Sensory Neuron Fates Are Distinguished by a Transcriptional Switch that Regulates Dendrite Branch Stabilization

• Published in: Neuron (Cambridge, Mass.) Vol. 79; no. 2; pp. 266 - 280
• Main Authors: Smith, Cody J., O’Brien, Timothy, Chatzigeorgiou, Marios, Spencer, W. Clay, Feingold-Link, Elana, Husson, Steven J., Hori, Sayaka, Mitani, Shohei, Gottschalk, Alexander, Schafer, William R., Miller, David M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 24-07-2013; Elsevier Limited
• Subjects: Animals; Animals, Genetically Modified; Caenorhabditis elegans; Cell adhesion & migration; Cloning; Defects; Dendrites - physiology; Dendritic Spines - physiology; Drosophila; Experiments; Gene expression; Glycerol; Insects; Morphology; Neurogenesis - physiology; Neurons; Sensory Receptor Cells - physiology; Transcription factors; Transcription Factors - physiology; Transcription, Genetic - physiology
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/j.neuron.2013.05.009

Sensory neurons adopt distinct morphologies and functional modalities to mediate responses to specific stimuli. Transcription factors and their downstream effectors orchestrate this outcome but are incompletely defined. Here, we show that different classes of mechanosensory neurons in C. elegans are distinguished by the combined action of the transcription factors MEC-3, AHR-1, and ZAG-1. Low levels of MEC-3 specify the elaborate branching pattern of PVD nociceptors, whereas high MEC-3 is correlated with the simple morphology of AVM and PVM touch neurons. AHR-1 specifies AVM touch neuron fate by elevating MEC-3 while simultaneously blocking expression of nociceptive genes such as the MEC-3 target, the claudin-like membrane protein HPO-30, that promotes the complex dendritic branching pattern of PVD. ZAG-1 exercises a parallel role to prevent PVM from adopting the PVD fate. The conserved dendritic branching function of the Drosophila AHR-1 homolog, Spineless, argues for similar pathways in mammals.
•A transcriptional switch distinguishes alternative mechanosensory neuron fates•AHR-1/Spineless limits sensory neuron dendritic branching•Sensory neuron identity is defined by different levels of MEC-3 expression•A membrane protein, HPO-30/Claudin, stabilizes dendrite branches
Responses to external stimuli are defined by genetic programs that specify sensory neuron architecture and function. Smith et al. show that nociceptor and touch neuron fates are distinguished by a transcriptional switch that regulates expression of the dendritic branching protein HPO-30/Claudin.