XASH-3, a novel Xenopus achaete-scute homolog, provides an early marker of planar neural induction and position along the mediolateral axis of the neural plate.
XASH-3, a novel Xenopus achaete-scute homolog, provides an early marker of planar neural induction and position along the mediolateral axis of the neural plate.
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发表时间：
1993-09
期刊：
影响因子：
4.6
通讯作者：
K. Zimmerman;J. Shih;J. Bars;A. Collazo;D. Anderson
中科院分区：
文献类型：
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作者：
K. Zimmerman;J. Shih;J. Bars;A. Collazo;D. Anderson
我们已经分离出一种新的果蝇无毛鳞状突起基因的非洲爪哇同源物，称为XASH-3。XASH-3的表达是神经特异性的，早在111/2期就被检测到，使其成为迄今描述的神经诱导的最早标志之一。此外，XASH-3在神经板内的表达受到区域限制。XASH-3mRNA的横向条带标记沿前后轴的离散位置，而纵向条带标记沿内侧轴的离散位置。XASH-3表达的后一个部位似乎是未来的沟界限的分界线，这个界限区后来将功能上不同的脊髓背侧(翼部)和腹侧(基底)区域分开。在缺乏下中胚层的三明治外植体中，XASH-3在位于中线侧面的纵向条纹中表达。这提供了第一个迹象，即平面或中线派生的感应信号足以建立沿神经板内侧轴的位置一致性的至少某些方面。相反，没有检测到XASH-3表达的横向条纹，这表明在没有垂直传递信号的情况下，这一方面的前后神经模式丢失或延迟。XASH-3的限制性内侧表达表明，神经板的内侧模式是一个早期事件，在缺乏来自底层中胚层的诱导信号的情况下，这种区域化可以实现。
We have isolated a novel Xenopus homolog of the Drosophila achaete-scute genes, called XASH-3. XASH-3 expression is neural specific and is detected as early as stage 11 1/2, making it one of the earliest markers of neural induction so far described. Moreover, XASH-3 expression within the neural plate is regionally restricted. Transverse bands of XASH-3 mRNA mark discrete positions along the anteroposterior axis, while longitudinal bands mark a discrete position along the mediolateral axis. This latter site of XASH-3 expression appears to demarcate the prospective sulcus limitans, a boundary zone that later separates the functionally distinct dorsal (alar) and ventral (basal) regions of the spinal cord. In sandwich explants lacking any underlying mesoderm, XASH-3 is expressed in longitudinal stripes located lateral to the midline. This provides the first indication that planar or midline-derived inductive signals are sufficient to establish at least some aspects of positional identity along the mediolateral axis of the neural plate. By contrast, the transverse stripes of XASH-3 expression are not detected, suggesting that this aspect of anteroposterior neural pattern is lost or delayed in the absence of vertically passed signals. The restricted mediolateral expression of XASH-3 suggests that mediolateral patterning of the neural plate is an early event, and that this regionalization can be achieved in the absence of inducing signals derived from underlying mesoderm.