Anatomy and Embryology

, Volume 188, Issue 3, pp 239–245

The ventralizing effect of the notochord on somite differentiation in chick embryos


  • Beate Brand-Saberi
    • Institute of Anatomy, University of Freiburg
  • Cecilia Ebensperger
    • Institute of Anatomy, University of Freiburg
  • Jörg Wilting
    • Institute of Anatomy, University of Freiburg
  • Rudi Balling
    • Department of Developmental BiologyMax-Planck-Institute of Immunobiology
  • Bodo Christ
    • Institute of Anatomy, University of Freiburg
Original Articles

DOI: 10.1007/BF00188215

Cite this article as:
Brand-Saberi, B., Ebensperger, C., Wilting, J. et al. Anat Embryol (1993) 188: 239. doi:10.1007/BF00188215


The dorso-ventral pattern formation of the somites becomes manifest by the formation of the epithelially organized dorsal dermomyotome and the mesenchymal ventrally situated sclerotome. While the dermomyotome gives rise to dermis and muscle, the sclerotome differentiates into cartilage and bone of the axial skeleton. The onset of muscle differentiation can be visualized by immunohistochemistry for proteins associated with muscle contractility, e.g. desmin. The sclerotome cells and the epithelial ventral half of the somite express Pax-1, a member of a gene family with a sequence similarity to Drosophila paired-box-containing genes. In the present study, changes of Pax-1 expression were studied after grafting an additional notochord into the paraxial mesoderm region. The influence of the notochord and the floor-plate on dermomyotome formation and myotome differentiation has also been investigated. The notochord is found to exert a ventralizing effect on the establishment of the dorso-ventral pattern in the somites. Notochord grafts lead to a suppression of the formation and differentiation of the dorsal somitic derivatives. Simultaneously, a widening of the Pax-1-expressing domain in the sclerotome can be observed. In contrast, grafted roof-plate and aorta do not interfere with dorso-ventral patterning of the somitic derivatives.

Key words

NotochordSomitePax-1MyogenesisChick embryo
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Copyright information

© Springer-Verlag 1993