we hypothesize that the expression of pathogenicity/virulence factors in Xf occurs after the bacterial population reach high cell densities. Since pathogenicity/virulence factors of some bacteria are quorum-sensing regulated, it would be interesting to determine whether this mechanism of genetic regulation occurs in Xf, and which genes are regulated by cell-density. In order to determine whether Xf putative pathogenesis-related genes are modulated by cell-density in culture media, Xf was grown in liquid PW and cells were sampled at early log (low cell density) and stationary phase (high cell density) and total RNA was extracted. Fragmentos of 20 putative pathogenicity-related genes from Xf were hybridized on ordered arrays nylon membranes to alkaline phosphatase-labeled first strand cDNA from low and high celldensity conditions as probes, at high stringency conditions. Detection was performed using chemiluminescence. Our results indicate that the following putative pathogenicity-related genes are significantly suppressed (p < 0.05) at high cell-density conditions: fur (XF-2344), gumC (XF-2369), serine-protease (XF-1851) and rsmA (XF-0125). The expression of rpfF (XF-1115) was significantly induced (p < 0.06) at high cell-density conditions. Expression of gumD (XF-2367), gumJ (XF-2362) and rpfA (XF-0290) was detected only at high cell-density conditions, whereas expression of rpfB (XF-0287) was detected only at low cell-density conditions. The expression of cellulase (XF0818), mdoH (XF-1623), pluxR (XF-0972), protease-RE (XF-1823), rpoN (XF-1408), xpsK (XF-1523) and xpsL (XF-1524) was not affected by the Xf population density in PW medium, whereas expression of luxR/UHPA (XF-2608), polygalacturonase (XF-2466), rpfC (XF-1114) and rsmB (XF-0928) was not detected under our experimental conditions. Using RT-PCR, transcripts for all genes, except gumC, were detected under low or high cell densities, indicating that the expression of some putative pathogenesis-related genes in culture medium is very low. Our results suggest that EPS may be synthesized by Xf mainly at high cell density conditions in PW medium. Additionally, our data suggest that Xf may synthesize a signal molecule similar to the Xcc in PW medium at high cell density conditions, and that iron availability may be important for gene regulation at high cell density conditions. It is possible that gene expression patterns observed under our experimental conditions may be altered with the culture medium used or when Xf grows in planta.
Pope, David D. "A biometrical study of the effect of nonspecific pathogenicity genes on host and pathogen fitness related characters in the Ustilago hordei-Hordeum vulgare system." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/27187.
Повний текст джерелаScience, Faculty of
Botany, Department of
Graduate
Lee, Nakhyung. "Characterization of an ATP-binding cassette (ABC) transport system involved in nucleoside uptake in Mycoplasma bovis strain M23, and discovery of its pathogenicity genes." [Ames, Iowa : Iowa State University], 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3373444.
Повний текст джерелаRezende, Janayne Maria. "Diversidade filogenética e expressão de genes de virulência de Metarhizium com ênfase em isolados brasileiros associados a cultura da cana-de-açúcar." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-04022015-151555/.
Повний текст джерелаBiological control of spittlebug with Metarhizium (Hypocreales: Clavicipitaceae) in sugarcane is an example of the successful application of sustainable pest management in Brazil. However little is known about the richness, distribution and ecology of Metarhizium species in agroecosystems and natural environments of Brazil. In this study, the genotypic diversity was accessed and species designation was assigned for 96 Metarhizium strains deposited in the Collection of Entomopathogens \"Prof. Sérgio Batista Alves\" from ESALQ-USP using the sequence variation at 5\'-TEF and the nuclear intergenic loci MzFG543igs and MzIGS3. Sequence diversity at these loci included 10, 11 and 17 sequence haplotypes, according to these loci, respectively. 41 strains were recovered from two sugarcane fields and consisted of 9 haplotypes according to MzIGS3. Five species of Metarhizium were observed, being the two most abundant taxa, Metarhizium anisopliae, Metarhizium robertsii and an additional three taxonomically unassigned lineages are referred to here as Metarhizium sp. indet. 1, Metarhizium sp. indet. 2 and Metarhizium sp. indet. 3. With a single exception, all strains isolated from insects belong to single clade of M. anisopliae, including the isolates infecting spittlebugs in sugarcane agroecosystems. M. robertsii was only recovered from soil or rhizosphere samples. Despite providing a greater degree of genetic resolution among strains, MzIGS3 revealed the inability to recapitulate the consensus phylogeny for the PARB clade and complicates its use as a stand-alone tool for species identification or phylogenetic analysis of Metarhizium. In addition, a laboratory bioassay technique was developed for pathogenicity screening of Metarhizium spp. on M. fimbriolata with low mortality on control group (8-12%) after 28 days of evaluation. The expression of genes pr1A, Mad1 and mpl of three M. anisopliae strains (ESALQ 1037, ESALQ1204 and ESALQ 1641) grown in minimal medium and minimal medium with M. fimbriolata, D. saccharalis or T. molitor cuticle apparently was not related to virulence of the fungi in vivo. Together these data will serve as resources for identification, discovery and communicating about Metarhizium biodiversity for insect biological control applications in Brazil and adjacent countries in South America, as well as assist in the ongoing development and monitoring of the biological control program of M. fimbriolata with Metarhizium in sugarcane fields.
Muñoz, Bodnar Alejandra. "Function of TALE1Xam in cassava bacterial blight : a transcriptomic approach." Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20009.
Повний текст джерелаXanthomonas axonopodis pv. manihotis (Xam) is a gram negative bacteria causing the Cassava Bacterial Blight (CBB) in Manihot esculenta Crantz . Cassava represents one of the most important sources of carbohydrates for around one billion people around the world as well as a source of energy due to its high starch levels content. The CBB disease represents an important limitation for cassava massive production and little is known about this pathosystem. Bacterial pathogenicity often relies on the injection in eucaryotic host cells of effector proteins via a type III secretion system (TTSS). Between all the type III effectors described up to now, Transcription Activator-Like Type III effectors (TALE) appear as particularly interesting. Once injected into the plant cell, TAL effectors go into the nucleus cell and modulate the expression of target host genes to the benefit of the invading bacteria by interacting directly with plant DNA. In Xam, only one gene belonging to this family has been functionally studied so far. It consists on TALE1xam. This work aim to identify cassava genes whose expression will be modified upon the presence of TALE1xam. By means of cassava plants challenged with Xam Δ TALE1xam vs. Xam + TALE1xam together with the TAL effectors code, statistical analyses between RNAseq experiments and a microarray containing 5700 cassava genes, we seek out direct TALE1xam target genes. Hence, through transcriptomic, functional qRT validation and specific artificial TALEs design we proposed that TALE1xam is potentially interacting with a Heat Shock Transcription Factor B3. Moreover we argue that this gene is responsible of the susceptibility during Xam infection. Furthermore this work represents the first complete transcriptomic approach done in the cassava/Xam interaction and open enormous possibilities to understand and study CBB
Beinhoff, Malte Verfasser], Petr [Akademischer Betreuer] Karlovsky, Andrea [Akademischer Betreuer] Polle, and Heiko [Akademischer Betreuer] [Becker. "Molecular and functional characterization of potential pathogenicity related genes from Verticillium longisporum / Malte Beinhoff. Gutachter: Petr Karlovsky ; Andrea Polle ; Heiko C. Becker. Betreuer: Petr Karlovsky." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2012. http://d-nb.info/1043765417/34.
Повний текст джерелаPadilla, Sirera Natàlia. "Novel approaches for in silico identification of pathogenic variants in BRCA1 and BRCA2 hereditary breast and ovarian cancer predisposition genes." Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/670705.
Повний текст джерелаVariantes germinales en las proteínas BRCA1 y BRCA2 pueden alterar la función protectora de estas en el ADN, incrementando el riesgo de desarrollar cáncer de mama y ovario hereditario (HBOC). Identificación de aquellos individuos portadores de variantes patogénicas permite canalizarlos hacia programas específicos de prevención y vigilancia, aumentando sus tasas de supervivencia. Para ello, en primer lugar, es necesario identificar cuáles de las variantes son patogénicas. Desafortunadamente, no siempre hay suficiente información para llegar a una conclusión. En esta situación, los predictores de patogenicidad diseñados para estimar computacionalmente el daño causado por las variantes pueden proporcionar una valiosa información. En este trabajo presentamos una nueva familia de predictores de patogenicidad para BRCA1 y BRCA2. Estos predictores difieren en su objetivo: uno está entrenado para estimar el impacto molecular de las variantes en la función HDR de BRCA1 y BRCA2, y el otro está entrenado para estimar la significancia clínica de una variante, es decir, si su clasificación es patogénica o neutra. Sus rendimientos han sido probados y son comparables a los de los métodos ampliamente utilizados en el campo. Además, presentamos los predictores al desafío ENIGMA de la 5ª Evaluación Crítica de la Interpretación del Genoma (CAGI), encontrando que nuestros métodos, especialmente aquellos que estiman el impacto funcional de las variantes, se clasifican en las primeras posiciones en comparación con las otras herramientas. Para difundir esta familia de predictores a la comunidad científica, hemos construido el sitio web BRASS (https://www.biotoclin.org/BRASS), donde los usuarios pueden analizar sus variantes de BRCA1 y BRCA2 con cambio de sentido. Los usuarios más avanzados también pueden interpretar las predicciones utilizando una métrica de confiabilidad y varios gráficos que contextualizan su puntuación a la de un conjunto de variantes seleccionadas manualmente. De forma independiente, aplicamos nuestro conocimiento sobre los predictores de patogenicidad en un gran proyecto internacional para caracterizar un nuevo trastorno neurológico pediátrico causado por variantes patogénicas en la histona H3.3. Combinamos el uso de predictores patogénicos estándar con evidencia de análisis estructurales y cálculos biofísicos para proporcionar una visión mecanicista del impacto de las variantes causales.
Germline variants in BRCA1 and BRCA2 can disrupt the DNA protective role of these proteins resulting in an increased risk of developing hereditary breast and ovarian cancer (HBOC). Identification of those individuals carrying pathogenic variants will allow channeling them into specific programs of prevention and surveillance, incrementing their survival rates. For this purpose, first, it is necessary to identify which of the variants are pathogenic. Unfortunately, there is not always enough information to reach a conclusion. In this situation, pathogenicity predictors designed to computationally estimate the damage caused by variants, can provide valuable information. Here, we present a novel family of pathogenicity predictors for BRCA1 and BRCA2. These predictors differ in their objective: one is trained to estimate the molecular impact of variants on the HDR function of BRCA1 and BRCA2, and the other is trained to estimate the clinical significance of a variant, that is, whether it should be classified as pathogenic or neutral. Their performances have been tested and are comparable to those of widely used predictors in the field. Additionally, we presented them to the ENIGMA challenge from the 5th Critical Assessment of Genome Interpretation (CAGI), finding that our predictors, especially those estimating the functional impact of variants, ranked in the top positions compared to other tools. In order to disseminate this family of predictors to the scientific community, we have built the BRASS website (https://www.biotoclin.org/BRASS), where users can analyze their missense BRCA1 and BRCA2 variants. More advanced users can also interpret the predictions using a reliability metric and several plots contextualizing the score to that of a set of manually curated variants. Independently, we applied our knowledge about pathogenicity predictors in a large international effort to characterize a novel pediatric neurologic disorder caused by pathogenic variants in histone H3.3. We combined the use of standard pathogenic predictors with evidence from structural analyses and biophysical computations to provide a mechanistic view of the impact of the causative variants.
Cabral, Ana Cristina Garcia Pereira. "New insights in Ilyonectria black foot disease of grapevine." Doctoral thesis, ISA/UTL, 2012. http://hdl.handle.net/10400.5/5192.
Повний текст джерелаConsidering the growing importance of black foot disease of grapevine, this study was aimed to deeply understand details on taxonomy, genetics, biology and pathological behaviour of its main causal agents, previously attributed mostly to Ilyonectria liriodendri and I. macrodidyma. A multi-gene analysis of a collection of Ilyonectria isolates, along with morphological characterisation, enabled the description of 12 species from I. radicicola and four from I. macrodidyma complexes. Among these, pathogenicity experiments revealed I. lusitanica, I. estremocensis and I. europaea as more virulent to grapevine than I. liriodendri and I. macrodidyma. The entire mating-type loci of I. liriodendri and of species from the I. macrodidyma complex were obtained. While the idiomorph structure of species from the latter matches that of other heterothallic Hypocreales, the organization of the mating-type loci in I. liriodendri seems unique, suggesting a potential pseudo-heterothallism. Soilborne inoculum is accepted to contribute significantly to initiate black foot disease in grapevine plants. qPCR amplification from DNA soil samples demonstrate that rotation can reduce the levels of Ilyonectria in nurseries, and that levels of infestation in vineyard soils are lower than in nursery or mother-plant soils. Additionally, a protoplast transformation protocol is presented for the stable integration of the GFP gene in the genome of I. liriondendri, enabling future downstream functional genetic studies.
Xu, Hai Quan [Verfasser], Petr [Akademischer Betreuer] Karlovsky, and Andreas von [Akademischer Betreuer] Tiedemann. "Determination of fungal gene expression in planta by qRT-PCR and characterization of putative pathogenicity related genes of Verticillium longisporum / Hai Quan Xu. Gutachter: Andreas von Tiedemann ; Petr Karlovsky. Betreuer: Petr Karlovsky." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://d-nb.info/1044249463/34.
Повний текст джерелаMerighi, Massimo. "Molecular biology and biochemistry of regulation of Hrp/type III secretion genes in the corn pathogen Pantoea stewartii pv. stewartii." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1069854564.
Повний текст джерелаDocument formatted into pages; contains xxxiii, 421 p. Includes bibliographical references. Abstract available online via OhioLINK's ETD Center; full text release delayed at author's request until 2005 Dec. 2.
Lucas, Darren Edward. "Coordinated Regulation of Salmonella Virulence Genes by the BarA/SirA Two-Component System and the Csr Global Regulatory System." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1374087620.
Повний текст джерелаPaiva, Jacqueline Boldrin de 1984. "Mutagênese sítio-dirigida em uma linhagem de Escherichia coli (APEC) causadora de síndrome da cabeça inchada em aves = análises in vitro e in vivo." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317392.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Escherichia coli patogênica para aves (APEC) é responsável por inúmeras perdas no setor avícola mundial, por causar uma série de doenças nas aves que se apresentam de forma sistêmica ou localizada as quais são, coletivamente, denominadas colibacilose. Os mecanismos de virulência destas linhagens patogênicas para aves e, possivelmente, patogênicas para seres humanos ainda não foram totalmente elucidados. Este trabalho foi desenvolvido com o intuito de estudar genes possivelmente envolvidos com a patogenicidade de uma linhagem APEC causadora de Síndrome da Cabeça Inchada (SCI-07) ONT:H31, a partir de resultados obtidos em um microarranjo realizado in vitro, o qual comparou a linhagem em estudo à linhagem padrão E. coli EHEC 8624 (linhagem enterohemorrágica). Nove genes, detectados como sendo super-expressos no microarranjo, nas condições estudadas, foram selecionados para construção de mutantes nulos e de seus complementos [feoA (transporte de ferro), nirC (transportador de nitrito), flgE ( gancho flagelar), tyrR (regulador de transcrição da síntese de aminoácidos aromáticos), potF (subunidade periplasmática do transportador putrescina), yehD (possível fimbria), bfr (bacterioferrina), csgA ( subunidade principal da curlina) e entD (enteroquelina)]. Os mutantes construídos foram avaliados quanto as suas capacidades de adesão e invasão em cultivos celulares, e quanto ao seu potencial patogênico em aves de um dia de idade em comparação à cepa selvagem. As linhagens ?bfr, ?csgA e ?nirC apresentaram diminuição da capacidade de adesão em fibroblastos de aves (linhagem FEG) em comparação à linhagem selvagem em ambos os modelos adotados: na presença e ausência de alpha-D-mannopyranoside; a linhagem ?potF apresentou diminuição da adesão apenas na ausência de alpha-D-mannopyranoside. Os mutantes ?csgA e ?tyrR apresentaram redução na capacidade de invadir linhagem de células de trato respiratório humano (linhagem Hep-2). Nenhum mutante avaliado mostrou alteração na capacidade de invadir fibroblastos de aves (linhagem CEC-32). Os mutantes ?flgE e ?tyrR mostraram diminuição na capacidade de invadir e sobreviver em macrófagos de aves (linhagem HD11). A motilidade das linhagens mutantes ?csgA, ?bfr, ?yehD, ?potF, ?entD, ?nirC e ?feoA foi aumentada enquanto o mutante ?tyrR mostrou redução de motilidade e o mutante ?flgE tornou-se imóvel. Nenhuma linhagem mutante obtida mostrou a mesma capacidade da linhagem selvagem em causar mortalidade em aves de um dia; ?feoA tornou-se hipervirulenta e todos os demais mutantes apresentaram atenuação em diferentes graus, sendo a linhagem ?entD totalmente atenuada e, portanto, promissora quanto ao seu uso como linhagem vacinal.para o combate à colibacilose em aves, ou como linhagem carreadoras de epítopos presentes em outras linhagens APEC
Abstract: Avian Pathogenic Escherichia coli (APEC) is responsible for significant economic loses in the poultry industry worldwide, by cause a range of systemic or localized diseases in poultry collectively termed colibacillosis. The virulence mechanisms of these pathogenic strains for poultry and possibly pathogenic for humans have not been fully elucidated. This work was developed in order to study genes potentially involved in the pathogenicity of an APEC strain isolated from a Swollen Head Syndrome case (SCI- 07) ONT:H31; since the results obtained in a microarray performed in vitro, which compared the SCI-07 strain to the standard strain E. coli 8624 EHEC (enterohemorrhagic strain). Nine overexpressed genes in microarray under the conditions studied were selected for construction of null mutants and their complements [feoA (iron transport), nirC (nitrite transporter), flgE (flagellar hook), tyrR (transcriptional regulator of the aromatic amino acids biosynthesis), potF (periplasmic putrescine transporter subunit), yehD (putative adhesin), bfr (bacterioferritin), csgA (major curling subunit) and entD (enterochelin)]. The mutants constructed were evaluated for their capacity for adhesion and invasion in cell cultures, and for its pathogenic potential in one-day-old chickens in comparison to the wild type strain (WT). The ?bfr, ?csgA and ?nirC strains showed decreased adhesion capacity on avian fibroblasts (CEF cells) compared to the WT in both models adopted: in the presence and absence of alpha-D-mannopyranoside, the ?potF strain showed decrease on adhesion only in the absence of alpha-D-mannopyranoside. The ?csgA and ?tyrR mutants had reduced ability to invade human larynx cell line (Hep-2 cells). No mutant showed changes in the capacity of invade avian fibroblasts birds (CEC-32cells). The ?flgE and ?tyrR mutants showed decreased ability to invade and survive into avian macrophages (HD11 cells). The motility of mutant strains ?csgA, ?bfr, ?yehD, ?potF, ?entD, ?nirC and ?feoA was increased while the ?tyrR mutant showed reduced motility and the mutant ?flgE became nonmotile. No mutant strain showed the same capacity of the WT in cause mortality in one-day-old chickes; ?feoA became hipervirulenta and all other mutants showed attenuation in different degrees, including the ?entD that was completely attenuated and a promising vaccine candidate strain to combat colibacillosis in poultry, or as a carrier strain of epitopes present in other APEC strains
Doutorado
Genetica de Microorganismos
Doutora em Genética e Biologia Molecular
Ferreira, Gerson Moura. "Regulação da adesão de Escherichia coli enteropatogênica (EPEC) por genes de resposta à limitação nutricional e estresse." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/42/42132/tde-02122009-125957/.
Повний текст джерелаEnteropathogenic E. coli (EPEC) is one of the causes of diarrhea in children. Phosphate (Pi) shortage induces transcription of the genes known as the PHO regulon. These genes are controlled by the Pst system, that is also a high-affinity Pi transporter, and represses PHO expression under Pi-replete conditions. PHO is also controlled by the two-component system PhoB/PhoR. Deletion of the pst operon reduced the adhesion of EPEC to epithelial cells in vitro due to a decrease in the expression of the regulators PerA and PerC that in turn control the expression of genes related to adhesion. The constitutive expression of the PHO genes in the pst mutant was not the cause of adhesion inhibition. Expression of bfp and the regulators PerA and PerC was also dependent on ppGpp, an alarmone involved in the regulation of genes related to nutrient limitation. On the other hand, RpoS, the factor that controls the general stress response, negatively affected EPEC adhesion and bfpA expression.
Jansson, Désirée S. "Genus Brachyspira in birds : phenotypes, phylogeny and pathogenicity /." Uppsala : Dept. of Clinical Sciences, Swedish University of Agricultural Sciences, 2009. http://epsilon.slu.se/200914.pdf.
Повний текст джерелаGarosi, Paola. "A study of gene expression in the take-all fungus Gaeumannomyces graminis." Thesis, University of East Anglia, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267543.
Повний текст джерелаHeckel, Thierry. "Pathogenicity determinants and gene expression of maize streak virus." Thesis, University of East Anglia, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338099.
Повний текст джерелаAllen, Caitilyn. "Evolution of a gene for pathogenicity: endo-pectate lyase." Diss., Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/82610.
Повний текст джерелаPh. D.
Slater, Holly. "The regulation of pathogenicity gene expression in Xanthomonas campestris mediated by a small diffusible molecule." Thesis, University of East Anglia, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301935.
Повний текст джерелаKim, Vic Narry. "Analysis of components of HIV in the development of new gene transfer systems." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389043.
Повний текст джерелаBeacham, Andrew Mark. "Pathogenicity determinants of Fusarium graminearum on wheat ears." Thesis, University of Exeter, 2011. http://hdl.handle.net/10036/3035.
Повний текст джерелаSheikh, Md Arif. "Structural biology of Vibrio cholerae pathogenicity factors." Thesis, St Andrews, 2009. http://hdl.handle.net/10023/696.
Повний текст джерелаSoanes, Darren Mark. "Regulation of the pathogenicity gene MPG1 in the rice blast fungus Magnaporthe grisea." Thesis, University of Exeter, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368367.
Повний текст джерелаMohmad, Mahyudin Murnita Binti. "Agrobacterium-mediated transformation of Corynespora cassiicola as a tool for pathogenicity gene discovery." Thesis, University of Bristol, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.707740.
Повний текст джерелаCunnac, Sébastien. "Identification à l'échelle génomique des effecteurs dépendant du système de sécrétion de type III de la bactérie phytopathogène Ralstonia solanacearum." Toulouse 3, 2004. http://www.theses.fr/2004TOU30197.
Повний текст джерелаRalstonia solanacearum is the causal agent of bacterial wilt disease. Hrp genes encode a type III protein secretion apparatus that allows virulence effectors injection into the host plant cell. The regulatory gene hrpB controls expression of the structural components of the secretion machinery as well as its substrates. Characterization of the mode of action of HrpB allowed the definition of the hrpII box, a conserved cis-operator motif required for activity of the promoters belonging to this regulon. A search for this motif on R. Solanacearum GMI1000 genome sequence produced a list of 114 candidate genes. The next step involved the functional analysis of a group of these candidate genes : 48 of them were shown to belong to the hrpB regulon. Nine brg (hrpB-regulated genes) are homologous to known type III effectors from other plant pathogenic bacteria. The remaining 31 brg encode unknown or hypothetical proteins harbouring a putative type III-translocation signal. Hrp-dependent translocation into plant cells was confirmed for five candidate proteins. Only a few of the insertion mutants generated displayed an altered virulence when tested onto two host species. Finally, we identified and characterized the avrA gene which is necessary for elicitation of the hypersensitive response on some Nicotiana species. Altogether, these data suggest that R. Solanacearum genome contains a large type III effector repertory (50 to 70). Understanding their relative contribution to R. Solanacearum pathogenicity will await future elucidation of their molecular activity on the plant cell metabolism
Meyer, Tanja. "Agrobacterium tumefaciens-mediated transformation of Fusarium oxysporum f. sp. cubense for pathogenicity gene analysis." Diss., University of Pretoria, 2008. http://hdl.handle.net/2263/25473.
Повний текст джерелаDissertation (MSc)--University of Pretoria, 2008.
Microbiology and Plant Pathology
unrestricted
Meyer, Tania. "Agrobacterium tumefaciens-mediated transformation of Fusarium oxysporum f. sp. cubense for pathogenicity gene analysis." Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-06122009-132700/.
Повний текст джерела