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Characterization of germline alterations affecting genes influencing development and prognosis of specific adult cancers
Jelínková, Sandra ; Kleibl, Zdeněk (advisor) ; Hlaváč, Viktor (referee) ; Hájková, Nikola (referee)
In my dissertation, I studied the genetic predisposition of selected types of cancer that have not been systematically studied in the Czech Republic. We used next-generation panel sequencing to identify germline pathogenic variants. Analysis of 1333 patients with ovarian cancer, 527 patients with endometrial cancer, and 334 patients with hepatocellular carcinoma included sequencing using the CZECANCA panel. A specific CZMELAC panel was prepared for the analysis of 264 melanoma patients. We focused on the identification of pathogenic variants in known predisposition genes. We also evaluated candidate genes and phenotypic characteristics in carriers of pathogenic variants. Analysis of high-risk melanoma patients revealed pathogenic variants in melanoma associated genes in 9/264 (3.4%) patients, and an additional 22 (8.3%) patients carried a pathogenic variant in one of the other predisposition genes. The odds of carrying a pathogenic variant were increased in probands with multiple melanomas and in the presence of melanoma in relatives. The incidence of germline pathogenic variants was highest in ovarian cancer, where pathogenic variants were found in 427/1332 (32.0%) patients, with a predominance of mutations in BRCA1, BRCA2, followed by alterations in other ovarian predisposition genes. Breast and...
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Analysis of NGS data for study of transposon activity in cancer cells
Hrazdilová, Ivana ; Čegan,, Radim (referee) ; Eduard, Kejnovský (advisor)
Theoretical part of this diploma thesis gives a brief characteristic of human mobile elements (transposons), which represents nearly 50% of human genome. It provides basic transposon clasification and describes types of transposons present in hunam genome, as well as mobilization, activation and regulation mechanisms. The work also deals with the domestication of transposons, describes the ways in which TE contribute to DNA damage and summarizes the diseases caused by mutagenic activity of transposons in the human genome. Conclusion of theoretical part describes next-generation sequencing technologies (NGS). As practical part, data from RNA-seq experimet were analyzed in order to compare differen transposon activity in normal and cancer cells from prostate and colorectal tissues. As like as publicly available sophisticated tools (TopHat), new scripts were created to analyze these data. The results show that cancer cells exhibit overexpression of transposons. This corresponds with the published results and suggests a connection of transposon activation with cancer development.
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Eucaryotic Genomes Comparison
Puterová, Janka ; Vogel, Ivan (referee) ; Martínek, Tomáš (advisor)
Main motive of this master thesis was the need of good bioinformatics tools for genome comparison and improvement of one of the existing tools - RepeatExplorer. This work offers an overview of transposable elements in DNA, existing tools for identification and analysis of repetitions in sequenced genomes, summary of currently used genome sequencing methods. This work describes shortcomings of RepeatExplorer tool with focus on comparative analysis of genomes. Two solutions to remove these problems were designed and implemented. The first solution is designed for comparing pairs of genomes. The principle of this solution is based on comparison of similarity of distribution of contigs coverages using Kolmogorov-Smirnov test, thanks to which we are able to determine different parts in the genomes.The second solution, which is used to compare multiple genomes, is based on the method of mapping reads from compared genomes to the reference genome contigs and provides contigs coverage graphs, by which we are able to determine the variability of the repeats.Their functionality was verified on real NGS data of organism Silene latifolia.
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Analysis of C. necator genome changes after evolutionary adaptation
Kroupa, Štěpán ; Obruča, Stanislav (referee) ; Brázda, Václav (advisor)
This bachelor’s thesis deals with analysis of mutations in bacterial populations of Cupriavidus necator H16 evolved in distinct stress conditions. This analysis was performed by processing data from the genome sequencing method „Next Generation Sequencing“, outsourced through the company DNALink. A list of mutations for each adapted population was constructed through bioinformatic methods. These mutations were then associated with specific areas of the reference Cupriavidus necator H16 genome from NCBI and analysed according to available information. Finally, the effect of these mutations on production of storage polymers polyhydroxyalkanoates was discussed.
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Differential Gene expression using a negative binomial model
Janáková, Tereza ; Tkacz, Ewaryst (referee) ; Abo Khayal, Layal (advisor)
Hlavním cílem této diplomové práce je analýza diferenciální exprese genů na základě negativního binomického modelu. Úvodní část je věnována teoretickému základu, pojednává o sekvenování RNA, sekvenování nové generace, výhodách a možném využití, formátu fastQ aj. Následující část už se zabývá samotnou praktickou částí, zde byl vybrán vhodný set genů, které budou později analyzovány a příslušná data byla stažena. Tato data byla zarovnána k lidskému genomu verze 37 Burrowsovou-Wheelerovou transformací s využitím bowtie mapovače, byly tak vytvořeny soubory ve formátu SAM. Toto soubory dat byly později setříděny pomocí nástroje SAMtools. Následně byly v programovém prostředí Matlab (verze R2013b) vytvořeny anotované objekty genů s využitím služby Ensembl´s BioMart. Dále byla určena genová exprese a byly odhadnuty faktory velikosti knihovny. Na závěr byly odhadnuty parametry negativního binomického rozložení a byla vyhodnocena diferenciální exprese genů.
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Bioinformatic analysis of RNA dynamics during mammalian oocyte-to-embryo transition
Horvat, Filip ; Svoboda, Petr (advisor) ; Bruce, Alexander (referee) ; Vioristo, Sanna (referee)
The oocyte-to-embryo transition (OET) is a complex biological process during which a terminally differentiated oocyte undergoes numerous and coordinated changes to emerge as a collection of totipotent cells - initial blastomeres of a preimplantation embryo. In mammals, this process is primarily controlled through post-transcriptional regulation of maternal RNAs and transcriptional induction of zygotic RNAs. Technological advancements of next-generation sequencing methods during the last decade enabled studying OET through bioinformatic studies of high-throughput transcriptomics and genomics datasets. The work presented in this thesis explores mechanisms of post-transcriptional regulation and dynamics of different RNAs during OET by utilizing in-depth computational analyses. The presented work is divided into three topics, all covering distinct regulatory facets of the mammalian OET and illustrating roles of different RNA species. The first topic discusses dynamics of maternal transcriptomes in mouse. In our research, we explored roles of deadenylase CNOT6L in the maternal mRNA turnover in mice. We provided evidence that animals deficient in Cnot6l expression are subfertile, due to disruption in deadenylation and degradation of maternal mRNAs deposited in the oocyte. In another study, we...
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Sequence variants in metastatic colorectal cancer and their evolution during the disease course and treatment
Jandová, Eliška ; Boublíková, Ludmila (advisor) ; Vymetálková, Veronika (referee)
A deeper understanding of the molecular background of colorectal cancer (CRC) can help explain the development of the disease and its resistance to treatment, predict disease progression, and improve treatment prognosis. Some minimal molecular testing has been incorporated into standard clinical management to determine if a particular patient will benefit from a particular therapy, but more and more new genetic alterations are being discovered that appear to be associated with the development of resistance. Tissue biopsy of the tumor is the gold standard in terms of molecular testing, but there is an increasing demand for more non- invasive methods such as liquid biopsy. Using targeted next-generation sequencing, we analyzed sequence variants present in primary tumor, metastases, and cell-free tumor DNA - ctDNA of patients with metastatic CRC. The objectives were to analyze sequence variants of the primary tumor and identify possible pathogenic variants, to analyze differences between DNA of the primary tumor and metastases, to evaluate the use of ctDNA as a diagnostic tool, and to identify potential tumor-specific markers in ctDNA that can be used to monitor disease progression. Our results suggest the feasibility of using ctDNA for diagnostic purposes or even to monitor disease progression, but...
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Evolutionary dynamics of satellite DNA in plant genomes
ÁVILA ROBLEDILLO, Laura
Satellite DNA (satDNA) belongs to the highly repetitive fraction of eukaryotic genomes. It is best characterized by the formation of long arrays of almost identical sequences that are tandemly repeated. These repeats are widely distributed in plant species where they can make up a substantial proportion of their genomes. Despite the long history of satDNA research, the classic methodology did not allow for its comprehensive characterization. Consequently, the fragmentary information gathered during the last 60 years does not answer the many questions surrounding the evolution of these elements. The development of new techniques in sequencing, together with the availability of new bioinformatics tools for analyzing different genome fractions, has presented an opportunity to advance studies of tandem repeats. This thesis describes the landscape characterization of satDNA in the genome of Fabeae species by exploring the diversity of satDNA within a genome, the association of these elements with functional centromeres, as well as their genome-wide organization. We employed new computational pipelines specifically designed for the analysis of tandem repeats from next generation sequencing data, and combined their results with molecular and cytogenetic methods to achieve comprehensive characterization of the satellite repeats.
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