|
|
Adaptive evolution of Toll-like receptors in birds
Velová, Hana ; Vinkler, Michal (advisor) ; Elleder, Daniel (referee) ; Novák, Karel (referee)
Adaptive evolution of Toll-like receptors in birds Hana Velová, PhD thesis 6 Abstract Toll-like receptors (TLRs) are one of the key and presumably also evolutionary most original components of animal immune system. As Pattern recognition receptors they form the first line of innate immune defence against various pathogens. The proper receptor binding of pathogenic ligands is crucial for their correct recognition and for subsequent triggering of an appropriate immune response. Because there exists a direct interaction between the receptor surface and the pathogenic ligand, host-pathogen coevolution on molecular level can be predicted. Thus, through variability of their ligands, TLRs are exposed to extensive selective pressures that may be detected on both genetic and protein levels. Surprisingly, the variability we revealed in birds is even higher than previously expected based on the reports from other vertebrates, mainly mammals. In my doctoral thesis I summarise the results of my contribution to the avian TLR research. We were the first who experimentally verify the absence of functional TLR5 in several avian species and duplication of TLR7 in others. We finally resolved the origin of duplication in TLR1 and in TLR2 family. An important part of my research project focused on the prediction of potentially...
|
|
|
Evolution by gene duplication with regard to subfunctionalization.
Romášek, Marek ; Krylov, Vladimír (advisor) ; Reifová, Radka (referee)
Evolution by gene duplication has been a prominent topic of biology for various decades. Novel methods and approaches recently brought about a considerable progress in our understanding of this phenomenon. The aim of this thesis is to review the modern conceptions of preservation of duplicate genes in genomes of organisms and the processes involved. Another goal is to assess the significance of the concept of subfunctionalization, resolving of ancestral functions among the duplicates, leading to their preservation.
|
|
|
Adaptive evolution of Toll-like receptors in birds
Velová, Hana ; Vinkler, Michal (advisor) ; Elleder, Daniel (referee) ; Novák, Karel (referee)
Adaptive evolution of Toll-like receptors in birds Hana Velová, PhD thesis 6 Abstract Toll-like receptors (TLRs) are one of the key and presumably also evolutionary most original components of animal immune system. As Pattern recognition receptors they form the first line of innate immune defence against various pathogens. The proper receptor binding of pathogenic ligands is crucial for their correct recognition and for subsequent triggering of an appropriate immune response. Because there exists a direct interaction between the receptor surface and the pathogenic ligand, host-pathogen coevolution on molecular level can be predicted. Thus, through variability of their ligands, TLRs are exposed to extensive selective pressures that may be detected on both genetic and protein levels. Surprisingly, the variability we revealed in birds is even higher than previously expected based on the reports from other vertebrates, mainly mammals. In my doctoral thesis I summarise the results of my contribution to the avian TLR research. We were the first who experimentally verify the absence of functional TLR5 in several avian species and duplication of TLR7 in others. We finally resolved the origin of duplication in TLR1 and in TLR2 family. An important part of my research project focused on the prediction of potentially...
|
|
|
Utilization of trehalose in orchids: evolution of trehalase genes
Šoch, Jan ; Ponert, Jan (advisor) ; Hála, Michal (referee)
All orchid species studied so far have been shown to participate in orchideoid mycorrhizal symbiosis. Morover, this symbiosis is absolutely vital component of their life cycle. Exchange of nutrients occurs between symbionts where the fungi provides the orchid with energy and carbon supply at least in its early developmental stages. This study focuses on the possible role of trehalose in this transfer. In vitro experiments have showed in five species from three different subfamilies of Orchidaceae family that they can utilize trehalose comparably with sucrose and glucose. Thus, the ability of trehalose utilization seems to be conserved among orchids. Trehalase enzyme activity was localized histochemically in orchid mycorrhizas. The activity strongly colocalized with colonized tissue supporting a hypothesis that trehalose transfer occurs in this site and is mediated by trehalase. Using bioinformatic methods, trehalase gene duplications were identified in many taxons of Embryophyta including three orchid species. Interestingly, highest number of trehalase gene copies was identified in genome of orchid Dactylorhiza majalis. Trehalose utilization, high trehalase activity in mycorrhizas and trehalase gene duplications in some orchids together indicate that trehalose transfer in orchid myccorhizas...
|
|
|
Evolution and expression of the Odorant Binding Proteins in selected species of mice
Vinkler, David ; Stopka, Pavel (advisor) ; Trachtulec, Zdeněk (referee)
Odorant-binding proteins (OBPs) are small soluble proteins expressed at high levels in the proximity of olfactory receptors. OBPs act as solubilizers and carriers of the lipophilic odorants in the aqueous mucus of mammals and other vertebrates. OBPs have now been studied nearly thirty years, but in comparison to the wealth of data available on their structural chemistry and molecular biology, our knowledge about gene expression and function of these proteins is still insufficient. This work provides new insights into the tissue specificity of OBP and presents several new sequences of genes governing these proteins in selected species of mice.
|
|
|
Evolution by gene duplication with regard to subfunctionalization.
Romášek, Marek ; Reifová, Radka (referee) ; Krylov, Vladimír (advisor)
Evolution by gene duplication has been a prominent topic of biology for various decades. Novel methods and approaches recently brought about a considerable progress in our understanding of this phenomenon. The aim of this thesis is to review the modern conceptions of preservation of duplicate genes in genomes of organisms and the processes involved. Another goal is to assess the significance of the concept of subfunctionalization, resolving of ancestral functions among the duplicates, leading to their preservation.
|
guest ::
