Chemosensory receptors in tsetse flies provide link between chemical and behavioural ecology

Abstract

Tsetse flies survive in a variety of environments across tropical Africa, often rising to large numbers, despite their low birth rate of one offspring every seven to nine days. They use olfactory receptors to process chemical signals in their environments to find food, escape from predators, and locate suitable larviposition sites. We discuss the identification of odorant and gustatory receptors in Glossina morsitans morsitans and the role genomics could play in management of nuisance insects.

Keywords: chemosensory proteins; ecology; genomics; gustatory receptors; odorant receptors; tsetse flies.

Figure I

Schematic representation of insect olfaction. (A) shows the antennae of tsetse, with extensive branching to which sensilla (little hairs) are attached. Sensilla details are shown, with the structure depicting pores through which odorants enter. (B) shows how odorants are transported through sensillum fluid to the olfactory receptors in the neurons. Two olfactory receptors are necessary for activation – a specific receptor and a common receptor. Odorant binding triggers a signal transduction cascade that results in neuronal firing and brain-centered perception of the odorant, which triggers the appropriate behavioral response. For additional details, see [12]. Photo of tsetse fly head courtesy of Geoff Attardo, Yale School of Public Health; graphics by Brian Mwashi, icipe.