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Production and development of haploid mouse embryos
Jettmarová, Dominika ; Fulka, Josef (advisor) ; Petelák, Aleš (referee)
This bachelor thesis summarizes current knowledge of haploid embryos that are used for haploid embryonic stem cell derivation. The subject matter of this background research are production methods of haploid blastocysts of mice (Mus musculus) and the particularities of their development. Haploid blastocysts can be prepared parthenogenetically, gynogenetically or androgenetically. The development of haploid embryos is substantially different from the development of diploid embryos. The division of blastomeres is delayed by several hours and the success rate of development to blastocysts is low. The reason for the impaired development of haploid embryos is hypothesized to be improper activation and/or non-standard gene expression. The follow-up study that utilizes the Primo Vision monitoring system is described in the experimental part. Knowledge of this topic is crucial to raising the effectiveness of haploid blastocyst production and derivation of stable haploid embryonic stem cell lines for further biological and medical research. Powered by TCPDF (www.tcpdf.org)
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Effect of ubiquitin-proteasome system on spermiogenesis in mammals
Kroumanová, Kristýna ; Petelák, Aleš (advisor) ; Krejčová, Tereza (referee)
Spermiogenesis is a complicated process in which the haploid spermatids differentiate into morphologically mature sperm. Morphological changes include condensation of chromatin and histone-to-protamine replacement, fusion of Golgi-derived vesicles to form acrosomal cap, flagellum formation, reduction of cytoplasmic volume and organelles rearrangement. Ubiquitin-proteasome system plays a key role in these processes. Ubiquitination is a posttranslational modification, leading to the labelling of intracellular proteins targeted for degradation by 26S proteasome. Importance of sperm ubiquitination, is supported by the fact, that deficiency of ubiquitin-proteasome system can lead to infertility at various degrees. During the subsequent sperm maturation in the epididymis extracellular ubiquitination of abnormal sperm and sperm quality control take place. Ubiquitin-proteasome system plays a key role during fertilization, when the sperm 26S proteasome is co-responsible in zona pellucida penetration. The purpose of this assay is to describe the effect of ubiquitin- proteasome system during different stages of spermiogenesis in mammals.
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The Role of Bmp4 and Bmp8b proteins in genesis of mouse primordial germ cells
Vegrichtová, Markéta ; Tlapáková, Tereza (advisor) ; Petelák, Aleš (referee)
Primordial germ cells are precursors of sexual breeding organisms. For induction of their formation are necessary growth factors from extraembryonic ectoderm. There are key proteins BMP4 a BMP8b among these factors. These proteins form both homodimers and heterodimers and through receptor complexes and SMAD proteins are indicating the competent cells of proximal epiblast, which give rise to the primordial germ cells and other structures of embryonic mezoderm. Although BMP4 and BMP8b proteins signal similarly, they are mutually indispensable and though for induction of primordial germ cells are both necessary. Up to now, it was proposed several models of their interaction, but not yet completely accurate.
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Effect of the sperm ubiquitination in the early embryonic development in pig
Petelák, Aleš ; Krylov, Vladimír (advisor) ; Petr, Jaroslav (referee)
The intracellular sperm injection (ICSI) technique is a very effective tool for the fertilization research. In the newly established laboratory at the Faculty of Science of the Charles University it was necessary to introduce this method and define the early developmental potential of fertilized oocytes. After fertilization oocytes were incubated to the blastocyst stage with a success comparable with other laboratories (17%). The ubiquitin-proteasome system which plays a major role in a protein degradation within cells is involved in a regulatory mechanism of sperm maturation. It is also responsible for a penetration of a vitelline membrane. In these processes ubiquitin residues are localized extracellulary. High level of sperm ubiquitination correlates with their low quality. Hypotetically it can be expected that the ubiqutination of impaired sperm cells can be used as a negative marker for their recognition and degradation by 26S proteasome complex localized. Experiments in this diploma thesis were designed based on the hypothesis that the executive part of the selective mechanism is the 26S proteasome. Therefore the effect of MG132 peptide inhibition of the 20S proteasome on the pronuclei formation and subsequent early embryonic development after ICSI was studied. Inhibition of 20S proteasome...
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