怎样获得具有mES样形态的人ES克隆

开心果王

请教各位战友，能否通过某种外源培养条件使人ES获得一个mES样的形态呢！记得好想有这样的文献，但是一时又找不到，请高人帮帮忙！因为EpiSCs可以通过添加小分子抑制剂变为ES样形态。类似的，现阶段人ES的形态类似于EpiSC，能否通过外界的信号通路的干预，使得hES获得类似于mES样的形态呢？

tpwang

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“类似mES样形态”如何定义的。9 H  e- g" z- ?+ K) i

1 p% S  o6 V3 O0 V这里有一片获得双X人胚胎干模式的文章，也算一种类似mES的形态：
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5 ~2 p. o; E- G# H+ E3 xCell. 2010 May 28;141(5):872-83. Epub 2010 May 13., a" w7 g7 l# ~8 x" B

' z5 p/ S3 Z* ~; k1 F2 F( kDerivation of pre-X inactivation human embryonic stem cells under physiological oxygen concentrations.
9 X# t* y* E: o! D: q6 xLengner CJ, Gimelbrant AA, Erwin JA, Cheng AW, Guenther MG, Welstead GG, Alagappan R, Frampton GM, Xu P, Muffat J, Santagata S, Powers D, Barrett CB, Young RA, Lee JT, Jaenisch R, Mitalipova M.
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Whitehead Institute for Biomedical Sciences, 9 Cambridge Center, Cambridge, MA 02142, USA.! S- k- r8 K$ V
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The presence of two active X chromosomes (XaXa) is a hallmark of the ground state of pluripotency specific to murine embryonic stem cells (ESCs). Human ESCs (hESCs) invariably exhibit signs of X chromosome inactivation (XCI) and are considered developmentally more advanced than their murine counterparts. We describe the establishment of XaXa hESCs derived under physiological oxygen concentrations. Using these cell lines, we demonstrate that (1) differentiation of hESCs induces random XCI in a manner similar to murine ESCs, (2) chronic exposure to atmospheric oxygen is sufficient to induce irreversible XCI with minor changes of the transcriptome, (3) the Xa exhibits heavy methylation of the XIST promoter region, and (4) XCI is associated with demethylation and transcriptional activation of XIST along with H3K27-me3 deposition across the Xi. These findings indicate that the human blastocyst contains pre-X-inactivation cells and that this state is preserved in vitro through culture under physiological oxygen.
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tpwang

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开心果王

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# i4 M2 Y6 \* H多谢tpwang，获得双Xa的hES的确是一种mES-like状态。但是我想说的是具有类似mES克隆形态（compact morphology）即3D样形态的hES。因为最近看到一篇将MEF诱导为iEpiSCs的文章，发现从MEF到iEpiSC（3-5weeks）要比MEF到iPS（1-2weeks）的时间久，而事实上，EpiSC处在“primed”状态，从MEF到iEpiSCs理论上应该较获得iPS要快，但文中的现象却不是如此。这是为什么呢？文章解释说：iEpiSCs其形态更像hES，而从forskin到hiPS也需要3w左右。我觉的这样解释的有点生硬，所以想看看是否有类似的文章来回答一下这个问题。