Identification and functional characterization of a sex pheromone receptor in the silkmoth Bombyx mori

doi:10.1073/pnas.0407596101

Identification and functional characterization of a sex pheromone receptor in the silkmoth Bombyx mori

Divisions of ^*Applied Biosciences and ^††Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa, Kyoto 606-8502, Japan; ^†Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo 135-0064, Japan; ^‡Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Chiba 277-8562, Japan; ^§Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; and ^∥National Institute of Agrobiological Sciences, Owashi 1-2, Tsukuba, Ibaraki 305-8634, Japan

Communicated by Yoshito Kaziro, Kyoto University, Kyoto, Japan, October 13, 2004 (received for review September 15, 2004)

Abstract

Sex pheromones released by female moths are detected with high specificity and sensitivity in the olfactory sensilla of antennae of conspecific males. Bombykol in the silkmoth Bombyx mori was the first sex pheromone to be identified. Here we identify a male-specific G protein-coupled olfactory receptor gene, B. mori olfactory receptor 1 (BmOR-1), that appears to encode a bombykol receptor. The BmOR-1 gene is located on the Z sex chromosome, has an eight-exon/seven-intron structure, and exhibits male-specific expression in the pheromone receptor neurons of male moth antenna during late pupal and adult stages. Bombykol stimulation of Xenopus laevis oocytes expressing BmOR-1 and BmGαq elicited robust dose-dependent inward currents on two-electrode voltage clamp recordings, demonstrating that the binding of bombykol to BmOR-1 leads to the activation of a BmGαq-mediated signaling cascade. Antennae of female moths infected with BmOR-1-recombinant baculovirus showed electrophysiological responses to bombykol but not to bombykal. These results provide evidence that BmOR-1 is a G protein-coupled sex pheromone receptor that recognizes bombykol.

Footnotes

↵ ** To whom correspondence should be addressed. E-mail: touhara{at}k.u-tokyo.ac.jp or nishioka{at}scl.kyoto-u.ac.jp.
↵ ¶ Present address: Department of Biology and Biochemistry, University of Houston, Houston, TX 77204-5513.
Abbreviations: OR, olfactory receptor; BmOR, Bombyx mori OR; PBP, pheromone-binding protein; DIG, digoxigenin; EAG, electroantennogram; HyNPV, hybrid nuclear polyhedrosis virus.
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. AB059431, AB100454, AB105070, and AB101293 for cDNA sequences of BmOR-1, BmOR-2, and BmGαq and genomic DNA sequence of BmOR-1, respectively).
↵ ‡‡ Rogers, M. E., Peterlin, Z. A., Chesler, A. T. & Firestein, S. (2002) Chem. Senses 27, A72 (abstr.).
Freely available online through the PNAS open access option.