Transgenic Xenopus embryos reveal that anterior neural development requires continued suppression of BMP signaling after gastrulation
Transgenic Xenopus embryos reveal that anterior neural development requires continued suppression of BMP signaling after gastrulation
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DOI：
10.1006/dbio.2001.0398
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发表时间：
2001-10-01
影响因子：
2.7
通讯作者：
Papalopulu, N
中科院分区：
文献类型：
--
作者：
Hartley, KO;Hardcastle, Z;Papalopulu, N
在脊椎动物中，原肠胚形成前的 BMP 信号传导会抑制神经发育。在发展的后期，BMP 信号传导指定了前脑的背侧和腹侧命运以及脊髓的背侧命运。因此，外胚层响应 BMP 信号传导的能力可能会在发育的某个时刻发生变化。我们报告说，在原肠胚形成前将前神经板暴露于 BMP4 会导致所有测试的神经标记物受到抑制。为了确定原肠胚形成后 BMP4 的影响，我们在转基因青蛙胚胎中使用 Pax-6 启动子片段错误表达 BMP4，并将浸泡在 BMP4 中的珠子植入前神经板中。观察到大多数前神经标记物的抑制。我们得出的结论是，大多数神经基因在神经胚阶段仍然需要抑制 BMP 信号传导。此外，我们报告 BMP4 和 BMP7 在神经胚阶段胚胎的脊索前中胚层中大量表达。这就提出了一个悖论：如果大多数神经基因可以被 BMP 信号传导抑制，那么它们的表达如何得以维持。我们发现前神经板中至少有一个基因抑制外胚层对 BMP 信号传导的反应。我们提出，BMP 信号传导对神经基因表达的抑制作用与 BMP 信号传导的局部抑制因子相结合，导致前神经板中基因表达的微调。 (C) 2001 年学术出版社。
In vertebrates, BMP signaling before gastrulation suppresses neural development. Later in development, BMP signaling specifies a dorsal and ventral fate in the forebrain and dorsal fate in the spinal cord. It is therefore possible that a change in the competence of the ectoderm to respond to BMP signaling occurs at some point in development. We report that exposure of the anterior neural plate to BMP4 before gastrulation causes suppression of all neural markers tested. To determine the effects of BMP4 after gastrulation, we misexpressed BMP4 using a Pax-6 promoter fragment in transgenic frog embryos and implanted beads soaked in BMP4 in the anterior neural plate. Suppression of most anterior neural markers was observed. We conclude that most neural genes continue to require suppression of BMP signaling into the neurula stages. Additionally, we report that BMP4 and BMP7 are abundantly expressed in the prechordal mesoderm of the neurula stage embryo. This poses the paradox of how the expression of most neural genes is maintained if they can be inhibited by BMP signaling. We show that at least one gene in the anterior neural plate suppresses the response of the ectoderm to BMP signaling. We propose that the suppressive effect of BMP signaling on the expression of neural genes coupled with localized suppressors of BMP signaling result in the fine-tuning of gene expression in the anterior neural plate. (C) 2001 Academic Press.