From head to tail: links between the segmentation clock and antero-posterior patterning of the embryo.
Periodic production of somites along the anteroposterior axis of the vertebrate body involves a molecular oscillator, the 'segmentation clock', which can be visualized through the periodic activation of genes linked to the Notch pathway. Recent findings show that oscillations initiate at gastrula stages and point to a role for FGF signaling in positioning the segmental boundaries. This clock also controls aspects of spatio-temporal Hox gene activation thus ensuring a perfect match between segment boundary position and future regional identity of the somites.
Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, Missouri 64110, USA.
Julien
J
Dubrulle
Olivier
O
Pourquié
D000818:Animals; D001683:Biological Clocks / Q000502:physiology*; D019521:Body Patterning / Q000502:physiology*; D002642:Chick Embryo / Q000166:cytology / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D005346:Fibroblast Growth Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D005775:Gastrula; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D019170:Somites / Q000166:cytology* / Q000378:metabolism; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D005346:Fibroblast Growth Factors