title: Identification of candidate odorant degrading gene/enzyme systems in the antennal transcriptome of Drosophila melanogaster.
abstract: The metabolism of volatile signal molecules by odorant degrading enzymes (ODEs) is crucial to the ongoing sensitivity and specificity of chemoreception in various insects, and a few specific esterases, cytochrome P450s, glutathione S-transferases (GSTs) and UDP-glycosyltransferases (UGTs) have previously been implicated in this process. Significant progress has been made in characterizing ODEs in Lepidoptera but very little is known about them in Diptera, including in Drosophila melanogaster, a major insect model. We have therefore carried out a transcriptomic analysis of the antennae of D. melanogaster in order to identify candidate ODEs. Virgin male and female and mated female antennal transcriptomes were determined by RNAseq. As with the Lepidoptera, we found that many esterases, cytochrome P450 enzymes, GSTs and UGTs are expressed in D. melanogaster antennae. As olfactory genes generally show selective expression in the antennae, a comparison to previously published transcriptomes for other tissues has been performed, showing preferential expression in the antennae for one esterase, JHEdup, one cytochrome P450, CYP308a1, and one GST, GSTE4. These largely uncharacterized enzymes are now prime candidates for ODE functions. JHEdup was expressed heterologously and found to have high catalytic activity against a chemically diverse group of known ester odorants for this species. This is a finding consistent with an ODE although it might suggest a general role in clearing several odorants rather than a specific role in clearing a particular odorant. Our findings do not preclude the possibility of odorant degrading functions for other antennally expressed esterases, P450s, GSTs and UGTs but, if so, they suggest that these enzymes also have additional functions in other tissues.
authors.affiliation: CSIRO Ecosystems Sciences, Black Mountain, Clunies Ross Street, Canberra, ACT 0200, Australia; Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia.
authors.forename: Faisal
authors.initials: F
authors.lastname: Younus
authors.affiliation: Université Pierre et Marie Curie, Institut d'Ecologie et des Sciences de l'Environnement de Paris, F-75252 Paris, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Chertemps
authors.affiliation: CSIRO Ecosystems Sciences, Black Mountain, Clunies Ross Street, Canberra, ACT 0200, Australia; Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia.
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Pearce
authors.affiliation: CSIRO Ecosystems Sciences, Black Mountain, Clunies Ross Street, Canberra, ACT 0200, Australia.
authors.forename: Gunjan
authors.initials: G
authors.lastname: Pandey
authors.affiliation: Université Pierre et Marie Curie, Institut d'Ecologie et des Sciences de l'Environnement de Paris, F-75252 Paris, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Bozzolan
authors.affiliation: CSIRO Ecosystems Sciences, Black Mountain, Clunies Ross Street, Canberra, ACT 0200, Australia.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Coppin
authors.affiliation: CSIRO Ecosystems Sciences, Black Mountain, Clunies Ross Street, Canberra, ACT 0200, Australia.
authors.forename: Robyn J
authors.initials: RJ
authors.lastname: Russell
authors.affiliation: Université Pierre et Marie Curie, Institut d'Ecologie et des Sciences de l'Environnement de Paris, F-75252 Paris, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Maïbèche-Coisne
authors.affiliation: CSIRO Ecosystems Sciences, Black Mountain, Clunies Ross Street, Canberra, ACT 0200, Australia. Electronic address: john.oakeshott@csiro.au.
authors.forename: John G
authors.initials: JG
authors.lastname: Oakeshott
mesh_terms: D000818:Animals; D057506:Arthropod Antennae / Q000378:metabolism*; D001483:Base Sequence; D004331:Drosophila melanogaster / Q000201:enzymology* / Q000235:genetics*; D004798:Enzymes / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D020869:Gene Expression Profiling; D019476:Insect Proteins / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009812:Odorants; D016133:Polymerase Chain Reaction; D012098:Reproduction / Q000502:physiology; D012737:Sex Factors; D059467:Transcriptome
chemical_list: D004798:Enzymes; D019476:Insect Proteins
keywords: Antenna; Cytochrome P450; Esterase; Odorant degradation; Transcriptome