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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

IDENTIFICATION OF NOVEL SLEEP RELATED GENES FROM LARGE SCALE PHENOTYPING EXPERIMENTS IN MICE

Joshi, Shreyas 01 January 2017 (has links)
Humans spend a third of their lives sleeping but very little is known about the physiological and genetic mechanisms controlling sleep. Increased data from sleep phenotyping studies in mouse and other species, genetic crosses, and gene expression databases can all help improve our understanding of the process. Here, we present analysis of our own sleep data from the large-scale phenotyping program at The Jackson Laboratory (JAX), to identify the best gene candidates and phenotype predictors for influencing sleep traits. The original knockout mouse project (KOMP) was a worldwide collaborative effort to produce embryonic stem (ES) cell lines with one of mouse’s 21,000 protein coding genes knocked out. The objective of KOMP2 is to phenotype as many as of these lines as feasible, with each mouse studied over a ten-week period (www.mousephenotype.org). The phenotyping for sleep behavior is done using our non-invasive Piezo system for mouse activity monitoring. Thus far, sleep behavior has been recorded in more than 6000 mice representing 343 knockout lines and nearly 2000 control mice. Control and KO mice have been compared using multivariate statistical approaches to identify genes that exhibit significant effects on sleep variables from Piezo data. Using these statistical approaches, significant genes affecting sleep have been identified. Genes affecting sleep in a specific sex and that specifically affect sleep during daytime and/or night have also been identified and reported. The KOMP2 consists of a broad-based phenotyping pipeline that consists of collection of physiological and biochemical parameters through a variety of assays. Mice enter the pipeline at 4 weeks of age and leave at 18 weeks. Currently, the IMPC (International Mouse Phenotyping Consortium) database consists of more than 33 million observations. Our final dataset prepared by extracting biological sample data for whom sleep recordings are available consists of nearly 1.5 million observations from multitude of phenotyping assays. Through big data analytics and sophisticated machine learning approaches, we have been able to identify predictor phenotypes that affect sleep in mice. The phenotypes thus identified can play a key role in developing our understanding of mechanism of sleep regulation.
2

Investigação de Polimorfismos nos Genes IGF2 e CYP21 em Bovinos de Raças Zebuínas e Análise das Possíveis Associações com Características de Interesse Econômico / Investigation of Polimorphisms in IGF2 and CYP21 Genes in Zebu Breeds and Possible Associations with Economic Interest Traits

Silva, Andrea Martins da 05 July 2010 (has links)
Existe um relevante interesse em pesquisar a ocorrência de polimorfismos no genoma bovino por diferentes motivos, e mais recentemente, com a finalidade de agregar mais informações ao estudo de características quantitativas visando selecionar animais geneticamente superiores com considerável valor comercial. Os polimorfismos de base única (SNPs) neste estudo foram identificados como RFLP/MboII e RFLP/HpaII sendo que o polimorfismo RFLP/MboII está situado no exon 6 do gene IGF2 (insulin-like growth factor 2), localizado no cromossomo 29 em bovinos, e desempenha um papel importante na proliferação e diferenciação celular para o crescimento e desenvolvimento dos mamíferos. O polimorfismo RFLP/HpaII encontra-se no elemento Bov-A2 (considerado um elemento SINE - Short Interspersed Nucleotide Element) presente na região promotora do gene CYP21 (Steroid 21-hydroxylase gene) no cromossomo 23 em bovinos. Para avaliar a ocorrência dos SNPs utilizou-se a técnica de PCR-RFLP em amostras de DNA a partir de sangue/sêmen de cerca de 300 animais bovinos das raças zebuínas Gir, Guzerá e Nelore. As frequências alélicas mostraram maior incidência do alelo T quando comparado ao C enquanto que as frequências genotípicas apresentaram alta ocorrência do heterozigoto TC em comparação aos homozigotos CC e TT para o polimorfismo IGF2 - RFLP/MboII. Com relação ao polimorfismo CYP21 RFLP/HpaII, a frequência alélica revelou alto valor do alelo T. A população encontrou-se em equilíbrio de Hardy-Weinberg para os SNPs estudados. Ferramentas de bioinformática foram utilizadas para investigações in silico revelando que os sítios polimórficos estão em regiões com potencial regulatório. A associação desses polimorfismos com DEPs das características reprodutivas e produtivas foram investigadas, entretanto mostrou-se significativas apenas para DP550 (IGF2 - RFLP/MboII) e DP450 (CYP21 - RFLP/HpaII). Os resultados obtidos sugerem que protocolos de Biologia Molecular in vitro podem ser usados para identificar novos marcadores moleculares, como SNPs funcionais adicionando informações que certamente contribuirão para estratégias de melhoramento dessas raças bovinas de grande importância para a produção de carne e leite em nosso país. Este foi o primeiro estudo sobre a ocorrência desses polimorfismos em raças zebuínas criadas no Brasil. / There is a considerable interest in researching the occurrence of polymorphisms in the bovine genome for different reasons, and more recently, in order to add more information to the study of quantitative traits to select genetically superior animals with considerable commercial value. The single nucleotide polymorphisms (SNPs) in this study were identified as RFLP/MboII and RFLP/HpaII polymorphisms being the RFLP/MboII is situated in exon 6 of the IGF2 gene (insulin-like growth factor 2), located on chromosome 29 in cattle, perform an important role in cell proliferation, differentiation for growth and in the development of mammals. Polymorphism RFLP/HpaII is the element Bov-A2 (considered an element SINE - Short Interspersed Nucleotide Element) present in the promoter region of CYP21 gene (Steroid 21-hydroxylase gene) on chromosome 23 in cattle. To evaluate the occurrence of SNPs, we used the PCR-RFLP method on DNA samples from blood/semen of about 300 cattle breeds from Zebu Gyr, Guzerat and Nellore. The allele frequencies showed a higher incidence of T allele compared to C while the genotype frequencies showed high incidence of heterozygous CT compared to CC and TT homozygous for the IGF2 polymorphism - RFLP/MboII. On the subject of the CYP21 polymorphism - RFLP/HpaII, the allele frequency showed high value T. The population was found in Hardy-Weinberg equilibrium for the SNPs studied. Bioinformatics tools, used for in silico investigations, revealed that the polymorphic sites are in regions with regulatory potential. The association of these polymorphisms with EPDs of reproductive and productive traits were investigated, but proved to be significant only for DP550 (IGF2 - RFLP/MboII) and DP450 (CYP21 - RFLP/HpaII). The results suggest that protocols of molecular biology in vitro can be used to identify new molecular markers, such as functional SNPs adding information that certainly will contribute to the improvement strategies of these breeds of great importance for the production of meat and milk in our country. It has been the first study on the occurrence of these polymorphisms in Zebu breeds raised in Brazil.
3

Investigação de Polimorfismos nos Genes IGF2 e CYP21 em Bovinos de Raças Zebuínas e Análise das Possíveis Associações com Características de Interesse Econômico / Investigation of Polimorphisms in IGF2 and CYP21 Genes in Zebu Breeds and Possible Associations with Economic Interest Traits

Andrea Martins da Silva 05 July 2010 (has links)
Existe um relevante interesse em pesquisar a ocorrência de polimorfismos no genoma bovino por diferentes motivos, e mais recentemente, com a finalidade de agregar mais informações ao estudo de características quantitativas visando selecionar animais geneticamente superiores com considerável valor comercial. Os polimorfismos de base única (SNPs) neste estudo foram identificados como RFLP/MboII e RFLP/HpaII sendo que o polimorfismo RFLP/MboII está situado no exon 6 do gene IGF2 (insulin-like growth factor 2), localizado no cromossomo 29 em bovinos, e desempenha um papel importante na proliferação e diferenciação celular para o crescimento e desenvolvimento dos mamíferos. O polimorfismo RFLP/HpaII encontra-se no elemento Bov-A2 (considerado um elemento SINE - Short Interspersed Nucleotide Element) presente na região promotora do gene CYP21 (Steroid 21-hydroxylase gene) no cromossomo 23 em bovinos. Para avaliar a ocorrência dos SNPs utilizou-se a técnica de PCR-RFLP em amostras de DNA a partir de sangue/sêmen de cerca de 300 animais bovinos das raças zebuínas Gir, Guzerá e Nelore. As frequências alélicas mostraram maior incidência do alelo T quando comparado ao C enquanto que as frequências genotípicas apresentaram alta ocorrência do heterozigoto TC em comparação aos homozigotos CC e TT para o polimorfismo IGF2 - RFLP/MboII. Com relação ao polimorfismo CYP21 RFLP/HpaII, a frequência alélica revelou alto valor do alelo T. A população encontrou-se em equilíbrio de Hardy-Weinberg para os SNPs estudados. Ferramentas de bioinformática foram utilizadas para investigações in silico revelando que os sítios polimórficos estão em regiões com potencial regulatório. A associação desses polimorfismos com DEPs das características reprodutivas e produtivas foram investigadas, entretanto mostrou-se significativas apenas para DP550 (IGF2 - RFLP/MboII) e DP450 (CYP21 - RFLP/HpaII). Os resultados obtidos sugerem que protocolos de Biologia Molecular in vitro podem ser usados para identificar novos marcadores moleculares, como SNPs funcionais adicionando informações que certamente contribuirão para estratégias de melhoramento dessas raças bovinas de grande importância para a produção de carne e leite em nosso país. Este foi o primeiro estudo sobre a ocorrência desses polimorfismos em raças zebuínas criadas no Brasil. / There is a considerable interest in researching the occurrence of polymorphisms in the bovine genome for different reasons, and more recently, in order to add more information to the study of quantitative traits to select genetically superior animals with considerable commercial value. The single nucleotide polymorphisms (SNPs) in this study were identified as RFLP/MboII and RFLP/HpaII polymorphisms being the RFLP/MboII is situated in exon 6 of the IGF2 gene (insulin-like growth factor 2), located on chromosome 29 in cattle, perform an important role in cell proliferation, differentiation for growth and in the development of mammals. Polymorphism RFLP/HpaII is the element Bov-A2 (considered an element SINE - Short Interspersed Nucleotide Element) present in the promoter region of CYP21 gene (Steroid 21-hydroxylase gene) on chromosome 23 in cattle. To evaluate the occurrence of SNPs, we used the PCR-RFLP method on DNA samples from blood/semen of about 300 cattle breeds from Zebu Gyr, Guzerat and Nellore. The allele frequencies showed a higher incidence of T allele compared to C while the genotype frequencies showed high incidence of heterozygous CT compared to CC and TT homozygous for the IGF2 polymorphism - RFLP/MboII. On the subject of the CYP21 polymorphism - RFLP/HpaII, the allele frequency showed high value T. The population was found in Hardy-Weinberg equilibrium for the SNPs studied. Bioinformatics tools, used for in silico investigations, revealed that the polymorphic sites are in regions with regulatory potential. The association of these polymorphisms with EPDs of reproductive and productive traits were investigated, but proved to be significant only for DP550 (IGF2 - RFLP/MboII) and DP450 (CYP21 - RFLP/HpaII). The results suggest that protocols of molecular biology in vitro can be used to identify new molecular markers, such as functional SNPs adding information that certainly will contribute to the improvement strategies of these breeds of great importance for the production of meat and milk in our country. It has been the first study on the occurrence of these polymorphisms in Zebu breeds raised in Brazil.
4

Genotype-phenotype correlation using phylogenetic trees

Habib, Farhat 14 September 2007 (has links)
No description available.
5

Apport de la phylogénomique pour l’étude des interactions moléculaires entre Henipavirus et leurs réservoirs : les chauves-souris du genre Pteropus / Contribution of phylogenomics to the study of molecular interactions between Henipaviruses and their reservoir : Pteropus Bats

Fouret, Julien 14 December 2018 (has links)
Les chauve-souris représentant un réservoir important pour de nombreux virus pathogènes pour l’homme, un ensemble d’études en évolution moléculaire converge vers l’évidence d’une forte pression de sélection au niveau de gènes impliqués dans l’immunité dans l’ordre Chiroptera. En particulier, les chauves-souris du genre Pteropus hébergent des virus de la famille Henipavirus: Nipah et Hendra. Ces virus sont responsables d'épidémies en Asie du sud-est, et bien qu'ayant un taux d'incidence bas, les maladies résultantes de l'infection ont un taux de létalité allant de 40% à 90% chez l'homme. L’infection atteint aussi la plupart des mammifères avec des symptômes clinique graves, (e.g. porc ou cheval : espèces d’intérêt agronomique). La particularité du genre Pteropus est de ne pas développer ces symptômes cliniques graves d’infection. Afin d'en identifier les bases génétiques, nous avons utilisé l'analyse de sélection positive sur l’ensemble du génome codant sans restreindre notre analyse aux gènes de l’immunité. Nous avons mis en place les outils informatiques innovants et nécessaires au déploiement de cette démarche. Ces analyses, reposent sur des séquences de références pour les génomes de différentes espèces, et en absence du génome de référence pour P. giganteus, nous l’avons préalablement séquencé et assemblé. Or, tous les gènes sous sélection ne sont pas forcément liés à notre phénotype d’intérêt mais possiblement à d’autres (e.g. capacité de vol). Nous avons mis en place un algorithme afin d’établir un lien fonctionnel potentiel entre ces gènes identifiés sous sélection positive et un phénotype d’intérêt. / Bats represent a considerable reservoir for an extensive group of human pathogenic viruses. A number of molecular evolution studies points toward the evidence of a strong selection pressure in Chiroptera immune-related genes. Notably, Pteropus bats host viruses from Henipavirus genus: Nipah and Hendra. These viruses are responsible for epidemics in South-Est Asia, and, while the incidence is low, the resulting diseases are highly lethal, ranging between 40 to 90% in humans. Most of mammals are susceptible to the infection (including pigs and horses, animals valued in agronomy), and develop severe clinical symptoms. Specificity of Pteropus genus lies in the absence of clinical symptoms following the infection. In order to identify the genetic basis of this interesting phenomenon, we applied positive selection analysis to the entire coding genome, without bounding our analysis to immune-regulating genes. We have set breakthrough computational tools, without which our analysis would not have been possible. Reference sequences from genome of several species are the groundwork for our analysis. As P. giganteus reference genome has not yet been resolved, we sequenced and assembled it. However, not all genes under positive selection are necessarily linked to a phenotype of interest, but may be linked to other phenotypes (such as the flying ability). We have thus developed an algorithm to establish a possible functional link between the genes identified under positive selection and a phenotype of interest, which allows new perspectives in phylogenomic research.

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