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Updated: May 20, 2026

Oct4GiP Reporter Assay to Study Genes that Regulate Mouse Embryonic Stem Cell Maintenance and Self-renewal
Published on: May 30, 2012
Transcriptional activation by Oct4 is sufficient for the maintenance and induction of pluripotency
Fella Hammachi1, Gillian M Morrison, Alexei A Sharov
1MRC Centre for Regenerative Medicine - Institute for Stem Cell Research, School of Biological Sciences, 5 Little France Drive, University of Edinburgh, EH16 4UU Edinburgh, UK.
Abstract:
Oct4 is an essential regulator of pluripotency in vivo and in vitro in embryonic stem cells, as well as a key mediator of the reprogramming of somatic cells into induced pluripotent stem cells. It is not known whether activation and/or repression of specific genes by Oct4 is relevant to these functions. Here, we show that fusion proteins containing the coding sequence of Oct4 or Xlpou91 (the Xenopus homolog of Oct4) fused to activating regions, but not those fused to repressing regions, behave as Oct4, suppressing differentiation and promoting maintenance of undifferentiated phenotypes in vivo and in vitro. An Oct4 activation domain fusion supported embryonic stem cell self-renewal in vitro at lower concentrations than that required for Oct4 while alleviating the ordinary requirement for the cytokine LIF. At still lower levels of the fusion, LIF dependence was restored. We conclude that the necessary and sufficient function of Oct4 in promoting pluripotency is to activate specific target genes.
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