Heterologous investigation of metabotropic and ionotropic odorant receptors in ab3A neurons of Drosophila melanogaster

Abstract

In insects, antennal ionotropic receptors (IRs) and odorant receptors (ORs) are among the main sensors of olfactory cues. To functionally characterize the subunits from these receptors, the use of ab3A neurons from transgenic Drosophila melanogaster represented one of the most powerful tools, allowing the identification of ligands (deorphanization) and decrypting their pharmacological properties. However, further investigation is needed to shed light on possible metabotropic functionalities behind insect olfactory receptors and test potentials from the up-to-now-used empty neuronal systems to express subunits belonging to variegate receptor classes. In this project, we adopted the most updated system of Drosophila ab3A empty neurons to test various olfactory receptors, ranging from human ORs working as metabotropic G-protein coupled receptors to insect ionotropic IRs and ORs. Testing transgenic Drosophila expressing human ORs into ab3A neurons by single sensillum recording did not result in an OR response to ligands, but it rather re-established neuronal spiking from the empty neurons. When transgenic D. melanogaster expressed ionotropic IRs and ORs, both heterologous and cis-expressed IRs were non-functional, but the Drosophila suzukii OR19A1 subunit responded to a wide asset of ligands, distinguishing phasic or tonic compound-dependent effects. Despite the use of Drosophila ab3A neurons to test the activation of some metabotropic and ionotropic receptor subunits resulted non-functional, this study deorphanized a key OR of D. suzukii demonstrating its binding to alcohols, ketones, terpenes, and esters.

Keywords

metabotropic receptors (mGluRs); ionotropic receptors; heterologous expression; transgenic Drosophila melanogaster; empty ab3A neurons; single sensillum recording; functional characterization of chemoreceptors; deorphanization

Published in

Frontiers in Molecular Biosciences
2024, volume: 10, article number: 1275901
Publisher: FRONTIERS MEDIA SA

SLU Authors

• Pettersson, Johan

  • Cultivation Unit, Swedish University of Agricultural Sciences
    

• Cattaneo, Alberto Maria

  • Department of Plant Protection Biology, Swedish University of Agricultural Sciences
    
  • University of Florida
  • University of Lausanne

UKÄ Subject classification

Biochemistry and Molecular Biology

Publication identifier

• DOI: https://doi.org/10.3389/fmolb.2023.1275901

Permanent link to this page (URI)

https://res.slu.se/id/publ/128681