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Studying the evolution of chromosome rearrangements in pipid frogs using in situ hybridization
Bergelová, Barbora ; Knytl, Martin (advisor) ; Johnson Pokorná, Martina (referee)
In African pipid frogs we can find at least eight polyploidization events in which a lot of levels of ploidy arose. This group includes diploid, tetraploid, octoploid, and/or dodecaploid species. Due to this great variability in ploidy levels, representatives of the genus Xenopus are excellent model organisms for studying the evolution of whole-genome duplications and chromosomal rearrangements. Currently, little information is known about chromosomal rearrangements within the Xenopus species, specifically, there are only two known cases of large-scale rearrangements. The first is a fusion of chromosomes 9 and 10 in the subgenus Xenopus and the other rearrangement is a non-reciprocal translocation occurring between chromosomes 2 and 9 in the subgenus Silurana. In this diploma thesis, we attempted to expand the knowledge about chromosomal rearrangements using the fluorescence in situ hybridization method. We confirmed the fusion of chromosomes 9 and 10 in other species of the Xenopus genus, such as X. pygmaeus, and proposed a hypothesis about the possibility that this fusion occurred in the common diploid ancestors of this subgenus. We also gained further insights into the origin of non-reciprocal translocation within the Silurana subgenus. This translocation was not detected in the species X....
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Energy metabolism and apoptotsis markers in cold heart aclimated rat.
Pospíšilová, Barbora ; Horníková, Daniela (advisor) ; Knytl, Martin (referee)
Cold adaptation and her effects has been known for many decates. Positive or negative impact depends especially on its length and strength. The lower temperature can very often cause the stress for organism. On the other hand in expreriment with long-term adapatation were found positive consequences on cardiovascular system. We found the lack of studies devoted to the energy metabolism and apoptosis in heart tissue during long-term cold adaptation. In this work we used a model with milder conditions of the adaptation (10žC±1), so there wouldn't be damage of the experimental animals. We compared the resuls betwen control, cold and regressive group of rats. In this expreriment we used methods of electrophoresis and Western blot. The target of the work was found if we can find any differences betwen chosen HIF targeted genes. The next goal was to detect the differences betwen chosen pro-apoptotic and anti-apoptotic markers. Keywords: cold adaptation, heart, energetic metabolism, HIF, apoptosis
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The effect of DMD gene mutation on the growth and development of muscle tissue
Paliesková, Anna Mária ; Knytl, Martin (advisor) ; Haberlová, Jana (referee)
Duchenne muscular dystrophy is one of the most frequent and very severe congenital myopathies, affecting mainly boys. The disease is caused by a mutation in the gene encoding the dystrophin protein. The gene is located in the muscle tissue cells on the inner side of the sarcolemma. Dystrophin provides a link between the actin filaments and the extracellular matrix. It is important for the proper functioning of muscles during contraction and relaxation. As explained in this thesis, the production of dystrophin is of critical importance already at the muscle tissue development stage. The DMD gene expression also affects the expression of the other genes which play a key role in the right development and growth of muscle tissue. Mutations in the DMD gene cause changes in the signalling pathway genes such as PKA, thus affecting the expression control of other genes. Mdx mice used in DMD studies show abnormalities at prenatal stages, which are manifested through wrong organisation of microtubules and location of muscular cell nuclei, and a general increase in the number of fast myosin fibres (FMyHC). The absence of dystrophin also has an adverse effect on the satellite stem cells. The signalling pathway required for the correct spindle apparatus orientation is damaged. The wrong orientation causes the...
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Correlation of morphokinetic parameters of human preimplantation embryos with their chromosomal status
Kosařová, Zuzana ; Jelínková, Ladislava (advisor) ; Knytl, Martin (referee)
A significant amount of human preimplantation embryos is aneuploid. Preimplantation genetic testing of aneuploidies (PGT-A) enables us to examine the number of chromosomes in a few trophectoderm cells biopsied from developing embryos, and only euploid embryos are then recommended to be transferred. Biopsy of trophectoderm cells is an invasive method, PGT is quite expensive, the examination is not performed at all patients. Therefore, non-invasive methods for determining the highest quality embryos are searching. Non- invasive continual monitoring in a time-lapse system is able to observe the morphokinetic parameters of embryonic development, and can select the best developing embryos with a good prognosis for successful implantation. However, there is still the question of whether and how morphokinetic parameters and embryonic ploidy correlate. Most studies on this topic show that a combination of both of these approaches is the best way for selecting the highest quality embryo for transfer.
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Sex chromosome evolution in ray-finned fishes (Actinopterygii)
Pavlica, Tomáš ; Sember, Alexandr (advisor) ; Knytl, Martin (referee)
Ray-finned fishes (Actinopterygii) possess strikingly diverse sex sex differentiation strategies (including gonochorism, unisexuality and several types of hermaphroditism) and mechanisms of sex determination (both environmental and genetic), including frequent turnovers between abovementioned strategies and mechanisms. Although exhibiting remarkable diversity of sex determination mechanisms, only about 5% of analyzed teleost species possess cytologically recognizable (i.e. heteromorphic) sex chromosomes. Still, nine different male- or female- heterogametic sex chromosome systems at various stages of differentiation have been described along with high rate of inter- and intraspecific variability. Given that early sex chromosome evolution is best studied in evolutionarily young nascent sex chromosomes, ray- finned fishes and especially the teleost lineage (Teleostei) represent vital model group for these investigations offering new insights into the evolution of these rapidly evolving regions of vertebrate genomes. Moreover, handful of studies available so far has provided evidence for a role of emerging sex chromosomes and their turnover in processes such as ecologial adaptation, speciation or genomic conflict. Besides cytogenetic studies, which had a major impact on our current knowledge about fish...
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Mechanisms of chromosome rearrangements and their relation to the formation of polyploid species
Vaňková, Tereza ; Knytl, Martin (advisor) ; Forman, Martin (referee)
Polyploid species are significantly represented among plants and some animals. Whole- genome duplication (WGD) is an unstable process with rapid changes in a genome and also changes in chromosomes. These changes includes chromosomal aberrations, such as translocations, duplications, insertion and inversions. Chromosomal aberrations and WGD are strongly represented in the evolution of organisms. Therefore the study of their mechanisms is important for an understanding of genomic development. At present, there are developments in cytogenetic technique helping study polypoid genomes and also helping add polyplodozation events to evolutionary contexts. These techniques includes banding as well as fluorescent in situ hybridization, which, thanks to the applicability of various probes, helps to detected chromosomal rearrangements. Keywords: Chromosome rearrangements, polyploid, WGD, cytogenetic techniques, FISH
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Mechanisms of chromosomal rearrangements in the context of polyploid species and its forming
Vaňková, Tereza ; Knytl, Martin (advisor) ; Forman, Martin (referee)
Polyploid species are significantly represented among plants and some animals. Whole- genome duplication (WGD) is an unstable process with rapid changes in a genome and also changes in chromosomes. These changes includes chromosomal aberrations, such as translocations, duplications, insertion and inversions. Chromosomal aberrations and WGD are strongly represented in the evolution of organisms. Therefore the study of their mechanisms is important for an understanding of genomic development. At present, there are developments in technique helping study polypoid genomes and also helping add polyplodozation events to evolutionary contexts. These techniques includes banding as well as fluorescent in situ hybridization, which, thanks to the applicability of various probes, helps to detected chromosomal rearrangements.
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Energy metabolism and apoptotsis markers in cold heart aclimated rat.
Pospíšilová, Barbora ; Horníková, Daniela (advisor) ; Knytl, Martin (referee)
Cold adaptation and her effects has been known for many decates. Positive or negative impact depends especially on its length and strength. The lower temperature can very often cause the stress for organism. On the other hand in expreriment with long-term adapatation were found positive consequences on cardiovascular system. We found the lack of studies devoted to the energy metabolism and apoptosis in heart tissue during long-term cold adaptation. In this work we used a model with milder conditions of the adaptation (10žC±1), so there wouldn't be damage of the experimental animals. We compared the resuls betwen control, cold and regressive group of rats. In this expreriment we used methods of electrophoresis and Western blot. The target of the work was found if we can find any differences betwen chosen HIF targeted genes. The next goal was to detect the differences betwen chosen pro-apoptotic and anti-apoptotic markers. Keywords: cold adaptation, heart, energetic metabolism, HIF, apoptosis
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