A highly conserved candidate chemoreceptor expressed in both olfactory and gustatory tissues in the malaria vector Anopheles gambiae

Anopheles gambiae is a highly anthropophilic mosquito responsible for the majority of malaria transmission in Africa. The biting and host preference behavior of this disease vector is largely influenced by its sense of smell, which is presumably facilitated by G protein-coupled receptor signaling Takken, W. Vosshall, L. B., Amrein, H., Morozov, P. S., Rzhetsky, A. & Axel, R. (1999) Cell 96, 725-736. We have observed AgOr7 expression in olfactory and gustatory tissues in adult An. gambiae and during several stages of the mosquitoes' development. Within the female adult peripheral chemosensory system, antiserum against the AgOR7 polypeptide labels most sensilla of the antenna and maxillary palp as well as a subset of proboscis sensilla. Furthermore, AgOR7 antiserum labeling is observed within the larval antenna and maxillary palpus. These results are consistent with a role for AgOr7 in both olfaction and gustation in An. gambiae and raise the possibility that AgOr7 orthologs may also be of general importance to both modalities of chemosensation in other insects.