Transcriptional programs controlled by NGF signaling in developing mouse dorsal root ganglia neurons

During embryogenesis, nociceptive sensory neurons of the dorsal root ganglia depend intimately on Nerve Growth Factor (NGF) for neuronal survival, maturation and target innervation. NGF is a secreted molecular signal synthesized by neuronal target tissues. In developing nociceptors, NGF engages the receptor tyrosine kinase TrkA to activate a gene transcriptional program involving the regulation of hundreds of transcripts. To identify NGF-dependent genes in developing mouse nociceptors, we have designed and performed two separate microarray screens to compare gene expression profiles of DRG neurons either with or lacking NGF signaling. For the first screen comparing DRGs of Bax−/− and Ngf−/−; Bax−/− mice, DRGs were dissected and pooled from E14.5 Ngf−/−; Bax−/− and Bax−/− embryos. Total RNA was extracted and directly subjected to microarray analysis. For the second screen comparing mouse DRG explants grown in the presence or absence of NGF, E13.5 mouse DRG explants were cultured for two days with 50 ng/ml of either NGF or NT3. Total RNA was extracted and then subjected to microarray analysis.