Nucleus transfer Dotaz Zobrazit nápovědu
- MeSH
- buněčné jádro MeSH
- buněčný cyklus MeSH
- cytoplazma MeSH
- oocyty MeSH
- savci MeSH
- techniky jaderného přenosu MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
sv.
- MeSH
- buněčné jádro * MeSH
- genetické jevy MeSH
- techniky jaderného přenosu MeSH
- Publikační typ
- periodika MeSH
- Konspekt
- Biologické vědy
- NLK Obory
- genetika, lékařská genetika
- MeSH
- buněčné jádro MeSH
- druhová specificita MeSH
- embryo savčí cytologie MeSH
- hospodářská zvířata embryologie genetika MeSH
- klonování organismů metabolismus MeSH
- přenos embrya MeSH
- techniky jaderného přenosu MeSH
- vývoj plodu MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
Achieving successful somatic cell nuclear transfer (SCNT) in the human and subhuman primate relative to other mammals has been questioned for a variety of technical and logistical issues. Here we summarize the gradual evolution of SCNT technology from the perspective of oocyte quality and cell cycle status that has recently led to the demonstration of feasibility in the human for deriving chromosomally normal stem cells lines. With these advances in hand, prospects for therapeutic cloning must be entertained in a conscientious, rigorous, and timely fashion before broad spectrum clinical applications are undertaken.
- MeSH
- dějiny 20. století MeSH
- embryonální vývoj MeSH
- lidé MeSH
- oocyty cytologie MeSH
- ovce embryologie genetika MeSH
- techniky jaderného přenosu dějiny MeSH
- zvířata MeSH
- Check Tag
- dějiny 20. století MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- historické články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
It is now approximately 25 years since the sheep Dolly, the first cloned mammal where the somatic cell nucleus from an adult donor was used for transfer, was born. So far, somatic cell nucleus transfer, where G1-phase nuclei are transferred into cytoplasts obtained by enucleation of mature metaphase II (MII) oocytes followed by the activation of the reconstructed cells, is the most efficient approach to reprogram/remodel the differentiated nucleus. In general, in an enucleated oocyte (cytoplast), the nuclear envelope (NE, membrane) of an injected somatic cell nucleus breaks down and chromosomes condense. This condensation phase is followed, after subsequent activation, by chromatin decondensation and formation of a pseudo-pronucleus (i) whose morphology should resemble the natural postfertilization pronuclei (PNs). Thus, the volume of the transferred nuclei increases considerably by incorporating the content released from the germinal vesicles (GVs). In parallel, the transferred nucleus genes must be reset and function similarly as the relevant genes in normal embryo reprogramming. This, among others, covers the relevant epigenetic modifications and the appropriate organization of chromatin in pseudo-pronuclei. While reprogramming in SCNT is often discussed, the remodeling of transferred nuclei is much less studied, particularly in the context of the developmental potential of SCNT embryos. It is now evident that correct reprogramming mirrors appropriate remodeling. At the same time, it is widely accepted that the process of rebuilding the nucleus following SCNT is instrumental to the overall success of this procedure. Thus, in our contribution, we will mostly focus on the remodeling of transferred nuclei. In particular, we discuss the oocyte organelles that are essential for the development of SCNT embryos.
- MeSH
- buněčné jádro metabolismus MeSH
- chromatin metabolismus MeSH
- oocyty MeSH
- ovce genetika MeSH
- savci genetika MeSH
- techniky jaderného přenosu * veterinární MeSH
- zvířata MeSH
- zygota * metabolismus MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: The endosymbiotic birth of organelles is accompanied by massive transfer of endosymbiont genes to the eukaryotic host nucleus. In the centric diatom Thalassiosira pseudonana the Psb28 protein is encoded in the plastid genome while a second version is nuclear-encoded and possesses a bipartite N-terminal presequence necessary to target the protein into the diatom complex plastid. Thus it can represent a gene captured during endosymbiotic gene transfer. METHODOLOGY/PRINCIPAL FINDINGS: To specify the origin of nuclear- and plastid-encoded Psb28 in T. pseudonana we have performed extensive phylogenetic analyses of both mentioned genes. We have also experimentally tested the intracellular location of the nuclear-encoded Psb28 protein (nuPsb28) through transformation of the diatom Phaeodactylum tricornutum with the gene in question fused to EYFP. CONCLUSIONS/SIGNIFICANCE: We show here that both versions of the psb28 gene in T. pseudonana are transcribed. We also provide experimental evidence for successful targeting of the nuPsb28 fused with EYFP to the diatom complex plastid. Extensive phylogenetic analyses demonstrate that nucleotide composition of the analyzed genes deeply influences the tree topology and that appropriate methods designed to deal with a compositional bias of the sequences and the long branch attraction artefact (LBA) need to be used to overcome this obstacle. We propose that nuclear psb28 in T. pseudonana is a duplicate of a plastid localized version, and that it has been transferred from its endosymbiont.
- MeSH
- buněčné jádro genetika MeSH
- molekulární sekvence - údaje MeSH
- plastidy genetika MeSH
- proteiny chemie genetika MeSH
- rozsivky genetika MeSH
- sekvence aminokyselin MeSH
- sekvenční homologie aminokyselin MeSH
- symbióza genetika MeSH
- technika přenosu genů MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
