title: The generation of vertebral segmental patterning in the chick embryo.
abstract: We have carried out a series of experimental manipulations in the chick embryo to assess whether the notochord, neural tube and spinal nerves influence segmental patterning of the vertebral column. Using Pax1 expression in the somite-derived sclerotomes as a marker for segmentation of the developing intervertebral disc, our results exclude such an influence. In contrast to certain teleost species, where the notochord has been shown to generate segmentation of the vertebral bodies (chordacentra), these experiments indicate that segmental patterning of the avian vertebral column arises autonomously in the somite mesoderm. We suggest that in amniotes, the subdivision of each sclerotome into non-miscible anterior and posterior halves plays a critical role in establishing vertebral segmentation, and in maintaining left/right alignment of the developing vertebral elements at the body midline.
authors.affiliation: Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
authors.forename: Biruntha
authors.initials: B
authors.lastname: Senthinathan
authors.forename: Cátia
authors.initials: C
authors.lastname: Sousa
authors.forename: David
authors.initials: D
authors.lastname: Tannahill
authors.forename: Roger
authors.initials: R
authors.lastname: Keynes
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D002642:Chick Embryo; D054259:Neural Tube / Q000196:embryology / Q000502:physiology; D009672:Notochord / Q000196:embryology / Q000502:physiology; D051761:Paired Box Transcription Factors / Q000378:metabolism; D013127:Spinal Nerves / Q000196:embryology / Q000502:physiology; D013131:Spine / Q000196:embryology* / Q000502:physiology
chemical_list: D051761:Paired Box Transcription Factors; C070835:PAX1 transcription factor