In this article, we focused on the impact of precisely chemically modified FLI maturation medium enriched with fibroblast growth factor 2 (FGF2), leukemia inhibitory factor (LIF), insulin-like growth factor 1 (IGF1), and polyvinyl alcohol (PVA) and its potential to improve the efficiency of in vitro production of porcine embryos. We hypothesized that enhancing the composition of the maturation medium could result in an elevated production of embryos in vitro and can affect EGA. FLI medium resulted in a significantly higher rate of oocyte blastocyst maturation and formation compared to the control DMEM medium. In addition, immunocytochemical labelling confirmed the detection of UBF in 4-cell FLI parthenogenic embryos, suggesting similarities with natural embryo development. Through RNAseq analysis, upregulated genes present in 4-cell FLI embryos were found to play key roles in important biological processes such as cell proliferation, cell differentiation, and transcriptional regulation. Based on our findings, we demonstrated the positive influence of FLI medium in the evaluation of in vitro embryo production, EGA detection, transcriptomic and proteomic profile, which was confirmed by the positive activation of the embryonal genome in the 4-cell stage of parthenogenetically activated embryos.
- MeSH
- blastocysta účinky léků metabolismus MeSH
- fertilizace in vitro MeSH
- fibroblastový růstový faktor 2 * farmakologie MeSH
- insulinu podobný růstový faktor I * farmakologie MeSH
- kultivační média * chemie farmakologie MeSH
- leukemický inhibiční faktor * farmakologie MeSH
- oocyty MeSH
- prasata embryologie genetika MeSH
- proteomika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The statement that fully-grown porcine oocytes (oocytes from follicles with diameter from 3 to 6 mm) are transcriptionally quiescent is not as strongly supported as it was before. Currently, we know that there is a difference between the transcription profile of germinal vesicle (GV) and metaphase II (MII) oocytes. The goal of our study was to compare the transcription profile of GV, germinal vesicle breakdown (GVBD), metaphase I (MI), and MII oocytes matured in the chemically defined medium FLI. Oocytes were sequenced, and the results were subsequently validated using quantitative reverse transcription polymerase chain reaction (RT-qPCR). We detected multiple differentially transcribed mRNAs, of which many were upregulated. Among them we found mRNAs necessary for protein production, mitochondrial functions and cytoplasmic maturation. Collectively, these data support the hypothesis that transcription activity in fully-grown porcine oocytes is necessary for key processes during their successful maturation in vitro in a chemically defined maturation medium.
- MeSH
- buněčné jádro metabolismus MeSH
- IVM techniky * veterinární metody MeSH
- messenger RNA genetika metabolismus MeSH
- oocyty * metabolismus MeSH
- prasata MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The nucleolus is an important nucleus sub-organelle found in almost all eukaryotic cells. On the one hand, it is known as a differentiated active site of ribosome biogenesis in somatic cells, but on the other hand, in fully grown oocytes, zygotes, and early embryos (up to the major embryonic genome activation), it is in the form of a particular homogenous and compact structure called a fibrillar sphere. Nowadays, thanks to recent studies, we know many important functions of this, no doubt, interesting membraneless nucleus sub-organelle involved in oocyte maturation, embryonic genome activation, rRNA synthesis, etc. However, many questions are still unexplained and remain a mystery. Our aim is to create a comprehensive overview of the recent knowledge on the fibrillar sphere and envision how this knowledge could be utilized in further research in the field of biotechnology and nucleolotransfer therapy.
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Brilliant cresyl blue (BCB) vital labelling is a powerful method for analyzing the quality of porcine cumulus-oocyte complexes. Our aim was to investigate the correlation between the selection of porcine oocytes using BCB labelling and selected intranuclear characteristics of porcine oocytes and parthenotes. Moreover, BCB labelling was correlated with the diameter of the oocyte and the developmental potential of the parthenotes. The following methods were used: BCB labelling, measurement of the diameter of the oocyte, parthenogenetic activation, immunocytochemistry, transmission electron microscopy, enucleation and relative protein concentration (RPC) analysis. We determined that the diameter of the oocytes in the BCB-positive (BCB+) group was significantly larger than in the BCB-negative (BCB-) group. Immediately after oocyte selection according to BCB labelling, we found significant difference in chromatin configuration between the analyzed groups. BCB+ oocytes were significantly better at maturation than BCB- oocytes. BCB+ embryos were significantly more competent at cleaving and in their ability to reach the blastocyst stage than BCB- embryos. Ultrastructural analyses showed that the formation of active nucleoli in the BCB+ group started at the 8-cell stage. Conversely, most BCB- embryos at the 8-cell and 16-cell stages were fragmented. No statistically significant difference in RPC in nucleolus precursor bodies (NPBs) between BCB+ and BCB- oocytes was found. We can conclude that BCB labelling could be suitable for assessing the quality of porcine oocytes. Moreover, the evaluation of RPC indicates that the quantitative content of proteins in NPB is already established in growing oocytes.
- MeSH
- barvení a značení metody MeSH
- blastocysta chemie cytologie metabolismus MeSH
- buněčné jádro chemie ultrastruktura MeSH
- embryo savčí chemie cytologie ultrastruktura MeSH
- jaderné proteiny metabolismus MeSH
- konfokální mikroskopie MeSH
- oocyty chemie cytologie metabolismus MeSH
- oxaziny chemie MeSH
- prasata MeSH
- reprodukovatelnost výsledků MeSH
- transmisní elektronová mikroskopie MeSH
- velikost buňky MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The oocyte GV/GVs (germinal vesicle/germinal vesicles) and zygot PN/PNs (pronucleus/pronuclei) of some mammals contain clearly visible nucleoli which exhibit an atypical morphological structure. These nucleoli (NCLs) can be relatively easily manipulated, i.e. removed from GVs/PNs or eventually transferred into another oocyte/zygote. Thus, with the help of micromanipulation techniques it was possible to uncover the real function(s) they play in processes of oocyte maturation and early embryonic development. The purpose of our review is to describe briefly the micromanipulation techniques that can be used for oocyte/zygote nucleoli manipulation. Moreover, we present some examples of results that were obtained in nucleolus manipulation experiments.
- MeSH
- buněčné jadérko metabolismus transplantace MeSH
- mikromanipulace metody MeSH
- myši MeSH
- oocyty cytologie účinky léků MeSH
- partenogeneze MeSH
- prasata MeSH
- zvířata MeSH
- zygota cytologie MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
It is well known that nucleoli of fully grown mammalian oocytes are indispensable for embryonic development. Therefore, the embryos originated from previously enucleolated (ENL) oocytes undergo only one or two cleavages and then their development ceases. In our study the interspecies (mouse/pig) nucleolus transferred embryos (NuTE) were produced and their embryonic development was analyzed by autoradiography, transmission electron microscopy (TEM) and immunofluorescence (C23 and upstream binding factor (UBF)). Our results show that the re-injection of isolated oocyte nucleoli, either from the pig (P + P) or mouse (P + M), into previously enucleolated and subsequently matured porcine oocytes rescues their development after parthenogenetic activation and some of these develop up to the blastocyst stage (P + P, 11.8%; P + M, 13.5%). In nucleolus re-injected 8-cell and blastocyst stage embryos the number of nucleoli labeled with C23 in P + P and P + M groups was lower than in control (non-manipulated) group. UBF was localized in small foci within the nucleoli of blastocysts in control and P + P embryos, however, in P + M embryos the labeling was evenly distributed in the nucleoplasm. The TEM and autoradiographic evaluations showed the formation of functional nucleoli and de novo rRNA synthesis at the 8-cell stage in both, control and P + P group. In the P + M group the formation of comparable nucleoli was delayed. In conclusion, our results indicate that the mouse nucleolus can rescue embryonic development of enucleolated porcine oocytes, but the localization of selected nucleolar proteins, the timing of transcription activation and the formation of the functional nucleoli in NuTE compared with control group show evident aberrations.
- MeSH
- blastocysta cytologie metabolismus MeSH
- buněčné jadérko fyziologie transplantace MeSH
- embryo savčí cytologie metabolismus MeSH
- embryonální vývoj fyziologie MeSH
- klonování organismů MeSH
- myši MeSH
- oocyty cytologie fyziologie MeSH
- oogeneze fyziologie MeSH
- prasata MeSH
- přenos embrya MeSH
- těhotenství MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Global transcription silencing occurs in the oocyte during its final phase of growth. The particular mechanism of this silencing is not well understood. Here, we investigated the silencing of RNA polymerase II transcription in porcine oocytes. First, we investigated the transcriptional activity of germinal vesicle oocytes derived from stimulated and non-stimulated gilts, but no transcriptional activity was observed. Second, we focused on the fate of RNA polymerase II in growing and fully grown oocytes. Active and inactive forms of RNA polymerase II were detected in growing oocytes by immunofluorescence and Western blots. In contrast, only the inactive form of RNA polymerase II was detected in fully grown oocytes. To evaluate if the inactive form of RNA polymerase II is released from DNA, the oocytes were subsequently permeabilized and fixed in one step. After this modified fixation protocol, the immunofluorescent labeling was negative in fully grown oocytes, but remained unchanged (positive) in growing oocytes. These results indicate that the inactive form of RNA polymerase II is not bound to DNA during the oocyte growth. Finally, based on Western blot analysis of different stages of oocyte maturation, the inactive form of RNA polymerase II was detected in metaphase I but not in metaphase II. Our study confirmed the global transcription silencing of fully grown oocytes. Compared with other mammalian species (e.g., mouse), the mechanism of RNA polymerase II silencing in porcine oocytes seems to be similar, despite some differences in dynamics.
- MeSH
- adenosin chemie metabolismus MeSH
- autoradiografie MeSH
- fosforylace MeSH
- genetická transkripce MeSH
- gonadotropiny metabolismus MeSH
- imunohistochemie MeSH
- izotopové značení MeSH
- myši MeSH
- oocyty chemie růst a vývoj metabolismus fyziologie MeSH
- prasata MeSH
- RNA-polymerasa II chemie genetika metabolismus MeSH
- umlčování genů * MeSH
- uridin chemie metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
