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Replication and transcription of nucleolar DNA
Flusser, Michal ; Smirnov, Evgeny (advisor) ; Staněk, David (referee)
The nucleolus is the most prominent compartment of the cell nucleus and is the place where ribosomal RNAs (rRNAs) are synthesized, processed and assembled with ribosomal proteins. Although the nucleolus has been studied for decades its structural and functional organization is still unclear. In particular, the role of various types of DNA participating in the formation of nucleoli along with ribosomal genes is not understood. The present thesis summarizes the current knowledge and views on the nucleolus, focusing on the two synthetic processes, replication and transcription, in mammalian cells. Specific features of these processes in the context of nucleolar ultrastructure remains an unsolved problem of the modern molecular biology.
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Study of the mechanism of gene expression regulation at the level of functional organization of chromatin domains.
Hornáček, Matúš ; Cmarko, Dušan (advisor) ; Kučera, Tomáš (referee) ; Stixová, Lenka (referee)
- 1 - ABSTRACT Nucleoli are formed on the basis of genes of ribosomal DNA (rDNA) clusters called Nucleolus Organizer Regions (NORs). The essential structural components of the nucleoli, Fibrillar Centers (FC) and Dense Fibrillar Components (DFC), together compose FC/DFC units. These units are centers of rDNA transcription by RNA polymerase I (pol I), as well as the early processing events, in which an essential role belongs to fibrillarin. Each FC/DFC unit probably corresponds to a single transcriptionally active gene. In our work we study changes of FC/DFC units in the course of cell cycle. Correlative light and electron microscopy analysis showed that the pol I and fibrillarin positive nucleolar beads correspond to individual FC/DFC units. In vivo observations showed that at early S phase, when transcriptionally active ribosomal genes were replicated, the number of the units in each cell increased by 60 to 80 %. During that period the units transiently lost pol I, but not fibrillarin. Then, until the end of interphase, number of the units did not change, and their duplication was completed only after the cell division, by mid G1 phase. This peculiar mode of reproduction suggests that a considerable subset of ribosomal genes remain transcriptionally silent from mid S phase to mitosis but become again active...
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Replication and transcription of nucleolar DNA
Flusser, Michal ; Smirnov, Evgeny (advisor) ; Staněk, David (referee)
The nucleolus is the most prominent compartment of the cell nucleus and is the place where ribosomal RNAs (rRNAs) are synthesized, processed and assembled with ribosomal proteins. Although the nucleolus has been studied for decades its structural and functional organization is still unclear. In particular, the role of various types of DNA participating in the formation of nucleoli along with ribosomal genes is not understood. The present thesis summarizes the current knowledge and views on the nucleolus, focusing on the two synthetic processes, replication and transcription, in mammalian cells. Specific features of these processes in the context of nucleolar ultrastructure remains an unsolved problem of the modern molecular biology.
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Security standards, history, comparison and application on particular problem
Myšík, Pavel ; Svatá, Vlasta (advisor) ; Juříček, Jan (referee)
The aim of this thesis is to provide current information about chosen security standards, management approaches and metodics, clarify their development and compare them. Gathered knowledge is used for assessing maturity of chosen processes with connection to security using COBIT in software developing enterprise. That is followed by assessing the situation of enterprise and recommendation about future managing of processes using COBIT.
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Standardy bezpečnosti, vývoj a porovnání
Böhmová, Lucie ; Svatá, Vlasta (advisor) ; Doucek, Petr (referee)
This thesis deals with information security management. The theoretical part explains the conception of information system security. Then deals with various concepts of management and related technologies. The next part provides a basic overview of standards and norms in America and Europe. These concepts, methodologies and standards are defined in the historical development and logically compared. Practical part deals with evaluation and analysis of selected maturity of IT processes in the Digital Solutions Ltd. by COBIT methodology.
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