National Repository of Grey Literature 7 records found  Search took 0.00 seconds. 
Effect of sperm ubiquitination in early embryonic development of porcine embryos
Petelák, Aleš ; Krylov, Vladimír (advisor) ; Šušor, Andrej (referee) ; Procházka, Radek (referee)
The PhD thesis is focused on the effect of porcine sperm cell extracellular ubiquitination on early embryonic development up to the blastocyst stage after ICSI. In addition, it also presents a potential improvement of the technique of in vitro fertilization using oocyte incubation with ion channels regulators. To address these aims, we established an entirely novel methodology for sperm cell sorting using flow cytometry and subsequent cryopreservation. We determined the conditions for successful sperm cell sorting based on extracellular ubiquitination rate providing highly specific selection as well as sufficient numbers of viable sperms for fertilization using the ICSI method. Concerning the following cryopreservation, established methods were optimized to enable freezing of a minimal sperm cell suspension volume with low cell numbers. The performed experiments showed a direct relationship between the rate of extracellular ubiquitination and the capability of sperms to give rise to a properly developing embryo. Highly ubiquitinated sperm cells were less successful regarding the embryonic development to the blastocyst stage if compared with the lowly ubiquitinated group (6,2 % vs. 16,7 %, P<0,001). Interestingly, the rate of extracellular ubiquitination showed no effect on the pronuclear formation...
Regulation of mTOR pathway in the oocyte meiosis
Schmidtová, Barbara ; Šušor, Andrej (advisor) ; Krylov, Vladimír (referee)
Mammalian Target of Rapamycin (mTOR) is serin-threonin kinase, which has become a major topic in many studies in the last decade, leading to new insights into how cell works. This kinase is involved in proteosynthesis, metabolism, cell cycle regulation, proliferation and responses to nutrients and growth factors. There are certain diseases caused by mutations in mTOR gene, which lead to abnormal function of this kinase. These diseases include cancer or fertility disorders. mTOR research is also beneficial due to the search for drugs that could rescue its function and thus provide treatment for these diseases. The best-known drug is inhibitor Rapamycin and its derivates. The aim of this bachelor thesis is to summarize the knowledge about how mTOR can be regulated, the role of its substrates in cell function and to define the role of mTOR in oocyte development, translation and human health. Keywords: Oocyte, mTOR, translation, 4E-BP1, MPF, meiosis, AKT
Monitoring of protein network dynamics: the role of FcRL proteins during sperm-egg membrane interaction
Bašus, Kryštof ; Komrsková, Kateřina (advisor) ; Šušor, Andrej (referee)
Sperm-­-egg membrane interaction and fusion is mediated by various molecules of the different protein network that are located on both egg and sperm membrane. So far, many proteins have been selected to be fusion candidates, some of them (Izumo1, CD9, Juno) were proven to be essential, whereas others were discovered to play an unsuspected new active role (CD46, tetraspanins). After the adhesion of sperm to an egg, Juno located on the oolema associates with monomeric Izumo1 on sperm membrane, which is results in Izumo1 dimerization following quick removal of Juno from the egg surface as described in mouse. It implies that additional receptor on the egg membrane is required to play a role in sperm-­-egg fusion. To find a human fusogenic receptor for IZUMO1 protein we used one-­-bead-­-one-­-compound (OBOC) assay, a random screening approach. A bead, fulfilling all the requirements when interacting with the human sperm, carried a peptide sequence showing homology with the conserved Ig domain of the human specific Fc receptor-­-like protein 3 (FcRL3). In general, the ...
Regulation of translation in mammalian oocytes and early embryos
Jindrová, Anna ; Šušor, Andrej (advisor) ; Flemr, Matyáš (referee) ; Fulková, Helena (referee)
Fully grown oocytes undergo their further development in the absence of transcription. Completion of meiosis and early embryo development rely on the maternal mRNAs synthetized and stored during earlier development. Thus, the regulation of gene expression in oocytes during that period is controlled almost exclusively at the level of mRNA stabilization and translation. In the same vein, any mRNA metabolism could play a critical function at this stage of development. RNA localization followed by a local translation is a mechanism responsible for the control of spatial and temporal gene expression in the cell. We focused on visualization of mRNA and in situ translation in the mammalian oogenesis and embryogenesis. We characterized localization of global RNA population in the oocyte and early embryo nucleus together with RNA binding proteins. Additionally we visualized specific ribosomal proteins that contribute to translation in the oocyte and embryo. We have shown that the key player of cap-dependent translation mTOR becomes highly active post nuclear envelope breakdown (NEBD) and in turn its substrate, translational repressor 4E-BP1 becomes inactive. Precise localization of inactivated 4E-BP1 at the newly forming spindle of the oocyte indicates the ongoing translation in this area. Furthermore, from...
Effect of sperm ubiquitination in early embryonic development of porcine embryos
Petelák, Aleš ; Krylov, Vladimír (advisor) ; Šušor, Andrej (referee) ; Procházka, Radek (referee)
The PhD thesis is focused on the effect of porcine sperm cell extracellular ubiquitination on early embryonic development up to the blastocyst stage after ICSI. In addition, it also presents a potential improvement of the technique of in vitro fertilization using oocyte incubation with ion channels regulators. To address these aims, we established an entirely novel methodology for sperm cell sorting using flow cytometry and subsequent cryopreservation. We determined the conditions for successful sperm cell sorting based on extracellular ubiquitination rate providing highly specific selection as well as sufficient numbers of viable sperms for fertilization using the ICSI method. Concerning the following cryopreservation, established methods were optimized to enable freezing of a minimal sperm cell suspension volume with low cell numbers. The performed experiments showed a direct relationship between the rate of extracellular ubiquitination and the capability of sperms to give rise to a properly developing embryo. Highly ubiquitinated sperm cells were less successful regarding the embryonic development to the blastocyst stage if compared with the lowly ubiquitinated group (6,2 % vs. 16,7 %, P<0,001). Interestingly, the rate of extracellular ubiquitination showed no effect on the pronuclear formation...
Protein synthesis and protein degradation in mammalian oocyte development
Šušor, Andrej ; Motlík, Jan (advisor) ; Pěknicová, Jana (referee) ; Petr, Jaroslav (referee)
Concr,usroNs We anďysed eucaryoticinitiation t,anslation factorsthat are responsiblefor protein qmthesisin mammalianoocýes. As well we examinedthe affinity.of this factorsto.'mCap, Sepharoseduring in útro conďtion...Inour'laboratorywas optimisedthe protocol for generation of poreine parttrenotesthat serve us as a model for anďysis of. cellular processos in .rygotes with biochemical approaches.. : , , - Antibod}r micÍoanay analysis was used to investigate the: regulation of signalling pathways primarily during meiotic maturationof pig oocytesand subsequentlyin comparisonto other species(bovine,frog andseastar). on the base of proteomeanďysis of maturationof oocýes was chosenUCH-LI molebuleandis studiedin detail in mammalian oocyte. Abnost thorougily was analysed function of UCH-LI in porcine and bovine oocyte using specific inhibitors and overexpression. The mechanism that is involved UCH-LI in antipolyspermydefencein mammalian oocyte was unveiled in our laboratory.
Identification of key regulators of gene expression in mammalian oocyte and embryo
Jansová, Denisa ; Šušor, Andrej (advisor) ; Gahurová, Lenka (referee) ; Lin, Chih-Jen Lance (referee)
Mammalian oocyte is a highly differentiated cell which gives rise to an embryo after fertilization. Importantly, fully-grown oocytes become transcriptionally inactive at the end of the growth phase. During following stages of development, i. e. meiotic maturation of the oocyte and early embryonic development, only transcripts previously synthesized and stored are used. The tight correlation between mRNA distribution and subsequent protein localization and function provides a mechanism of spatial and temporal regulation of gene expression used by various cell types. However, not much is known about mRNA localization and translation in the mammalian oocyte and early embryo. The aim of my thesis was to determine the localization of transcripts and components of translational machinery in the mammalian oocyte and embryo and to uncover the mechanisms of spatiotemporal regulation of translation as a prerequisite for correct oocyte and embryo development. We have shown that nuclei of both mouse and human oocytes contain RNA molecules and RNA binding proteins. Following the nuclear envelope breakdown (NEBD), translational hot-spots occur in the area surrounding the nuclear region. We suppose that mRNAs previously retained in the nucleus are released to the cytoplasm during NEBD and their subsequent...

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