Cloned Calves from Chromatin Remodeled In Vitro
TLDR
This is the first successful demonstration of a method for directly manipulating the somatic donor chromatin prior to transplantation, and should be useful for investigating mechanisms of nuclear reprogramming and for making improvements in the efficiency of mammalian cloning.Abstract:
We have developed a novel system for remodeling mammalian somatic nuclei in vitro prior to cloning by nuclear transplantation. The system involves permeabilization of the donor cell and chromatin condensation in a mitotic cell extract to promote removal of nuclear factors solubilized during chromosome condensation. The condensed chromosomes are transferred into enucleated oocytes prior to activation. Unlike nuclei of nuclear transplant embryos, nuclei of chromatin transplant embryos exhibit a pattern of markers closely resembling that of normal embryos. Healthy calves were produced by chromatin transfer. Compared with nuclear transfer, chromatin transfer shows a trend toward greater survival of cloned calves up to at least 1 mo after birth. This is the first successful demonstration of a method for directly manipulating the somatic donor chromatin prior to transplantation. This procedure should be useful for investigating mechanisms of nuclear reprogramming and for making improvements in the efficiency of mammalian cloning.read more
Citations
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References
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Journal ArticleDOI
Somatic cell nuclear transfer.
Ian Wilmut,Nathalie Beaujean,P.A. De Sousa,Andras Dinnyes,Andras Dinnyes,Tim King,L A Paterson,D.N. Wells,Lorraine E. Young,Lorraine E. Young +9 more
TL;DR: This work has shown that when a nucleus is placed in oocyte cytoplasm, the changes in chromatin structure that govern differentiation can be reversed, and the nucleus can be made to control development to term.
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Delayed and incomplete reprogramming of chromosome methylation patterns in bovine cloned embryos
Déborah Bourc'his,D. Le Bourhis,D Patin,Alain Niveleau,P Comizzoli,Jean-Paul Renard,E Viegas-Pequignot +6 more
TL;DR: It is proposed that the abnormal time-dependent methylation events spanning the preimplantation development of clones may significantly interfere with the epigenetic reprogramming, contributing to the high incidence of physiological anomalies occurring later during pregnancy or after clone birth.
Journal ArticleDOI
Reprogramming fibroblasts to express T-cell functions using cell extracts.
Anne Mari Håkelien,Helga B. Landsverk,James M. Robl,Bjørn Steen Skålhegg,Philippe Collas,Philippe Collas +5 more
TL;DR: The functional reprogramming of a somatic cell is demonstrated using a nuclear and cytoplasmic extract derived from another somatics cell type and creates possibilities for producing isogenic replacement cells for therapeutic applications.
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Global Chromosome Positions Are Transmitted through Mitosis in Mammalian Cells
TL;DR: It is proposed that chromosome specific timing of sister chromatid separation transmits chromosomal positions from one cell generation to the next through the cell cycle in mammalian cells.
Journal ArticleDOI
Epigenetic reprogramming in early mammalian development and following somatic nuclear transfer
TL;DR: The concept of 'epigenetic checkpoints' for normal progression of development and the loss of totipotency is proposed and highlighted those areas with relevance to somatic nuclear cloning and the possibility of improving the efficiency of this process.