National Repository of Grey Literature 30 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
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...
Cell-penetrating peptides - pitfall of endosomal entrapment and its overcoming
Kadlecová, Julie ; Váňová, Jana (advisor) ; Holá, Dana (referee)
The aim of the thesis is to introduce cell penetrating peptides as a potential way of transporting cargo into cells. Their ability to penetrate cell membranes with attached cargo is demonstrated. The structure and sequences of these peptides, on which their unique property to penetrate through the cell membranes is built, are described with respect to the different modes of transport. The difficulty of internalizing these CPPs via endocytosis is the frequent trapping of peptide with attached cargo in the endosome. If this occurs, the endosome content is degraded and the CPP with attached cargo is not released into the cytosol or nucleus, their target site. This work focuses on creative options, how to make release from endosome easier for CPPs with attached cargo. The introduction of such modified CPPs would accelerate their use in clinical medicine to enable the treatment of diseases such as cancer or antibiotic- resistant diseases.
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 (
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

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1 Holá, D.
1 Holá, Daniela
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