Molecular probes for the development and plasticity of neural crest derivatives

We have isolated cDNA clones for several mRNAs expressed in sympathetic neurons but not in adrenal chromaffin cells, two neural crest derivatives thought to share a common precursor. The tissue specificity, developmental expression, and hormonal regulation of these genes have been characterized using Northern blot and in situ hybridization analysis. We find that these mRNAs are independently regulated in development rather than synchronously induced. Our evidence also implicates Nerve Growth Factor (NGF) in the induction of one of these genes in postmigratory crest cells. Two of these genes become induced in mature chromaffin cells, which express a neuronal morphology in response to NGF. These results support the idea that the phenotypic plasticity of neural crest derivatives reflects a common precursor, the multipotentiality of which is sustained through terminal differentiation.