VIRALLY MEDIATED MISEXPRESSION OF HOXC-6 IN THE CERVICAL MESODERM RESULTS IN SPINAL NERVE TRUNCATIONS

Members of the Hox gene family appear to regulate anterior-posterior ( A-P) regionalization in embryos. Genetic manipulation of numerous Hox genes in the developing trunk region of vertebrates results in changes in the morphology of individual vertebrae. We have used virally media ted, targeted misexpression to ectopically express the Hoxc-6 protein in chick embryos. Hoxc-6 has an anterior border of expression at the c ervical-thoracic transition in tetrapods. Misexpression of this gene i n the cervical mesoderm of chick embryos results in dramatic truncatio ns of the ventral rami of cervical spinal nerves in the infected regio n. These data point to a role for Hoxc-6 in axon guidance, and suggest that in addition to regulating proliferative rates, Hox gene expressi on provides positional information utilized in producing domain-specif ic extracellular signals. (C) 1996 Academic Press, Inc.