Drosophila Gr5a encodes a taste receptor tuned to trehalose

doi:10.1073/pnas.2135339100

Drosophila Gr5a encodes a taste receptor tuned to trehalose

^*Imperial College London, Wye Campus, Kent TN25 5AH, United Kingdom; and ^†Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520

Abstract

Recent studies have suggested that Drosophila taste receptors are encoded by a family of G protein-coupled receptor genes comprising at least 56 members. One of these genes, Gr5a, has been shown by genetic analysis to be required by the fly for behavioral and sensory responses to a sugar, trehalose. Here, we show that Gr5a is expressed in neurons of taste sensilla located on the labellum and legs. Expression is observed in most if not all labellar sensilla and suggests that many taste neurons express more than one receptor. We demonstrate by heterologous expression in a Drosophila S2 cell line that Gr5a encodes a receptor tuned to trehalose. This is the first functional expression of an invertebrate taste receptor.

Footnotes

↵ ‡ To whom correspondence should be addressed. E-mail: john.carlson{at}yale.edu.
This paper results from the Arthur M. Sackler Colloquium of the National Academy of Sciences, ”Chemical Communication in a Post-Genomic World,” held January 17-19, 2003, at the Arnold and Mabel Beckman Center of the National Academies of Science and Engineering in Irvine, CA.