Identification of genes regulating sensory neuron genesis and differentiation in the avian dorsal root ganglia.

The dorsal root ganglia (DRG) derive from a population of migrating neural crest cells that coalesce laterally to the neural tube. As the DRG matures, discrete cell types emerge from a pool of differentiating progenitor cells. To identify genes that regulate sensory genesis and differentiation, we have designed screens to identify members from families of known regulatory molecules such as receptor tyrosine kinases, and generated full-length and subtractive cDNA libraries between immature and mature DRG for identifying novel genes not previously implicated in DRG development. Several genes were identified in these analyses that belong to important regulatory gene families. Quantitative PCR confirmed differential expression of candidate cDNAs identified from the subtraction/differential screening. In situ hybridization further validated dynamic expression of several cDNAs identified in our screens. Our results demonstrate the utility of combining specific and general screening approaches for isolating key regulatory genes involved in the genesis and differentiation of discrete cell types and tissues within the classic embryonic chick model system.