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Exosomes in parasitic protists
Horáčková, Jana ; Tachezy, Jan (advisor) ; Štáfková, Jitka (referee)
Most cells release extracellular vesicles. These vesicles are exosomes, ectosomes and apoptotic bodies. The main function of ectosomes and exosomes is the intracellular communication and transport of molecules between cells. The goal of this bachelor thesis is to review the current knowledge about exosomes and ectosomes and how these vesicles contribute to the pathogenicity of parasitic protists. The parasitic protists release exosomes and ectosomes that contribute to their development in the host and play a key role in their pathogenicity. Exosomes and ectosomes can also affect the immune system of the host and facilitate the invasion of parasitic protists into the host cells.
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Mitochondrion-related organelles in diplomonads
Stoklasa, Michal ; Tachezy, Jan (advisor) ; Kolísko, Martin (referee)
Order Diplomonadida includes parasitic and free-living species that adapted to the oxygen-poor environment. They possess reduced form of mitochondria (hydrogenosome or mitosome). These organelles lack Krebs cycle and membrane electron-transport chain. ATP synthesis by oxidative phosphorylation and other mitochondrial metabolic pathways are modified or entirely absent. Main difference between hydrogenosome and mitosome is synthesis of hydrogen using the enzyme hydrogenase and ATP synthesis by substrate level phosphorylation in hydrogenosomes that are absent in mitosomes. The most studied diplomonads are a human pathogen Giardia intestinalis possessing the mitosomes and a salmon parasite Spironucleus salmonicida with hydrogenosomes. This thesis was focused on determining the type of mitochondrial organelles in angelfish parasite Spironucleus vortens and free living Hexamita sp. It has not been described whether they possess the hydrogenosomes or the mitosomes so far. In both protists transmission electron microscopy revealed presence of double membrane vesicles, possibly their mitochondrial organelles. Homologous S. vortens anti- hydrogenase and anti-HydE antibodies were produced and tested in order to determine their cellular localization. Using the western blot analysis and immunofluorescence...
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Applications of CRISPR-Cas9 for genetic engineering in parasitic protists
Ročeň, Milan ; Tachezy, Jan (advisor) ; Rada, Petr (referee)
The CRISPR / Cas system serves as a cellular defense mechanism that protects bacteria and archaea from foreign DNA, especially bacteriophages. Its product forms a ribonucleoprotein complex, whose components are sgRNA and Cas endonucleases. Using sgRNAs, which are complementary to foreign DNA, this complex recognizes the DNA and Cas endonucleases induce double-strand breaks. This method is applied both in primary research, where it is applicable for functional analysis of proteins and the study of gene expression, as well as in applied research, where it can apply, for example, in the production of genetically modified organisms or genetically attenuated vaccines. This work summarizes the current knowledge of the CRISPR / Cas system and its application for gene manipulation in parasitic protists.
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Organelle proteomics of parasitic protists
Jedelský, Petr ; Tachezy, Jan (advisor) ; Kolářová, Libuše (referee) ; Půta, František (referee)
Advances in DNA sequencing led to a technological breakthrough, that allowed analyzis of complete genomes including those of parasitic protists Trichomonas vaginalis and Giardia intestinalis . These organisms are studied not only for their clinical importance, but also from the evolutionary point of view for their adaptation to anaerobic environment. Genome sequencing and annotations of predicted proteins alone did not bring detail view into functioning of their mitochondrion related organelles in G. intestinalis mitosomes, notparticipating in energetic metabolism, in T. vaginalis hydrogenosomes, producing molecular hydrogen and ATP by means of substrate phosphorylation. Traditional methods based on a fractionation by ultracentrifuging in density gradient and subsequent biochemical and enzymological analyzes were extended by one and twodimensional electrophoresis with subsequent identification of proteins by mass spectrometry. Methods of multidimensional separation of peptides produced by specific proteolysis of a complex mixture...
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Utilization of cellulose and hemicellulose as a source of energy by symbiotic protists and other organisms
Hammerbauerová, Iva ; Tachezy, Jan (advisor) ; Hrdý, Ivan (referee)
In this thesis I focus on the enzymatic degradation of plant structural polysaccharides cellulose and hemicellulose. I describe the enzymes involved in their lysis and their breakdown and their function and occurence among organisms. I also pay attention to the mechanisms of xylose and arabinose catabolism as pentoses found in hemicellulose. I describe some niches where cellulose and hemicellulose degradation takes place and organisms that take part in it. Finally I shortly point out the biotechnological importance of these organisms in the production of bioethanol.
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