Zuñiga Nikole R, Stoeckli Esther T
Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
J Dev Biol. 2017 Feb 8;5(1):2. doi: 10.3390/jdb5010002.
As reflected by the term morphogen, molecules such as Shh and Wnts were identified based on their role in early development when they instruct precursor cells to adopt a specific cell fate. Only much later were they implicated in neural circuit formation. Both in vitro and in vivo studies indicated that morphogens direct axons during their navigation through the developing nervous system. Today, the best understood role of Shh and Wnt in axon guidance is their effect on commissural axons in the spinal cord. Shh was shown to affect commissural axons both directly and indirectly via its effect on Wnt signaling. In fact, throughout neural circuit formation there is cross-talk and collaboration of Shh and Wnt signaling. Thus, although the focus of this review is on the role of Shh in neural circuit formation, a separation from Wnt signaling is not possible.
正如形态发生素这个术语所反映的那样，诸如 Sonic Hedgehog（Shh）和 Wnt 等分子是根据它们在早期发育中的作用而被识别出来的，当时它们指导前体细胞采用特定的细胞命运。直到很久以后，人们才发现它们与神经回路形成有关。体外和体内研究均表明，形态发生素在轴突穿越发育中的神经系统进行导航时引导轴突。如今，Shh 和 Wnt 在轴突导向中最被理解的作用是它们对脊髓连合轴突的影响。研究表明，Shh 通过对 Wnt 信号传导的影响，直接和间接地影响连合轴突。事实上，在整个神经回路形成过程中，Shh 和 Wnt 信号传导存在相互作用和协作。因此，尽管本综述的重点是 Shh 在神经回路形成中的作用，但与 Wnt 信号传导分离是不可能的。
