Differentiated nuclei can be reprogrammed/remodelled to totipotency after their transfer to enucleated metaphase II (MII) oocytes. The process of reprogramming/remodelling is, however, only partially characterized. It has been shown that the oocyte nucleus (germinal vesicle - GV) components are essential for a successful remodelling of the transferred nucleus by providing the materials for pseudo-nucleus formation. However, the nucleus is a complex structure and exactly what nuclear components are required for a successful nucleus remodelling and reprogramming is unknown. Till date, the only nuclear sub-structure experimentally demonstrated to be essential is the oocyte nucleolus (nucleolus-like body, NLB). In this study, we investigated what other GV components might be necessary for the formation of normal-sized pseudo-pronuclei (PNs). Our results showed that the removal of the GV nuclear envelope with attached chromatin and chromatin-bound factors does not substantially influence the size of the remodelled nuclei in reconstructed cells and that their nuclear envelopes seem to have normal parameters. Rather than the insoluble nuclear lamina, the GV content, which is dissolved in the cytoplasm with the onset of oocyte maturation, influences the characteristics and size of transferred nuclei.

• Klíčová slova
• Nucleus transfer, Oocyte, Selective enucleation,
• MeSH
• buněčné jadérko metabolismus   MeSH
• buněčné jádro metabolismus   MeSH
• chromatin metabolismus   MeSH
• cytoplazma metabolismus   MeSH
• jaderná lamina metabolismus   MeSH
• jaderný obal metabolismus   MeSH
• messenger RNA metabolismus   MeSH
• myši MeSH
• oocyty cytologie   metabolismus   MeSH
• oogeneze MeSH
• ovariální folikul metabolismus   MeSH
• přeprogramování buněk * MeSH
• techniky jaderného přenosu * MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chromatin MeSH
• messenger RNA MeSH

DNA methylation/demethylation pattern, determined by 5-methylcytosine (5-MeC) immunostaining, was evaluated in porcine "in vivo" produced embryos from zygote up to the blastocyst stage. In one-cell stage embryos, only the maternal pronucleus showed a positive labeling whilst the paternal pronucleus showed almost no labeling. The intensity of labeling is high until the late morula stage. Blastocysts containing less than 100 cells showed the same intensity of labeling in both the inner cell mass (ICM) nuclei and the trophectodermal (TE) cell nuclei. Interestingly, with further cell multiplication, cells of the ICM became more intensively labeled when compared to TE cells. This distinct methylation pattern is even more profound in blastocysts containing about 200-300 cells and is not caused by the difference in the cell volume of ICM and TE cells.

• MeSH
• blastocysta metabolismus   MeSH
• chromatin metabolismus   MeSH
• embryo savčí embryologie   metabolismus   MeSH
• metylace DNA * MeSH
• prasata MeSH
• zvířata MeSH
• zygota metabolismus   MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chromatin MeSH