O gene fator regulador de interferon 4 (IRF4), localizado na região cromossômica 6p25- p23, é um membro da família de fatores reguladores de interferon (IRF), um grupo de fatores de transcrição de ligação ao DNA, sendo IRF4 primariamente associado ao desenvolvimento e resposta imune e expresso exclusivamente em células do sistema imunológico e em linhagens melanocíticas. Embora muitos estudos tenham associado IRF4 a diversas condições, como melanoma e leucemia linfocítica crônica, um recente Genome-Wide Association Study (GWAS) identificou que alelos do SNP rs12203592 (intron 4) estão associados com variação fenotípica em relação à presença de sardas, pigmentação da pele, cabelos e olhos. Estudos funcionais realizados em células melanocíticas humanas e de camundongos revelaram que este SNP está diretamente envolvido na regulação da expressão de IRF4, sugerindo uma clara função na pigmentação do melanócito. Apesar destes achados, a diversidade das regiões regulatórias e codificadora de IRF4 não foi até o momento analisada em populações miscigenadas. A fim de avaliar se outros sítios de variação ao longo do gene IRF4 podem estar associados à pigmentação humana, as regiões regulatórias (promotora e 3´UTR) e codificadora (9 exons e regiões intrônicas flanqueadoras, incluindo o SNP rs12203592) foram analisadas por sequenciamento de nova geração em uma amostra miscigenada da população brasileira. A amostra populacional foi composta por 228 indivíduos não aparentados de Ribeirão Preto, estado de São Paulo, Brasil, os quais foram estratificados de acordo com a pigmentação da pele (clara, média e escura), olhos (azul, verde, castanho-claros e castanho-escuros), cabelo (ruivo, loiro-claro, loiroescuro, castanho-claro, castanho-escuro e preto) bem como em relação à presença de sardas e intensidade de cabelos grisalhos. Bibliotecas de DNA foram preparadas utilizando o Sistema de Enriquecimento de Alvo Haloplex (Agilent Technologies) e sequenciadas na plataforma MiSeq (Illumina). Os pacotes de software CutAdapt, BWA and GATK foram utilizados, respectivamente, para trimagem das sequências dos adaptadores, alinhamento e identificação de variantes. Haplótipos e alelos não identificados foram inferidos pelo método PHASE, embora a fase conhecida entre os sítios de variação (obtida pelo GATK) tenha sido levada em consideração. Um total de 105 sítios de variação foram identificados. Apenas dois deles apresentaram frequências genotípicas que não atendem ao esperado pelo equilíbrio de Hardy-Weinberg (EHW). Dezoito destes SNPs apresentaram forte associação a pelo menos uma característica de pigmentação. Entretanto, se a conservadora correção de Bonferroni para múltiplos testes for levada em consideração, apenas duas associações, ambas envolvendo o SNP rs12203592, permanecem significativas: a associação do alelo T com pele clara e olhos azuis. Este resultado está de acordo com estudos prévios, que reportam que o alelo rs12203592*T leva a uma menor ativação de IRF4 e a uma expressão reduzida da tirosinase, resultando em sensibilidade ao sol e olhos azuis. Foi inferido um total de 101 haplótipos, estando a distribuição destes de acordo com o esperado pelo EHW. Quando os haplótipos foram divididos em haplótipos da promotora, codificadora e 3´UTR foram observadas, respectivamente, 17, 29 e 37 diferentes combinações haplotípicas. Várias associações foram identificadas, particularmente envolvendo o haplótipo mais frequente da promotora, os dois haplótipos mais frequentes da codificadora e o haplótipo mais frequente da 3´UTR, todos associados com pele clara, olhos azuis, cabelos castanhos e cabelos grisalhos. Estes resultados sugerem que outras variantes além de rs12203592, quando consideradas em um contexto haplotípico, são associadas com a pigmentação humana. / The Interferon Regulatory Factor 4 (IRF4) gene, located at chromosomal region 6p25- p23, is a member of the interferon regulatory factor (IRF) family, a group of DNAbinding transcription factors, with the IRF4 primarily associated with immune system development and response and expressed exclusively in immune system cells and melanocytic lineages. Although many studies have shown that IRF4 is associated with many human conditions, such as melanoma and chronic lymphocytic leukemia, a recent Genome-Wide Association Study (GWAS) identified that alleles from the SNP rs12203592 (intron 4) is also associated with phenotypic variation regarding presence of freckles, hair, eye and skin pigmentation. Functional studies in human and mice melanin-containing cells revealed that such SNP is directly involved in the regulation of IRF4 expression, suggesting a clear role in melanocyte pigmentation. In spite of these findings, the regulatory and coding IRF4 diversities in admixed populations have not been evaluated so far. In order to verify if other variation sites spread across the IRF4 gene may be associated with human pigmentation, the regulatory (promoter and 3\'UTR regions) and coding (9 exons and flanking intronic regions, including the SNP rs12203592) regions were analyzed by next-generation sequencing procedures in a Brazilian admixed population sample. The population sample was composed of 228 unrelated individuals from the Ribeirão Preto area, São Paulo State, Brazil, which were stratified according to eye (blue, green, hazel, light-brown, and dark-brown), hair (red, blond, dark-blond, light-brown, dark-brown and black) and skin (light, intermediate and dark) pigmentation, as well as regarding the presence of freckles and intensity of hair greying. DNA libraries were prepared using the Haloplex Target Enrichment System (Agilent Technologies) and sequenced at the MiSeq platform (Illumina). CutAdapt, BWA and GATK software packages were used for trimming adaptor sequences, alignment and genotype calling, respectively. Missing alleles and haplotypes were inferred by using the PHASE method, although the known phase between variable sites (obtained by GATK) was taken into account. A total of 105 variation sites were identified. Only two of them presented genotype frequencies that did not fit Hardy- Weinberg equilibrium (HWE) expectations. Eighteen of these SNPs presented strong association with at least one pigmentation feature. However, if the conservative Bonferroni correction for multiple tests is taken into account, only two associations, both of them involving the rs12203592 SNP, remain significant: allele T associated with light skin and blue eyes. This result is in agreement with previous reports that the rs12203592*T allele leads to reduced IRF4 activation and reduced tyrosinase expression, leading to sun sensitivity and blue eyes. A total of 101 different haplotypes were inferred, and haplotype distribution was in agreement to HWE expectations. When haplotypes were subdivided in promoter, coding and 3\'UTR haplotypes, 17, 29 and 37 different haplotypes were observed, respectively. Various associations were identified, particularly involving the most frequent promoter haplotype, the two most frequent coding (only one of them with allele rs12203592*T), and the most frequent 3\'UTR, all of them with light skin, blue eyes, brown hair and hair greying. These results suggest that other variation sites besides rs12203592, when considered in a haplotypic background, are associated with human pigmentation.

Univerzita Karlova v Praze Přírodovědecká fakulta Studijní program: Molekulární biologie, genetika a virologie Bc. Jan Röslein Mutační a substituční tempo u sexuálních a klonáních forem: možný klíč k vysvětlení persistence sexu u modelové skupiny sekavců Mutation AND substitution rates in sexual and asexual forms: a clue to the persistence of sex in a model group of Cobitis? Typ závěrečné práce Diplomová Vedoucí závěrečné práce: Mgr. Karel Janko, Ph.D. Praha, 2015 Velký dík náleží mému školiteli Mgr. Karlu Jankovi, Ph.D. za velmi nápomocné, direktivní vedení práce. Též bych rád poděkoval panu Mgr. Janu Pačesovi, Ph.D. za více než vzdělávací rozměr v oblasti bioinformatické analýzy a Mgr. Ladislavu Pekárikovi, Ph.D., Mgr. Janu Kočímu za pomoc při analýze vybraných kapitol. Také bych rád poděkoval rodině za podporu. Všem participantům na této diplomové práci se hluboce omlouvám za způsobenou psychickou újmu. Prohlášení: Prohlašuji, že jsem závěrečnou práci zpracoval/a samostatně a že jsem uvedl/a všechny použité informační zdroje a literaturu. Tato práce ani její podstatná část nebyla předložena k získání jiného nebo stejného akademického titulu. V Praze dne 12. 8. 2015 Podpis: Abstrakt Klíčová slova: Abstract Key words: Obsah 1...

This diploma thesis provides an overview of gene conversion, its role in the pathogenesis of human diseases and the use of methods based on next-generation sequencing (NGS) for detection rare variants of DNA sequence. Labeling of target DNA molecules by random nucleotides in primer and NGS were used for detection point mutations arising de novo in the β-glucocerebrosidase gene by gene conversion between it and its pseudogene in meiotic and mitotic cells of control subjects. Primers specific for the active gene were used to selectively amplify the ninth and tenth exon of the gene where "recombinant" variants occur most frequently. Sequences generated from 20 genomic DNA samples on Illumina MiSeq platform were quality filtered, sorted by unique labels and consensus sequences were created from alignments of sequences carrying the same DNA tag. The number of potential point mutations in the samples ranged between 12 and 48. The mutations were manually re-evaluated from the alignments. The number of alignments with unique labeling was in the range of 7-15 thousand per sample. Only three samples carried possible recombinant mutations, suggesting a lower frequency of conversion in the region than reported by other techniques. Analysis of unique sequences in primer indicated possible ways to improve the...

Abstract Breast cancer is the most common malignancy in women and it is strongly influenced by hereditary risk factors. So far, most of the breast cancer-associated genes, including BRCA1/2, have been identified among those that encode proteins involved in DNA damage response (DDR) pathways. However, known genetic risk factors explain less than half of the familial risk of breast cancer. Identification of novel genes and mutations that predispose to breast cancer is important for the understanding of the mechanisms that contribute to the disease development and also for the identification of those individuals who are at high risk. The first aim of this study was to resolve the complementation groups of Finnish patients with Fanconi anemia (FA), which is a rare genetic disease caused by defects in a specific DDR pathway, and to study the role of the causative gene mutations in breast cancer predisposition. The second aim of this study was to identify novel breast cancer susceptibility genes and alleles by targeted next-generation sequencing (NGS) of multiple (~800) DDR related genes. In both approaches, the identified gene mutations were subjected to case-control association analysis utilizing DNA samples of over 1,000 breast cancer cases and 1,000 healthy controls. Investigation of the Finnish FA patients revealed six different disease-causing mutations in three different genes (FANCA, FANCG and FANCI). All of the studied mutations were recurrent in the Finnish population but did not associate with breast cancer. Targeted NGS identified three novel potential breast cancer susceptibility genes. A significant enrichment of TEX15 c.7253dupT and FANCD2 c.2715+1G>A mutations was observed among the hereditary breast cancer cases (P = 0.018 and P = 0.036, respectively). The strongest evidence was found for a Finnish founder mutation in MCPH1 (c.904_916del), which associated with breast cancer susceptibility both in familial (P = 0.003, OR 8.3) and unselected (P = 0.016, OR 3.3) patient cohorts. The tumor suppressive function of MCPH1 was indicated by the loss of the wild-type allele of MCPH1 in 40% of the studied carrier tumors. Furthermore, carriers exhibited a significant increase in genomic instability measured by spontaneous chromosomal rearrangements in peripheral blood lymphocytes. / Tiivistelmä Rintasyöpä on naisten yleisin syöpä. Sairastumisriskiin vaikuttavat voimakkaasti perinnölliset alttiustekijät, ja suurin osa tähän asti tunnistetuista rintasyöpäalttiusgeeneistä, kuten BRCA1/2, koodaa DNA-vauriovasteessa (DDR) toimivia proteiineja. Tunnistetut tekijät selittävät yhä kuitenkin vain alle puolet rintasyövän perinnöllisestä alttiudesta. Uusien alttiusgeenien tunnistaminen on tärkeää rintasyövän patomekanismien ymmärtämiseksi sekä korkean rintasyöpäriskin omaavien henkilöiden tunnistamiseksi. Tämän tutkimuksen tarkoituksena oli määrittää viallisesta DDR-signaalinsiirtoreitistä johtuvan Fanconin anemian (FA) komplementaatioryhmät suomalaisilta FA-potilailta sekä tutkia sairauden taustalla olevien geenimutaatioden yhteyttä rintasyöpäriskiin. Uusia alttiusgeenejä etsittiin myös kohdennetulla uuden sukupolven sekvensointimenetelmällä, jonka avulla tutkittiin yhtäaikaisesti n. 800 DDR-geeniä. Molemmilla lähestymistavoilla tunnistettujen geenimuutosten yhteyttä rintasyöpään selvitettiin tapaus-verrokkitutkimuksen avulla, jossa tutkittiin DNA-näytteitä yli tuhannelta rintasyöpäpotilaalta sekä yli tuhannelta terveeltä henkilöltä. Suomalaisten FA-potilaiden geenimuutoksia selvittävässä tutkimuksessa tunnistettiin yhteensä kuusi mutaatiota kolmessa eri geenissä (FANCA, FANCG ja FANCI). Kaikki tutkimuksessa tunnistetut mutaatiot olivat toistuvia suomalaisessa väestössä, mutta merkitsevää assosiaatiota näiden mutaatioiden ja rintasyöpäalttiuden välillä ei havaittu. DDR-geenien sekvensoinnin avulla tunnistettiin kolme uutta mahdollista rintasyöpäalttiusgeeniä. Tutkimuksessa havaittiin TEX15 c.7253dupT ja FANCD2 c.2715+1G>A mutaatioiden rikastuminen perinnöllisessä rintasyöpäaineistossa (P = 0.018 ja P = 0.036). Merkittävin yhteys rintasyöpäalttiuden kanssa todettiin MCPH1-geenin perustajamutaatiolle (c.904_916del). Tämä mutaatio assosioitui rintasyöpäalttiuden kanssa sekä perinnöllisessä (P = 0.003, OR 8.3) että valikoimattomassa potilasaineistossa (P = 0.016, OR 3.3). Useissa mutaatiokantajien tuumoreissa (40 %) normaali MCPH1 vastinalleeli oli hävinnyt, mikä viittaisi siihen, että MCPH1 toimii tuumorisuppressorina. Mutaatiokantajilla todettiin myös kohonnut määrä kromosomaalisia muutoksia veren periferaalisissa lymfosyyteissä, mahdollisesti kohonneeseen genomiseen epävakauteen liittyen.

The decomposition of organic substrates represents an important part of the global carbon cycle and affects its global change through CO2 release. In temperate forests, deadwood represents a large carbon stock, its amount and decomposition is crucial for ecosystem biodiversity and functioning. The fungi are omnipresent powerful decayers in all terrestrial ecosystems. Their ability to decompose all deadwood compounds, mainly lignocellulose, is highly important. Without fungi, the wood decompositions and the release of withheld nutrients back to nutrient cycles couldn't be performed. While many studies were concerned with the estimation of decomposition rates of deadwood, still deeper knowledge about microbial decomposition processes and the diversity of saproxylic species and their interaction is needed. The fungi are still underrepresented in dead wood studies. This study had two main objectives. First was to describe the fungal community on downed deadwood of Fagus sylvatica and Abies alba in natural forest of Salajka in the Czech Republic, to reflect the substrate changes during the different decay stages, and to link the enzyme activities to fungal community composition and their described ecophysiologies. Second aim was to describe the fungal communities on standing and downed dead logs of...

Les cellules cancéreuses sont caractérisées par des altérations de l'ADN causées par des facteurs exogènes, comme l'exposition à des agents environnementaux tels que le tabac ou les UV, ou par des mécanismes endogènes tels que les erreurs de polymérase lors de la réplication de l'ADN. L'analyse des causes et des conséquences de ces altérations permet de mieux comprendre les facteurs et mécanismes à l'origine du développement d'un cancer. Les technologies de séquençages à haut débit offrent l'opportunité d'étudier la nature précise de ces altérations à l'échelle du génome et permettent de révéler des signatures mutationnelles distinctes et spécifiques de cancérigènes, fournissant ainsi des hypothèses sur l'étiologie des cancers.L'objectif de ma thèse a consisté à développer des méthodes et des outils bioinformatiques accessibles et conviviaux permettant de faciliter l'analyse et l'interprétation des signatures mutationnelles à partir de données de séquençage à haut débit. L'application de ces outils et méthodes à des séries originales de tumeurs humaines et de systèmes expérimentaux de mutagénèse et carcinogénèse a permis de mieux caractériser la signature mutationnelle de l'acide aristolochique (AA) ainsi que d'autres cancérigènes d'intérêt / Cellular genomes accumulate alterations following exposures to exogenous factors, like environmental agents such as tobacco smoking or UV, or to endogenous mechanisms such as DNA replication errors. Analysing the causes and consequences of these changes allows a better understanding of the mechanisms underlying cancer development and progression. Next-generation sequencing (NGS) technologies provide the opportunity tostudy the nature of the resulting alterations on a genome-wide scale and started to reveal distinct mutational signatures specific to past carcinogenic exposures providing clues on cancer aetiology.The aim of my thesis was to develop user-friendly bioinformatic tools and methods for facilitating the analysis and interpretation of carcinogen-specific mutational signatures from NGS data. Applying these tools and methods to human tumours and experimental models of mutagenesis led to a better characterisation the mutational signature of aristolochic acid (AA), as well as other carcinogens of interest

Hypoxia pathways are associated with the pathogenesis of both ischaemic and neoplastic diseases. In response to hypoxia the transcription factor hypoxia‐inducible factor (HIF) induces the expression of hundreds of genes with diverse functions. These enable cells to adapt to low oxygen availability. To date, pan-genomic analyses of these transcriptional responses have focussed on protein-coding genes and microRNAs. However, the role of other classes of non-coding RNAs, in particular lncRNAs, in the hypoxia response is largely uncharacterised. My thesis aimed at improving understanding of the transcriptional regulation of the non-coding transcriptome in hypoxia. I performed an integrated genomic analysis of both non-coding and coding transcripts by massively parallel sequencing. This was interfaced with pan-genomic analyses of DNAse hypersensitivity and HIF, H3k4me3 and RNApol2 binding in hypoxic cells. These analyses have revealed that hypoxia profoundly regulated all RNA classes. snRNAs and tRNAs are globally downregulated in hypoxia, whilst miRNAs, mRNAs and lncRNAs are both up- and downregulated with an overall trend towards slight upregulation. In addition, a significant number of previously non-annotated (and largely hypoxia upregulated) transcripts were identified, including novel intergenic transcripts and natural antisense transcripts. HIF bound close to genes for mRNAs, miRNAs and lncRNAs that were upregulated by hypoxia, but was excluded from binding at genes for RNA classes that showed global downregulation. This suggests that HIF acts as a transcriptional activator (but not repressor), of lncRNAs as well as mRNAs and miRNAs. Consistent with direct regulation by HIF, many of these hypoxia-inducible, HIF-binding lncRNAs were downregulated following HIF knockdown. Analysis of RNApol2 binding and DNAse HSS signals at HIF transcriptional target genes indicated that HIF-dependent transcriptional activation occurs through release of RNApol2 that is pre-bound to open promoters of lncRNAs as well as mRNAs. In these datasets, NEAT1 was the most hypoxia-upregulated, HIF-targeted lncRNA in MCF-7 cells and, despite binding of both HIF-1 and HIF-2 isoforms at its promoter, was selectively regulated by HIF-2 alone. Furthermore, NEAT1 was induced by hypoxia in a wide range of breast cancer cell lines and in hypoxic xenograft models. Functionally, NEAT1 is required for the assembly of nuclear paraspeckle structures. Increased nuclear paraspeckle formation was observed in hypoxia and was dependent on both NEAT1 and HIF-2. Knockdown of hypoxia-induced NEAT1 significantly reduced cell proliferation and survival and induced apoptosis. Finally, high expression of NEAT1 correlated with poor clinical outcome in a large cohort of breast cancer patients. These findings extend the role of the hypoxic transcriptional response in cancer into the spectrum of non-coding transcripts and provide new insights into molecular roles of hypoxia-regulated lncRNAs, which may provide the basis for novel therapeutic targets in the future.

La mucoviscidose (CF) est la maladie génétique récessive létale la plus fréquente dans la population caucasienne. Elle est caractérisée par une obstruction et des infections des voies respiratoires et une inflammation chronique. La morbidité et la mortalité sont principalement dues à l'atteinte pulmonaire, qui est variable chez les patients, même lorsqu’ils sont porteurs du même génotype. Les facteurs responsables sont multiples : les mutations dans CFTR (le gène responsable de la maladie), les gènes modificateurs, mais aussi les facteurs environnementaux et les modifications épigénétiques. L'objectif principal de ce projet était de déterminer s'il y avait une corrélation entre la méthylation de l'ADN et la sévérité de l'atteinte pulmonaire chez les patients CF. Nous avons obtenu la cohorte METHYLCF (49 patients CF p.Phe508del homozygotes et 24 témoins sains) ainsi qu’une biobanque d'ADN à partir de sang total et de cellules épithéliales nasales (NEC). Les patients CF ont été stratifiés en fonction de leur VEMS, ajusté à l’âge. D’une part, nous avons analysé la méthylation de l'ADN dans CFTR plus 13 gènes modificateurs en utilisant la méthode de conversion au bisulfite et séquençage de nouvelle génération (plateforme 454 Roche). D’autre part, nous avons réalisé une analyse pan-génomique de la méthylation de l'ADN avec la plateforme 450k BeadChip (Illumina). Les sites différentiellement méthylés (DMS) sélectionnés ont été validés par pyroséquençage (PyroMark Q24, Qiagen). Deux gènes modificateurs ont été identifiés comme différentiellement méthylés chez les patients CF par rapport aux témoins: EDNRA dans le sang et HMOX1 dans le sang et dans les NEC. De façon intéressante, dans les NEC, la méthylation de EDNRA, HMOX1 et GSTM3 a été corrélée avec la sévérité de l’atteinte pulmonaire. De plus, de faibles niveaux de méthylation d'ADN dans GSTM3 ont été associés à la présence de l'allèle GSTM3*B, un polymorphisme de séquence qui a un effet protecteur chez les patients CF. Grâce à l'analyse tout-génome, nous avons identifié 1267 DMS, associés à 638 gènes, chez les patients CF par rapport aux témoins, et 187 DMS, associés à 116 gènes, chez les patients CF sévères par rapport aux modérés. Parmi ces gènes, il y a de nombreux gènes importants pour l’adhésion cellulaire et les réponses immunitaire et inflammatoire. Les DMS identifiés sont enrichis dans des régions prédites comme enhancers, pouvant représenter des séquences régulatrices, mais également en régions intergéniques. De façon intéressante, 80 gènes différentiellement méthylés sur 638 étaient différentiellement exprimés (méta-analyse de données transcriptomiques disponibles). Six sur neuf DMS sélectionnés ont été validés et cinq DMS sur six ont été répliqués dans une population indépendante. De plus, 23 DMS, dont 10 intergéniques, étaient corrélés avec le VEMS. Notre étude a montré que la méthylation de l'ADN est profondément modifiée dans le sang et dans les NEC des patients CF. Des faibles changements de méthylation de l'ADN ont été observés dans des gènes modificateurs connus ; des changements de méthylation plus importants ont été observés dans d'autres gènes qui pourraient représenter de nouveaux modificateurs de la fonction pulmonaire. Ensemble, ces gènes pourraient moduler la sévérité de l’atteinte pulmonaire chez les patients CF. / Cystic fibrosis (CF) is the most common life-threatening recessive genetic disease in the Caucasian population. It is characterized by airway obstruction, respiratory infection and inflammation. Morbidity and mortality are mainly due to lung disease, which is variable among CF patients, even for those having the same genotype. Contributing factors are mutations in CFTR (the disease-causing gene), modifier genes, but also environmental factors and epigenetics. The main goal of this project was to determine whether there was a correlation between DNA methylation and the severity of CF lung disease. We built the METHYLCF cohort (49 p.Phe508del homozygous CF patients and 24 healthy controls) and a DNA biobank from whole blood and nasal epithelial cells (NEC). CF patients were stratified accordion to their FEV1% predicted, adjusted to age. We profiled DNA methylation at 14 modifier genes using bisulfite conversion and next-generation sequencing (454 Roche). Genome-wide DNA methylation was analyzed with the 450K Beadchip (Illumina). Selected differentially methylated sites (DMS) were validated by pyrosequencing. Using the candidate modifier gene approach, we showed that two CF modifier genes were differentially methylated in CF patients compared to controls: EDNRA in blood and HMOX1 in blood and NEC. Methylation of EDNRA, HMOX1 and GSTM3 was associated with lung disease severity in NEC. Interestingly, low DNA methylation levels at GSTM3 were associated with the GSTM3*B allele, a polymorphic 3-bp deletion that has a protective effect on CF patients. In addition, through the genome-wide analysis, we identified 1267 DMS, associated with 638 genes, between CF patients and controls and 187 DMS, associated with 116 genes, between severe CF and mild CF patients. DMS were enriched at predicted enhancers, which may represent regulatory sequences, and also at intergenic regions. Gene ontology analyses highlighted cellular processes relevant to CF, i.e. cell adhesion and inflammatory and immune response. Interestingly, 80 out of 638 differentially methylated genes were differentially expressed in publicly available NEC transcriptomic data. Six out of 9 selected DMS were validated and five out of six DMS were replicated in an independent set of patients. Additionally, 23 DMS, 10 of which were intergenic, correlated with FEV1% predicted. Our study has shown that DNA methylation is altered in blood and NEC of CF patients. Small DNA methylation changes were observed at known CF modifier genes; more dramatic DNA methylation changes were found at other genes that may impact lung function. Collectively, these epigenomic variations may lead to different degrees of lung disease severity in CF patients.

The subject of this research is to find a continuous solution, which allows the description, the creation, the provisioning, and the execution of value-added telecommunication services. This work proposes a framework for an easy and timesaving creation and provisioning of value-added telecommunication services in Next Generation Networks. As research method, feasibility, comparative methods are used in this study. Criteria and requirements for service description, service creation, service execution, and service provisioning, are defined and existing technologies are compared with each other and evaluated regarding these criteria and requirements. Extensions to the selected technologies are proposed and possibilities to combine these technologies are researched. From the results of the previous steps, a framework is defined which offers a continuous solution for the description, creation, provisioning and execution of value-added services. In order to test the proof of concept, this framework is prototypically implemented. For a qualitative analysis of the research targets and the proof of concept, an example service is created and executed within the framework prototype. Furthermore, in order to examine the validity of the quantitative aims and objectives of this research work, a second example service is created, and its characteristics are measured and analysed. The result of this research is a novel continuous approach for the creation of value-added telecommunication services. This research introduces new possibilities for the service description, service creation, service provisioning, and service execution through an extension of the common telecommunication real-time execution environment JAIN SLEE. Value-added services are described by using the business process execution language BPEL. This language facilitates a simple and fast service design. The service can automatically be composed from pre-defined and pre-deployed components.

An important goal of modern data networks is to support multiple applications over a single network infrastructure. The combination of data, voice, video and conference traffic, each requiring a unique Quality of Service (QoS), makes resource dimensioning a very challenging task. To guarantee QoS by mere over-provisioning of bandwidth is not viable in the long run, as network resources are expensive. The aim of proper resource dimensioning is to provide the required QoS while making optimal use of the allocated bandwidth. Dimensioning parameters used by service providers today are based on best practice recommendations, and are not necessarily optimal. This dissertation focuses on resource dimensioning for the DiffServ network architecture. Four predefined traffic classes, i.e. Real Time (RT), Interactive Business (IB), Bulk Business (BB) and General Data (GD), needed to be dimensioned in terms of bandwidth allocation and traffic regulation. To perform this task, a study was made of the DiffServ mechanism and the QoS requirements of each class. Traffic generators were required for each class to perform simulations. Our investigations show that the dominating Transport Layer protocol for the RT class is UDP, while TCP is mostly used by the other classes. This led to a separate analysis and requirement for traffic models for UDP and TCP traffic. Analysis of real-world data shows that modern network traffic is characterized by long-range dependency, self-similarity and a very bursty nature. Our evaluation of various traffic models indicates that the Multi-fractal Wavelet Model (MWM) is best for TCP due to its ability to capture long-range dependency and self-similarity. The Markov Modulated Poisson Process (MMPP) is able to model occasional long OFF-periods and burstiness present in UDP traffic. Hence, these two models were used in simulations. A test bed was implemented to evaluate performance of the four traffic classes defined in DiffServ. Traffic was sent through the test bed, while delay and loss was measured. For single class simulations, dimensioning values were obtained while conforming to the QoS specifications. Multi-class simulations investigated the effects of statistical multiplexing on the obtained values. Simulation results for various numerical provisioning factors (PF) were obtained. These factors are used to determine the link data rate as a function of the required average bandwidth and QoS. The use of class-based differentiation for QoS showed that strict delay and loss bounds can be guaranteed, even in the presence of very high (up to 90%) bandwidth utilization. Simulation results showed small deviations from best practice recommendation PF values: A value of 4 is currently used for both RT and IB classes, while 2 is used for the BB class. This dissertation indicates that 3.89 for RT, 3.81 for IB and 2.48 for BB achieve the prescribed QoS more accurately. It was concluded that either the bandwidth distribution among classes, or quality guarantees for the BB class should be adjusted since the RT and IB classes over-performed while BB under-performed. The results contribute to the process of resource dimensioning by adding value to dimensioning parameters through simulation rather than mere intuition or educated guessing. / Dissertation (MEng (Electronic Engineering))--University of Pretoria, 2007. / Electrical, Electronic and Computer Engineering / unrestricted