DNA demethylation is necessary for the epigenetic reprogramming of somatic cell nuclei

@article{Simonsson2004DNADI,
  title={DNA demethylation is necessary for the epigenetic reprogramming of somatic cell nuclei},
  author={Stina Simonsson and J. B. Gurdon},
  journal={Nature Cell Biology},
  year={2004},
  volume={6},
  pages={984-990}
}
Nuclear transplantation experiments in amphibia and mammals have shown that oocyte and egg cytoplasm can extensively reprogram somatic cell nuclei with new patterns of gene expression and new pathways of cell differentiation; however, very little is known about the molecular mechanism of nuclear reprogramming. Here we have used nuclear and DNA transfer from mammalian somatic cells to analyse the mechanism of activation of the stem cell marker gene oct4 by Xenopus oocytes. We find that the… 

Gradual DNA demethylation of the Oct4 promoter in cloned mouse embryos

The results suggest that the Oct4 gene, as compared to the other pluripotency regulators, needs to undergo extensive demethylation during nuclear reprogramming, and that the failure of such dem methylation is associated with inefficient development of cloned somatic cell embryos.

The cytoplasm of mouse germinal vesicle stage oocytes can enhance somatic cell nuclear reprogramming

It is found that the GV oocyte cytoplasm could remodel somatic cell nuclei, completely demethylate histone H3 at lysine 9 and partially deacetylate histones 9 and 14, which could facilitate cloning technology and is useful for research on the mechanisms involved in histone de acetylation and demethylation.

Epigenetic memory of active gene transcription is inherited through somatic cell nuclear transfer.

  • R. K. NgJ. Gurdon
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 2005
It is concluded that an epigenetic memory is established in differentiating somatic cells and applies to genes that are in a transcriptionally active state in some nuclear transplant embryos.

Epigenetic reprogramming and DNA demethylation

This study examines changes in DNA methylation that are induced at imprinted loci and pluripotency-associated genes when somatic cells are fused with either mouse embryonic stem (ES) or embryonic germ (EG) cells and provides evidence that Tet proteins are dispensable for pluripotent reprogramming using CRISPR-Cas9 genome editing to abrogate the expression of both Tet1 and Tet2.

Evaluation in mammalian oocytes of gene transcripts linked to epigenetic reprogramming.

Some of the mechanisms that the oocyte may employ to reprogram a foreign genome either in form of a spermatozoa or a somatic nucleus are elucidated for the first time and may be of importance for advancing the fields of stem cell research and regenerative medicine.

Epigenetic marks in somatic chromatin are remodelled to resemble pluripotent nuclei by amphibian oocyte extracts

It is demonstrated that axolotl oocyte extracts are a useful tool for studying epigenetic remodelling of somatic cells to a stem cell configuration, and for elucidating oocyte specific mechanisms of nuclear reprogramming.

Active tissue-specific DNA demethylation conferred by somatic cell nuclei in stable heterokaryons

It is reported that differentiated mesodermal somatic cells can confer tissue-specific changes in DNA methylation on epidermal progenitor cells after fusion in stable multinucleate heterokaryons, suggesting the possibility of directing the reprogramming of readily available postnatal human progenitors cells toward specific tissue cell types.

Examination of DNA methyltransferase expression in cloned embryos reveals an essential role for Dnmt1 in bovine development

An essential role for Dnmt1 during bovine preimplantation development is indicated, and proper transcriptional reprogramming of this gene family in SCNT embryos is suggested, to better understand the epigenetic events underlying SCNT reprograming.
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