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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.
11

Molecular Genetic Study of Autism and Intellectual Disability Genes on the X-chromosome

Noor, Abdul 30 August 2012 (has links)
Autism is a neurodevelopmental disorder with an estimated prevalence of 1 in 150 children which makes it more common than childhood cancer and juvenile diabetes. It is estimated that there are more than 100,000 individuals affected by autism in Canada and tens of millions worldwide. It is well established that genetic factors play important role in the pathophysiology of autism; still, our current understanding of these genetic factors is limited and cause of autism remains an important question. During the past decade, after completion of human genome, several new high throughput genome scan technologies have been developed such as microarrays. In the present study, we undertook the challenge of identifying X-chromosomal genes involved in autism by performing genome-wide copy number variation analysis of more than 400 probands with autism using Affymetrix 500K single nucleotide polymorphism (SNP) microarrays. We identified copy number variants implicating several genes on the chromosome X such as PTCHD1, IL1RAPL1, IL1RAPL2 and TSPAN7 as autism candidate genes. We also demonstrated that autism and intellectual disability may share some of these genes as etiologic factors. We performed a comprehensive analysis of PTCHD1 locus and showed that mutations at this locus are associated with autism in ~1 % of the cases. This study also demonstrated that PTCHD1 mutations can cause intellectually disability with or without autism, and that the PTCHD1 protein may act as a receptor in Hedgehog signaling pathway. We have also carried out a detailed analysis of TSPAN7 and IL1RAPL1 to explore the contributions of these genes in autism. We identified one family with intronic deletion of IL1RAPL1 and another case with a missense mutation in this gene, thus implicating this known intellectual disability gene in autism. Our findings highlight the importance of the X chromosome in the etiology of autism, and demonstrate the power of copy number variation analysis coupled with other technologies in identification of disease genes, in particular for complex genetic disorders such as autism.
12

Molecular Genetic Study of Autism and Intellectual Disability Genes on the X-chromosome

Noor, Abdul 30 August 2012 (has links)
Autism is a neurodevelopmental disorder with an estimated prevalence of 1 in 150 children which makes it more common than childhood cancer and juvenile diabetes. It is estimated that there are more than 100,000 individuals affected by autism in Canada and tens of millions worldwide. It is well established that genetic factors play important role in the pathophysiology of autism; still, our current understanding of these genetic factors is limited and cause of autism remains an important question. During the past decade, after completion of human genome, several new high throughput genome scan technologies have been developed such as microarrays. In the present study, we undertook the challenge of identifying X-chromosomal genes involved in autism by performing genome-wide copy number variation analysis of more than 400 probands with autism using Affymetrix 500K single nucleotide polymorphism (SNP) microarrays. We identified copy number variants implicating several genes on the chromosome X such as PTCHD1, IL1RAPL1, IL1RAPL2 and TSPAN7 as autism candidate genes. We also demonstrated that autism and intellectual disability may share some of these genes as etiologic factors. We performed a comprehensive analysis of PTCHD1 locus and showed that mutations at this locus are associated with autism in ~1 % of the cases. This study also demonstrated that PTCHD1 mutations can cause intellectually disability with or without autism, and that the PTCHD1 protein may act as a receptor in Hedgehog signaling pathway. We have also carried out a detailed analysis of TSPAN7 and IL1RAPL1 to explore the contributions of these genes in autism. We identified one family with intronic deletion of IL1RAPL1 and another case with a missense mutation in this gene, thus implicating this known intellectual disability gene in autism. Our findings highlight the importance of the X chromosome in the etiology of autism, and demonstrate the power of copy number variation analysis coupled with other technologies in identification of disease genes, in particular for complex genetic disorders such as autism.
13

Evolutionary patterns of group B Sox binding and function in Drosophila

Carl, Sarah Hamilton January 2015 (has links)
Genome-wide binding and expression studies in Drosophila melanogaster have revealed widespread roles for Dichaete and SoxNeuro, two group B Sox proteins, during fly development. Although they have distinct target genes, these two transcription factors bind in very similar patterns across the genome and can partially compensate for each other's loss, both phenotypically and at the level of DNA binding. However, the inherent noise in genome-wide binding studies as well as the high affinity of transcription factors for DNA and the potential for non-specific binding makes it difficult to identify true functional binding events. Additionally, externalfactors such as chromatin accessibility are known to play a role in determining binding patterns in Drosophila. A comparative approach to transcription factor binding facilitates the use of evolutionary conservation to identify functional features of binding patterns. In order to discover highly conserved features of group B Sox binding, I performed DamID-seq for SoxNeuro and Dichaete in four species of Drosophila, D. melanogaster, D. simulans, D. yakuba and D. pseudoobscura. I also performed FAIRE-seq in D. pseudoobscura embryos to compare the chromatin accessibility landscape between two fly species and to examine the relationship between open chromatin and group B Sox binding. I found that, although the sequences, expression patterns and overall transcriptional regulatory targets of Dichaete and SoxNeuro are highly conserved across the drosophilids, both binding site turnover and rates of quantitative binding divergence between species increase with phylogenetic distance. Elevated rates of binding conservation can be found at bound genomic intervals overlapping functional sites, including known enhancers, direct targets of Dichaete and SoxNeuro, and core binding intervals identified in previous genome-wide studies. Sox motifs identified in intervals that show binding conservation are also more highly conserved than those in intervals that are only bound in one species. Notably, regions that are bound in common by SoxNeuro and Dichaete are more likely to be conserved between species than those bound by one protein alone. However, by examining binding intervals that are uniquely bound by one protein and conserved, I was able to identify distinctive features of the targets of each transcription factor that point to unique aspects of their functions. My comparative analysis of group B Sox binding suggests that sites that are commonly bound by Dichaete and SoxNeuro, primarily at targets in the developing nervous system, are highlyconstrained by natural selection. Uniquely bound targets have different tissue expression profiles, leading me to propose a model whereby the unique functions of Dichaete and SoxNeuro may arise from a combination of differences in their own expression patterns and the broader nuclear environment, including tissue-specific cofactors and patterns of accessible chromatin. These results shed light on the evolutionary forces that have maintained conservation of the complex functional relationships between group B Sox proteins from insects to mammals.
14

GENETICS AND GENOMICS OF CULTIVATED EGGPLANTS AND WILD RELATIVES

Gramazio, Pietro 25 June 2018 (has links)
Alimentar a la futura población en crecimiento en un contexto de cambio climático exige nuevos enfoques y herramientas de mejora genética para desarrollar nuevas variedades de cultivos que sean resilientes y eficientes en el uso de los recursos. Entre las hortalizas, la berenjena (Solanum melongena) es reconocida como un cultivo importante y como tal está incluida en el Anexo 1 del Tratado Internacional sobre los Recursos Fitogenéticos para la Alimentación y la Agricultura, que incluye 34 cultivos considerados como los más relevantes para la humanidad. Antes del inicio de esta tesis, se disponía de pocas herramientas genéticas y genómicas para la mejora genética de la berenjena, las cuales se revisan en un capítulo introductorio. Asimismo, hemos reconocido la importancia de los parientes silvestres de la berenjena, que apenas se han utilizado en la mejora genética de la misma. A este respecto, para hacer un uso más eficiente de los parientes silvestres en la mejora genética, propusimos un enfoque ambicioso, llamado "introgressiomics", que consiste en un desarrollo sistemático y masivo de materiales que lleven introgresiones de parientes silvestres (CWR), los cuales generalmente son una fuente inexplorada e desaprovechada de variación genética. Los trabajos realizados en esta tesis están relacionados con la aplicación de este enfoque a la berenjena. En este marco, los objetivos generales de la tesis son el desarrollo de la información y herramientas genéticas y genómicas en el acervo genético de la berenjena, utilizando un enfoque multidisciplinario y multifacético para la mejora genética en el desarrollo de nuevas variedades mejoradas y resistentes usando especies relacionadas como fuente de variación. Concretamente, en el primer capítulo de esta tesis, secuenciamos el transcriptoma de dos especies relacionadas con la berenjena, la silvestre Solanum incanum y la especie cultivada africana S. aethiopicum, que tienen un gran interés en la mejora genética de la berenjena. Los transcriptomas se ensamblaron en 83,905 y 87,084 unigenes para S. incanum y S. aethiopicum respectivamente, los cuales fueron extensivamente anotados estructuralmente y funcionalmente. La busqueda de variantes alélicas identificó decenas de miles de polimorfismos intraespecíficos e interespecíficos, así como alrededor de un millar de SSRs en cada especie. En el segundo capítulo, un subconjunto de esos marcadores (11 SSRs y 35 SNPs) se analizaron para confirmar su utilidad para la huella genética, la evaluación de la diversidad y el establecimiento de relaciones entre las berenjenas cultivadas (común, escarlata y gboma). Observamos que los SSRs y los SNPs proporcionaron resultados diferentes en el establecimiento de las relaciones, lo que sugiere que cada tipo de marcador muestreó diferentes niveles de variación genética. Sin embargo, aunque ambos marcadores proporcionaron un nivel similar de información, los SNPs parecen proporcionar una mejor resolución que los SSRs para materiales filogenéticamente más distantes. En el tercer capítulo, para ampliar la estimación de la diversidad genética y las relaciones genéticas entre y dentro de las especies silvestres y cultivadas pertenecientes al complejo berenjena, realizamos un genotipado masivo, mediante un enfoque de genotipado por secuenciación, de 76 accesiones pertenecientes a 17 especies del acervo genético primario, secundario y terciario de la berenjena común. De los 75,399 sitios polimórficos identificados, 12,859 se asociaron a regiones CDS y se usaron para establecer una evaluación exhaustiva y detallada de la diversidad alélica natural y las relaciones genéticas en el acervo genético de la berenjena utilizando tres enfoques diferentes (estructura jerárquica de la población, dendrograma basado en UPGMA y análisis de PCoA). En el cuatro capítulo, desarrollamos un mapa genético interespecífico entre S. incanum y S. melongena, vinculado a otros / Feeding the future burgeoning population in a climate change scenario demands new breeding approaches and tools to develop new resource-efficient and resilient crop varieties. Among vegetable crops, eggplant (Solanum melongena) is recognized as an important food crop and as such is included in the Annex 1 of the International Treaty on Plant Genetic Resources for Food and Agriculture, which includes 34 crops considered as most relevant for mankind. Before the start of this thesis, few genetic and genomic tools and resources for eggplant breeding, which are reviewed in an introductory chapter, were available. We have recognized the importance of wild eggplant relatives, which have been barely used in eggplant breeding. In this respect, in order to make a more efficient use of wild relatives in plant breeding, we proposed an ambitious approach, called "introgressiomics", consisting of a systematic and massive development of materials carrying introgressions from crop wild relatives (CWRs), which usually are an unexplored and unexploited source of genetic variation for breeding traits. The works done in this thesis are related to the application of the introgressiomics approach to eggplant. In this framework, the general objectives of the thesis are the development of genetic and genomic information and tools in eggplant genepool, using a multidisciplinary and multi-pronged approach to assist eggplant breeding in the development of new improved and resilient varieties using eggplant relatives as a source of variation. Specifically, in the first chapter of this thesis, we sequenced the transcriptome of two eggplant related species, the wild Solanum incanum and the cultivated S. aethiopicum, that have a great interest in eggplant breeding. The transcriptomes were assembled in 83,905 and 87,084 unigenes for S. incanum and S. aethiopicum respectively, which were extensively structurally and functionally annotated. The variant call analysis identified tens of thousands intraspecific and interspecific polymorphisms, as well as around a thousand of SSRs in each species. In the second chapter, a subset of those markers (11 SSRs and 35 SNPs) was tested for confirming their usefulness for genetic fingerprinting, diversity evaluation and the establishment of relationships in cultivated eggplant (common, scarlet and gboma) genepools. We observed that SSRs and SNPs provided different results in the establishment of the relationships, suggesting that each marker type sampled different levels of genetic variation. However, although both markers provided a similar level of information, SNPs seem to provide a better resolution than SSRs for materials phylogenetically more distant. In the third chapter, in order to broaden the estimation of the genetic diversity and genetic relationships among and within wild and cultivated species belonging to eggplant complexes, we performed a massive genotyping, by a genotype-by-sequencing approach, of 76 accessions belonging to 17 species from the primary, secondary and tertiary genepool of common eggplant. Out of 75,399 polymorphic sites identified, 12,859 were associated to CDS regions and used to establish an exhaustive and detailed evaluation of the natural allelic diversity and genetic relationships in eggplant genepool using three different approaches (hierarchical population structure, UPGMA-based dendrogram, and PCoA analysis). In the four chapter, we developed an interspecific genetic map between S. incanum and S. melongena, linked to four previous eggplant maps and to one tomato map. A total of 243 molecular markers were successfully mapped consisting of 42 COSII, 99 SSRs, 88 AFLPs, 9 CAPS, 4 SNPs and one morphological polymorphic markers encompassed 1085 cM distributed in 12 linkage groups. Based on the syntheny with tomato, the candidate genes involved in the core chlorogenic acid synthesis pathway in eggplant (PAL, C4H, 4CL, HCT, C3¿H, HQT), five polyphenol oxidase genes (PPO1, PPO2, PPO3, PP / Alimentar la futura població en creixement en un context de canvi climàtic exigeix nous enfocaments i eines de millora genètica per desenvolupar noves varietats de cultius que siguin resilients i eficients en l'ús dels recursos. Entre les hortalisses, l'albergínia (Solanum melongena) és reconeguda com un cultiu important i com a tal està inclosa en l'Annex 1 del Tractat Internacional sobre els Recursos Fitogenètics per a l'Alimentació i l'Agricultura, que inclou 34 cultius considerats com els més rellevants per a la humanitat. Abans de l'inici d'aquesta tesi, es disposava de poques eines genètiques i genòmiques per a la millora genètica de l'albergínia, les quals es revisen en un capítol introductori. Així mateix, hem reconegut la importància dels parents silvestres de l'albergínia, que tot just s'han utilitzat en la millora genètica de la mateixa. Referent a això, per fer un ús més eficient dels parents silvestres a la millora genètica, vam proposar un enfocament ambiciós, anomenat "introgressiomics", que consisteix en un desenvolupament sistemàtic i massiu de materials que portin introgresions de parents silvestres (CWR), els quals generalment són una font inexplorada i desaprofitada de variació genètica. Els treballs realitzats en aquesta tesi estan relacionats amb l'aplicació d'aquest enfocament a l'albergínia. En aquest marc, els objectius generals de la tesi són el desenvolupament de la informació i eines genètiques i genòmiques en el patrimoni genètic de l'albergínia, utilitzant un enfocament multidisciplinari i multifacètic per a la millora genètica en el desenvolupament de noves varietats millorades i resistents emprent spècies relacionades com a font de variació. Concretament, en el primer capítol d'aquesta tesi, seqüenciem el transcriptoma de dues espècies relacionades amb l'albergínia, la silvestre Solanum incanum i l'espècie cultivada africana S. aethiopicum, que tenen un gran interès en la millora genètica de l'albergínia. Els transcriptomes s'ensamblaren en 83,905 i 87,084 unigenes per S. incanum i S. aethiopicum respectivament, els quals van ser extensivament anotats estructuralment i funcionalment. La recerca de variants al·lèliques va identificar desenes de milers de polimorfismes intraespecífics i interespecífics, així com al voltant d'un miler de SSRs en cada espècie. En el segon capítol, un subconjunt d'aquests marcadors (11 SSRs i 35 SNPs) es van analitzar per confirmar la seva utilitat per l'empremta genètica, l'avaluació de la diversitat i l'establiment de relacions entre les albergínies conreades (comú, escarlata i gboma). Observem que els SSRs i els SNPs van proporcionar resultats diferents en l'establiment de les relacions, el que suggereix que cada tipus de marcador va mostrejar diferents nivells de variació genètica. No obstant això, encara que tots dos marcadors van proporcionar un nivell similar d'informació, els SNPs semblen proporcionar una millor resolució que els SSRs per materials filogenèticament més distants. En el tercer capítol, per a ampliar l'estimació de la diversitat genètica i les relacions genètiques entre i dins de les espècies silvestres i conreades pertanyents al complex albergínia, vam realitzar un genotipat massiu, mitjançant un enfocament de genotipat per seqüenciació, de 76 accessions pertanyents a 17 espècies del patrimoni genètic primari, secundari i terciari de l'albergínia comuna. Dels 75,399 llocs polimòrfics identificats, 12,859 es van associar a regions CDS i es van usar per a establir una avaluació exhaustiva i detallada de la diversitat al·lèlica natural i les relacions genètiques en el patrimoni genètic de l'albergínia utilitzant tres enfocaments diferents (estructura jeràrquica de la població, dendrograma basat en UPGMA i anàlisi de PCoA). En el quart capítol, desenvolupem un mapa genètic interespecífic entre S. incanum i S. melongena, vinculat a altres quatre mapes anterior / Gramazio, P. (2018). GENETICS AND GENOMICS OF CULTIVATED EGGPLANTS AND WILD RELATIVES [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/104605 / TESIS
15

The Acquisition of Student Nurses' Knowledge of Genetics and Genomics and Attitudes Toward the Application of their Knowledge in Clinical Practice

Munroe, Theresa 01 August 2014 (has links)
BACKGROUND: Nurses have the opportunity to bring a unique perspective to genetic and genomic healthcare through their emphasis of health promotion, prevention, screening, caring, and patient, family, and community relationships. Nurses are expected to have genetic and genomic knowledge that can be integrated into clinical practice. However, researchers today are finding nursing students are not competent or comfortable in the clinical applications of genetics and genomics, even though these students will soon be working in healthcare as it advances in these fields. The purpose of this research was to evaluate the genetic and genomic knowledge of nursing undergraduate students and explore their attitudes about using this knowledge in practice. METHOD: A pre- and posttest design was used. Student knowledge was measured online using the Genomic Nursing Concept Inventory (GNCI©) in both tests. Demographic questions were included in the pretest and questions regarding attitudes toward comfort and readiness to apply that knowledge were included in the posttest. The pretest was administered at the beginning of the Spring 2014 semester. The posttest was administered at the end of the same semester, after the nursing students received the majority of genetic and genomic instruction from their program's curriculum. Descriptive statistics were used to examine all data. Total and subscale knowledge scores on the GNCI© were computed for each test. A paired t-test was used to compare pre- and post-GNCI© total and subscale scores. Correlations were calculated at both time points. A Spearman correlation was used to examine the relationship between prior experience with genetic education or exposure to people with a genetic condition and total pre-score knowledge on the pretest. For the posttest, a total attitude score was calculated to examine the relationship between attitude and post total knowledge scores using a Pearson's r correlation. FINDINGS: 109 undergraduate junior nursing students participated. Gains in total and subscale knowledge between the pre- and posttest were statistically significant (p < 0.05), except for the Mutations subscale. For the pretest GNCI©, the average mean score was 45%, which improved to 50% at the time of the posttest. Lowest scoring items were in the Genome Basics subscale, whereas highest scoring items were found within the Inheritance subscale for the posttest. Mean total attitude scores were 28.33 (SD = 5.17) indicating students had a relatively positive attitude towards using their knowledge base in practice. The majority of students (87.1%) agreed that it is important for the nurse to incorporate genetic and genomic knowledge into clinical practice although only 34.9% felt ready to do so. DISCUSSION: Genetics and genomic knowledge and preparedness were low among nursing students. This demonstrates a need for more integration of genetic and genomic content within nursing curriculum, including a review of basic concepts. Nurses are expected to perform comprehensive health assessments by incorporating knowledge of genetic, environmental, and genomic influences and risk factors. Lack of a basic understanding could lead to patient consequences related to inadequate risk assessment, referrals for genetic counseling, and patient education.
16

Identifying causative elements within structural variants associated with developmental disorders

Boulding, Hannah January 2013 (has links)
It has been well established that copy number variation contributes substantially to genetic variation within human populations. However, the extent to which de novo and inherited copy number variants (CNVs) underlie human disease is not well known. In this thesis, I investigate the role of de novo and inherited CNVs in a wide range of developmental abnormalities. First, I compare disease associated and apparently benign CNVs for structural differences, with the aim of identifying distinguishing features of disease causing CNVs. I identified significant enrichments of protein-coding genes, protein-coding genes associated with disease in OMIM and miRNAs amongst disease associated disease. Conversely, inherited CNVs observed in healthy individuals show depletions of these features. Following this, I employ functional enrichment approaches to identify the copy number variable genes within these de novo CNVs that contribute to the patient’s developmental abnormalities. I predict candidate genes for 143 different developmental abnormalities, with 65% of the candidate genes not having been previously associated with disease in OMIM. Through examining the distribution of these candidate genes within the patient’s CNVs, I found evidence of extensive pleiotropy and epistasis as well as a small number of simple additive effects. Finally, I extend my analyses to examine the role of inherited CNVs as the underlying cause of human developmental disorders. I implicate inherited CNVs and their overlapping copy number variable genes in the underlying causes of 45 human developmental abnormalities. Additionally, I re-examine the patients possessing both de novo CNVs and inherited CNVs using functional enrichment analyses. I reveal significant enrichments for a greater number of human developmental abnormalities when combining both the de novo and inherited CNVs, suggesting it is de novo mutations in combination with the inherited genomic background that are responsible for many instances of human developmental abnormalities.
17

Relationships between chromatin features and genome regulation

Stempor, Przemyslaw January 2018 (has links)
Regulation of gene expression is an essential process for all living organisms. Transcriptional regulation, associated with chromatin, is governed by: (1) DNA sequence, which creates regulatory sites (promoters, enhancers and silencers), where sequence motifs and features (e. g. CpG) can attract transcription factors (TFs) and influence chromatin structure or RNA polymerase II (Pol II) binding, initiation and elongation; (2) non-sequence, epigenetic factors - histone modifications, TF binding, chromatin remodelling (histone placement, eviction and reconstitution), and non-coding RNA regulation. These factors interact with each other, creating a complex network of interactions. In this thesis I describe computational studies of heterochromatin factors in regulation of gene and repeat expression, an analysis of active regulatory elements, and global analyses of big datasets in C. elegans. I first show that a team of heterochromatin factors - HPL-2/HP1, LIN-13, LIN-61, LET-418/Mi-2, and H3K9me2 histone methyltransferase MET-2/SETDB1 - collaborates with piRNA and nuclear RNAi pathways to silence repetitive elements and protect the germline. I also found that the TACBGTA motif is particularly enriched on repeats and heterochromatin factors binding sites, and that repeat elements are derepressed in the soma during normal C. elegans ageing. I then describe the work on active regulatory regions. I show that CFP-1/CXXC1 binds CpG dense, nucleosome depleted promoters and, along SET-2, is required for H3K4me3 deposition at these loci. Using expression profiling I determined that the majority of CFP-1 binding targets are not significantly mis-regulated in cfp-1 mutants, but are weakly upregulated in bulk analyses. I also show that CFP-1 functionally interacts with the Sin3S/HDAC complex. In cfp-1 mutant I observed both loss and gain of SIN-3 binding, depending on chromatin context. Finally, I performed a data driven study on a large collection of ChIP-seq profiles using non-parametric sparse factor analyses (NSFA) and compared it to other, unsupervised machine learning algorithms. This study uncovered interactions and structure in genomic datasets. In addition, I present a collection of computational tools and methods I developed to facilitate processing, storage, retrieval, annotation, and analyses of large datasets in genomics.
18

Computational analysis of susceptibility genes for diabetes and cardiovascular diseases in animal models

Wilder, Steven P. January 2007 (has links)
No description available.
19

Evolutionary Patterns and Occurrences of the fish Viral Hemorrhagic Septicemia Virus in the Laurentian Great Lakes

Niner, Megan 06 September 2019 (has links)
No description available.
20

BSN Students’ Knowledge of Genetics and Genomics

Besse, Kevin Troy January 2014 (has links)
No description available.

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