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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

Phylogeography and Genetic Diversity of the Commercially-Collected Caribbean Blue-Legged Hermit Crab: Implications for Conservation

Stark, Tiara Elizabeth January 2018 (has links)
No description available.
12

Ecology and reproduction of neotropical soil-feeding termites from the Termes group

Hellemans, Simon 24 April 2019 (has links) (PDF)
The traditional view of a lifelong monogamy between a king and a queen has recently been challenged in termites. In several species, multiple parthenogenetically-produced secondary queens replace the primary queen and mate with the primary king; this strategy is referred to as “Asexual Queen Succession” (AQS). The aim of my thesis was to investigate the modalities of reproduction and the ecology of neotropical soil-feeding termites from the Termitinae, with a focus on the inquiline termite Cavitermes tuberosus in the Termes group.In the first axis, we investigated the modalities of reproduction of C. tuberosus. (i) AQS is the main reproductive strategy of this species. (ii) The evolution of AQS requires the propensity of parthenogens to develop into neotenic queens. In C. tuberosus, secondary queens develop from a developmental stage of “aspirants” which participate to the social tasks usually undertaken by workers, as long as the primary queen is alive. (iii) In AQS species, a female-biased sex ratio is expected in the dispersing reproductives. In C. tuberosus, sex ratio varies among years and according to the type of reproductives, and the population sex ratio is balanced. These results raise hints on queen-king conflict over the sex ratio.In the second axis, we described the ecology and symbioses of C. tuberosus. (iv) Wolbachia, an endosymbiotic bacterium mainly known for manipulating the reproduction of arthropods in order to enhance its own transmission, infects all individuals in societies. This bacterium, particularly abundant in a gut-associated bacteriome, may play a role in the nutrition of C. tuberosus; both partners would have evolved a mutualistic symbiosis. (v) Inquiline termites live in a nest built by other termite species and do not forage outside. Physico-chemical measures and microbiota sequencing revealed that C. tuberosus is a generalist nest-feeder.Finally, we expanded our study of the breeding systems in the phylogenetic proximity of C. tuberosus. (vi) We described Palmitermes impostor, a new genus and species as a sister-group to the genus Cavitermes. (vii) AQS is the main reproductive strategy in P. impostor, and queens of Spinitermes trispinosus and Inquilinitermes inquilinus are able to reproduce parthenogenetically. Therefore, it appears likely that the conditional use of sexual and asexual reproductions is a preadaptation common to the whole Termes group, and that it evolved into a stable element of their breeding system at least in some species.Overall, our results open new perspectives in the understanding of reproductive strategies in termites and their relationships with their bacterial symbionts. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
13

Free-Living and Symbiotic Bacterial Communities in Contrasting Hydrothermally Active Habitats

Forget, Nathalie 29 August 2013 (has links)
Prokaryotic microorganisms, which are at the base of deep-sea hydrothermal vent food webs, adapt rapidly to environmental fluctuations. This study aimed at comparing bacterial communities in contrasting hydrothermal habitats to better understand compositional adaptations to local conditions. I first used small subunit (SSU) ribosomal RNA (rRNA) gene sequences to compare mat-forming bacterial communities associated with iron oxides at two hydrothermal vent sites on the Tonga Arc, southwest Pacific. Operational taxonomic units (OTUs), defined at 97% sequence similarity, were affiliated to a great diversity of autotrophic and heterotrophic groups. Metabolically diverse Gammaproteobacteria dominated the sample from Volcano 19, collected at 992 m depth. The sample from Volcano 1, collected at 197 m depth, was dominated by iron-oxidizing bacteria from the class Zetaproteobacteria. The depth of the sampling sites was proposed to explain clone library dissimilarities. In the following studies, I compared bacterial communities associated with the vestimentiferan tubeworm Ridgeia piscesae, a foundation species at the Juan de Fuca Ridge. Samples of the polychaete were collected from tubeworm habitats in contrasting flow regimes that influenced temperature and hydrogen sulphide concentrations. Free-living bacteria were analyzed using both sequencing and 454 pyrosequencing of the SSU rRNA gene. Statistical analyses suggested a predictable pattern of bacterial community composition for the two habitats, with higher proportions of sulphur and hydrogen oxidizers in High Flow and more heterotrophic groups in Low Flow environments. Temperature, available energy for metabolism, and stability of the habitat were suggested to explain these distinctive bacterial communities. Symbiotic assemblages were investigated using the same sequencing methods together with catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). Gammaproteobacteria dominated all sequence libraries, followed by Epsilonproteobacteria. CARD-FISH confirmed the co-occurrence of these groups within R. piscesae trophosomes. Statistical analyses indicated distinctive membership and structure of trophosome assemblages between sampling sites. Analysis of R. piscesae juvenile showed distinctive structural properties when compared to adult individuals, but similar membership, within sampling sites. These results suggested that the composition of trophosome assemblages might be affected by specific physical and chemical conditions at each vent site and that a selection process might occur during R. piscesae’s development. / Graduate / 0410 / 0416 / 0329 / nathalieforget@gmail.com
14

Desenvolvimento de metodologias para identificação molecular do HPV

Rocha, Bruno Garcia 31 March 2016 (has links)
Submitted by Livia Mello (liviacmello@yahoo.com.br) on 2016-10-14T19:44:04Z No. of bitstreams: 1 TeseBGR.pdf: 2376550 bytes, checksum: 4ee6a0f02e589ae693965093fa4f2f42 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-11-08T18:48:20Z (GMT) No. of bitstreams: 1 TeseBGR.pdf: 2376550 bytes, checksum: 4ee6a0f02e589ae693965093fa4f2f42 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-11-08T18:48:29Z (GMT) No. of bitstreams: 1 TeseBGR.pdf: 2376550 bytes, checksum: 4ee6a0f02e589ae693965093fa4f2f42 (MD5) / Made available in DSpace on 2016-11-08T18:48:36Z (GMT). No. of bitstreams: 1 TeseBGR.pdf: 2376550 bytes, checksum: 4ee6a0f02e589ae693965093fa4f2f42 (MD5) Previous issue date: 2016-03-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The Human Papiloma Virus (HPV) is a Sexually Transmitted Disease (STD) very common in the world. It infects the human epithelium may persisting of asymptomatic form or causing some neoplasia. Many studies report the association between HPV and many kinds of cancer such as: lap utero, anus, penis, vagina and vulva. According to INCA data for the year of 2016 are expected 16.340 new cases of lap utero cancer, being the second most frequent case in the female population in Brazil. For the recognition of the virus, there`s a lots of tracking methods, as morphological test (pap test), that observes cytopathic effects caused by the virus on human cells, suggesting the existence of infection, however this type of test presents low results and has shown high taxes of false negative and positive results. To overcome this problems, countless studies has shown the effect of molecular techniques utilization to increase the sensibility and especially, getting recognize and genotyping the HPV virus. On this recent studies, were tested distinct molecular techniques for typing the HPV virus, as Conventional PCR followed by Sanger Sequencing , Real time PCR (SYBRGreen® e Taqman ®) and Sequencing of New Generation. Altogether were collected 318 samples pf cervix grated, and from this material were collected the DNA using an adapted protocol (POWELL; GANNON, 2002). Using the conventional PCR technique followed by Sanger Sequencing we obtained 65 positives samples for the HPV(21%), in 49 samples(75,3%) it was possible to identify the HPV type, in the other 16 samples(24,7%) it was not possible the identification, probably because the infection was formed for two or more types of the virus. With the real time PCR technique using SYBRGreen®, were accomplished an experimente with 30 samples, which was possible to confirm the results in 28 of it, using Sanger Sequencing. In two samples the results are not confirmed, being possible to positive the sample, showing high sensibility of the real time PCR technique. The methodology of New Generation Sequencing (NGS) it showed useful for HPV identification, being one of the first studies published for routine use. And it has great prospects because besides HPV can identify other microorganisms in the sample and quantifies them as well. / O Papilomavírus humano conhecido como HPV é uma doença sexualmente transmissível frequente em todo mundo, ele infecta o epitélio de seres humanos, podendo persistir de forma assintomática ou causar neoplasias. Diversos estudos relatam a associação entre o HPV (Alto Risco) e diversos tipos de câncer como: colo de útero, ânus, orofaringe, pênis, vagina e vulva. Segundo dados do INCA para o ano de 2016, são esperados 16.340 novos casos de câncer de colo de útero, sendo de maior frequência na população feminina no Brasil. Para a identificação do vírus existem inúmeros métodos de rastreio como testes morfológicos (exame do Papanicolau), que observam os efeitos citopáticos que o vírus provoca nas células sugerindo a existência da infecção, mas este tipo de teste apresenta baixa especificidade e vem apresentando altas taxas de falsos-negativos e positivos. Para contornar estes problemas inúmeros estudos têm demostrando a eficácia da utilização de técnicas moleculares, para aumentar a sensibilidade e especificidade, conseguindo identificar e genotipar o vírus do HPV. No presente estudo foram testadas diferentes técnicas moleculares para a identificação do vírus do HPV como: PCR convencional seguida por sequenciamento Sanger, PCR em tempo real (SYBRGreen® e Taqman®) e sequenciamento de nova geração. Ao todo foram coletadas 318 de amostras de raspado do colo cervical. Deste material foi extraído o DNA utilizando um protocolo adaptado (POWELL, GANNON, 2002). Utilizando a técnica da PCR convencional seguida por sequenciamento Sanger obtivemos 65 amostras positivas para o HPV (21%), destas 49 amostras (75,3%) foi possível identificar o tipo do HPV e em 16 casos (24,7%) não foi possível identificar o vírus, sendo possivelmente uma infecção formada por dois ou mais tipos do vírus. Com a técnica de PCR em tempo real utilizando SYBRGreen® foi realizado um experimento com 30 amostras sendo possível confirma o resultado destas com o sequenciamento Sanger em 28 casos. Em duas amostras os resultados não corroboraram, sendo possível positivar a amostra. Mostrando a maior sensibilidade da técnica de PCR em tempo real. A metodologia de sequenciamento de nova geração (NGS) se mostrou útil para identificação do HPV, demonstrada neste trabalho de maneira inédita. O uso do NGS apresenta boas perspectivas pois além do HPV pode identificar outros microrganismos na amostra e quantifica-los.
15

Mutations impliquées dans la progression du cancer épithélial de l'ovaire

El-Masri, Rayane 08 1900 (has links)
Le cancer épithélial de l’ovaire (CEO) est le cancer gynécologique le plus létal. Plus de 70% des patientes diagnostiquées avec une tumeur de stade avancé rechutent suite aux traitements chimiothérapeutiques de première ligne, la survie à cinq ans étant ainsi très faible. Afin de mieux comprendre l’évolution de la maladie, nous avons recherché de nouveaux gènes, responsables de l’initiation et de la progression du CEO. Précédemment, des lignées cellulaires ont été dérivées à partir de la tumeur primaire et récurrente et/ou d’ascites de trois patientes. Le séquençage de l’ARN de ces lignées par la technologie de séquençage de nouvelle génération (TSNG) nous a permis d’identifier des mutations ponctuelles qui pourraient nous indiquer des gènes dérégulés dans le CEO. La TSNG est un bon outil qui permet d’identifier et de cribler à grande échelle des mutations. Nous avons sélectionné PLEC1, SCRIB, NCOR2, SEMA6C, IKBKB, GLCE et ITGAE comme gènes candidats présentant des mutations dans nos lignées et ayant une relation fonctionnelle avérée avec le cancer. Étant donné que la TSNG est une technique à taux de fiabilité limité, nous avons validé ces mutations par séquençage Sanger. Ensuite, nous avons étudié l’effet de ces mutations sur la structure protéique et l’expression de PLEC1, de SCRIB et de SEMA6C. Seules certaines mutations dans les gènes PLEC1, SCRIB et SEMA6C ont pu être confirmées. PLEC1 et SCRIB sont deux protéines d’échafaudage dont la mutation, rapportée dans plusieurs cancers, pourrait induire des changements de leurs conformations et affecter leurs interactions et leurs fonctions. Les conséquences de ces mutations sur la tumorigenèse de l’ovaire devront être étudiées. / Epithelial ovarian cancer (EOC) is the most lethal gynecological cancer. Over 70% of the patients diagnosed with advanced stage of cancer relapse following first-line chemotherapy treatments; consequently the five-year survival is very low. To better understand the evolution of the disease, our aim was to identify new genes responsible for the initiation and progression of EOC. Previously, cell lines derived from solid tumors or ascites were developed from the primary and recurrent tumor or ascites of three patients. RNA sequencing of these cell lines by next-generation sequencing technology (NGST) allowed us to identify mutations that might point to genes whose deregulation is important in EOC. Mutations were detected in PLEC1, SCRIB, NCOR2, SEMA6C, IKBKB, GLCE and ITGAE. We selected these genes for further studies as they have previously been identified as being associated with cancer. First, we validated these mutations by Sanger sequencing in order to determine the concordance with NGST data. Secondly, we studied the impact of the validated mutations on protein structure and gene expression. Only certain mutations in PLEC1, SCRIB and SEMA6C were confirmed. Of interest, PLEC1 and SCRIB are two scaffold proteins, where mutations have been reported in several cancers and, possibly leading to changes in their conformation and thereby affecting their interactions and functions. The consequences of these mutations on ovarian tumorigenesis remain to be determined.
16

Mutations impliquées dans la progression du cancer épithélial de l'ovaire

El-Masri, Rayane 08 1900 (has links)
Le cancer épithélial de l’ovaire (CEO) est le cancer gynécologique le plus létal. Plus de 70% des patientes diagnostiquées avec une tumeur de stade avancé rechutent suite aux traitements chimiothérapeutiques de première ligne, la survie à cinq ans étant ainsi très faible. Afin de mieux comprendre l’évolution de la maladie, nous avons recherché de nouveaux gènes, responsables de l’initiation et de la progression du CEO. Précédemment, des lignées cellulaires ont été dérivées à partir de la tumeur primaire et récurrente et/ou d’ascites de trois patientes. Le séquençage de l’ARN de ces lignées par la technologie de séquençage de nouvelle génération (TSNG) nous a permis d’identifier des mutations ponctuelles qui pourraient nous indiquer des gènes dérégulés dans le CEO. La TSNG est un bon outil qui permet d’identifier et de cribler à grande échelle des mutations. Nous avons sélectionné PLEC1, SCRIB, NCOR2, SEMA6C, IKBKB, GLCE et ITGAE comme gènes candidats présentant des mutations dans nos lignées et ayant une relation fonctionnelle avérée avec le cancer. Étant donné que la TSNG est une technique à taux de fiabilité limité, nous avons validé ces mutations par séquençage Sanger. Ensuite, nous avons étudié l’effet de ces mutations sur la structure protéique et l’expression de PLEC1, de SCRIB et de SEMA6C. Seules certaines mutations dans les gènes PLEC1, SCRIB et SEMA6C ont pu être confirmées. PLEC1 et SCRIB sont deux protéines d’échafaudage dont la mutation, rapportée dans plusieurs cancers, pourrait induire des changements de leurs conformations et affecter leurs interactions et leurs fonctions. Les conséquences de ces mutations sur la tumorigenèse de l’ovaire devront être étudiées. / Epithelial ovarian cancer (EOC) is the most lethal gynecological cancer. Over 70% of the patients diagnosed with advanced stage of cancer relapse following first-line chemotherapy treatments; consequently the five-year survival is very low. To better understand the evolution of the disease, our aim was to identify new genes responsible for the initiation and progression of EOC. Previously, cell lines derived from solid tumors or ascites were developed from the primary and recurrent tumor or ascites of three patients. RNA sequencing of these cell lines by next-generation sequencing technology (NGST) allowed us to identify mutations that might point to genes whose deregulation is important in EOC. Mutations were detected in PLEC1, SCRIB, NCOR2, SEMA6C, IKBKB, GLCE and ITGAE. We selected these genes for further studies as they have previously been identified as being associated with cancer. First, we validated these mutations by Sanger sequencing in order to determine the concordance with NGST data. Secondly, we studied the impact of the validated mutations on protein structure and gene expression. Only certain mutations in PLEC1, SCRIB and SEMA6C were confirmed. Of interest, PLEC1 and SCRIB are two scaffold proteins, where mutations have been reported in several cancers and, possibly leading to changes in their conformation and thereby affecting their interactions and functions. The consequences of these mutations on ovarian tumorigenesis remain to be determined.
17

Molekulárně genetická vyšetření u klinicky definované skupiny pacientů se syndromovou poruchou zraku a sluchu u vzácných genetických syndromů asociovaných s hluchoslepotou v ČR a SR / Molecular genetic examinations in clinically defined group of patients with syndromic sight and hearing impairment in rare genetic disorders associated with deafblindness in the CR and SR

Čopíková, Jana January 2021 (has links)
Deafblindness is a combined impairment of vision and hearing with an incidence of about 1: 8000 children and 1: 5500 adults. The most common genetic causes are the Stickler (STL) and Usher (USH) syndromes. The main goal of this work is to provide an up-to-date overview of STL and USH in the Czech and Slovak Republic (CR and SR), to determine the correlations between the genotype and phenotype in our population and the associated diagnostic criteria. Using sequencing and MLPA we examined 45 patients from 28 families for suspected STL. We found potentially causal variants of STL genes in 39 patients from 22 families. Fifteen different COL2A1 variants (8 being novel) were found in 28 patients from 18 families and 4 novel COL11A1 variants were found in 11 patients from 4 families. We identified the cause of the disease in 79 % of the families. The USH study involved 30 patients from 27 families. The most frequent cause was USH2A pathogenic variants, i.e. 19 variants in 14 families, 9 being novel. Less common were pathogenic variants in MYO7A (6 variants in 3 families, 5 being novel), USH1C and CDH23 (3 variants, 2 being novel, in 2 families both) genes. In 2 families, compound heterozygosity was found for variants in two different USH genes. The deafblindness etiology was clarified for 24 patients from...
18

Molekulárně genetické příčiny vývojových onemocnění předního segmentu oka / Anterior segment dysgenesis disorders and their molecular genetic cause

Moravíková, Jana January 2018 (has links)
Proper eye development depends on expression and mutual regulation of many genes. Anterior segment dysgenesis (ASD) are a highly heterogeneous group of diseases exhibiting all types of Mendelian inheritance, which manifest as combination of congenital abnormalities of the cornea, iris, anterior chamber angle or lens. Screening of genes associated with ASD does not often lead to the identification of the underlying genetic cause implying that there are still novel variants or genes to be discovered. Molecular genetic analysis in 12 probands with ASD using Sanger and whole-exome sequencing were performed. Functional analysis by Exon trapping assay was provided in variants predicted to effect pre-mRNA splicing. Four PAX6 mutations evaluated as pathogenic or likely pathogenic in a heterozygous state were found in four probands c.183C˃G; p.(Tyr61*), c.1032+1G>A, c.1183+1G>T and c.622C>T; p.(Arg208Trp). One proband was found to be a compound heterozygote for c.244A>G; p.(Met82Val) and c.541delG; p.(Glu181Lysfs*26) mutations in FOXE3. In 7 probands, no potentially pathogenic variants were identified. Exon trapping assay confirmed that mutations c.1032+1G>A and c.1183+1G>T have an effect on pre-mRNA splicing of the PAX6 gene. Detailed molecular-genetic analysis in patients with ASD may contribute to...
19

Vyšetření genů DNM2, GARS, MORC2, TRPV4 a SOD1 u českých pacientů s dědičnou neuropatií axonálního typu / Examination of the genes DNM2, GARS, MORC2, TRPV4 and SOD1 among Czech patients with hereditary neuropathy axonal type

Neupauerová, Jana January 2019 (has links)
Examination of the genes DNM2, GARS, MORC2, TRPV4 and SOD1 among Czech patients with hereditary neuropathy axonal type For my PhD thesis I chose to work with patients with axonal form of CMT, because at that time axonal forms were less likely to be clarified by classical methods of molecular genetics. For further examination in patients with unclear cause of the axonal CMT, the genes DNM2, GARS and TRPV4 were selected. The aim was to determine the significance of pathogenic mutations in these genes as the cause of CMT2 in Czech patients. In the course, we identified causal variants in the genes MORC2 and SOD1 with WES. Therefore, we have tested additional CMT2 patients for the presence of these variants. Using Sanger sequencing, I examined a representative set of patients for the DNM2 (37), GARS (10) and TRPV4 (24) genes without finding a causal mutation, then we investigated genes SOD1 (43 patients) and MORC2 (161 patients). The cohort (50 patients) was also subjected to MLPA analysis using a P406-A1 CMT2 duplication and deletion detection kit for genes RAB7A, GARS, HSPB1, HSBP8 and SPTLC1 (kit P406-A1 CMT2). At that time, massively parallel sequencing (MPS) was becoming important. We compared the cost of classical sequencing versus MPS, and accordingly, we decided that the genes DNM2, GARS, MORC2, TRPV4...
20

Molekulárně genetická analýza pacientů s Usherovým syndromem / Molecular genetic analysis of patients with Usher syndrome

Průšová, Kateřina January 2020 (has links)
The work focuses on molecular genetic testing of patients with Usher syndrome to confirm the diagnosis, to determine the causal cause of the disease and describe new mutations causing Usher syndrome in Czech patients. Usher syndrome is a clinically and genetically heterogeneous disease that is the most common cause of hereditary deafblindness. Based on responsible genes and disease onset is classified into three clinical subtypes. Given the fact that there is currently no specific treatment, there is a need to understand the pathophysiology of this disease and to broaden the spectrum of causal mutations. The theoretical part of the thesis deals with the anatomy of the eye, especially the structure of the retina. Attention is also paid to retinal diseases, such as the progressive loss of vision characteristic for retinitis pigmentosa (RP). RP may occur either as an isolated disorder or also affecting other organs, so-called syndromic RP. Classic syndromic RP includes Usher's syndrome, which the work mainly deals with. The theoretical part of the thesis describes mainly the mechanism of the disease, the functions of individual Usher proteins and the genes that encode these proteins. The haplotype analysis has been previously done for the most common mutations causing Usher's syndrome in Europe Based...

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