Int J Biol Sci 2013; 9(5):481-495. doi:10.7150/ijbs.6109 This issue Cite
Research Paper
1. INRA, UMR 1272, Physiologie de l'Insecte : Signalisation et Communication, route de Saint-Cyr, F-78026 Versailles cedex, France;
2. IRD, UR 072, c/o CNRS, Laboratoire Evolution, Génomes et Spéciation, 91198 Gif-sur-Yvette Cedex, France;
3. IRISA, équipe GenScale, Campus universitaire de Beaulieu, 35042 Rennes cedex, France;
4. UPMC - Université Paris 6, UMR 1272 Physiologie de l'Insecte : Signalisation et Communication, 7 quai Saint-Bernard, F-75252 Paris cedex 05, France;
5. Université Paris-Sud 11, 91405 Orsay Cedex, France;
6. CNRS UPR9034, Laboratoire Evolution, Génomes et Spéciation, 91198 Gif-sur-Yvette Cedex, France.
7. IRD, UR 072, c/o ICIPE, NSBB Project, PO Box 30772-00100, Nairobi, Kenya.
The stemborer Sesamia nonagrioides is an important pest of maize in the Mediterranean Basin. Like other moths, this noctuid uses its chemosensory system to efficiently interact with its environment. However, very little is known on the molecular mechanisms that underlie chemosensation in this species. Here, we used next-generation sequencing (454 and Illumina) on different tissues from adult and larvae, including chemosensory organs and female ovipositors, to describe the chemosensory transcriptome of S. nonagrioides and identify key molecular components of the pheromone production and detection systems. We identified a total of 68 candidate chemosensory genes in this species, including 31 candidate binding-proteins and 23 chemosensory receptors. In particular, we retrieved the three co-receptors Orco, IR25a and IR8a necessary for chemosensory receptor functioning. Focusing on the pheromonal communication system, we identified a new pheromone-binding protein in this species, four candidate pheromone receptors and 12 carboxylesterases as candidate acetate degrading enzymes. In addition, we identified enzymes putatively involved in S. nonagrioides pheromone biosynthesis, including a ∆11-desaturase and different acetyltransferases and reductases. RNAseq analyses and RT-PCR were combined to profile gene expression in different tissues. This study constitutes the first large scale description of chemosensory genes in S. nonagrioides.
Keywords: chemosensory receptors, pheromone biosynthesis, transcriptome, next-generation sequencing, Sesamia nonagrioides.