|
|
Impact of the rRNA modifications on protein synthesis
Kročová, Eliška ; Pospíšek, Martin (advisor) ; Holá, Dana (referee)
A ribosome is a supramolecular structure, which mediates synthesis of all cellular proteins, and therefore is essential for cell life. The fact, that some nucleotides of ribosomal RNA are modified, is known for forty years. However only recently, successful deeper studies on how the individual modifications are synthesized and what is their effect on ribosome synthesis and function appear. Some particular nucleotide modifications are important for the ribosome formation (like m1 acp3 Ψ1191 SSU), some others influence proper function of the ribosome (e.g. Um2921, Gm2922, Ψ2923 LSU, m1 acp3 Ψ1191 SSU). Majority of modified nucleotides in eukaryotic rRNA is being recognized by small nucleolar RNA (snoRNA). Few nucleotides is, however, recognized and subsequently modified by specific proteins. These proteins also play crucial role in ribosome maturation. In thesis presented, current knowledge on the role of ribosomal RNA nucleotide modifications during their formation and maturation, and on their function is summarized and overviewed.
|
|
|
Targeted next generation sequencing of candidate genes responsible for impaired spermatogenesis and male infertility
Daňková, Michaela ; Liška, František (advisor) ; Holá, Dana (referee)
Infertility is a widespread health problem, caused by the male factor in about half of all cases, and in about a half of the infertile men the cause is unknown. In a significant number of these men, genetic etiology is assumed. Current routine methods of laboratory diagnostics, which include karyotype examination, exclusion of mutations in the CFTR gene, and Y chromosome microdeletions, do not usually reveal the cause of infertility. That is why researchers' efforts aim at detecting mutations in other genes that are causing male infertility. In recent years, animal models have been used to identify many genes necessary for fertility. Based on these findings, 12 candidate genes have been selected (CAPZA3, CDC14B, CDC42, CNTROB, CSNK2A2, GOPC, HOOK1, HRB, OAZ3, ODF1, RIMBP3, SPATA16) that are essential for spermatogenesis. Mouse or rat mutants in these genes are primarily associated with oligoasthenoteratozoospermia, since they are involved in sperm morphogenesis. However, the phenotype spectrum may comprise also azoospermia. The purpose of the thesis was to determine the sequence of the afore mentioned genes in infertile men with impaired spermatogenesis and to reveal presence or absence of pathogenic mutations in these genes, using cDNA and genomic DNA from peripheral blood. The candidate genes were...
|
|
|
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.
|
|
|
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...
|
|
|
Analysis of primary photosynthetic processes in conifers: A comparison of selected methods and their possible utilisation for the study of genetic variability
Palovská, Markéta ; Holá, Dana (advisor) ; Albrechtová, Jana (referee)
Conifers are important both ecologically and socioeconomically, however, same parts of their biology are not that well researched. This includes genetics and breeding and partly even physiology. Because quantitative genetic analyzes applied in breeding necessitate an analysis of a large number of samples, and conventional methods of analysis are quite time-consuming, certain parameters describing e.g. the activity of photosynthetic electron-transport chain (ETC) are considered for such use. Several methods of the measurement of the activity of photosynthetic ETC exist, but there are some problems with their usage in conifers. I studied this issue from different points of view in three parts of this thesis. 1) I compared the photosynthetic ETC activity in 8 species of conifers using chlorophyll (Chl) fluorescence measurements on intact needles and polarographic measurements in isolated chloroplasts. Each method brought different information. 2) I measured Chl fluorescence parameters, reflectance spectra and pigment content in 536 genetically defined trees of Pinus sylvestris L. Many parameters showed relatively high genetic variability and heritability. I have also determined the suitability of various reflectance indices to estimate pigment and water content of needles. 3) I have optimized the...
|
|
|
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.
|
|
|
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.
|
|
| |
|
| |
guest ::
RSS feed.