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The transplantation of somatic cell nuclei to enucleated eggs has shown that genes can be reprogrammed to an embryonic pattern of expression, thereby indicating a reversal of their epigenetic state. However, in Xenopus nuclear transfer experiments using both endoderm and neuroectoderm donor cells, we have observed substantial overexpression of donor cell type-specific genes, both spatially and temporally, in the wrong cell type in some nuclear transplant embryos. For example, more than half of the embryos prepared from transplanted neuroectoderm nuclei overexpressed the neuroectodermal marker gene Sox2 to an excessive level in their endoderm cells. Because, in Xenopus, there is no transcription for the first 12 cell cycles, some somatic cell nuclei must remember a developmentally activated gene state and transmit this to their mitotic progeny in the absence of the conditions that induced that state. We also find that donor cell-specific genes are transcribed at an earlier stage than normal in an inappropriate cell type. This phenomenon of epigenetic memory applies to genes that are transcribed in donor nuclei; it does not influence those genes that are competent to be transcribed in nuclear transplant embryotissue, but were not actually transcribed in donor nuclei at the time of nuclear transfer. We conclude that an epigenetic memory is established in differentiating somatic cells and applies to genes that are in a transcriptionally active state.
Bird,
DNA methylation patterns and epigenetic memory.
2002, Pubmed
Bird,
DNA methylation patterns and epigenetic memory.
2002,
Pubmed
Boiani,
Oct4 distribution and level in mouse clones: consequences for pluripotency.
2002,
Pubmed
Bortvin,
Incomplete reactivation of Oct4-related genes in mouse embryos cloned from somatic nuclei.
2003,
Pubmed
Briggs,
Transplantation of Living Nuclei From Blastula Cells into Enucleated Frogs' Eggs.
1952,
Pubmed
Byrne,
From intestine to muscle: nuclear reprogramming through defective cloned embryos.
2002,
Pubmed
,
Xenbase
Chan,
Nuclear transplantation from stably transfected cultured cells of Xenopus.
1996,
Pubmed
,
Xenbase
DiBerardino,
Gene reactivation in erythrocytes: nuclear transplantation in oocytes and eggs of Rana.
1983,
Pubmed
Eggan,
X-Chromosome inactivation in cloned mouse embryos.
2000,
Pubmed
Etkin,
Regulation of the mid-blastula transition in amphibians.
1988,
Pubmed
,
Xenbase
Green,
Responses of embryonic Xenopus cells to activin and FGF are separated by multiple dose thresholds and correspond to distinct axes of the mesoderm.
1992,
Pubmed
,
Xenbase
Gurdon,
The developmental capacity of nuclei transplanted from keratinized skin cells of adult frogs.
1975,
Pubmed
,
Xenbase
GURDON,
The developmental capacity of nuclei taken from differentiating endoderm cells of Xenopus laevis.
1960,
Pubmed
,
Xenbase
GURDON,
The developmental capacity of nuclei taken from intestinal epithelium cells of feeding tadpoles.
1962,
Pubmed
,
Xenbase
Kimelman,
The events of the midblastula transition in Xenopus are regulated by changes in the cell cycle.
1987,
Pubmed
,
Xenbase
Kintner,
Expression of Xenopus N-CAM RNA in ectoderm is an early response to neural induction.
1987,
Pubmed
,
Xenbase
Lewis,
Imprinting on distal chromosome 7 in the placenta involves repressive histone methylation independent of DNA methylation.
2004,
Pubmed
Mizuseki,
Xenopus Zic-related-1 and Sox-2, two factors induced by chordin, have distinct activities in the initiation of neural induction.
1998,
Pubmed
,
Xenbase
Newport,
A major developmental transition in early Xenopus embryos: II. Control of the onset of transcription.
1982,
Pubmed
,
Xenbase
Newport,
A major developmental transition in early Xenopus embryos: I. characterization and timing of cellular changes at the midblastula stage.
1982,
Pubmed
,
Xenbase
Nichols,
Formation of pluripotent stem cells in the mammalian embryo depends on the POU transcription factor Oct4.
1998,
Pubmed
Niwa,
Quantitative expression of Oct-3/4 defines differentiation, dedifferentiation or self-renewal of ES cells.
2000,
Pubmed
Paro,
Heritable chromatin states induced by the Polycomb and trithorax group genes.
1998,
Pubmed
Pesce,
Oct-4: gatekeeper in the beginnings of mammalian development.
2001,
Pubmed
Reik,
Evolution of imprinting mechanisms: the battle of the sexes begins in the zygote.
2001,
Pubmed
Reik,
Epigenetic reprogramming in mammalian development.
2001,
Pubmed
Rideout,
Nuclear cloning and epigenetic reprogramming of the genome.
2001,
Pubmed
Sasai,
Endoderm induction by the organizer-secreted factors chordin and noggin in Xenopus animal caps.
1996,
Pubmed
,
Xenbase
Shi,
Epigenetic reprogramming in mammalian nuclear transfer.
2003,
Pubmed
SIMNETT,
THE DEVELOPMENT OF EMBRYOS DERIVED FROM THE TRANSPLANTATION OF NEURAL ECTODERM CELL NUCLEI IN XENOPUS LAEVIS.
1964,
Pubmed
,
Xenbase
Simonsson,
DNA demethylation is necessary for the epigenetic reprogramming of somatic cell nuclei.
2004,
Pubmed
,
Xenbase
Stancheva,
Transient depletion of xDnmt1 leads to premature gene activation in Xenopus embryos.
2000,
Pubmed
,
Xenbase
Willadsen,
Nuclear transplantation in sheep embryos.
,
Pubmed
Wilmut,
Somatic cell nuclear transfer.
2002,
Pubmed
Wilmut,
Viable offspring derived from fetal and adult mammalian cells.
1997,
Pubmed
Wilson,
Concentration-dependent patterning of the Xenopus ectoderm by BMP4 and its signal transducer Smad1.
1997,
Pubmed
,
Xenbase
Wilson,
Induction of epidermis and inhibition of neural fate by Bmp-4.
1995,
Pubmed
,
Xenbase
Wylie,
Vegetal pole cells and commitment to form endoderm in Xenopus laevis.
1987,
Pubmed
,
Xenbase
