Dale K J, Pourquié O
Laboratoire de Génétique et de Physiologie du Développement (LGPD), Developmental Biology Institute of Marseille (IBDM), CNRS-INSERM-Université de la méditerranée-AP de Marseille, Marseille, France.
Bioessays. 2000 Jan;22(1):72-83. doi: 10.1002/(SICI)1521-1878(200001)22:1<72::AID-BIES12>3.0.CO;2-S.
Somites are transient structures which represent the most overt segmental feature of the vertebrate embryo. The strict temporal regulation of somitogenesis is of critical developmental importance since many segmental structures adopt a periodicity based on that of the somites. Until recently, the mechanisms underlying the periodicity of somitogenesis were largely unknown. Based on the oscillations of c-hairy1 and lunatic fringe RNA, we now have evidence for an intrinsic segmentation clock in presomitic cells. Translation of this temporal periodicity into a spatial periodicity, through somite formation, requires Notch signaling. While the Hox genes are certainly involved, it remains unknown how the metameric vertebrate axis becomes regionalized along the antero-posterior (AP) dimension into the occipital, cervical, thoracic, lumbar, and sacral domains. We discuss the implications of cell division as a clock mechanism underlying the regionalization of somites and their derivatives along the AP axis. Possible links between the segmentation clock and axial regionalization are also discussed. BioEssays 22:72-83, 2000.
体节是脊椎动物胚胎中最明显的分段特征的短暂结构。体节发生的严格时间调控对于发育至关重要，因为许多分段结构都基于体节的周期性呈现出周期性。直到最近，体节发生周期性的潜在机制在很大程度上仍不为人知。基于c-hairy1和lunatic fringe RNA的振荡，我们现在有证据表明在体节前体细胞中存在一个内在的分割时钟。通过体节形成将这种时间周期性转化为空间周期性需要Notch信号传导。虽然Hox基因肯定参与其中，但脊椎动物的分节轴如何沿着前后（AP）维度区域化为枕骨、颈椎、胸椎、腰椎和骶骨区域仍不清楚。我们讨论了细胞分裂作为一种时钟机制在体节及其衍生物沿AP轴区域化中的意义。还讨论了分割时钟与轴向区域化之间可能的联系。《生物论文》22:72 - 83，2000年。
