Dorsal and intermediate neuronal cell types of the spinal cord are established by a BMP signaling pathway.
Dorsal and intermediate neuronal cell types of the spinal cord are established by a BMP signaling pathway.
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发表时间：
2000-03
期刊：
影响因子：
4.6
通讯作者：
Vu H. Nguyen;Jamie Trout;Stephanie A. Connors;P. Andermann;Eric Weinberg;Mary C. Mullins
中科院分区：
文献类型：
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作者：
Vu H. Nguyen;Jamie Trout;Stephanie A. Connors;P. Andermann;Eric Weinberg;Mary C. Mullins
我们通过在斑马鱼中使用突变体来研究BMP信号在形成神经组织模式中的作用，这些突变体扰乱了BMP信号通路的三个不同成分：Swir1/bmp2b、Snailhouse/Bmp7和Somitabun/Smad5。我们证明了BMP信号对于建立预期的神经脊和脊髓背侧感觉Rohon-Beard神经元是必不可少的。此外，BMP信号对限制脊髓中定位的Lim1+中间神经元的数量是必要的，正如许多突变胚胎中这些预期中间神经元的戏剧性扩张所观察到的那样。我们的分析还表明，BMP信号在这些中间神经元的规范中发挥了积极的作用，这与Bmp2b/Swirl的活性无关。我们发现，一个假定的腹侧信号，HH信号，作用于限制背感觉神经元和主干神经峰的数量。这种限制似乎发生在神经组织发育的非常早期，很可能是在脊索或底板形成之前。BMP信号在背部神经细胞类型的规范中也有类似的早期作用，因为Bmp2b/Swir1和Bmp7/Snailhouse基因只在原肠胚和尾芽中共表达，而在背侧神经管或上覆的表皮外胚层中不存在。因此，原肠胚Bmp2b/Swirl和Bmp7/Snailhouse依赖的活动梯度不仅可能在胚胎背腹轴的指定中起作用，而且可能在建立脊髓背侧和中间神经细胞类型方面发挥作用。
We have studied the role of Bmp signaling in patterning neural tissue through the use of mutants in the zebrafish that disrupt three different components of a Bmp signaling pathway: swirl/bmp2b, snailhouse/bmp7 and somitabun/smad5. We demonstrate that Bmp signaling is essential for the establishment of the prospective neural crest and dorsal sensory Rohon-Beard neurons of the spinal cord. Moreover, Bmp signaling is necessary to limit the number of intermediate-positioned lim1+ interneurons of the spinal cord, as observed by the dramatic expansion of these prospective interneurons in many mutant embryos. Our analysis also suggests a positive role for Bmp signaling in the specification of these interneurons, which is independent of Bmp2b/Swirl activity. We found that a presumptive ventral signal, Hh signaling, acts to restrict the amount of dorsal sensory neurons and trunk neural crest. This restriction appears to occur very early in neural tissue development, likely prior to notochord or floor plate formation. A similar early role for Bmp signaling is suggested in the specification of dorsal neural cell types, since the bmp2b/swirl and bmp7/snailhouse genes are only coexpressed during gastrulation and within the tail bud, and are not found in the dorsal neural tube or overlying epidermal ectoderm. Thus, a gastrula Bmp2b/Swirl and Bmp7/Snailhouse-dependent activity gradient may not only act in the specification of the embryonic dorsoventral axis, but may also function in establishing dorsal and intermediate neuronal cell types of the spinal cord.