Farnesol-Detecting Olfactory Neurons in Drosophila

The Journal of Neuroscience : The Official Journal of the Society for Neuroscience (Impact Factor: 6.34). 03/2014; 34(11):3959-68. DOI: 10.1523/JNEUROSCI.4582-13.2014
Source: PubMed


We set out to deorphanize a subset of putative Drosophila odorant receptors expressed in trichoid sensilla using a transgenic in vivo misexpression approach. We identified farnesol as a potent and specific activator for the orphan odorant receptor Or83c. Farnesol is an intermediate in juvenile hormone biosynthesis, but is also produced by ripe citrus fruit peels. Here, we show that farnesol stimulates robust activation of Or83c-expressing olfactory neurons, even at high dilutions. The CD36 homolog Snmp1 is required for normal farnesol response kinetics. The neurons expressing Or83c are found in a subset of poorly characterized intermediate sensilla. We show that these neurons mediate attraction behavior to low concentrations of farnesol and that Or83c receptor mutants are defective for this behavior. Or83c neurons innervate the DC3 glomerulus in the antennal lobe and projection neurons relaying information from this glomerulus to higher brain centers target a region of the lateral horn previously implicated in pheromone perception. Our findings identify a sensitive, narrowly tuned receptor that mediates attraction behavior to farnesol and demonstrates an effective approach to deorphanizing odorant receptors expressed in neurons located in intermediate and trichoid sensilla that may not function in the classical "empty basiconic neuron" system.

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Available from: Chun-Chieh Lin, Dec 05, 2015
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    • "Or23a and Or83c as well as Or2a, Or19a and Or43a were initially described as being expressed in the trichoid sensilla at2 and at3 [7]. Ronderos et al.[32] describe Or23a and Or83c OSNs as being housed in an intermediate sensillum and thus rename at2 to ai2. "
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    ABSTRACT: Odors elicit complex patterns of activated olfactory sensory neurons. Knowing the complete olfactome, i.e. responses in all sensory neurons for all odorants, is desirable to understand olfactory coding. The DoOR project combines all available Drosophila odorant response data into a single consensus response matrix. Since its first release many studies were published: receptors were deorphanized and several response profiles were expanded. In this study, we add to the odor-response profiles for four odorant receptors (Or10a, Or42b, Or47b, Or56a). We deorphanize Or69a, showing a broad response spectrum with the best ligands including 3-hydroxyhexanoate, alpha-terpineol, 3-octanol and linalool. We include these datasets into DoOR, and provide a comprehensive update of both code and data. The DoOR project has a web interface for quick queries (, and a downloadable, open source toolbox written in R, including all processed and original datasets. DoOR now gives reliable odorant-responses for nearly all Drosophila olfactory responding units, listing 693 odorants, for a total of 7381 data points.
    Full-text · Article · Oct 2015
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    • "79 tested at low concentrations , probably reflecting those typically encountered by the 176 insect in their environment ( Mathew et al . , 2013 ) . Dedicated OSN circuits have also been 177 identified in Drosophila for geosmin ( DmOr56a ( Stensmyr et al . , 2012 ) ) , citrus terpenes 178 ( DmOr19a ( Dweck et al . , 2013 ) ) , farnesol ( DmOr83c ( Ronderos et al . , 2014 ) ) , polyphenolics 179 ( Dweck et al . , 2015b ) , and for pheromones ( DmOr47b , DmOr67d , and DmOr88a ( Dweck et 180 al . , 2015a ; Ha and Smith , 2006 ) ) . Boyle et al . ( 2013 ) used a computational approach to 181 explore the pharmacophore space of OrXs predicting ~ 500 new activators and inhibitors for 182 each of nine DmOrXs . "
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    Full-text · Article · Sep 2015 · Insect Biochemistry and Molecular Biology
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    • "sed from the peal of citrus fruit ( Ronderos et al . , 2014 ) . In contrast to the OR19a pathway , activation of farnesol - sensitive OSNs induces attraction . This might suggest two distinct pathways of which one ( via OR83c ) is essential for citrus attraction and the other ( via OR19a ) for citrus oviposition preference ( Dweck et al . , 2013 ; Ronderos et al . , 2014 ) . However , the ecological significance of farnesol and the OR83c pathway was recently questioned by Mansourian and Stensmyr ( 2015 ) . Farnesol is present in minor quantities only in some citrus varieties , and the fact that the projection neurons from the glomerulus that receives input from Or83c expressing OSNs terminate in the bra"
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    Full-text · Article · May 2015
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