Abstract
Olfactory signaling is initiated by interactions between odorants and olfactory receptors. We show that the C. elegans
odr-10 gene is likely to encode a receptor for the odorant diacetyl.
odr-10 mutants have a specific defect in chemotaxis to diacetyl, one of several odorants detected by the AWA olfactory neurons.
odr-10 encodes a predicted seven transmembrane domain receptor; a green fluorescent protein–tagged Odr-10 protein is localized to the AWA sensory cilia.
odr-10 expression is regulated by
odr-7, a transcription factor implicated in AWA sensory specification. Expression of
odr-10 from a heterologous promoter directs behavioral responses to diacetyl, but not to another odorant detected by the AWA neurons. These results provide functional evidence for a specific interaction between an olfactory receptor protein and its odorant ligand.