Virally Mediated Misexpression of Hoxc-6 in the Cervical Mesoderm Results in Spinal Nerve Truncations

AbstractMembers of theHoxgene family appear to regulate anterior–posterior (A–P) regionalization in embryos. Genetic manipulation of numerousHoxgenes in the developing trunk region of vertebrates results in changes in the morphology of individual vertebrae. We have used virally mediated, targeted misexpression to ectopically express the Hoxc-6 protein in chick embryos.Hoxc-6has an anterior border of expression at the cervical–thoracic transition in tetrapods. Misexpression of this gene in the cervical mesoderm of chick embryos results in dramatic truncations of the ventral rami of cervical spinal nerves in the infected region. These data point to a role forHoxc-6in axon guidance, and suggest that in addition to regulating proliferative rates,Hoxgene expression provides positional information utilized in producing domain-specific extracellular signals