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Characterisation of proteins whose degradation is necessary for normal course of embryonic genome activation in mammals
Svobodová, Nika ; Toralová, Tereza (advisor) ; Krejčová, Tereza (referee)
Early embryonic development is controlled by maternal mRNAs and proteins synthesized during oogenesis. A key period for preimplantation development is the transition from maternal control of development to embryonic control. This process, known as maternal-to-zygotic transition (MZT), requires the coordinated degradation of accumulated maternal mRNAs and proteins and subsequent embryonic genome activation (EGA). Maternal mRNAs are gradually removed from the embryo, but the degradation of maternal proteins is not well understood yet. In mammals, only a few proteins are known whose degradation is necessary for normal course of EGA. The activation of the embryonic genome is closely related to the reorganization of chromatin structure. The initiation of gene expression requires the loosening of chromatin at the gene region and the presence of appropriate transcription factors. Maternal proteins that need to be degraded for the normal course of EGA are involved in regulating chromatin structure and the translocation of necessary factors. This thesis aims to characterize selected proteins (PIASy, CBX5, TAB1 and H1FOO) and describe the role they play during the transition from maternal to embryonic control of development. While PIASy, CBX5, and H1FOO need to be degraded to loosen the chromatin structure...
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Identifikace genů nezbytně nutných pro normální průběh oplození a preimplantačního vývoje skotu v podmínkách in vitro
Toralová, Tereza ; Kaňka, Jiří (advisor) ; Pěknicová, Jana (referee) ; Ješeta, Michal (referee)
The aim of this work was to find and characterize genes that seem to be important for normal preimplantation development. We characterized three genes in more detail - centromeric protein F (CENPF; mitosin), ubiquitin C-terminal hydrolase-L1 (UCHL1) and nucleophosmin (NPM1; B23; numatrin; NO38). CENPF and nucleophosmin were shown to start their expression at late 8-cell stage, i.e. at major embryonic genome activation (EGA), and were hence supposed to be important during bovine preimplantation development. CENPF plays crucial role during cell division, especially by mediating the interaction of kinetochores and microtubules. Nucleophosmin is a multifunctional nucleolar phosphoprotein, whose most important roles are rRNA processing, chaperoning, ribosome biogenesis and centriole duplication control. Further, we characterized the role of UCHL1 during fertilization of bovine oocytes. UCHL1 is a deubiquitinating enzyme that controls cytoplasmic protein degradation, recycling of free ubiquitin from proteasome products and is involved in regulation of physiological apoptosis. We studied the function of CENPF and nucleophosmin using RNA interference approach. Since UCHL1 protein is very stable, this method is not suitable for studying the UCHL1 function. We thus used two UCHL1 inhibitors that block its...
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