|
|
Fish Herpesviruses
Čečetka, Petr ; Forstová, Jitka (advisor) ; Kuthan, Martin (referee)
Herpetic viruses that attack fish are ones of the most widespread virus pathogens, threatening modern day fish population not only in the wild but also those that are farmed. There are many types of the pathogen, from the ones those do not cause severe diseases to those that are extremly dangerous, spread without any control and caused vast losses in commercial farming and in wild populations. Most of the viruses exhibit increased sensitivity on heat and stress factors, which are the most common reasons of the repeating outbreak of disease. To the best described fis herpesvirus viruses attacking fresh water fishes belong. Nowadays more and more herpetic viruses which attack mainly salt water fis are beeing discovered. Powered by TCPDF (www.tcpdf.org)
|
|
|
Bacterial adhesion to surfaces
Budil, Jakub ; Beranová, Jana (advisor) ; Kuthan, Martin (referee)
Bacterial adhesion is a process of attachment of a planktonic cell to the surface and the necessary step for further biofilm formation. Most bacterial species are capable of biofilm formation. Bacteria within biofilm exhibit increased resistance to antibiotics and other external factors, which makes the eradication of adhered bacteria rather difficult. Bacterial adhesion is very complex process affected by many physical and chemical factors as well as by the adhesive molecules present on the substrate and cell surface. Accurate description of these factors enables to design appropriate modifications of both the substrate and the environment with the aim to fabricate the antiadhesive and antibacterial surfaces or to increase the efficiency in bacteria-based biotechnological processes. Whereas in medical applications the main goal is to decrease bacterial adhesion, the increased adhesion is desirable in certain processes employing bacteria, as is for example the wastewater treatment. This thesis reviews main theories used for prediction of bacterial adhesion, describes the process of adhesion and physical, chemical and biological factors that influence it. It also contains an overview of antiadhesive and antibacterial surfaces. Key words: Bacteria, adhesion, pili, flagellum, antiadhesive and...
|
|
|
The influence of PRDM9 histon H3K4 tri-methyltransferase on chromosomal sterility
Svatoňová, Martina ; Forejt, Jiří (advisor) ; Kuthan, Martin (referee)
The influence of PRDM9 histon H3K4 tri-methyltransferase on chromosomal sterility The Prdm9 gene encodes a meiotic histone methyltransferase, which enables tri- methylation of lysine 4 on histon H3. H3K4 tri-methylation is associated with gene expression activation. The same gene was identified in the mouse as the hybrid sterility 1gene. The regulation of hotspots of meiotic recombination in mouse and human is its other function. The aim of diploma thesis was be to verify the influence of supernumerary copies of Prdm9 gene on chromosomal sterility using transgenic mice. Sterility will be induced by chromosomal translocation T43H. It was found that the gene Prdm9 itself has no influence of the observed fenotyp changes. Significant position effect in T43H translocation was confirmed. Translocation inherited from the father causes downgrade of parameters of fertility compared to that derived from the mother.
|
|
|
Studies of S. cerevisiae BR-S strain with deletion of SIR2 gene
Novotná, Pavla ; Kuthan, Martin (advisor) ; Pichová, Iva (referee)
Yeasts are unicellular eukaryotic microorganisms, capable of forming of organised multicellular communities, the colonies. Many yeast strains possess a characteristic colony morphology under defined living conditions. Another feature typical for many feral and pathogenic yeast strains is the ability to switch their morphotype. This phenomenon, called the phenotypic switching, contributes to a rapid adaptation to the changing harmful environment and is often connected with changes of the stress resistance or with the changes of virulence of pathogenic yeasts. Phenotypic switching can be observed even in non-pathogenic yeast Saccharomyces cerevisiae. The strain BR-F, isolated from nature, switches under laboratory conditions from fluffy to smooth morphology of the strain BR-S. This phenotypic switch is accompanied by broad changes in the phenotype. Transcriptome analyses of the strains BR-F and BR-S have shown, among others, changes in expression of the subtelomeric genes that are under control of the histone acetylases and deacetylases. My work was aimed to the histone deacetylase Sir2p, which could influence the phenotypic switching in Saccharomyces cerevisiae. The sir2 deletion mutant of the strain BR-S, prepared in our laboratory, was used for my studies. The results show, that the strain BR-S...
|
|
|
Bovinne papillomaviruses
Voběrková, Eva ; Drda Morávková, Alena (advisor) ; Kuthan, Martin (referee)
Bovine papillomaviruses (BPV) are small nonenveloped dsDNA viruses belong to the family Papillomaviridae. One of the characters of this family is strong species and tissue specificity, but some BPVs are represent an exception and they are able to infecting other groups of vertebrates. However transmission on human has not been proved yet. All viruses from this groups, including BPV have considerable tumorigenic potential, in particular for the infection non-permissive cells. In the natural host, they are causing clinical disease, which manifest papillomas, that may interfere with host of life what cause considerable economic loss. BPV served as model organisms for study. Papillomavirus family and these findings helps understand their human counterparts (human papillomaviruses, HPV). Recently, studies of BPV are not so frequent, overshadowed the success of vaccines against HPV. To the other hand, this success is encouradged for as to develop the similar vaccines against BPV order to avoid disease of farm animals. The successful development working on such a vaccine, is needed understand function virus and viral proteins and mechanism their interaction with the host cell. It is also necessary to map individual BPV their similarites and differences that to the specifics of each types. This work...
|
|
|
Optimization of miRNA analysis in fine-needle biopsy samples of pancreatic cancer tissue.
Čuperková, Romana ; Benešová, Lucie (advisor) ; Kuthan, Martin (referee)
Pancreatic cancer (PC) is extremely severe malignant disease with a five-year survival of less than 5%. Currently there is no reliable tool for the diagnosis of PC in its early stages. At the time of clinical symptoms most patients are in an advanced stage of the disease and the treatment does not usually have a significant effect. For these reasons emphasis is gradually shifting to the search for the suitable molecular markers for improvement of the diagnosis and assessment of the survival prognosis with respect to a possibility of surgical treatment. MiRNA represent one of the most promising markers, although, their examination in pancreatic tissue is a complicated process. One of the reasons is the very small amount of the source material coming from a fine needle biopsy. A second cause of problems is the subtle character of the pancreatic tissue resulting in significantly lower yields of molecular genetic analysis when compared to other epithelial tissues. An additional negative factor is heterogeneity of the tissue resulting in disproportionate representation of tumor cells within the sample. A suitable choice of procedures for isolation of nucleic acids (NA) and subsequent analysis including quantification of tumor cells is critical for accurate evaluation of the miRNA levels. This work is...
|
|
|
Extracellular matrix in yeast populations
Novotná, Pavla ; Kuthan, Martin (advisor) ; Dvořáček, Lukáš (referee)
The microorganisms in a natural environment are frequently found in multicellular forms, most commonly in biofilms. Biofilm is characterized as a community of cells living at the interface of two environments, embedded in the extracellular matrix. ECM is a significant component of biofilms in yeast populations. Extracellular matrix acts as a protective barrier and allows cells to survive under adverse conditions and better compete with other microorganisms. It also forms an effective barrier against antibiotics and other harmful substances, what makes biofilms a serious problem in medicine and industry. Formation of the matrix may be influenced by the morphological forms of colonies. Increased formation of ECM is commonly connected in phenotypic switching in response to changes of their living conditions. The compositeion of the ECM is a genus-and species-specific. The main component of the matrix consists of polysaccharides and proteins.
|
|
|
Retargeting of viral particles for directed cargo delivery into cells
Váňová, Jana ; Španielová, Hana (advisor) ; Kuthan, Martin (referee)
Due to their structure and ability to enter cells where they release their content, viral particles represent an attractive tool to deliver cargo to a cell. For therapeutic usage of viruses it is necessary to ensure the specific and highly efficient entry to target cells. This thesis offers an overview of methods used for virus retargeting with the intention to evaluate the success of retargeting in terms of specificity and efficiency of designed viral particles when entering a cell. On the basis of published data and considering the mechanisms of viral infection, the thesis demonstrates the difficulty to prevent the nonspecific viral particles from entering the cell and concludes that reaching total specificity is apparently impossible. Despite these small limitations, viral nanoparticles are a revolutionary therapeutic tool for delivering cargo to the cell and it is necessary to exploit their potential.
|
|
|
Carbon nanomaterials and their interactions with bacteria
Jurková, Blanka ; Beranová, Jana (advisor) ; Kuthan, Martin (referee)
Recently, carbon nanomaterials gain attention especially for their interesting, often unique, properties. They can be used in wide range of applications, such as electronics, optics, cosmetics, solar cells, construction materials, air filters, polishing materials, protective coatings and dry lubricants. Whereas their physical and chemical attributes have already been intensively examined, the research on their effects on living organisms is still at the preliminary stage. This work is focused on the interactions of carbon nanomaterials, namely graphene, fullerene, carbon nanotubes and nanodiamonds, with bacterial cells and their antibacterial and antiadhesive properties. The mechanisms of the toxic action of carbon nanomaterials against bacteria include damage of outer cell structures as a consequence of the direct contact with a nanomaterial, impairment of bacterial metabolism or reactive oxygen species production. Exact understanding of the processes that take place between bacterial cell and carbon nanomaterials can contribute to the research on their medical applications and ecological recycling in the future.
|
|
|
Study of the function of selected genes in the colonies of wild yeast strains
Tarabová, Eva ; Kuthan, Martin (advisor) ; Heidingsfeld, Olga (referee)
Saccharomyces cerevisiae strains isolated from the wild are able to exhibit multicellular social behaviour and to form complex structured colonies resembling in many properties highly resistant biofilms of pathogenic yeasts. The capability of phenotypic variability, i.e. high frequency transition between two or more different phenotypes, is another feature typical for the wild yeast strains. Such phenotypic changes are in case of pathogenic yeast often connected with changes in virulence and resistance to stress and antifungal treatment. Long-term cultivation of the wild yeast strains under laboratory conditions leads to their domestication, i.e. transition to smooth colonies and loss of some features typical for structured colonies. This process is, similarly to phenotypic switching, accompanied by significant changes in gene expression and global change of colony lifestyle. Mechanisms underlying yeast phenotypic transitions are ascribed to epigenetic regulation of gene expression via transcriptional silencing conferred by histone deacetylases. This work deals with the study of such mechanisms using knock-outs of selected genes with putative function in formation of structured colonies in wild and domesticated strains. The achieved results show, that NAD+-dependent histone deacetylase Sir2p influences...
|
guest ::
