title: Nuclei of adult mammalian somatic cells are directly reprogrammed to oct-4 stem cell gene expression by amphibian oocytes.
abstract: Nuclear reprogramming by the transplantation of somatic cell nuclei to eggs (in second meiotic metaphase) is always followed by a phase of chromosome replication and cell division before new gene expression is seen. To help understand the mechanism of nuclear reprogramming, we have asked whether the nuclei of normal, nontransformed, nondividing, and terminally differentiated mammalian cells can be directly reprogrammed, without DNA replication, by Xenopus oocytes. We find that nuclei of adult mouse thymocytes and of adult human blood lymphocytes, injected into Xenopus oocytes, are induced to extinguish a differentiation marker and to strongly express oct-4, the most diagnostic mammalian stem cell/pluripotency marker. In the course of 2 days at 18 degrees C, the mammalian oct-4 transcripts are spliced to mature mRNA. We conclude that normal mammalian nuclei can be directly reprogrammed by the nucleus (germinal vesicle) of amphibian oocytes to express oct-4 at a rate comparable to that of oct-4 in mouse ES cells. To our knowledge, this is the first demonstration of a stem cell marker being induced in a differentiated adult human cell nucleus. This is an early step toward the long-term aim of developing a procedure for reprogramming readily accessible human adult cells for cell replacement therapy.
authors.affiliation: Wellcome Trust/Cancer Research UK Institute, and Department of Zoology, University of Cambridge, CB2 1QR, United Kingdom.
authors.forename: James A
authors.initials: JA
authors.lastname: Byrne
authors.forename: Stina
authors.initials: S
authors.lastname: Simonsson
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Western
authors.forename: John B
authors.initials: JB
authors.lastname: Gurdon
mesh_terms: D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000235:genetics; D002874:Chromosome Mapping; D019976:Cloning, Organism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000502:physiology; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008214:Lymphocytes / Q000166:cytology; D051379:Mice; D053652:Nuclear Transfer Techniques; D050814:Octamer Transcription Factor-3; D009865:Oocytes / Q000166:cytology*; D016133:Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology*; D014157:Transcription Factors; D014981:Xenopus
chemical_list: D004268:DNA-Binding Proteins; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; C494174:Pou5f1 protein, mouse; D014157:Transcription Factors