Bugs use their sense of smell to find food and mates and to avoid predators. New research suggests that a single gene may be behind all that smelling in a broad range of insect species.
Many insects detect scents through odor receptors along their antennae. When a particular scent molecule matches the shape of an odor receptor, as a key fits in a lock, nerves transmit information about that smell to the brain.
The proteins that make up odor receptors can vary significantly, giving different smelling capabilities even to individual insects within a species. Despite this variability, Leslie Vosshall and her colleagues of Rockefeller University in New York City reported last year that the protein encoded by a single odor-receptor gene, known as Or83b, works in conjunction with almost every odor receptor in fruit flies. When the scientists engineered flies that lacked the gene, the insects were unable to smell.
Because genes corresponding to Or83b turn up in a variety of insect species, Vosshall’s team investigated whether the genes fill a similar role in overseeing smell.
First, the researchers isolated genes analogous to Or83b from three other species: the medfly (Ceratitis capitata), a mosquito (Anopheles gambiae), and a moth (Helicoverpa zea). They inserted these genes into fruit flies engineered to lack their own Or83b gene. Tests showed that the gene transplants gave the fruit fly recipients a normal sense of smell.
The results, published in the Feb. 22 Current Biology, suggest that these genes have retained the same function among even distantly related species.
Vosshall says that researchers may eventually apply these findings to developing new insect repellents that work by interfering with Or83b.