title: Extensive molecular differences between anterior- and posterior-half-sclerotomes underlie somite polarity and spinal nerve segmentation.
abstract: BACKGROUND
  The polarization of somite-derived sclerotomes into anterior and posterior halves underlies vertebral morphogenesis and spinal nerve segmentation. To characterize the full extent of molecular differences that underlie this polarity, we have undertaken a systematic comparison of gene expression between the two sclerotome halves in the mouse embryo.
  
  
  RESULTS
  Several hundred genes are differentially-expressed between the two sclerotome halves, showing that a marked degree of molecular heterogeneity underpins the development of somite polarity.
  
  
  CONCLUSIONS
  We have identified a set of genes that warrant further investigation as regulators of somite polarity and vertebral morphogenesis, as well as repellents of spinal axon growth. Moreover the results indicate that, unlike the posterior half-sclerotome, the central region of the anterior-half-sclerotome does not contribute bone and cartilage to the vertebral column, being associated instead with the development of the segmented spinal nerves.
authors.affiliation: Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB3 2DY, UK. dsthughes@gmail.com
authors.forename: Daniel S T
authors.initials: DS
authors.lastname: Hughes
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Keynes
authors.forename: David
authors.initials: D
authors.lastname: Tannahill
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000502:physiology; D002454:Cell Differentiation; D004622:Embryo, Mammalian / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D051379:Mice; D055495:Neurogenesis; D012313:RNA / Q000378:metabolism; D019170:Somites / Q000166:cytology* / Q000196:embryology / Q000378:metabolism; D013127:Spinal Nerves / Q000166:cytology* / Q000196:embryology* / Q000378:metabolism
chemical_list: D012313:RNA