|Walker, William - Swedish University Of Agricultural Sciences|
|Gonzalez, Francisco - Swedish University Of Agricultural Sciences|
|Witzgall, Peter - Swedish University Of Agricultural Sciences|
Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/8/2016
Publication Date: 3/23/2016
Publication URL: http://handle.nal.usda.gov/10113/62767
Citation: Walker, W.B., Gonzalez, F., Garczynski, S.F., Witzgall, P. 2016. The chemosensory receptors of codling moth Cydia pomonella – expression in larvae and adults. Scientific Reports. doi: 10.1038/srep23518.
Interpretive Summary: Codling moth is a key insect pest of apple, pear and walnut worldwide, and new methods that are safe and effective are needed to control it. Scientists at the USDA-ARS, Yakima Agricultural Laboratory in Wapato, WA, Max Planck Institute for Chemical Ecology in Jena, Germany and at the Swedish University of Agricultural Sciences, Alnarp, Sweden used genomic technology to identify 99 chemosensory receptors, some of which are involved in mate and host plant finding behaviors. The results produced in this study make available a strong base of information that will provide insights in codling moth behavioral physiology and ecology, and may thus lead to the further development of biorational pest control strategies that involve behavioral manipulation.
Technical Abstract: Background: Codling moth, Cydia pomonella, is a worldwide key pest of apple and pear. Behavior-modifying semiochemicals are successfully used and are being further developed for environmentally safe control of codling moth. The chemical senses, olfaction and gustation, play critically important roles in the life history of insects and other animals. Vital behaviors, such as food, mate and host seeking, as well as predator and parasitoid avoidance, are all strongly guided by chemical signals. Chemosensory receptor proteins, including odorant receptors (ORs), gustatory receptors (GRs) and ionotropic receptors (IRs), are expressed in the membranes of chemosensory neurons and (function to) interface the insect with its chemical environment. Identification and expression analysis of chemosensory receptors leads to a more complete understanding the chemical ecology of codling moth and other insect herbivores. Results: We have produced an Illumina-based RNA-Seq olfactory transcriptome from neonate larval head tissue and the antennae of male and female moths, affording a qualitative and quantitative analysis of the chemosensory receptor gene repertoire of codling moth, C. pomonella. We have identified 58 ORs, 20 GRs and 21 IRs, and provide a revised nomenclature which is consistent with homologous sequences in related species. Importantly, we have identified several OR gene transcripts that display sex-biased or sex-specific expression in adult moths. We have also identified larval-enriched transcripts from the OR and GR families that may relate to larval behavior. Conclusions: We demonstrate that RNA-Seq methodology is viable for qualitative and quantitative expression analysis of insect chemosensory receptor transcripts. Identification of sex-biased and larval-enriched receptors suggests a molecular basis for sexually dimorphic and stage-specific olfactory-based behaviors, respectively. Collectively, this information serves as a foundation for further investigations of the chemical senses of codling moth at the molecular level. The results presented here will produce insights in codling moth behavioral physiology and ecology, and may thus lead to the further development of biorational control strategies against this insect pest.