The Pou5f1/Pou3f-dependent but SoxB-independent regulation of conserved enhancer N2 initiates Sox2 expression during epiblast to neural plate stages in vertebrates
The Pou5f1/Pou3f-dependent but SoxB-independent regulation of conserved enhancer N2 initiates Sox2 expression during epiblast to neural plate stages in vertebrates
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DOI：
10.1016/j.ydbio.2010.12.027
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发表时间：
2011-04-15
影响因子：
2.7
通讯作者：
Kondoh, Hisato
中科院分区：
文献类型：
--
作者：
Iwafuchi-Doi, Makiko;Yoshida, Yuzo;Kondoh, Hisato
转录因子Sox2是早期胚胎多能性控制回路的核心组成部分，后来控制了神经发育的许多方面。在这里，我们证明Sox2在外胚层（小鼠胚皮）和前神经板（ANP）中的表达是由上游增强子N2决定的。小鼠增强子N2在小鼠胚胎干细胞、外胚层和ANP中表现出较强的活性，并在鸡和斑马鱼胚胎中得到正确调控。在小鼠胚胎中靶向删除该增强子导致外胚层和ANP中Sox2表达量大幅下降至野生型水平的10%。然而，这是小鼠胚胎耐受的，可能是由于Sox3的功能补偿。增强子N2的活性依赖于73 bp核心序列中系统发育上保守的双部POU因子结合基序，这些基序协同作用，但这种激活不涉及Sox2。外成骨期主要表达的POU因子为Pou5f1 (Oct3/4)，前神经板表达的POU因子为Pou3f （Oct3/4）。Brn2等等)。这些因子在小鼠胚胎和外胚层干细胞（EpiSC）从外胚层到ANP阶段的过渡过程中逐渐交换。在EpiSC神经板细胞（NPC）的发育过程中，增强子N2活性从完全依赖Pou5f1转变为依赖Pou3f，这是通过这些细胞中特定的POU因子敲低来评估的。完全缺乏Pou5f1活性的斑马鱼突变胚胎不能激活增强子N2，也不能在胚皮和ANP中表达Sox2，这些缺陷可以通过外源提供Pou5f1来修复。在此之前，Pou5f1-Sox2协同依赖的Sox2激活通过增强子SRR2在胚胎干细胞中得到了强调，但这种机制仅限于胚胎干细胞和羊膜。相反，增强子n2介导。POU因子依赖的Sox2激活，在没有Sox2参与的情况下，是一种在系统发育上保守的核心机制，在胚胎早期基因调控网络中起作用。(C) 2010爱思唯尔公司版权所有。
The transcription factor Sox2 is a core component of the pluripotency control circuits in the early embryo, and later controls many aspects of neural development. Here, we demonstrate that Sox2 expression in the epiblast (mouse blastoderm) and anterior neural plate (ANP) is determined by the upstream enhancer N2. The mouse enhancer N2 exhibits strong activity in mouse ES cells, epiblast and ANP, and is regulated correctly in chicken and zebrafish embryos. Targeted deletion of this enhancer in mouse embryos caused a large reduction of Sox2 expression to 10% of that of wild-type levels in epiblast and ANP. However, this was tolerated by mouse embryo, probably due to functional compensation by Sox3. The activity of enhancer N2 depends on phylogenetically conserved bipartite POU factor-binding motifs in a 73-bp core sequence that function synergistically, but this activation does not involve Sox2. The major POU factor expressed at the epiblastic stage is Pou5f1 (Oct3/4), while those in the anterior neural plate are Pou3f factors (Oct6. Brn2 etc.). These factors are gradually exchanged during the transition from epiblast to ANP stages in mouse embryos and epiblast stem cells (EpiSC). Consistently, enhancer N2 activity changes from full Pou5f1 dependence to Pou3f dependence during the development of neural plate cells (NPC) from EpiSC, as assessed by specific POU factor knockdown in these cells. Zebrafish mutant embryos completely devoid of Pou5f1 activity failed to activate enhancer N2 and to express Sox2 in the blastoderm and ANP, and these defects were rescued by exogenous supply of pou5f1. Previously, Pou5f1-Sox2 synergism-dependent Sox2 activation through enhancer SRR2 in ES cells has been highlighted, but this mechanism is limited to ES cells and amniotes. In contrast, the enhancer N2-mediated. POU factor-dependent activation of Sox2, without involvement of Sox2, is a phylogenetically conserved core mechanism that functions in gene regulatory networks at early embryonic stages. (C) 2010 Elsevier Inc. All rights reserved.