National Repository of Grey Literature 46 records found  beginprevious20 - 29nextend  jump to record: Search took 0.00 seconds. 
The role of histone post-translational modifications in the regulation of gene expression in plants
Chromý, Jakub ; Čermák, Vojtěch (advisor) ; Holá, Dana (referee)
Chromatin structure, gene expression and consequently many important aspects of the plant development are under control of epigenetic regulation. Within epigenetic regulation, histones and their modifications play a pivotal role. The N-terminal tails of histones are dynamically modified by covalent post-translational modifications (PTMs). These modifications are key regulators modulating chromatin structure and thus regulating gene expression. In angiosperms, one of the processes finely regulated at the epigenetic level is the flowering. Flowering represents a very complex process, that is relevant for the study of epigenetic regulation as well as for practical application. In this work, I summarize current knowledge of the role of histone PTMs in the regulation of gene expression in plants, focused predominantly on two key regulators of flowering in Arabidopsis - FLC and FT.
Utilization of new generation sequencing methods to elucidate cystic fibrosis-like phenotype at patients with unclear illness of molecular type.
Matějčková, Iva ; Macek, Milan (advisor) ; Holá, Dana (referee)
Cystic fibrosis (CF) is genetically conditioned, autosomal recessive disease that occurs in the European population with a prevalence of about 1:2500 - 1:1800. In this disease we observe a mutation of the CTFR gene with subsequent fault in chloride channels. Such afflicted individuals usually suffer from chronic respiratory problems, pancreatic insufficiency, high concentration of chloride ions in sweat and obstructive azoospermia. Genetic testing of CFTR gene is indicated in individuals who meet the CF clinical picture and a positive sweat test (increased concentration of chlorides in the sweat). Genetic testing of the CFTR gene is usually done by using commercial kits detecting the most common mutations of the CFTR gene in the Czech Republic. If the testing results are negative, it is further performed an MLPA method that captures the larger deletions and duplications of gene, eventually a sequencing of all exons is. Despite the well-established algorithm of the testing, some patients suffering from symptoms of CF are left without genetic findings. Thanks to development of next generation sequencing, it is possible to make the diagnosis of CF more effective and uncover the variants that were not captured by previous methods.
Protein synthesis in cellular stress
Cienciala, Martin ; Pospíšek, Martin (advisor) ; Holá, Dana (referee)
Environmental stress is a daily bread for organisms across many different branches of life. Very complex response mechanisms have evolved to tackle such insults. Yeast Saccharomyces cerevisiae is adapted especially well for counteracting oxidative and osmotic stress. These unfavorable conditions usually lead to inhibition of protein synthesis. The GCN2 kinase is thought to be responsible for this phenomenon. General inhibition of protein synthesis is accompanied by an increase in expression of proteins engaging in stress response. Production of these proteins is often preceded by specialized regulatory processes, that operate on various stages of expression. This thesis will try to present the diversity and complexity of the individual regulatory layers.
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)
Study of population specific alterations of breast cancer predisposition genes in Czech Republic.
Judasová, Kristýna ; Ševčík, Jan (advisor) ; Holá, Dana (referee)
Breast cancer is the most frequent malignant disease in the female population worldvide. About 10 % of all cases are of hereditary origin. The inactivation of tumor suppressor gene BRCA1 is the main genetic predisposing factor in breast cancer in the Czech Republic. Primarily, BRCA1 participates in DNA double strand break repair. Depending on cell cycle phase, the damage is repaired by homologous recombination or non-homologous end joining. Alternative splicing variants of BRCA1 are frequently detected during the genetic screening of high risk patients. The clinical significance of these variants is unknown. Understanding of the nature of breast cancer genetics is the critical factor for early diagnosis. Based on earlier studies from the Institute of Biochemistry and Experimental Oncology 1st Faculty of Medicine Charles University, two alternative splicing variants which were repeatedly detected in patients, were chosen for functional analysis. The aim of this work is to investigate the impact of alternative splicing variants BRCA1Δ5 and BRCA1Δ10 on DNA double strand breaks repair. Particular variants were over- expressed in the cells of model system. Activity of homologous recombination (HR) and non-homologous end joining (NHEJ) was scored by in vitro DNA repair assay. The cellular localization of...
Molecular composition of constitutive heterochromatin
Pajpach, Filip ; Král, Jiří (advisor) ; Holá, Dana (referee)
Constitutive heterochromatin of eukaryotes includes various types of repetitive DNA and transposons characteristic for given region. DNA of centromeric and telomeric re- gions is usually highly methylated and transcribed to RNA transcripts, which participate in formation, functions and spreading of heterochromatin along with histones, their mod- ifications and non-histone proteins. The most typical histone modification in heterochro- matin is methylation, which forms the binding site for protein HP1. This protein (and his paralogues in other eukaryotes except for S. cerevisiae) participates in formation of com- plexes including other proteins like histone methylases SUV39H and their paralogues. Es- sential are also telosome proteins regulating telomeric heterochromatin, Polycomb group proteins and many others, for instance MBD1, Epe1, SUMO and DNA methylases DNMT. Many proteins form complexes, which partake in mechanisms necessary for heterochro- matin maintenance, for example RDRC and RITS complexes in RNA interference, SHREC complex in heterochromatin spreading, and PRC complexes forming heterochromatin in specific situations. Key words: centromere, DNA, histone, HP1, constitutive heterochromatin, methylation, modification, protein, RNA, specific, telomere
The use virus derived vectors for the expression of proteins in plants
Kratochvílová, Kateřina ; Moravec, Tomáš (advisor) ; Holá, Dana (referee)
The tobacco mosaic virus (TMV) is one of the most studied virus. Its properties (simplicity, self assembly of viral capsid, the ability to proliferate in a large variety of hosts) offers a lot of applications in various scientific or biological fields. Gene vectors based on the tobacco mosaic virus represent a very good way for expressing proteins in plants. Because the tobacco mosaic virus is well researched and a large number of his properties have already been discovered, it is used for nanotechnologic sectors in this period. Not only for the formation of nanoparticles, but also for example for a potential production of vaccines in plants. In this paper I summarize the known information about the process of self assembly of tobacco mosaic virus and the possibility of using this virus in the emerging fields of biology. Key words Tobacco mosaic virus, self assembly, viral vector, nanotechnology
Chromatin modifications in association with priming phenomenon in plants
Marková, Hana ; Holá, Dana (advisor) ; Fischer, Lukáš (referee)
Plants are exposed to many stressors to which they must be able to adapt. It has been found that plants can memorize the respective stress response and may respond to a subsequent stress exposure faster and to a greater extent. The mechanism of this so-called priming could be associated with the changes in the levels of chromatin modifications. Chromatin modifications are usually dynamically changing during the stress reaction. Some of these changes could persist for some time, thus the specific stress memory, mitotically and meiotically transmissible, could be established. Such a phenomenon was observed for stress caused by dehydration, salinity, mechanical damage, a combination of various stressors and a systemic resistance to pathogenic bacteria. So far, only a few studies on this topic exist; but even now it is clear that there are differences in the response of specific genes as well as the dependence on the length of the stress stimulus and the duration of the period between the first and second stress. A major disadvantage of existing studies is that they focus solely on histone modifications. Regarding the chromatin modifications studied so far, H3K4me3 could serve as the main mark for such priming. On the other hand, H3K27me3 modification is apparently not used as a memory tag. However, it is still...
Epigenetic regulation of DQB1 gene in patients with type 1 diabetes mellitus
Gécová, Dominika ; Kotrbová - Kozak, Anna Katarzyna (advisor) ; Holá, Dana (referee)
Background: Type 1 diabetes mellitus is a multifactorial disease caused by beta cell destruction of Langerhans pancreatic islets. From the genetic aspect the main predisposition lays on HLA class II genes (40 - 50%), molecules of which present exogenous peptides to CD4+ T lymphocytes. Enviromental factors play a crucial role in the etiopathogenesis of T1DM. Through epigenetic regulation (e.g. DNA methylation) the genetic and enviromental factors communicate. The level of methylation in the regulatory regions can significantly affect expression of these genes. Aims: The aim of the diploma thesis was to define methylation profile of HLA DQB1 alleles in type 1 diabetes mellitus patients and determine their expression. Methods: The genotyping of HLA class II genes (HLA-DRB1, HLA-DQA1, HLA-DQB1) was performed using sequence specific primers. DNA was treated with sodium bisulfite, regulatory region of HLA DQB1 was amplified and cloned into E.coli, strain DH5α/XL1-Blue. Positive clones were sent for sequencing and results analyzed. RNA was transcribed to cDNA by reverse transcription and the level of expression was analyzed by quantitative PCR. Results: Statistically significant differences were found in total methylation of DQB1*0201 and *0302 alleles in the B section of DQB1 gene. Difference in...

National Repository of Grey Literature : 46 records found   beginprevious20 - 29nextend  jump to record:
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1 Holá, D.
2 Holá, Daniela
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