Nuclear reprogramming, the conversion of the epigenome of a differentiated cell to one that is similar to the undifferentiated embryonic state, can be facilitated by several methods, such as nuclear transfer, cell fusion, use of embryonic stem cell extracts, and more recently, by the introduction of exogenous transcription factors. Amongst these various strategies, somatic cell nuclear transfer...

Vertebrate eggs can induce the nuclear reprogramming of somatic cells to enable production of cloned animals. Nuclear reprogramming is relatively inefficient, and the development of the resultant embryos is frequently compromised, in part due to the inappropriate expression of genes previously active in the donor nucleus. Here, we identify H3K4 methylation as a major epigenetic roadblock that l...

s:1202:"It is a truly amazing time to developmental biology. During recent decades, three important breakthroughs have been developed: (i) isolation of stem cells from embryo, (ii) animal cloning by nuclear transfer (NT), and (iii) and induced pluripotent stem cells (iPS). Considering these three approaches of "Cellular Reprogramming", it seems that the required elements for cell therapy now ex...

Many of the structural and mechanistic requirements of oocyte-mediated nuclear reprogramming remain elusive. Previous accounts that transcriptional reprogramming of somatic nuclei in mouse zygotes may be complete in 24-36 hours, far more rapidly than in other reprogramming systems, raise the question of whether the mere exposure to the activated mouse ooplasm is sufficient to enact reprogrammin...

Animal cloning by nuclear transplantation in amphibia was demonstrated almost half a century ago and raised the question of the mechanisms and genes involved in nuclear reprogramming. Here, we demonstrate nuclear reprogramming of permeabilized human cells using extracts from Xenopus laevis eggs and early embryos. We show upregulation of pluripotency markers Oct-4 and germ cell alkaline phosphat...

Background: At the outset of the somatic cell nuclear transfer (SCNT) process, the chromatin structure of the somatic cell which governs its state of differentiation undergoes dramatic changes, called reprogramming, and is compelled back to the embryonic stage. However, the overall epigenetic makeup of the resultant cloned embryos has been acknowledged far different from the fertilized embryos....

Retroviral overexpression of reprogramming factors (Oct4, Sox2, Klf4, c-Myc) generates induced pluripotent stem cells (iPSCs). However, the integration of foreign DNA could induce genomic dysregulation. Cell-permeant proteins (CPPs) could overcome this limitation. To date, this approach has proved exceedingly inefficient. We discovered a striking difference in the pattern of gene expression ind...