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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.
421

Marcadores moleculares microssatélites na investigação do genoma de Drosophila mediopunctata = desenvolvimento e construção de mapa genético de ligação / Microsatellite markers in the investigation of Drosophila mediopunctata genome : development and genetic linkage map construction

Laborda, Prianda Rios 18 August 2018 (has links)
Orientador: Anete Pereira de Souza / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-18T12:23:33Z (GMT). No. of bitstreams: 1 Laborda_PriandaRios_D.pdf: 3045492 bytes, checksum: d1a998a5b1c4300247471d90da1ee8da (MD5) Previous issue date: 2011 / Resumo: Drosophila mediopunctata, mosca não cosmopolita de distribuição neotropical e pertencente ao grupo tripunctata do subgênero Drosophila, é uma espécie utilizada por alguns grupos no Brasil como modelo em estudos com enfoque evolutivo. Abordagens que exploram a biologia da espécie, tais como a detecção de variação genética natural e a influência de inversões cromossômicas na dinâmica populacional são costumeiramente usadas. Todavia, essa espécie não possui disponíveis marcadores moleculares que facilitem a investigação das bases genéticas que norteiam os eventos explorados até agora. Os microssatélites são marcadores moleculares consagrados e a ferramenta de escolha no estudo de diversos organismos pela simplicidade de uso e de análise. Entretanto, para espécies que ainda não têm grande parte de seu genoma seqüenciado, a obtenção de marcadores desse tipo passa pela necessidade de desenvolvimento via bibliotecas genômicas. Esse trabalho objetivou desenvolver, caracterizar e mapear microssatélites em D. mediopunctata para que estudos de variação morfológica, de identificação de regiões genômicas associadas a fenótipos de interesse, de genética de populações entre outros possam ser realizados com o respaldo de dados moleculares. Uma biblioteca enriquecida em motivos repetitivos foi construída e, após o seqüenciamento de aproximadamente 2000 clones, 600 microssatélites foram identificados e 134 locos desenvolvidos. Os marcadores mostraram tamanho reduzido com relação ao número de repetições e preponderância de motivos AC/GT. A aplicação dos microssatélites de D. mediopunctata para amplificações heterólogas em outras trinta espécies foi feita com aproximadamente 50% de sucesso. Em adição, o uso de dados de presença/ausência nas espécies do grupo tripunctata recuperou algumas relações filogenéticas previamente conhecidas. Um mapa de ligação foi construído com 49 marcadores e revelou 450 cM de extensão. Os cinco principais cromossomos da espécie foram identificados por meio de comparações com o genoma de D. melanogaster e com os elementos de Müller. Essas comparações também confirmaram a grande sintenia prevista dentro do gênero Drosophila. Não houve concordância na ordem dos locos microssatélites nas duas espécies. No cromossomo II de D. mediopunctata foi mapeada uma região associada à característica "número de pintas abdominais" / Abstract: Drosophila mediopunctata, a non-cosmopolitan fly of Neotropical distribution that belongs to the tripunctata group of the Drosophila subgenus, was chosen by some Brazilian researchers as a model in evolutionary studies. Several approaches, such as the analysis of natural variation and the influence of chromosome inversions in population dynamics, are traditionally used. Nevertheless, molecular markers, which would enhance the investigation of the genetic bases of the already known phenomena, are still not available for the species. Microsatellites are celebrated molecular markers and the chosen tool for the exploration of various organisms due to their ease of use. Nonetheless, their application in species whose genomes have not yet been sequenced requires a prior development phase. This study intended to develop, characterize and map microsatellites for the species D. mediopunctata so that initiatives concerning morphological variation, identification of genomic regions linked to interesting phenotypes, population genetics, etc can be carried out in the light of molecular data. A repetitive DNA-enriched library was constructed and approximately 2000 clones were sequenced. Six hundred microsatellites were identified and 134 loci were developed. The loci are small in length, with reduced number of motif repetitions, and are mainly composed of AC/GT dinucleotides. The use of D. mediopunctata microsatellites for heterologous amplification in other thirty Drosophila species was done with a 50% success ratio. In addition, a clustering analysis carried out with binary data obtained from the tripunctata species recovered already known phylogenetic relationships. A linkage map was constructed with recombination data of 49 markers and is 450 cM in length. The five major species chromosomes were identified on the basis of comparisons with the D. melanogaster genome and the Müller elements. This strategy also confirmed the great synteny predicted for the genus Drosophila. It was not observed agreement in loci order between both species. A genomic region associated to the number of abdominal spots was mapped to the chromosome II of D. mediopunctata / Doutorado / Genetica Animal e Evolução / Doutor em Genetica e Biologia Molecular
422

Genetic Diversity in the Himalayan Populations of Nepal and Tibet

Gayden, Tenzin 19 March 2012 (has links)
The Himalayan Mountain range encompasses an unparalleled landscape featuring some of the planet’s highest peaks, including Mount Everest. In the heart of this massive orographic barrier lies Nepal, sandwiched in the historically geostrategic position between the Tibetan plateau to the north and India in the south. Until recently, Nepalese and Tibetan populations remained poorly characterized genetically, partly because of their inaccessible geographical locations. In the present study, the genetic diversity of these two Himalayan populations is evaluated using different marker systems, including mitochondrial DNA (mtDNA) and Short Tandem Repeats (STRs) in the autosomes as well as on the Y-chromosome (Y-STR). While autosomal STRs are distributed throughout the genome and are biparentally inherited, the Y-chromosome and mtDNA are haploid markers and provide the paternal and maternal histories of the population, respectively. Fifteen autosomal STR loci were typed in 341 unrelated individuals from three Nepalese populations (188), namely Tamang (45), Newar (66) and Kathmandu (77), and a general collection from Tibet (153). These samples were also sequenced for the mtDNA control region and all of them were subsequently assigned to 75 different mtDNA haplogroups and sub-haplogroups by screening their diagnostic sites in the coding region using Restriction Fragment Length Polymorphism analysis and/or sequencing, thus achieving an unprecedented level of resolution. The results from the autosomal and mtDNA data suggest a Northeast Asian origin for the Himalayan populations, with significant genetic influence from the Indian subcontinent in Kathmandu and Newar, corroborating our previous Y-chromosome study. In contrast, Tibet displays a limited Indian component, suggesting that the Himalayan massif acted as a natural barrier for gene flow from the south. The presence of ancient Indian mtDNA lineages in Nepal implies that the region may have been inhabited by the earliest settlers who initially populated South Asia. In addition, seventeen Y-STR loci were analyzed in 350 Tibetan males from three culturally defined regions of historical Tibet: Amdo (88), Kham (109) and U-Tsang (153). The results demonstrate that the 17 Y-STR loci studied are highly polymorphic in all the three Tibetan populations examined and hence are useful for forensic cases, paternity testing and population genetic studies.
423

Mécanismes d’alignement et de ségrégation des chromosomes lors de la mitose dans les zygotes de Caenorhabditis elegans / Mechanisms of chromosome alignment and segregation during mitosis in Caenorhabditis elegans zygotes

Edwards, Frances 03 July 2018 (has links)
La mitose permet la multiplication des cellules, contribuant ainsi à générer de nouveaux organismes unicellulaires, ou à construire des organismes multicellulaires. Pendant la mitose, le génome répliqué de la cellule mère est réparti entre les deux cellules filles. Les erreurs survenant lors de la répartition peuvent mener à l’aneuploïdie, une caractéristique de certaines maladies développementales dont les cancers. La fidélité de la répartition des chromatides sœurs dépend du fuseau mitotique, un réseau bipolaire de microtubules qui dirigent les chromosomes via leurs interactions avec les kinétochores assembles sur les chromatides sœurs. Ces interactions mènent à l’alignement des chromosomes, et à leur biorientation. Les chromatides sœurs sont alors attachés à des microtubules .manant des pôles opposés du fuseau. La ségrégation des chromatides sœurs a alors lieu en anaphase, et simultanément le fuseau central est assemblé entre les deux jeux de chromosomes. Cette structure composée de microtubules contribue à la ségrégation des chromatides sœurs en spécifiant la localisation et en favorisant l’ingression du sillon de division cellulaire. Pendant ma thèse, j’ai étudié les fonctions d’un ensemble de protéines du kinétochore, BUB-1, HCP-1/2CENP-F et CLS-2CLASP, lors de la mitose dans les zygotes de C. elegans. En combinant des approches de génétique et de vidéo-microscopie, j’ai montré que ces protéines participent à l’alignement et à la ségrégation des chromosomes. En particulier, BUB-1 contribue à l’alignement des chromosomes en accélérant l’attachement des microtubules aux kinétochores, tout en contrôlant la conformation et la maturation de ces attachements. Ces activités dépendent du recrutement de HCP-1/2 et CLS-2 par BUB-1, mais aussi du complexe RZZ et de la dynéine, ainsi que d’une activité de BUB-1 inhibant le recrutement du complexe SKA aux kinétochores. De plus, j’ai montré que BUB-1, HCP-1/2 and CLS-2 contribuent à l’assemblage des microtubules du fuseau central via l’activité polymérase de CLS-2. Cette fonction dépend du pré-recrutement de ces protéines aux kinétochores en métaphase, en aval de KNL-1, révélant une nouvelle fonction pour les kinétochores dans l’assemblage du fuseau central. Ce travail identifie donc des fonctions versatiles pour ces protéines, les plaçant comme des gardiennes majeures de l’intégrité génétique / Mitosis is a process by which cells multiply, contributing to the generation of new unicellular organisms, or the construction of multicellular organisms. During mitosis, the daughter cells inherit an identical copy of the mother cell’s replicated genome. Errors in genetic material distribution can lead to aneuploidy, a hallmark of developmental diseases including cancer. The accurate segregation of sister chromatids relies on the mitotic spindle, a bipolar network of microtubules that governs chromosome movements by interacting with the kinetochores assembled on sister chromatids. This drives chromosome alignment at the spindle equator, and chromosome bi-orientation meaning that sister kinetochores are connected to opposite spindle poles, laying the ground for sister chromatid segregation during anaphase. Once segregation has initiated, the microtubule-based central spindle is assembled between the two sets of chromosomes. This structure contributes to sister chromatid segregation, by specifying the location and favoring the ingression of the cytokinesis furrow. During my thesis, I have studied the functions of a subset of conserved kinetochore proteins called BUB-1, HCP-1/2CENP-F and CLS-2CLASP, during mitosis in C. elegans zygotes. By combining genetics and live imaging, I have shown that these proteins are involved both in chromosome alignment and segregation. In particular, I have shown that BUB-1 contributes to chromosome alignment by accelerating the establishment of end-on kinetochore-microtubule attachments, while controlling the conformation and maturation of these attachments. These activities rely on BUB-1’s downstream partners HCP-1/2CENP-F and CLS-2CLASP, but also on the RZZ complex and dynein, as well as an activity for BUB-1 in inhibiting the recruitment of the SKA complex. Additionally, I have shown that BUB-1, HCP-1/2CENP-F and CLS-2CLASP contribute to central spindle microtubule assembly, via CLS-2CLASP’s polymerase activity. This function relies on the prior kinetochore recruitment of these proteins during metaphase by the kinetochore scaffold protein KNL-1, revealing a new function for the kinetochore in central spindle assembly. Together, this work identifies versatile functions for this subset of conserved kinetochore proteins, making them major safe-keepers of genomic integrity
424

Automatizovaný návrh obrazových filtrů na základě kartézského genetického programování / Towards the Automatic Design of Image Filters Based on Cartesian Genetic Programming

Kečkéš, Miroslav January 2012 (has links)
The aim of this diploma thesis is using cartesian genetic programming on design image filters and creating basic structure for implement diferent type of problems. Genetic programming is rapidly growing method, which often using for solve dificult problems. This thesis analyze basic principle, way of application and implementing this method to design filters. Result of this thesis is program realize design filters define by specific parameters, overview of implementig method and achieve summary from this sphere.
425

Genome Size and Determination of DNA Content of the X Chromosomes, Autosomes, and Germ Line-Limited Chromosomes of Sciara Coprophila

Rasch, Ellen 01 November 2006 (has links)
The unique chromosome biology of the fungus fly Sciara coprophila has fascinated investigators for over 80 years. Male meiosis exhibits a monopolar spindle, nonrandom segregation of imprinted chromosomes and nondisjunction of the X chromosome. The unusual mechanism of sex determination requires selective elimination of X chromosomes in embryogenesis. Super-numerary (L) chromosomes are also eliminated from the soma during early cleavage divisions. Distinctive DNA puffs on the larval salivary gland chromosomes are sites of DNA amplification. As a foundation for future genome studies to explore these many unusual phenomena, we have used DNA-Feulgen cytophotometry to determine genome size from hemocyte nuclei of male (X0) and female (XX) larvae and adults. The DNA content of the X chromosome is ∼0.05 pg DNA and the autosomal complement is ∼0.45 pg DNA. Measurements of DNA levels for individual sperm from adults showed that the DNA contribution of the germ line-limited (L) chromosomes constitutes as much as 35% of the DNA of the male gamete. A parallel study using Sciara ocellaris, a related species lacking L chromosomes, confirmed the presence of two X chromosomes in the sperm of this species.
426

Analysis of SUMO dynamics and functions during meiosis in oocytes / 卵母細胞の減数分裂におけるSUMOの動態および機能の解析 / # ja-Kana

Ding, Yi 25 September 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(生命科学) / 甲第21400号 / 生博第401号 / 新制||生||53(附属図書館) / 京都大学大学院生命科学研究科高次生命科学専攻 / (主査)教授 松崎 文雄, 教授 石川 冬木, 教授 松本 智裕 / 学位規則第4条第1項該当 / Doctor of Philosophy in Life Sciences / Kyoto University / DFAM
427

Characterization of a Novel RING-type Ubiquitin E3 Ligase GhRING2 involved in Cotton Fiber Development

Soma, Shiva Theja Reddy 14 December 2013 (has links)
The ubiquitin-proteasome proteolysis pathway is responsible for the degradation of abnormal and short-lived proteins to regulate many important biochemical activities in eukaryotes. By employing affymetrix microarray analysis, we have identified a novel ubiquitin ligase E3 gene GhRING2 that is expressed differentially between two G. hirsutum lines - Texas Marker-1 and Chromosome Substitution Line CS-B25. The complete GhRING2 gene sequence was obtained by genomic and cDNA walking. The expression of GhRING2 in cotton fiber is developmentally regulated, suggesting that the ubiquitin-proteasome pathway may regulate cotton fiber growth and development. Using a yeast two-hybrid assay GhRING2 was found to interact with a PROTODERMAL FACTOR1 (GhPDF1) protein. GhPDF1 is expressed preferentially in immature ovules and fiber initials and the gene has been suggested to play a role in cell fate determination and fiber development. Pull down and plasmid swap assays were employed to confirm this interaction.
428

Functional analysis of the human androgen receptor using synthetic and naturally occurring mutations

Kazemi-Esfarjani, Parsa. January 1996 (has links)
No description available.
429

Analysis of two point mutations in the androgen receptor gene of patients with complete androgen resistance

Bordet, Sylvie January 1992 (has links)
No description available.
430

Genetic information and the family : a challenge to medical confidentiality

Lacroix, Mireille, 1971- January 2003 (has links)
No description available.

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