Neuronal cell identity is established during development and must be maintained throughout an animal's life (Fishell and Heintz 2013). Transcription factors critical for establishing neuronal identity can be required for maintaining it (Deneris and Hobert 2014). Post-transcriptional regulation also plays an important role in neuronal differentiation (Bian and Sun 2011), but its role in maintaining cell identity is less established. To better understand how post-transcriptional regulation might contribute to cell identity, we examined the proprioceptive neurons in the dorsal root ganglion (DRG), a highly specialized sensory neuron class, with well established properties that distinguish them from other neurons in the ganglion. By conditionally ablating Dicer in mice, using parvalbumin (Pvalb)-driven cre recombinase, we impaired post-transcriptional regulation in the proprioceptive sensory neuron population. KO animals display a progressive form of ataxia at the beginning of the fourth postnatal week that is accompanied by a cell-death within the DRG. Before cell-loss, expression profiling shows a reduction of proprioceptor specific genes and an increased expression of non-proprioceptive genes normally enriched in other ganglion neurons. Furthermore, although central connections of these neurons are intact, the peripheral connections to the muscle are functionally impaired. Post-transcriptional regulation is therefore necessary to retain the transcriptional identity and support functional specialization of the proprioceptive sensory neurons.
- Cell Identity
- Copyright © 2016, Journal of Neurophysiology