Sequential signaling crosstalk regulates endomesoderm segregation in sea urchin embryos.
Sequential signaling crosstalk regulates endomesoderm segregation in sea urchin embryos.
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DOI：
10.1126/science.1212867
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发表时间：
2012-02-03
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影响因子：
--
通讯作者：
Angerer LM
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作者：
Sethi AJ;Wikramanayake RM;Angerer RC;Range RC;Angerer LM
胚胎内中胚层分离成单独的内胚层和中胚层的命运还没有很好地了解后口动物。使用海胆胚胎，我们表明，Notch信号启动隔离的内中胚层前体领域抑制一个关键的内胚层转录因子的表达在假定的中胚层。由该转录因子激活的调节回路随后仅在内胚层前体中维持cWnt配体的转录。这种cWnt配体增强了内胚层状态，扩大了新兴内胚层和中胚层之间的区别。在原肠胚形成之前，来自中胚层的必需β-连环蛋白转录共激活因子的Notch依赖性核输出使其对cWnt信号不敏感，使其与内胚层命运绝缘。因此，我们报告内中胚层分离是一个渐进的过程，需要cWnt和Notch信号之间的一系列调控相互作用。
Segregation of embryonic endomesoderm into separate endoderm and mesoderm fates is not well understood in deuterostomes. Using sea urchin embryos, we show that Notch signaling initiates segregation of the endomesoderm precursor field by inhibiting expression of a key endoderm transcription factor in presumptive mesoderm. The regulatory circuit activated by this transcription factor subsequently maintains transcription of a cWnt ligand only in endoderm precursors. This cWnt ligand reinforces the endoderm state, amplifying the distinction between emerging endoderm and mesoderm. Before gastrulation, Notch-dependent nuclear export of an essential β-catenin transcriptional coactivator from mesoderm renders it refractory to cWnt signals, insulating it against an endoderm fate. Thus we report that endomesoderm segregation is a progressive process, requiring a succession of regulatory interactions between cWnt and Notch signaling.