An Expressed Sequence Tag collection from the male antennae of the Noctuid moth Spodoptera littoralis: a resource for olfactory and pheromone detection research
1 IRISA, équipe Symbiose, Campus universitaire de Beaulieu, 35042 Rennes Cedex, France
2 INRA, UMR-A 1272 INRA-UPMC PISC Physiologie de l'Insecte: Signalisation et Communication, route de Saint-Cyr, 78026 Versailles Cedex, France
3 INRA, UMR 1231 INRA-Université Montpellier II BIVI, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France
4 Genoscope, Centre National de Séquençage, 2 rue Gaston Crémieux, BP 191, F-91057 Evry Cedex, France
5 UMR 5548, University of Bourgogne, 6 bd Gabriel, F-21000 Dijon, France
6 Department of Neurobiology, University of Massachusetts Medical School, 01604, Worcester, MA, USA
BMC Genomics 2011, 12:86 doi:10.1186/1471-2164-12-86Published: 29 January 2011
Nocturnal insects such as moths are ideal models to study the molecular bases of olfaction that they use, among examples, for the detection of mating partners and host plants. Knowing how an odour generates a neuronal signal in insect antennae is crucial for understanding the physiological bases of olfaction, and also could lead to the identification of original targets for the development of olfactory-based control strategies against herbivorous moth pests. Here, we describe an Expressed Sequence Tag (EST) project to characterize the antennal transcriptome of the noctuid pest model, Spodoptera littoralis, and to identify candidate genes involved in odour/pheromone detection.
By targeting cDNAs from male antennae, we biased gene discovery towards genes potentially involved in male olfaction, including pheromone reception. A total of 20760 ESTs were obtained from a normalized library and were assembled in 9033 unigenes. 6530 were annotated based on BLAST analyses and gene prediction software identified 6738 ORFs. The unigenes were compared to the Bombyx mori proteome and to ESTs derived from Lepidoptera transcriptome projects. We identified a large number of candidate genes involved in odour and pheromone detection and turnover, including 31 candidate chemosensory receptor genes, but also genes potentially involved in olfactory modulation.
Our project has generated a large collection of antennal transcripts from a Lepidoptera. The normalization process, allowing enrichment in low abundant genes, proved to be particularly relevant to identify chemosensory receptors in a species for which no genomic data are available. Our results also suggest that olfactory modulation can take place at the level of the antennae itself. These EST resources will be invaluable for exploring the mechanisms of olfaction and pheromone detection in S. littoralis, and for ultimately identifying original targets to fight against moth herbivorous pests.