Letter | Published:

Nanog promotes transfer of pluripotency after cell fusion

Naturevolume 441pages9971001 (2006) | Download Citation



Through cell fusion, embryonic stem (ES) cells can erase the developmental programming of differentiated cell nuclei and impose pluripotency1,2. Molecules that mediate this conversion should be identifiable in ES cells. One candidate is the variant homeodomain protein Nanog, which has the capacity to entrain undifferentiated ES cell propagation3,4. Here we report that in fusions between ES cells and neural stem (NS) cells, increased levels of Nanog stimulate pluripotent gene activation from the somatic cell genome and enable an up to 200-fold increase in the recovery of hybrid colonies, all of which show ES cell characteristics. Nanog also improves hybrid yield when thymocytes or fibroblasts are fused to ES cells; however, fewer colonies are obtained than from ES × NS cell fusions, consistent with a hierarchical susceptibility to reprogramming among somatic cell types. Notably, for NS × ES cell fusions elevated Nanog enables primary hybrids to develop into ES cell colonies with identical frequency to homotypic ES × ES fusion products. This means that in hybrids, increased Nanog is sufficient for the NS cell epigenome to be reset completely to a state of pluripotency. We conclude that Nanog can orchestrate ES cell machinery to instate pluripotency with an efficiency of up to 100% depending on the differentiation status of the somatic cell.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Tada, M., Takahama, Y., Abe, K., Nakatsuji, N. & Tada, T. Nuclear reprogramming of somatic cells by in vitro hybridization with ES cells. Curr. Biol. 11, 1553–1558 (2001)

  2. 2

    Ying, Q. L., Nichols, J., Evans, E. P. & Smith, A. G. Changing potency by spontaneous fusion. Nature 416, 545–548 (2002)

  3. 3

    Chambers, I. et al. Functional expression cloning of Nanog, a pluripotency sustaining factor in embryonic stem cells. Cell 113, 643–655 (2003)

  4. 4

    Mitsui, K. et al. The homeoprotein Nanog is required for maintenance of pluripotency in mouse epiblast and ES cells. Cell 113, 631–642 (2003)

  5. 5

    Campbell, K. H. S., McWhir, J., Ritchie, W. A. & Wilmut, I. Sheep cloned by nuclear transfer from a cultured cell line. Nature 380, 64–66 (1996)

  6. 6

    Cowan, C. A., Atienza, J., Melton, D. A. & Eggan, K. Nuclear reprogramming of somatic cells after fusion with human embryonic stem cells. Science 309, 1369–1373 (2005)

  7. 7

    Kimura, H., Tada, M., Nakatsuji, N. & Tada, T. Histone code modifications on pluripotential nuclei of reprogrammed somatic cells. Mol. Cell. Biol. 24, 5710–5720 (2004)

  8. 8

    Matveeva, N. M. et al. In vitro and in vivo study of pluripotency in intraspecific hybrid cells obtained by fusion of murine embryonic stem cells with splenocytes. Mol. Reprod. Dev. 50, 128–138 (1998)

  9. 9

    Miller, R. A. & Ruddle, F. H. Teratocarcinoma × friend erythroleukemia cell hybrids resemble their pluripotent embryonal carcinoma parent. Dev. Biol. 56, 157–173 (1977)

  10. 10

    Tada, M., Tada, T., Lefebvre, L., Barton, S. C. & Surani, M. A. Embryonic germ cells induce epigenetic reprogramming of somatic nucleus in hybrid cells. EMBO J. 16, 6510–6520 (1997)

  11. 11

    Miller, R. A. & Ruddle, F. H. Pluripotent teratocarcinoma–thymus somatic cell hybrids. Cell 9, 45–55 (1976)

  12. 12

    Conti, L. et al. Niche-independent symmetrical self-renewal of a mammalian tissue stem cell. PLoS Biol. 3, 1596–1606 (2005)

  13. 13

    Pollard, S. M., Conti, L., Sun, Y., Goffredo, D. & Smith, A. Adherent neural stem (NS) cells from foetal and adult forebrain. Cerebral Cortex (in the press)

  14. 14

    Niwa, H. et al. Interaction between Oct3/4 and Cdx2 determines trophectoderm differentiation. Cell 123, 917–929 (2005)

  15. 15

    Smith, A. The battlefield of pluripotency. Cell 123, 757–760 (2005)

  16. 16

    Bao, S. et al. Initiation of epigenetic reprogramming of the X chromosome in somatic nuclei transplanted to a mouse oocyte. EMBO Rep. 6, 748–754 (2005)

  17. 17

    Chambers, I. & Smith, A. Self-renewal of teratocarcinoma and embryonic stem cells. Oncogene 23, 7150–7160 (2004)

  18. 18

    Yeom, Y. I. et al. Germline regulatory element of Oct-4 specific for the totipotent cycle of embryonal cells. Development 122, 881–894 (1996)

  19. 19

    Pratt, T., Sharp, L., Nichols, J., Price, D. J. & Mason, J. O. Embryonic stem cells and transgenic mice ubiquitously expressing a tau-tagged green fluorescent protein. Dev. Biol. 228, 19–28 (2000)

  20. 20

    Yates, A. & Chambers, I. The homeodomain protein Nanog and pluripotency in mouse embryonic stem cells. Biochem. Soc. Trans. 33, 1518–1521 (2005)

  21. 21

    Silva, J. et al. Establishment of histone h3 methylation on the inactive X chromosome requires transient recruitment of Eed–Enx1 polycomb group complexes. Dev. Cell 4, 481–495 (2003)

  22. 22

    de Napoles, M. et al. Polycomb group proteins Ring1A/B link ubiquitylation of histone H2A to heritable gene silencing and X inactivation. Dev. Cell 7, 663–676 (2004)

  23. 23

    Sheardown, S. A. et al. Stabilization of Xist RNA mediates initiation of X chromosome inactivation. Cell 91, 99–107 (1997)

  24. 24

    Mountford, P. et al. Dicistronic targeting constructs: reporters and modifiers of mammalian gene expression. Proc. Natl Acad. Sci. USA 91, 4303–4307 (1994)

  25. 25

    Mountford, P., Nichols, J., Zevnik, B., O'Brien, C. & Smith, A. Maintenance of pluripotential embryonic stem cells by stem cell selection. Reprod. Fertil. Dev. 10, 527–533 (1998)

  26. 26

    Do, J. T. & Scholer, H. R. Nuclei of embryonic stem cells reprogram somatic cells. Stem Cells 22, 941–949 (2004)

  27. 27

    Blelloch, R. et al. Reprogramming efficiency following somatic cell nuclear transfer is influenced by the differentiation and methylation state of the donor nucleus. Stem Cells doi:10.1634/stemcells.2006-0050 (18 May 2006)

  28. 28

    Avilion, A. A. et al. Multipotent cell lineages in early mouse development depend on SOX2 function. Genes Dev. 17, 126–140 (2003)

Download references


We thank J. Vrana for assistance with FACS and Y. Costa for critical reading of the manuscript. This research was supported by the Biotechnological and Biological Sciences Research Council and the Medical Research Council of the United Kingdom, the Wellcome Trust, and by an EMBO Long-term Fellowship (J.S.). Author Contributions J.S. designed and executed experiments, analysed data, and drafted the paper; I.C. and S.P. generated reagents and contributed to experimental design; and A.S. designed experiments and wrote the paper.

Author information


  1. Centre Development in Stem Cell Biology, Institute for Stem Cell Research, University of Edinburgh, Edinburgh, EH9 3JQ, UK

    • José Silva
    • , Ian Chambers
    • , Steven Pollard
    •  & Austin Smith
  2. Institute for Stem Cell Biology, University of Cambridge, Cambridge, CB2 1QT, UK

    • Austin Smith


  1. Search for José Silva in:

  2. Search for Ian Chambers in:

  3. Search for Steven Pollard in:

  4. Search for Austin Smith in:

Competing interests

The University of Edinburgh has filed a patent application related to this work and has licensed this patent to Stem Cell Sciences, PLC. A.S. is a scientific consultant to Stem Cell Sciences, PLC.

Corresponding author

Correspondence to Austin Smith.

Supplementary information

  1. Supplementary Notes

    This file contains Supplementary Methods, Supplementary Figure Legends, Supplementary Figures 1–8 and additional references. (PDF 3715 kb)

About this article

Publication history




Issue Date



Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.