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Etude fonctionnelle de Pacmmar1, élément transposable de type mariner isolé chez le crabe Pachygrapsus marmoratusDelaurière, Laurence Chenais, Benoît. Casse, Nathalie January 2008 (has links) (PDF)
Reproduction de : Thèse de doctorat : Biophysiologie des organismes et des populations : Le Mans : 2008. / Titre provenant de l'écran-titre. Bibliogr. p.168-186.
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Transposon Tn5 proteins and DNA sequences required for its transposition and control /Johnson, Reid Colt. January 1983 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
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A structural and functional analysis of transposon Tn602Stibitz, Earle Scott. January 1983 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. Description based on print version record. Includes bibliographical references.
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Gene organization in transposons Tn5 and Tn10Jorgensen, Richard A. January 1978 (has links)
Thesis--University of Wisconsin--Madison. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
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Molecular analysis of hobo and Himar 1 transpositionLipkow, Karen January 2003 (has links)
The aim of this study is to find out more about how eukaryotic transposons work. Transposons are widespread genetic elements that can autonomously change their position within a genome. Their translocation is mediated by the transposase enzyme, encoded by the transposon itself. Transposition is often associated with mutations and recombination in the host and may promote evolutionary change. Most knowledge of the principles and molecular mechanisms has so far come from prokaryotic transposons. Eukaryotic transposons have mostly been studied on the level of population dynamics. In this thesis, I studied two eukaryotic transposons on a molecular level, hobo and Himarl are members of very widespread transposon families, hAT and mariner-like elements, respectively. Their interest lies mainly in the preposition that the order of catalytic steps is the opposite of all prokaryotic transposons studied so far. I developed several protocols for the purification of hobo transposase. These preparations were assayed by several methods in vitro. DNA hairpin structures, which had been postulated to arise in the flanking DNA upon hobo excision, were assayed for with a newly developed very sensitive method, frayed duplex PCR. Here, and in reconstructed in vivo transposition systems, no specific transpositional activity, apart from a high toxicity for the host cells, was detected. This suggests a requirement for as yet unidentified host factors. For Himarl, I improved the published transposase purification protocol and optimised the in vitro reaction conditions, achieving a c. 10-fold increase in specific activity. Specific transposase-DNA binding is shown, representing the earliest intermediates in transposition. Later complexes studied are target capture and strand transfer complexes, which are the final stage of the transposition reaction. Hydroxyradical footprinting and band shift assays suggest that Himarl transposase binds a single DNA end as multimers while occupying only a single DNA binding site. Himarl can bind and commit to target DNA before as well as after excision from the donor. Target commitment is only clearly visible under conditions of macromolecular crowding, and insertions were found to be more efficient if the target is supercoiled. These are both conditions closely resembling the situation in the eukaryotic nucleus.
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Influência de dois elementos de transposição na arquitetura do genoma de Schistosoma mansoni / Influence of two transposable elements in the genome architecture of Schistosoma mansoniJacinto, Daniele Santini 25 April 2014 (has links)
Elementos transponíveis são elementos genéticos capazes de transpor para diferentes locais em um genoma hospedeiro. Na sua descoberta, considerou-se que tais elementos não apresentavam funções celulares úteis, classificando-os como genes parasitas. Atualmente, além do carácter deletério, reconhece-se que eles contribuam para a evolução dos genomas e, em alguns casos, podem realizar algumas funções celulares. Utilizando recursos de bioinformática, realizamos estudos para verificar a influência de duas famílias de retrotransposons non-LTR (Perere-3 e SR2) no genoma do Schistosoma mansoni. Estudos preliminares indicam que após a divergência entre S. japonicum e S. mansoni, esses elementos tiveram uma grande expansão em seu número de cópias em S. mansoni, sem paralelo em S. japonicum. Análises das regiões intrônicas que contêm inserções de qualquer uma destas duas famílias de retrotransposon em S. mansoni, mostrou que houve aproximadamente 30% de aumento no tamanho dos íntrons e aumento do conteúdo GC, quando comparado com os íntrons ortólogos de S. japonicum. As inserções foram diferencialmente representadas ao longo das estruturas dos genes com a acumulação preferencial nos íntrons localizados nas regiões terminais dos genes. As inserções dos dois elementos de transposição tendem a orientar-se na direção oposta da transcrição dos genes. As inserções de trechos do elemento SR2 enriquecidos em motivos CpG foram observados com maior frequência do que o esperado, sugerindo que estas inserções podem contribuir nas funções de genes. Nas regiões intergênicas, foi possível prever sítios para ligação de fatores de transcrição ao longo das sequências de ambos os retrotransposons. Também foi observado que elementos SR2 tendem a se fixar em regiões que flanqueiam genes codificando proteínas transmembranares, as quais podem estar envolvidas na relação hospedeiro-parasita. Usando dados de transcrição de S. mansoni disponíveis publicamente, foram detectados 94 casos possíveis de exonização de inserções dos retrotransposons, produzindo mudanças do produto proteico. Estes resultados sugerem que os elementos Perere-3 e SR2 podem promover mudanças funcionais e estruturais relevantes nos genes de S. mansoni e pode ter contribuído significativamente para a diferenciação entre S. mansoni e S. japonicum. / Transposable elements are genetic elements capable of transpose to different locations at a host genome. At their discovery, it was considered that such elements had no useful cellular functions, leading to their classification as parasitic genes. Currently, in addition to the deleterious character, it is recognized that they contribute to the evolution of genomes and, in some cases, may perform some cellular functions. Using bioinformatics resources, we have conducted studies to verify the influence of two families of non-LTR retrotransposons (Perere-3 and SR2) in the Schistosoma mansoni genome. Preliminary studies indicate that after the divergence between S. japonicum and S. mansoni, these elements had a great expansion in their copy number in S. mansoni, without parallel expansion in S. japonicum. The analysis of the intron regions containing insertions from either of these two families of transposons in S. mansoni, showed that there was approximately 30% of increase in the intron size and GC content when compared to orthologous introns from S. japonicum. Insertions were differentially represented along the gene structures with preferential accumulation in introns located at the terminal regions of the genes. Insertions of both transpositon elements tended to orientate themselves in the opposite direction of gene transcription. The insertions of SR2 transposon regions enriched in CpG motifs were observed in higher frequency than expected, suggesting that these regions might contributing in the gene functions. In the intergenic regions, it was possible to predict transcription factors binding sites along the sequences of both retrotransposons and also observed that SR2 elements were preferentially fixed at regions flanking genes coding for transmembrane proteins, which may be involved in parasite-host relationship. Using publicly available transcript data from S. mansoni, we detected 94 possible cases of exonization of transposon insertion, producing changes of the protein product. These results suggest that Perere-3 and SR2 insertions may promote relevant functional and structural changes in the S. mansoni genes and may have significantly contributed to the differentiation between S. mansoni and S. japonicum.
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Influência de dois elementos de transposição na arquitetura do genoma de Schistosoma mansoni / Influence of two transposable elements in the genome architecture of Schistosoma mansoniDaniele Santini Jacinto 25 April 2014 (has links)
Elementos transponíveis são elementos genéticos capazes de transpor para diferentes locais em um genoma hospedeiro. Na sua descoberta, considerou-se que tais elementos não apresentavam funções celulares úteis, classificando-os como genes parasitas. Atualmente, além do carácter deletério, reconhece-se que eles contribuam para a evolução dos genomas e, em alguns casos, podem realizar algumas funções celulares. Utilizando recursos de bioinformática, realizamos estudos para verificar a influência de duas famílias de retrotransposons non-LTR (Perere-3 e SR2) no genoma do Schistosoma mansoni. Estudos preliminares indicam que após a divergência entre S. japonicum e S. mansoni, esses elementos tiveram uma grande expansão em seu número de cópias em S. mansoni, sem paralelo em S. japonicum. Análises das regiões intrônicas que contêm inserções de qualquer uma destas duas famílias de retrotransposon em S. mansoni, mostrou que houve aproximadamente 30% de aumento no tamanho dos íntrons e aumento do conteúdo GC, quando comparado com os íntrons ortólogos de S. japonicum. As inserções foram diferencialmente representadas ao longo das estruturas dos genes com a acumulação preferencial nos íntrons localizados nas regiões terminais dos genes. As inserções dos dois elementos de transposição tendem a orientar-se na direção oposta da transcrição dos genes. As inserções de trechos do elemento SR2 enriquecidos em motivos CpG foram observados com maior frequência do que o esperado, sugerindo que estas inserções podem contribuir nas funções de genes. Nas regiões intergênicas, foi possível prever sítios para ligação de fatores de transcrição ao longo das sequências de ambos os retrotransposons. Também foi observado que elementos SR2 tendem a se fixar em regiões que flanqueiam genes codificando proteínas transmembranares, as quais podem estar envolvidas na relação hospedeiro-parasita. Usando dados de transcrição de S. mansoni disponíveis publicamente, foram detectados 94 casos possíveis de exonização de inserções dos retrotransposons, produzindo mudanças do produto proteico. Estes resultados sugerem que os elementos Perere-3 e SR2 podem promover mudanças funcionais e estruturais relevantes nos genes de S. mansoni e pode ter contribuído significativamente para a diferenciação entre S. mansoni e S. japonicum. / Transposable elements are genetic elements capable of transpose to different locations at a host genome. At their discovery, it was considered that such elements had no useful cellular functions, leading to their classification as parasitic genes. Currently, in addition to the deleterious character, it is recognized that they contribute to the evolution of genomes and, in some cases, may perform some cellular functions. Using bioinformatics resources, we have conducted studies to verify the influence of two families of non-LTR retrotransposons (Perere-3 and SR2) in the Schistosoma mansoni genome. Preliminary studies indicate that after the divergence between S. japonicum and S. mansoni, these elements had a great expansion in their copy number in S. mansoni, without parallel expansion in S. japonicum. The analysis of the intron regions containing insertions from either of these two families of transposons in S. mansoni, showed that there was approximately 30% of increase in the intron size and GC content when compared to orthologous introns from S. japonicum. Insertions were differentially represented along the gene structures with preferential accumulation in introns located at the terminal regions of the genes. Insertions of both transpositon elements tended to orientate themselves in the opposite direction of gene transcription. The insertions of SR2 transposon regions enriched in CpG motifs were observed in higher frequency than expected, suggesting that these regions might contributing in the gene functions. In the intergenic regions, it was possible to predict transcription factors binding sites along the sequences of both retrotransposons and also observed that SR2 elements were preferentially fixed at regions flanking genes coding for transmembrane proteins, which may be involved in parasite-host relationship. Using publicly available transcript data from S. mansoni, we detected 94 possible cases of exonization of transposon insertion, producing changes of the protein product. These results suggest that Perere-3 and SR2 insertions may promote relevant functional and structural changes in the S. mansoni genes and may have significantly contributed to the differentiation between S. mansoni and S. japonicum.
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Expression signals in retro-elementsRathjen, Peter David January 1988 (has links)
No description available.
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Caractérisation et analyse fonctionnelle des éléments transposables de type mariner issus de deux espèces des sources hydrothermales océaniques (Bythograea thermydron et Alvinella caudata)Halaimia Toumi, Nassima Laulier, Marc. January 2006 (has links) (PDF)
Reproduction de : Thèse de doctorat : biophysiologie des organismes et des populations : Le Mans : 2006. / Titre provenant de l'écran-titre. Bibliogr. p. 175-194.
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Transposon-mediated insertional mutagenesis in gene discovery and cancerKong, Jun January 2011 (has links)
No description available.
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