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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.
1

Genomic analysis of the horse Y chromosome

Santani, Avni Bhawan 17 February 2005 (has links)
Stallion fertility is of significant economic importance in the multibillion dollar equine industry. Presently, the underlying genetic causes of infertility in stallions are unknown. Analysis of the human genome has shown that in more than 25% of cases, male infertility is associated with deletions/rearrangements in the Y chromosome. Presently there is no gene map for the Y chromosome in the horse. Therefore, the primary aim of this study is to build a detailed physical map of the chromosome with a long-term aim to identify and analyze Y-specific factors affecting fertility in stallions. To materialize this, we constructed the first radiation hybrid and FISH map of the euchromatic region of the horse Y chromosome. This basic map was used to obtain Y-specific BAC clones that provided new STS markers from the end sequences. Chromosome walking provided 73 BACs comprising 7 contigs that were built across the euchromatic region using 124 markers for content mapping. The results were validated by restriction fingerprinting and Fiber FISH. The map is presently the most informative among the domestic species and second to only human and mouse Y chromosome maps. The construction of this map will pave the way for isolation and functional characterization of genes critical for normal male fertility and reproduction and will in the future lead to the development of a diagnostic test to facilitate early identification of deletions/rearrangements on the Y chromosome of potentially affected foals/stallions. The second part of the study comprised the first extended investigation to assess genetic variation in the horse Y chromosome. Approximately 4.5Mb of the euchromatic region was screened for polymorphic microsatellite markers. Of the 27 markers that were characterized and screened for polymorphism in 14 breeds of the domestic horse and eight extant equids, only one was polymorphic in the domestic horse, suggesting a low level of genetic variation on the chromosome. However, 21 of the markers showed noteworthy variation (on average four alleles/marker) among the eight equids. These markers will be vital in future studies aimed at elucidating the genetic relationships between the various equids through phylogenetic analysis.
2

A STATISTICAL ANALYSIS OF AMINO ACID CHANGES IN THE HUMAN GENOME

AMALAPURAPU, SUCHITRA S. 02 May 2003 (has links)
No description available.
3

Pirossequenciamento do transcriptoma de folha de Lippia alba por meio da plataforma 454 GS FLX (Roche)

Guedes, Fernanda Alves de Freitas 28 February 2011 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-09-15T12:46:42Z No. of bitstreams: 1 fernandaalvesdefreitasguedes.pdf: 2011976 bytes, checksum: 6684b1525d9f87a2f6e72eadaa42fc34 (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-09-26T20:18:53Z (GMT) No. of bitstreams: 1 fernandaalvesdefreitasguedes.pdf: 2011976 bytes, checksum: 6684b1525d9f87a2f6e72eadaa42fc34 (MD5) / Made available in DSpace on 2016-09-26T20:18:53Z (GMT). No. of bitstreams: 1 fernandaalvesdefreitasguedes.pdf: 2011976 bytes, checksum: 6684b1525d9f87a2f6e72eadaa42fc34 (MD5) Previous issue date: 2011-02-28 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Lippia alba, também conhecida popularmente como erva cidreira, é uma espécie amplamente distribuída pelas Américas podendo ser encontrada por praticamente todo o Brasil. Muito usada pela medicina popular para o tratamento de problemas gastrointestinais e respiratórios, a folha desta espécie produz um óleo essencial rico em terpenos, principalmente mono e sesquiterpenos. Estes compostos não são apenas de interesse farmacológico, como também industrial. A composição deste óleo pode variar em função de fatores abióticos e também de variações genotípicas. Diante da complexidade da síntese destes compostos a proposta deste trabalho foi uma ampla caracterização do transcriptoma de folha de Lippia alba, além da identificação de prováveis enzimas envolvidas na síntese de terpenos. Para isso, foi feito um sequenciamento deste transcriptoma usando a plataforma 454 (Roche) seguido de uma montagem de novo. Esta plataforma tem sido cada vez mais utilizada para o sequenciamento de transcriptomas numa abordagem conhecida como RNA-Seq. O sequenciamento de biblioteca preparada a partir de RNA total em 1/8 de placa gerou 104.631 leituras com comprimento médio de 184,48bp num total de 19.302.161 bases. Foram feitas montagens das leituras usando 2 diferentes assemblers a fim de compará-las. Com o Newbler 2.5 foi possível montar 2.686 contigs com comprimento médio de 349bp, enquanto o SeqMan2.2 gerou 13.448 contigs com média de 284bp. Em seguida, foi feita a anotação funcional com o Blast2GO para os contigs obtidos nas duas montagens, tendo sido anotados 51,49% e 30,88%, respectivamente, dos contigs do Newbler e do SeqMan. Por fim, a análise das sequências anotadas revelou algumas enzimas potencialmente envolvidas com a síntese de terpenos. Os resultados obtidos neste estudo pioneiro sobre a espécie comprovam que as tecnologias NGS podem ser uma ferramenta bastante eficiente para o sequenciamento de transcriptomas e servirão como referência para o preparo mais específico de novas bibliotecas. Futuros sequenciamentos devem contribuir para uma melhor cobertura do transcriptoma permitindo a descoberta inclusive de transcritos raros. / Lippia alba, popularly known as erva cidreira, is widely distributed throughout the Americas and can be found through almost whole Brazil. This species is largely used in folk medicine to treat gastrointestinal and respiratory problems, especially leaves, which produce an essential oil rich in terpenes, mainly mono-and sesquiterpenes. These compounds are not only of pharmacological interest, as well as industrial. Composition of essencial oil can vary depending on the developmental stage, the plant part and other abiotic factors. However, genotypic variations also contribute to oil composition variation. Given the complexity of terpenes synthesis, including diversity of enzymes involved in these metabolic pathways, the purpose of this work was a L. alba leaf transcriptome characterization, in addition to identifying some enzymes probably involved in terpene synthesis. For that, it was made a transcriptome sequencing using 454 platform (Roche) followed by a de novo assembly. This platform, along with other NGS technologies, has been increasingly used for transcriptome sequencing in an approach known as RNA-Seq. Sequencing of a library prepared from total RNA in 1/8 plate generated 104,631 reads with average length of 184.48 bp and a total of 19,302,161 bases. Read assemblies were made using two different assemblers in order to compare them. While Newbler 2.5, proprietary software platform, assembled 2686 contigs with average length of 349bp, SeqMan2.2 generated 13,448 contigs with an average of 284bp. Then, functional annotation was performed with Blast2GO for all contigs from both assemblies; 51.49% and 30.88% of contigs, respectively, from Newbler and SeqMan were annotated. Finally, analysis of annotated sequences revealed some enzymes potentially involved in terpene synthesis. Results obtained from this pioneering study on the species show that NGS technology can be a very efficient tool for transcriptome sequencing and they will serve as reference for preparation of other more specific libraries. New sequencings should contribute to a better coverage of this transcriptome, allowing discovery of even rare transcripts.
4

Identification par clonage positionnel du gène grey-lethal (gl) chez la souris

Chalhoub, Nader January 2003 (has links)
No description available.
5

An evolutionary genomics approach towards analysis of genes implicated in transmission of trypanosomes between tsetse fly and mammalian host

Mwangi, Sarah Wambui January 2009 (has links)
>Magister Scientiae - MSc / Human African trypanosomiasis is the world’s third most important parasitic disease affecting human health after malaria and schistosomiaisis. The world health organization estimates approximately 60 million people at risk in sub-Saharan Africa and up to 50,000 deaths per year caused by trypanosomiasis. Current management of human African trypanosomiasis relies on active surveillance and chemotherapy of infected patients. Efforts to develop a vaccine to immunize the human host have been hampered by antigenic variation of the parasites cell coat. The advent of the genome era has opened up opportunities for developing novel strategies for interrupting the transmission cycle of trypanosomes, specifically using any of the three players,the human host, the tsetse fly vector and/or the parasite. The human genome has been deciphered and the genomes of several trypanosome species have been sequenced. Sequencing of additional neglected trypanosome species is in progress. The tsetse fly genome is currently being sequenced as part of the genomic activities of the International Glossina genome initiative (IGGI). In an attempt to support the tsetse fly sequencing effort, expressed sequence tags (ESTs) from various tissues and developmental stages of Glossina morsitans have been generated.In this study, tsetse fly EST data was analyzed using bioinformatics approaches, focusing on transcripts encoding serpin genes implicated in the immune defenses of tsetse flies. Glossina morsitans homologues to Drosophila melanogaster serpin4, serpin5, and serpin27A and Anopheles gambiae serpin10 were identified in the tsetse fly EST contigs. Comparison of the reactive center loop of tsetse fly serpins with human α-1-antitrypsin suggests that these tsetse serpins are inhibitory. Preliminary EST clustering did not succeed in assembling 3564 Tsal encoded ESTs into one contig. In this study, these ESTs were assembled together with three published Tsal cDNAs. A total of 29 Tsal-encoded contigs were generated. An analysis of the sequence variation within the Tsal EST assembled contigs identified five single base mismatches namely A-T, T-A, G-T and T-G.Results from this study form a basis onto which genetic and biochemical experimental studies can be designed, a process that will be successfully carried out once we have a reference genome. Specifically, studies aimed at genetic modification of tsetse flies towards populations that are inhabitable to trypanosomes. Ultimately, this will supplement current vector control strategies towards elimination of human African trypanosomiasis.
6

Polimorfismo e expressão de genes de celulose sintase em eucalyptus / Polymorphism and expression of cellulose synthase genes in eucalyptus

Trigueiro, Elaine Lima January 2007 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-08-06T15:10:39Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Elaine Lima Trigueiro.pdf: 2172405 bytes, checksum: 872d4e471b17e830b4eafc478bfb3cf5 (MD5) / Made available in DSpace on 2014-08-06T15:10:39Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Elaine Lima Trigueiro.pdf: 2172405 bytes, checksum: 872d4e471b17e830b4eafc478bfb3cf5 (MD5) Previous issue date: 2007 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Cellulose is one of the most important and the most abundant biopolymer on the planet, playing a key role on the evolutionary history of plants. Important advances have been made in recent years, in particular on the identification of genes and co- expressed genes for the formation of cellulose in the primary and secondary cellular walls of plants. In addition to its biological relevance, cellulose has a great economic importance, not only in Brazil but in the world, especially due to the production of cellulose and paper from Eucalyptus. The high levels of production and competition in the international market are guaranteed by great investments, which are carried through by the forestal sector, in particular by the Genolyptus Project – Brazilian Network for Research on Eucalyptus Genome. This project is the result of a collective effort of companies involved on the production of cellulose and paper and various public research institutions. Their main goal is to identify and characterize genes involved in wood formation with the intent to genetically improve Eucalyptus. Based on this goal, this work was developed with two objectives. The first is doing a preliminary characterization of the cellulose synthase gene in Eucalyptus, which is associated with the synthesis of the secondary cellular wall and is orthologous to the gene EgCeA2, of E. grandis. The second objective is to study the linkage disequilibrium in another gene of cellulose synthase, orthologous to the EgCesA3 gene, sampled from a wild population of E. urophylla. Regarding the CesA2 gene, an exonic region with 427bp was sequenced from DNA samples of 12 individuals from different species and geographic regions. The next step was to proceed with an analysis to detect polymorphism which gave an estimate of three SNPs synonymous along the contig, with an estimated π = 0.00212 diversity index. A clone containing the CesA2 gene was identified through a selection from a BAC library generated in the scope of the Genolyptus Project. This clone gives the prospect for the development of a minute characterization of this gene structure in Eucalyptus. Additionally, concerning the CesA3 gene, the sequencing of 32 individuals allowed for the formation of a 770bp contig with a π = 0.00185 diversity index and detection of nine polymorphic loci distributed in intron and exon regions and at the 3’-UTR of the gene. The analysis of the extension of linkage disequilibrium in the CesA3 gene suggests that SNPs tend to be in strong linkage disequilibrium at a distance of approximately 600bp. The knowledge of the position of the SNPs in the genes CesA2 and CesA3 makes possible the use of these markers in future studies of genetic mapping. The lack of non-synonymous SNPs in exon regions ensures that cellulose is in fact a very important polymer for plant survival. Hence its synthesis machinery presents highly conserved characteristics and so mutations in regions with effective transcription tend mostly to be deleterious and therefore would not be fixed. Moreover, the analysis of CesA gene expression in different species of Eucalyptus, was made from two boardings: “Digital Differential Display”, from different libraries of ESTs and microarrays, optimized in the scope of the Genolyptus project. The analysis with data of microarrays showed less sensible in the detention of the distinguishing expression, probably had to the calls “crossed relations”. / A celulose é um dos biopolímeros mais importantes do planeta, sendo também o mais abundante, e sem dúvida uma característica chave na história evolutiva das plantas. Contudo, sua biossíntese e regulação ainda não são bem compreendidas, embora avanços importantes tenham ocorrido nos últimos anos, sobretudo na identificação de genes e grupos de genes co-expressos para a formação de celulose na parede celular primária e secundária de vegetais. Além de sua relevância biológica, a celulose possui uma grande importância econômica no Brasil e no mundo, com destaque para a produção de celulose e papel a partir de Eucalyptus. Para garantir os elevados níveis de produtividade e competitividade no mercado internacional, grandes investimentos têm sido realizados pelo setor florestal, destacando-se o Projeto Genolyptus – Rede Brasileira de Pesquisa do Genoma de Eucalyptus, fruto de um esforço de empresas do setor de produção de celulose e papel, e de diversas instituições públicas de pesquisa, que têm, dentre outros objetivos, o intuito de identificar e caracterizar genes envolvidos na formação da madeira, para, no futuro, usar essa informação no melhoramento genético do Eucalyptus. Nesse contexto, este trabalho foi desenvolvido com o objetivo de realizar uma caracterização preliminar de um gene de celulose sintase em Eucalyptus, que está relacionado à síntese da parede celular secundária, sendo ortólogo ao gene EgCesA2, de E. grandis, bem como estudar o desequilíbrio de ligação em outro gene de celulose sintase, ortólogo ao gene EgCesA3, em uma amostra de uma população natural de E. urophylla. Em relação ao gene CesA2, foi seqüenciada uma região exônica do gene, formada por 427pb, a partir de amostras de DNA de 12 indivíduos de diferentes espécies e regiões geográficas. Procedeu-se a uma análise de detecção de polimorfismo, e estimou-se a ocorrência de três SNPs sinônimos ao longo do contig. Foi estimado um índice de diversidade π= 0,00212. Foi feita também uma triagem em uma biblioteca de BAC, gerada no âmbito do Projeto Genolyptus, e foi identificado o clone que contém o gene CesA2, o que permitirá o desenvolvimento futuro de caracterização minuciosa da estrutura deste gene em Eucalyptus. Em relação ao gene CesA3, a partir do seqüenciamento de 32 indivíduos, formou-se um contig de 770pb, e foi encontrado um índice de diversidade π= 0,00185. Foi possível a detecção de nove locos polimórficos distribuídos em regiões intrônicas, exônicas, e de 3’-UTR do gene. A análise de extensão do desequilíbrio de ligação dentro do gene CesA3 sugere que os SNPs tendem a se encontrar em forte desequilíbrio a uma distância de aproximadamente 600pb. O conhecimento da posição dos SNPs nos genes CesA2 e CesA3 viabiliza a utilização destas marcas em futuros estudos de mapeamento genético. A existência de SNPs sinônimos nas regiões exônicas seqüenciadas corrobora com a idéia de que a celulose é um polímero muito importante à sobrevivência da planta, e, portanto, sua maquinaria de síntese apresenta características bastante conservadas, de modo que mutações em regiões efetivamente transcritas tenderiam a ser deletérias e não seriam fixadas. Além disso, foi feita uma análise da expressão gênica dos genes CesA em diferentes espécies de Eucalyptus, a partir de duas abordagens: a “Digital Differential Display”, a partir de diferente bibliotecas de ESTs e os microarrays, otimizados no âmbito do projeto Genolyptus. A análise com dados de microarrays revelou-se menos sensível na detecção da expressão diferencial, provavelmente devido às chamadas “relações cruzadas”.
7

Optimizing Parameters for High-quality Metagenomic Assembly

Kumar, Ashwani 29 July 2015 (has links)
No description available.
8

O ensino e aprendizagem de expressões numéricas para 5ª série do ensino fundamental com a utilização do jogo Contig 60®

Silva, Graziele Cristine Moraes da 14 May 2009 (has links)
Made available in DSpace on 2016-04-27T16:58:53Z (GMT). No. of bitstreams: 1 Graziele Cristine Moraes da Silva.pdf: 1632658 bytes, checksum: e83f2c95a08b868be50f260a29e863ab (MD5) Previous issue date: 2009-05-14 / Secretaria da Educação do Estado de São Paulo / This research aims to investigate the ownership of the numerical expression for students in 5th grade of elementary school, from conversions of Semiotics Representation Registers which will be addressed in this paper the following records: material, natural language and numerical, with the completion of arithmetic processing, and using as a tool the game Contig 60®. We have as a theoretical framework of the Didactic Situations Theory from Guy Brousseau and Semiotics Representation Registers of Raymond Duval. The research was qualitative and as a method it was adopted some assumptions of Engineering Teaching. The teaching sequence was developed to allow students interaction with the activities without requiring the use of rules for the resolution of the problem-situations. To do so, we used the strategy of the game Contig 60®, because it has the characteristic to develop the thinking and stimulate discussion. We stressed the importance of teaching mathematics with the use of games, because playing the student is concerned not with the error, but to participate in the activity, moreover, he can often play the role of researcher in the construction of knowledge. After intervention with the strategy game Contig 60® it was observed that the students improved knowledge on the numerical expression and use as a tool for modeling the problem-situations, and perform the treatments and conversions proposed satisfactorily / Esta pesquisa tem por objetivo investigar a apropriação da expressão numérica por alunos de 5ª série do Ensino Fundamental, a partir de conversões de Registros de Representação Semiótica. Neste trabalho, serão abordados os registros: material, língua natural e numérico, com a realização do tratamento aritmético, tendo como ferramenta o jogo Contig 60®. Temos por referencial teórico a Teoria das Situações Didáticas de Guy Brousseau e o Registro de Representação Semiótica de Raymond Duval. A investigação foi qualitativa e, como método, adotou-se alguns pressupostos da Engenharia Didática. A seqüência didática foi elaborada para permitir a interação dos sujeitos com as atividades, sem ser necessário o uso de regras para a resolução das situações problema. Para isso, utilizamos o jogo de estratégia Contig 60®, pois ele tem como característica desenvolver o raciocínio e estimular o questionamento. Ressaltamos a importância do ensino de Matemática com o uso de jogos, porque, ao jogar, o aluno não se preocupa com o erro e sim em participar da atividade, além disso, pode, muitas vezes, desempenhar o papel de pesquisador na construção do conhecimento. Após a intervenção com o jogo de estratégia Contig 60®, observamos que os sujeitos aprimoraram o conhecimento em relação às expressões numéricas e a passaram a utilizá-las como uma ferramenta para modelar as situações-problema, além de realizarem os tratamentos e conversões propostas de modo satisfatório
9

Towards Cloning the Leaf Rust Resistance Gene Rph5

Mammadov, Jafar 23 August 2004 (has links)
Leaf rust caused by Puccinia hordei is an important disease of barley (Hordeum vulgare) in many regions of the world. Yield losses up to 62% have been reported in susceptible cultivars. The Rph5 gene confers resistance to the most prevalent races (8 and 30) of barley leaf rust in the United States. Therefore, the molecular mapping of Rph5 is of great interest. Genetic studies were performed by analysis of 93 and 91 F2 plants derived from the crosses 'Bowman' (rph5) x 'Magnif 102' (Rph5) and 'Moore' (rph5) x Virginia 92-42-46 (Rph5), respectively. Linkage analysis positioned the Rph5 locus to the extreme telomeric region of the short arm of barley chromosome 3H at 0.2 cM proximal to RFLP marker VT1 and 0.5 cM distal from RFLP marker C970 in the Bowman x Magnif 102 population. Synteny between rice chromosome 1 and barley chromosome 3 was employed to saturate the region within the sub-centimorgan region around Rph5 using sequence-tagged site (STS) markers that were developed based on barley expressed sequence tags (ESTs) syntenic to the phage (P1)-derived artificial chromosome (PAC) clones comprising distal region of the rice chromosome 1S. Five rice PAC clones were used as queries to blastn 370,258 barley ESTs. Ninety four non-redundant EST sequences were identified from the EST database and used as templates to design 174 pairs of primer combinations. As a result, 10 EST-based STS markers were incorporated into the 'Bowman' x 'Magnif 102' high-resolution map of the Rph5 region. More importantly, six markers, including five EST-derived STS sequences, co-segregate with Rph5. Genes, represented by these markers, are putative candidates for Rph5. Results of this study demonstrate the usefulness of rice genomic resources for efficient deployment of barley EST resources for marker saturation of targeted barley genomic region. / Ph. D.

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