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A clock‐work somite
Author(s) -
Dale Kim J.,
Pourquié Olivier
Publication year - 2000
Publication title -
bioessays
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.175
H-Index - 184
eISSN - 1521-1878
pISSN - 0265-9247
DOI - 10.1002/(sici)1521-1878(200001)22:1<72::aid-bies12>3.0.co;2-s
Subject(s) - somitogenesis , somite , biology , hox gene , anatomy , vertebrate , neuroscience , paraxial mesoderm , evolutionary biology , microbiology and biotechnology , embryo , genetics , embryogenesis , gene , mesoderm , gene expression , embryonic stem cell
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. ©2000 John Wiley & Sons, Inc.