THE C-ELEGANS GENE ODR-7 ENCODES AN OLFACTORY-SPECIFIC MEMBER OF THE NUCLEAR RECEPTOR SUPERFAMILY

Olfactory discrimination is achieved through the action of olfactory n eurons with diverse chemical specificities. In C. elegans, at least te n different types of chemosensory neurons respond to different chemica ls. The odr-7 gene is required for the function of one pair of chemose nsory neurons called AWA neurons. odr-7 null mutants fail to respond t o all odorants detected by the AWA neurons, while a missense mutation in odr-7 causes a specific defect in one odorant response. odr-7 encod es a protein with similarity to the DNA-binding domain of the nuclear receptor genes; it is expressed predominantly in the AWA neurons. odr- 7 may regulate the expression of olfactory signaling molecules that de fine a single type of olfactory neuron.