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Polyploidy with specific view to paleopolyploidy and its detection
Kotz, Matěj ; Král, Jiří (advisor) ; Rothová, Olga (referee)
Polyploidy is a significant phenomenon in the evolution of eucaryotic organisms. It has been a subject of interest of biologists for decades and it has been studied particularly largely in plants, where it most often occurs. This thesis handles occurrence of poylploidy in organims and a special emphasis is laid on old polyploidization events occurrence of polyploidy in animal taxa. Furthermore, the types of polyploidy and obstacles are discussed here, that a polyploid organism has to tackle to stabilize its genome. That also includes the need to ensure the correct chromosome segregation in a meiotic division. A special case of polyploidy is paleopolyploidy (sometimes refered to as "ancient polyploidy" in English), which is an evolutionary old polyploidization event, that is followed by the process of diploidization. This process is characterized besides others by a large number of structural changes in chromosomes and a loss of some DNA sequences and a gradual transition of the polyploid genome to the cytologically diploid state. Because of these changes, it is difficult to detect a paleopolyploidy and the main part of this thesis is dedicated to this problem, in which the main approaches that might lead to its detection are discussed. Key words: polyploidy, animal, plant, meiosis, paleopolyploidy,...
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The role of small non-coding RNAs in the regulation of plant reproductive development
Hromadová, Michaela ; Honys, David (advisor) ; Rothová, Olga (referee)
Small RNAs (sRNA) are broadly defined as regulatory molecules of 21-24 nucleotides in length which belong to the class of noncoding RNAs. They usually originate in response to the presence of double-stranded RNA in the cells and facilitate transcriptional and posttranscriptional gene silencing of complementary sequences. Their role lies not only in defence against exogenous nucleic acids, but primarily in the regulation of endogenous genes. Typical target molecules of plant sRNA are transposable elements and genes encoding the transcription factors involved in the control of key developmental transitions like the initiation of the reproductive phase and the regulation of its progress. The aim of this thesis is a summary of functional roles of individual small RNA in plant reproductive development, with focus to the female and male gametophytes and in the protection against the transition of transposable elements to following generations. Both endogenous and exogenous sRNA are amply utilized in plants, because they provide an immediate and direct response of the organism to rapidly changing conditions, and thus undoubtedly belong to the key factors which contribute to their phenotypic plasticity.
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Molecular basis of human congenital anomalies
Kovačičová, Denisa ; Šípek, Antonín (advisor) ; Rothová, Olga (referee)
This bachelor thesis deals with the topic of congenital anomalies. The sorting of the congenital anomalies is discussed in the first two chapters. The third chapter concerns the mutations of the short arm of chromosome 17. I have chosen to describe the Smith - Magenis syndrome, which is caused by the deletion of 17p11.2, and the Potocki - Lupski syndrome, which is its reciprocal duplication. The gene RAI1 is specified in this part. The other topic mentioned in this thesis are RASopathies. The research of this section deals with the Noonan syndrome and focuses on mutations in genes PTPN11, SOS1, RAF1, KRAS and NRAS. In the fifth chapter the issue of thalidomide, its history and the mechanisms of action discovered up to now are described. The critical period and the mechanisms of limb reduction defects related to the timing of exposure are also defined here. New methods and findings related to these topics are discussed in the end of this work. Key words: congenital anomalies, teratology, ontogenesis, Potocki - Lupski syndrome, Smith - Magenis syndrome, RASopathies, Noonan syndrome, thalidomide
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Introduction of APEX-based labeling for the research of mitochondrial organelles of Giardia intestinalis and Trichomonas vaginalis.
Drašnarová, Zuzana ; Doležal, Pavel (advisor) ; Rothová, Olga (referee)
Giardia intestinalis and Trichomonas vaginalis are parasitic protists living in the environment without oxygen. For this reason, their mitochondria were transformed into organelles lacking the oxidative phosphorylation. We do not know anything about the intermembrane space (IMS) of these mitochondrial organelles. Main reason is that it is hard to isolate IMS proteins using the classical methods of the molecular biology, as cell fractionation. Recently, the new ascorbate peroxidase (APEX) tag has been developed. This tagging is suitable for the fluorescence as well as the electron microscopy. APEX can also behave like biotin ligase when exposed to biotin-phenol and this allows the labeling of the proteins of the compartment as well as their isolation. We optimized the conditions for optimal APEX activity and using this technique we were able to visualize the IMS of hydrogenosomes of T. vaginalis and to isolate hydrogenosomal proteins.
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Mutation and substitution rates in sexual and asexual forms: a clue to the persistence of sex in a model group of Cobitis?
Röslein, Jan ; Janko, Karel (advisor) ; Rothová, Olga (referee)
Univerzita Karlova v Praze Přírodovědecká fakulta Studijní program: Molekulární biologie, genetika a virologie Bc. Jan Röslein Mutační a substituční tempo u sexuálních a klonáních forem: možný klíč k vysvětlení persistence sexu u modelové skupiny sekavců Mutation AND substitution rates in sexual and asexual forms: a clue to the persistence of sex in a model group of Cobitis? Typ závěrečné práce Diplomová Vedoucí závěrečné práce: Mgr. Karel Janko, Ph.D. Praha, 2015 Velký dík náleží mému školiteli Mgr. Karlu Jankovi, Ph.D. za velmi nápomocné, direktivní vedení práce. Též bych rád poděkoval panu Mgr. Janu Pačesovi, Ph.D. za více než vzdělávací rozměr v oblasti bioinformatické analýzy a Mgr. Ladislavu Pekárikovi, Ph.D., Mgr. Janu Kočímu za pomoc při analýze vybraných kapitol. Také bych rád poděkoval rodině za podporu. Všem participantům na této diplomové práci se hluboce omlouvám za způsobenou psychickou újmu. Prohlášení: Prohlašuji, že jsem závěrečnou práci zpracoval/a samostatně a že jsem uvedl/a všechny použité informační zdroje a literaturu. Tato práce ani její podstatná část nebyla předložena k získání jiného nebo stejného akademického titulu. V Praze dne 12. 8. 2015 Podpis: Abstrakt Klíčová slova: Abstract Key words: Obsah 1...
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Mutations in brassinosteroid biosynthetic genes and their effects on plant phenotype
Frimlová, Klára ; Rothová, Olga (advisor) ; Mašková, Petra (referee)
Brassinosteroids are important group of phytohormones, whose presence affects anatomy, morphology and development of plants. They occur in all vegetative and mainly generative organs. Brassinosteroids are biosynthesized via two main paths named early C-6 oxidation pathway and late C- 6 oxidation pathway. Brassinosteroid biosynthesis is catalyzed by enzymes from the group of cytochrome P450. Gene mutations - which affect brassinosteroid biosynthesis - have been studied especially in Arabidopsis thaliana L., Pisum sativum L., Solanum lycopersicum L. and Oryza sativa L. Mutations lead to changes in the composition and amount of brassinosteroids in plants. The reduced content of brassinosteroids is manifested by typical phenotype that includes reduced growth, reduced size of plant organs, and dark green leaves in mutant plants. The mutant phenotype can be reversed by exogenous application of brassinosteroids, which is nevertheless dependent on the concentration of the brassinosteroids used. Higher concentrations of brassinosteroids cause mostly inhibition of root elongation. Keywords: brassinosteroids, biosynthesis, mutant, phenotype
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Gene expression of specific parts of CNS in a rat model for transgenerational transmission of drug addiction.
Radilová, Kateřina ; Černá, Marie (advisor) ; Rothová, Olga (referee)
Methamphetamine (MA) is a drug often abused by drug-addicted women and also is the mostly used drug in the Czech Republic. This drug crosses the placental and hematoencephalic barriers easily and therefore it can negatively affect not just mother herself, but also the development of the fetus. Even though there have been several published studies evincive negative effects of MA to posterity of drug-addicted mothers, the most critical term during pregnancy for the fetus remains unknown. In this study are examined CNS structures, which are directly influenced by methamphetamine action. Their function may lead to drug addiction through pleasurable feelings, such as reward feeling evoking. In the next chapter are analysed neurotransmitters and their transporters, which are related to methamphetamine effects. Studying their structure, localization or development during life may help to bring near the drug functioning in different life periods. Methamphetamine itself and its effects are closer described in the last part of this study. The problem of methamphetamine exposed fetus is outlined there - prenatal and postnatal so far known differences, but also sex differences in methamphetamine pharma- cokinetics.
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