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Human FADS genes and their adaptive evolution
Motysová, Natalia ; Priehodová, Edita (advisor) ; Kulichová, Iva (referee)
Long chain polyunsaturated fatty acids (LC-PUFA) are one of the key elements that help maintain the optimal health of our organism. Our body is unable to synthesize them de novo, thus we need to synthesize them using various enzymes including desaturases from the diet's precursors. The FADS1 and FADS2 genes encode Δ5D (FADS1) and Δ6D (FADS2) desaturases, which catalyse the desaturation steps of LC-PUFA biosynthesis. Within the FADS gene region, different genetic variants affecting desaturase activity have been identified, one example being single nucleotide mutations forming two haplotypes A (ancestral) and D (derived), a classification later redefined to haplogroup A and D. The activity of Δ5D and Δ6D fatty acid desaturases are influenced by the haplogroup. Individuals with haplogroup D show a higher level of FADS1 gene expression and haplogroup D is also associated with a more efficient conversion of 18-carbon PUFAs to LC-PUFAs. However, this feature varies across populations. Different types of environments require diverse adaptations, and it is adaptation to diet that is very evident in the FADS gene cluster. Higher FADS1 expression and more efficient conversion of 18-carbon PUFAs to LC-PUFAs will be favored in environments with reduced availability of these acids (Africa, India). On the...
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Pozitive and negative selection of mitochondrial genome
Svoboda, Matěj ; Kupková, Kristýna (referee) ; Maděránková, Denisa (advisor)
The bachelor thesis engages with problematics of positive and negative selection of mitochondrial genome. Thesis is divided into two parts. First part grapples with theory and explanation of fundamental definitions, in particular understates mitochondrial genome, nucleotide mutation, positive and negative selection and furthermore evolution models. Second part focuses on processing mitochondrial DNA practically and on establishing functions in programming environment R. The emphasis is foremost on gene sequencing alignment and exploring substitutions. Consequently, obtained outcomes are contrasted with PAML and KaKs Calculator programme outcomes.
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Host-microbiota, pro-inflammatory immunity and physiological senescence in wild birds
Těšický, Martin
Triggered by microbial ligands, inflammation serves as a "double-edged sword" to fight infections on the one hand, but on the other hand causing tissue damage due to oxidative stress if it is dysregulated. For example, chronic inflammation can contribute to inflammaging, which is now widely regarded as one of the causes of ageing. In my interdisciplinary dissertation, my colleagues and I investigated three interrelated aspects of inflammation, using an evolutionary framework and various free-living birds as models: (1) ecological and evolutionary determinants of gut microbiota (GM) composition and diversity, a driver of wild bird immunity, (2) diversity in immune genes affecting inflammatory responses in wild birds and (3) inflammation-related physiological senescence in a free-living passerine bird, the great tit (Parus major). Firstly, using 16S rRNA gene metabarcoding, we revealed high intra- and interspecific variation in passerine gut microbiota (GM) dominated by the major phyla Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. Although in mammals GM depends strongly on host phylogeny and diet, in birds we found only moderate effects of phylogeny and very limited effects of host geography and ecology on GM composition. While microbiota diverged between the upper and lower...
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Host-microbiota, pro-inflammatory immunity and physiological senescence in wild birds
Těšický, Martin ; Vinkler, Michal (advisor) ; Tschirren, Barbara (referee) ; Štěpánek, Ondřej (referee)
Triggered by microbial ligands, inflammation serves as a "double-edged sword" to fight infections on the one hand, but on the other hand causing tissue damage due to oxidative stress if it is dysregulated. For example, chronic inflammation can contribute to inflammaging, which is now widely regarded as one of the causes of ageing. In my interdisciplinary dissertation, my colleagues and I investigated three interrelated aspects of inflammation, using an evolutionary framework and various free-living birds as models: (1) ecological and evolutionary determinants of gut microbiota (GM) composition and diversity, a driver of wild bird immunity, (2) diversity in immune genes affecting inflammatory responses in wild birds and (3) inflammation-related physiological senescence in a free-living passerine bird, the great tit (Parus major). Firstly, using 16S rRNA gene metabarcoding, we revealed high intra- and interspecific variation in passerine gut microbiota (GM) dominated by the major phyla Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. Although in mammals GM depends strongly on host phylogeny and diet, in birds we found only moderate effects of phylogeny and very limited effects of host geography and ecology on GM composition. While microbiota diverged between the upper and lower...
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Study of endogenous retroviruses: Insight into the retroviral evolution and virus-host interactions
Hron, Tomáš ; Elleder, Daniel (advisor) ; Kejnovský, Eduard (referee) ; Hirsch, Ivan (referee)
In my doctoral project, I studied the evolution of retroviruses and long-term interactions with their hosts. Retroviruses infect a broad range of species including possibly all vertebrates. They are unique in their ability to efficiently create endogenous retroviruses (ERVs) - viral copies integrated into the host genomes and consequently inherited by successive generations as usual genomic locus. ERVs represent a significant portion of vertebrate genomes and play an important role in a variety of cellular processes and pathologies; however, their sequences are still largely unexplored. The results of my work contributed to the uncovering of ancient evolutionary history of retroviruses. In this regard, I employed the ERV sequences, as they represent "genetic fossils" of viral infections that occurred throughout entire retroviral evolution. By discovery and analysis of ancient ERV lineages, I shed light on the deep history of retroviruses and revealed how the past infections shaped the evolution of vertebrate antiviral defense. In addition to the investigation of retroviral evolution, I also studied process of ongoing endogenization and fixation of newly emerged ERVs in a mammalian host population. In this part of my work, I focused on a unique model of ERV that have been recently invading mule deer genome.
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Study of endogenous retroviruses: Insight into the retroviral evolution and virus-host interactions
Hron, Tomáš ; Elleder, Daniel (advisor) ; Kejnovský, Eduard (referee) ; Hirsch, Ivan (referee)
In my doctoral project, I studied the evolution of retroviruses and long-term interactions with their hosts. Retroviruses infect a broad range of species including possibly all vertebrates. They are unique in their ability to efficiently create endogenous retroviruses (ERVs) - viral copies integrated into the host genomes and consequently inherited by successive generations as usual genomic locus. ERVs represent a significant portion of vertebrate genomes and play an important role in a variety of cellular processes and pathologies; however, their sequences are still largely unexplored. The results of my work contributed to the uncovering of ancient evolutionary history of retroviruses. In this regard, I employed the ERV sequences, as they represent "genetic fossils" of viral infections that occurred throughout entire retroviral evolution. By discovery and analysis of ancient ERV lineages, I shed light on the deep history of retroviruses and revealed how the past infections shaped the evolution of vertebrate antiviral defense. In addition to the investigation of retroviral evolution, I also studied process of ongoing endogenization and fixation of newly emerged ERVs in a mammalian host population. In this part of my work, I focused on a unique model of ERV that have been recently invading mule deer genome.
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Pozitive and negative selection of mitochondrial genome
Svoboda, Matěj ; Kupková, Kristýna (referee) ; Maděránková, Denisa (advisor)
The bachelor thesis engages with problematics of positive and negative selection of mitochondrial genome. Thesis is divided into two parts. First part grapples with theory and explanation of fundamental definitions, in particular understates mitochondrial genome, nucleotide mutation, positive and negative selection and furthermore evolution models. Second part focuses on processing mitochondrial DNA practically and on establishing functions in programming environment R. The emphasis is foremost on gene sequencing alignment and exploring substitutions. Consequently, obtained outcomes are contrasted with PAML and KaKs Calculator programme outcomes.
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