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Charakterizace oocytů afrických rypošů
KOPECKÁ, Eva
This study is focused on characterisation of oocytes of long-lived rodents, naked mole-rat and giant mole-rat, that are emerging models of long-term oocyte and ovarian quality. In the second part, the effect of repeated ovulations on aging-associated quality decline of oocyte is studied, comparing mouse and giant mole-rat.
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DNA Methylation Patterns in patients with Neurodevelopmental Disorders
Vítková, Magdalena ; Steiner Mrázová, Lenka (advisor) ; Krejčík, Zdeněk (referee)
Neurodevelopmental disorders (NDDs) are diseases characterized by abnormal development of the central nervous system and brain. Simultaneously, the NDDs may also be associated with specific changes in DNA methylation. The rapid development of sequencing techniques, particularly whole genome sequencing (WGS) and whole exome sequencing (WES), has helped to uncover a number of genes associated with NDDs. Determining the pathogenicity of the variants found remains a challenge in the diagnosis of patients with NDDs. Finding the DNA methylation patterns by microarray or methylation sequencing in patients with NDDs carrying a variant of uncertain significance (VUS) may provide valuable information to address this problem. This thesis demonstrates the feasibility of using these approaches to functionally classify found variants in the KDM5C, ARID1B, ATRX, and BRWD3 genes. The aim was to determine whether there are changes in the DNA methylation patterns of patients with NDDs compared to probands and healthy controls, which could be used to confirm the diagnosis. Key words: DNA methylation patterns, DNA methylation, histone modifications, NDDs, KDM5C, ARID1B, ATRX, BRWD3
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Effect of cancer therapy on fertilization parameters in testicular germ cell tumour patients.
Kruf, Annabelle Elisabeth ; Vondráková, Jana (advisor) ; Nevoral, Jan (referee)
Testicular germ cell tumours (TGCTs) are a rare type of cancer. It is the most common type of cancer in the age group of 15-35 years. The consequences that TGCT and the treatment of this disease impose to these young men in terms of sperm parameters and fertility is yet unclear. This study involves 84 semen samples from 46 patients sorted in three time groups - before treatment, 3 months after the treatment and 6 months after the treatment. Several sperm parameters were studied and compared within the three time points. Adding on to this, the study takes two patients with complete set of semen samples and studies them individually. The results mostly show great differences in patients and this study underlines the individual characteristics that need to be taken into consideration when it comes to patients' fertility journeys after battling TGCT. Sperm viability, concentration, apoptosis, DNA damage, acrosomal integrity and leukocyte concentration nor histone modification evaluation showed any significant changes between said groups. DNA damage was correlated to the level of acrosomal permeability. IgA antibody levels rose significantly in samples after orchiectomy. IgG antibody levels did not show the same trend. A novel approach was optimized and applied using JUNO and FcRL3 double transfected...
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Epigenetic Dysregulation through Histone Modifications in Lymphoma
Hostaš, Ondřej ; Havránek, Ondřej (advisor) ; Malík, Radek (referee)
Lymphomas are a diverse group of malignant tumors that arise from lymphocytes, commonly affecting lymph nodes or the spleen. They are one of the most common types of tumors worldwide. Unfortunately, many subtypes have a poor prognosis, or are not currently fully curable with standard therapeutic approaches. Mutations in enzymes responsible for posttranslational modifications of histones are very common in certain subtypes of lymphoma, as well as in many other cancer types. These enzymes directly affect gene expression by changing the condensation state, and thus the accessibility, of chromatin. Some of these enzymes have been found to play an important role in the formation of germinal centers in lymphoid follicles. Therefore, their mutations can lead to uncontrolled proliferation and cancer development. Since many conventional therapeutic strategies are incapable of curing a large portion of lymphomas, novel and more targeted approaches are needed. Inhibition and/or modulation of the function of the aforementioned enzymes may be a basis for such approaches. Key words: lymphomas, epigenetic regulation, histone modifications, KMT2D, EZH2, CREBBP, EP300
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Effect of estrogens on in vitro models of testicular tissue and spermatogenesis
Jursová, Pavlína ; Děd, Lukáš (advisor) ; Tlapáková, Tereza (referee)
Although estrogens are primarily known for their functions in female reproductive system, their effect on male reproductive functions has also been well established. Physiological estrogen concentration is essential for a proper spermatogenesis. Estrogens regulate many functions in testicular tissue, including proliferation and apoptosis of all testicular cell types, dynamic restructuring of cell-cell junctions in the testis, and post-translation modifications of histones. Hence, the aim of this thesis was to study effect of estrogens on in vitro models of testicular tissue and spermatogenesis and thus to address their functions in testicular tissue more deeply. This project includes testicular organoid cultivation for further usage as in vitro model of spermatogenesis. To addresss the effect of various avaliable estrogen forms, experiments on MCF-7 cell line were done. Finally experiments with in vitro model of testicullar tissue - TM4 Sertoli cell line were done. In order to fulfill the aims and verify the hypotheses, some advanced methods such as CLARITY volume confocal imaging and holographic microscopy were used. It was found that estrogens can affect Sertoli cell morphology and the expression of some genes involved in cell-cell junction dynamics. Furthermore the process of spermatogenesis was...
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Differences in histone acetylation in normoxia and hypoxia
Čepek, Pavel ; Poljaková, Jitka (advisor) ; Eckschlager, Tomáš (referee)
Histones and their N and C terminal tails undergo different covalent modifications that regulate gene transcription. Among these histone modifications are methylation, ubiquitinilation, SUMOylation, ADP- ribosylation, phosphorylation, proline izomerization, deimination and acetylation. Histone acetylation is regulated by histonacetyltransferases (HATs) and histondeacetylases (HDACs). The balance between acetylation/deacetylation influences chromatin condensation and thus regulates gene transcription. Acetylation balance is disrupted in many human cancers and this fact can contribute to the development of malignant diseases. Histondeacetylase inhibitors (HDACi) can restore this acetylation imbalance. One of these HDACi is valproic acid (VPA) which has been used in treatment of epilepsy for decades. VPA shows antitumour effect in many studies. Decreased expression of n-myc oncoprotein, inhibition of tumour growth and angiogenesis are one of these anticancer effects observed in neuroblastoma cell lines after treatment with VPA. Despite the fact that exact mechanism of antitumour effect of VPA remains unclear, one of the most important mechanisms is hyperacetylation of histone H3 and H4. It is shown in this work that VPA increases acetylation of histones H3 and H4 in human neuroblastoma cell lines...
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The study of epigenetic regulation of gene HLA II. Clas within family relationships
Chmel, Martin ; Černá, Marie (advisor) ; Urbanová, Jana (referee)
Introduction: At our post-genomic era the studies of epigenetic regulation constitutes one of the tools for understanding the function of genes. Epigenetic regulation can directly control the temporal and spatial gene activity or silencing. The molecular basis of these regulations are DNA bases modifications, chromatin remodeling and RNA interference. At the same time, these mechanisms have a special way of transferring genetic information to subsequent generations called epigenetic inheritance. It has been proven epigenetic deregulation of certain genes as cause for many disease. For this reason, the study of epigenome HLA genes seems particularly important because these genes play a fundamental role in regulating the immune system. Aims: The aim of this work is to create a description of epigenetic modifications within families. It is an analysis of histone modifications and DNA methylation in the promoter region of the gene HLA DQA1. The aim was also to compare the differences in epigenetic modifications between alleles and compared the differences in these modifications between generations. The results will be compared with the analysis of the level of expression of the gene HLA DQA1. Methods: From collected peripheral blood of donors were isolated DNA, RNA, and leukocytes. DNA was used for...
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Recombination hot-spots in various organisms
Stočesová, Lucie ; Holá, Dana (advisor) ; Forman, Martin (referee)
Meiotic recombination is an important process which occurs in sexually reproducing organisms and creates new allelic combinations. Frequency and distribution of crossing-overs (COs) are affected by many internal and external factors. Regions with higher frequency of COs are called recombination hot-spots and in this thesis, they are divided into ancestral and derived hot-spots. Ancestral hot-spots are the more original ones and they are determined by histone modifications, nucleosome-depleted regions, promoters and sequence motifs. This type of hot-spots occurs, e.g., in yeasts, birds and plants. Derived hot-spots are determined by the PRDM9 protein, which searches for specific sequence motifs and creates histone modifications. These hot-spots are typical for most mammals except the canines which lost functional PRDM9 due to the mutation of the Prdm9 gene. Activity of PRDM9 destroys primary locations of hot- spots via gene conversion. This process is called "hot-spot paradox" and is solved by the rapid evolution of alleles of the Prdm9 gene. This thesis summarizes basic information on distribution and determination of hot-spots among various eukaryotes. It particularly focuses on the PRDM9 protein, its structure, function and evolution. A determination of location of recombination in species...
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Polyomavirus minichromosome structure
Satratzemis, Christos ; Forstová, Jitka (advisor) ; Mělková, Zora (referee)
The polyomavirus genome is present in the host cell as circular double-stranded DNA associated with nucleosomes. Consequently, the expression of polyomavirus genes is affected by the location of nucleosomes on DNA and histone modifications. This thesis reviews the current state of knowledge regarding the polyomavirus minichromosome structure and the effects of nucleosome phasing and histone modifications on polyomaviral replication cycle. In addition, factors conditioning these phenomena are discussed. Drawing on available literature, neither nucleosome phasing nor histone modifications appear to be random. However, not all viral DNA molecules are identical in these respects. Processes such as early and late transcription, replication and encapsidation thus occur only within certain fractions of the set of DNA molecules
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Association of chromatin modifications with transgenerational abiotic stress memory of plants
Vyskočilová, Barbara ; Holá, Dana (advisor) ; Fischer, Lukáš (referee)
Plants are constantly exposed to various stressors which usually leads to changes in the expression of many different genes. This can be controlled at multiple levels, including modifications of chromatin structure. Some of these modifications may persist even after the period when the plant is exposed to stress and could possibly act as a kind of "stress memory". This work deals with so-called meiotic/transgeneration "stress memory" of plants caused by abiotic stressors. Compilation of studies dealing with this topic showed that they are still rather rare and usually originated from only a few laboratories. The majority of these studies was aimed only at the examination of DNA methylation and their design was not always optimal. In my opinion, true proofs of transgeneration "stress memory" of plants still remain to be presented; further, more properly designed studies are necessary. Powered by TCPDF (www.tcpdf.org)
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