Ozbudak Ertuğrul M, Pourquié Olivier
Stowers Institute for Medical Research, United States.
Curr Opin Genet Dev. 2008 Aug;18(4):317-23. doi: 10.1016/j.gde.2008.06.007. Epub 2008 Aug 15.
The vertebrate segmentation clock was identified 10 years ago as a molecular oscillator associated with the rhythmic production of embryonic somites. Since then, three major signaling pathways--Notch, FGF, and Wnt--have been shown to be activated periodically during segmentation and proposed to constitute the clockwork of the system. However, recent results from zebrafish embryonic studies demonstrate that Notch signaling is involved in the coupling of oscillations among cells rather than in the pacemaker of the oscillator. Furthermore, genetic analyses in mouse indicate that Wnt and FGF play only a permissive role in the control of the oscillations. Therefore, the nature of the segmentation clock pacemaker still remains elusive.
脊椎动物体节时钟在10年前被确定为一种与胚胎体节节律性产生相关的分子振荡器。从那时起，三种主要信号通路——Notch、FGF和Wnt——已被证明在体节形成过程中周期性激活，并被认为构成了该系统的生物钟机制。然而，斑马鱼胚胎研究的最新结果表明，Notch信号通路参与细胞间振荡的耦合，而非振荡器的起搏器。此外，小鼠的遗传分析表明，Wnt和FGF在振荡控制中仅起允许作用。因此，体节时钟起搏器的本质仍然难以捉摸。
