Neural tube closure requires Dishevelled-dependent convergent extension of the midline
Neural tube closure requires Dishevelled-dependent convergent extension of the midline
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DOI：
10.1242/dev.00123
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发表时间：
2002-12-01
期刊：
影响因子：
4.6
通讯作者：
Harland, RM
中科院分区：
文献类型：
--
作者：
Wallingford, JB;Harland, RM
在非洲爪蟾中，Dishevelled（Xdsh）信号是神经管闭合和神经会聚延伸所必需的，但这两个形态发生过程之间的联系尚不清楚。事实上，正常的神经形成需要几种不同的细胞极性决定，其中任何一种都可能需要Xdsh信号。在本文中，我们解决两个问题：（1）正常神经形成的哪些方面需要Xdsh功能;（2）收敛延伸在神经管闭合中起什么作用。我们表明，Xdsh信号是不需要神经折叠的提升，内侧运动或融合。因此，破坏Xdsh信号提供了一个特定的工具，解偶联收敛延伸从其他过程的神经形成。使用中断Xdsh信号，我们证明了收敛扩展是至关重要的管关闭。靶向注射显示，Xdsh的功能是需要专门在中线正常神经管关闭。我们认为，神经褶皱的固有运动只能完成有限的内侧进展，中线的收敛延伸是必要的，以减少新生神经褶皱之间的距离，使它们能够满足和融合。非洲爪蟾斜视的类似结果暗示了平面细胞极性（PCP）信号级联在神经会聚延伸和管关闭。总之，这些数据表明，PCP介导的会聚延伸运动是至关重要的适当的脊椎动物神经形成。
In Xenopus, Dishevelled (Xdsh) signaling is required for both neural tube closure and neural convergent extension, but the connection between these two morphogenetic processes remains unclear. Indeed normal neurulation requires several different cell polarity decisions, any of which may require Xdsh signaling. In this paper we address two issues: (1) which aspects of normal neurulation require Xdsh function; and (2) what role convergent extension plays in the closure of the neural tube. We show that Xdsh signaling is not required for neural fold elevation, medial movement or fusion. Disruption of Xdsh signaling therefore provides a specific tool for uncoupling convergent extension from other processes of neurulation. Using disruption of Xdsh signaling, we demonstrate that convergent extension is crucial to tube closure. Targeted injection revealed that Xdsh function was required specifically in the midline for normal neural tube closure. We suggest that the inherent movement of the neural folds can accomplish only a finite amount of medial progress and that convergent extension of the midline is necessary to reduce the distance between the nascent neural folds, allowing them to meet and fuse. Similar results with Xenopus strabismus implicate the planar cell polarity (PCP) signaling cascade in neural convergent extension and tube closure. Together, these data demonstrate that PCP-mediated convergent extension movements are crucial to proper vertebrate neurulation.