A Novel Role for the Zinc-Finger Transcription Factor EGL-46 in the Differentiation of Gas-Sensing Neurons in Caenorhabditis Elegans

Oxygen (O-2) and carbon dioxide (CO2) provoke distinct olfactory behaviors via specialized sensory neurons across metazoa. In the nematode C. elegans, the BAG sensory neurons are specialized to sense changes in both O-2 and CO2 levels in the environment. The precise functionality of these neurons is specified by the coexpression of a membrane-bound receptor-type guanylyl cyclase GCY-9 that is required for responses to CO2 upshifts and the soluble guanylyl cyclases GCY-31 and GCY-33 that mediate responses to downshifts in O-2. Expression of these gas-sensing molecules in the BAG neurons is partially, although not completely, controlled by ETS-5, an ETS-domain-containing transcription factor, and EGL-13, a Sox transcription factor. We report here the identification of EGL-46, a zinc-finger transcription factor, which regulates BAG gas-sensing fate in partially parallel pathways to ETS-5 and EGL-13. Thereby, three conserved transcription factors collaborate to ensure neuron type-specific identity features of the BAG gas-sensing neurons.