p38 MAPK is essential for secondary axis specification and patterning in sea urchin embryos
p38 MAPK is essential for secondary axis specification and patterning in sea urchin embryos
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DOI：
10.1242/dev.02160
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发表时间：
2006-01-01
期刊：
影响因子：
4.6
通讯作者：
McClay, DR
中科院分区：
文献类型：
--
作者：
Bradham, CA;McClay, DR
动物界中的大多数卵在母体上建立了一个主要的动植物轴，并在发育过程中指定了其余的两个轴。在海胆胚胎中，Nodal 在胚胎口侧（腹侧）的表达是第一个已知的口-腹轴（胚胎背腹轴）的分子决定因素，并且对于口域的规范至关重要。我们发现 p38 MAPK 在 Nodal 上游发挥作用，并且是 Nodal 在口腔区域表达所必需的。 p38 在发育早期均匀激活，但在囊胚后期的短时间内，在未来的中核中不对称失活。实验表明，p38 激活的这种短暂不对称在时间上对应于口腔规范和口腔 Nodal 表达的开始。 p38 的均匀抑制会阻止 Nodal 表达和轴规范，导致胚胎缺损。当在 p38 抑制的胚胎中不对称表达时，Nodal 及其目标 Gsc 各自挽救口-口规范和模式。因此，我们的结果表明，p38 通过促进口腔区域的 Nodal 表达来实现口腔规范。
Most eggs in the animal kingdom establish a primary, animal-vegetal axis maternally, and specify the remaining two axes during development. In sea urchin embryos, the expression of Nodal on the oral (ventral) side of the embryo is the first known molecular determinant of the oral-aboral axis (the embryonic dorsoventral axis), and is crucial for specification of the oral territory. We show that p38 MAPK acts upstream of Nodal and is required for Nodal expression in the oral territory. p38 is uniformly activated early in development, but, for a short interval at late blastula stage, is asymmetrically inactivated in future aboral nuclei. Experiments show that this transient asymmetry of p38 activation corresponds temporally to both oral specification and the onset of oral Nodal expression. Uniform inhibition of p38 prevents Nodal expression and axis specification, resulting in aboralized embryos. Nodal and its target Gsc each rescue oral-aboral specification and patterning when expressed asymmetrically in p38-inhibited embryos. Thus, our results indicate that p38 is required for oral specification through its promotion of Nodal expression in the oral territory.