Sniffing out insect control.

• Position: Entomology - How insects smell

How do insects smell? Badly, according to a study, if they lack a certain kind of protein critical to their unique ability to detect and interpret pheromones--the insect equivalent of "smelling." Researchers at the University of Texas Southwestern Medical Center, Dallas, have discovered how an olfactory binding protein links incoming pheromone signals and specific nerve cells in an insect's brain, which in turn translates those signals. Pheromones are chemical signals given off by animals that, when detected by others of the same species, mediate a variety of behaviors, such as feeding, mating, and colonizing.

Scientists have discovered that fruit flies lacking a certain protein are unable to process pheromone signals properly into the appropriate behavior. Research by Dean Smith, associate professor of pharmacology, is the first to link pheromone-induced behavior directly with the activity of olfactory binding proteins, or OBPs, and may aid in the development of new insect control methods.

The nerve cells, or neurons, in insects responsible for picking up on pheromone signals have been studied for decades, as have pheromones themselves. However, the biochemical mechanism by which pheromones and other odorants selectively activate those sensory neurons is poorly understood. "We've known about OBPs for 20 years, but, until now, their function and significance was unclear," indicates Smith, who works in the Center for Basic Neuroscience. Olfactory binding proteins are produced by non-neural cells and...