Direct TGF-beta signaling via alk4/5/7 pathway is involved in gut bending in sea urchin embryos
Direct TGF-beta signaling via alk4/5/7 pathway is involved in gut bending in sea urchin embryos
复制标题
通过alk4/5/7途径的直接TGF-β信号传导参与海胆胚胎的肠道弯曲
DOI：
10.1002/dvdy.442
复制
发表时间：
2021
影响因子：
2.5
通讯作者：
Shunsuke Yaguchi
中科院分区：
文献类型：
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作者：
Haruka Suzuki;Shunsuke Yaguchi
研究背景精确的原肠胚形成是刺胞动物和双侧刺胞动物功能体形成的关键。之前，通过使用alk 4/5/7特异性抑制剂，我们发现转化生长因子-β（TGF-β）-alk 4/5/7信号通路对于海胆胚胎中正确的肠道弯曲很重要。然而，目前还不清楚在胚胎中收到的功能性TGF-β信号正确的肠道弯曲，因为alk 4/5/7的时空表达模式的细节还没有reported.ResultsWe揭示，alk 4/5/7表达从2细胞到早期pluteus阶段在整个身体，包括内陷肠。为了研究内胚层中直接接收的TGF-β信号是否是正确的肠弯曲所必需的，我们制备了其中alk 4/5/7翻译仅在内中胚层谱系中被抑制的嵌合体。因此，嵌合体胚胎的肠道没有弯曲精确，与对照chimeras.ConclusionWe的结论是，直接TGF-β信号转导内胚层通过alk 4/5/7途径调节正确的肠道弯曲。然而，TGF-β-alk 4/5/7通路与开口无关，因为口的形成没有TGF-β信号传导到内胚层。这项研究有助于理解导致原肠末端正确定位以形成通肠的机制，这是双侧性动物通常需要的。
BackgroundPrecise gastrulation is essential for formation of functional bodies in cnidarians and bilaterians. Previously, by using an alk4/5/7‐specific inhibitor, we showed that transforming growth factor‐beta (TGF‐ß)‐alk4/5/7 signaling pathway is important for correct gut bending in sea urchin embryos. However, it is still unclear where functional TGF‐ß signals are received in embryos for correct gut bending because details of the spatiotemporal expression pattern of alk4/5/7 have not been reported.ResultsWe revealed that alk4/5/7 are expressed from the 2‐cell to early pluteus stage throughout the entire body, including the invaginating gut. To investigate whether TGF‐ß signals directly received in endoderm are required for correct gut bending, we made chimeras in which alk4/5/7 translation was inhibited only in endomesoderm lineage. As a result, the gut of the chimeric embryos did not bend precisely, in contrast to the control chimeras.ConclusionWe conclude that direct TGF‐ß signaling to the endoderm via alk4/5/7 pathway regulates correct gut bending. However, TGF‐ß‐alk4/5/7 pathway is not related to mouth opening because the mouth is formed without TGF‐ß signaling to the endoderm. This research contributes to understanding the mechanisms leading to the proper positioning of the end of the archenteron for forming a through‐gut, which is commonly needed for bilaterians.