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An Expressed Sequence Tag collection from the male antennae of the Noctuid moth Spodoptera littoralis: a resource for olfactory and pheromone detection research.

Legeai F, Malpel S, Montagné N, Monsempes C, Cousserans F, Merlin C, François MC, Maïbèche-Coisné M, Gavory F, Poulain J, Jacquin-Joly E - BMC Genomics (2011)

Bottom Line: 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.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.

View Article: PubMed Central - HTML - PubMed

Affiliation: 1IRISA, Equipe Symbiose, Campus Universitaire de Beaulieu, 35042 Rennes Cedex, France.

ABSTRACT

Background: 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.

Results: 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.

Conclusions: 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.

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Phylogenetic tree of candidate olfactory receptors (ORs) from S. littoralis, B. mori and other lepidopterans, including pheromone receptor (PR) and OR2 (D. melanogaster OR83b orthologue) clades. The S. littoralis translated unigenes are shown in bold. Accession numbers are given in additional file 6. The tree was constructed as in figure 4. Bmor, Bombyx mori; Dind, Diaphania indica; Epos, Epiphyas postvittana; Hvir, Heliothis virescens; Msep, Mythimna separata; Pxyl, Plutella xylostella.
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Figure 5: Phylogenetic tree of candidate olfactory receptors (ORs) from S. littoralis, B. mori and other lepidopterans, including pheromone receptor (PR) and OR2 (D. melanogaster OR83b orthologue) clades. The S. littoralis translated unigenes are shown in bold. Accession numbers are given in additional file 6. The tree was constructed as in figure 4. Bmor, Bombyx mori; Dind, Diaphania indica; Epos, Epiphyas postvittana; Hvir, Heliothis virescens; Msep, Mythimna separata; Pxyl, Plutella xylostella.

Mentions: A phylogenetic analysis was conducted with the putative SlitORs and other lepidopteran OR sequences, including the annotated BmorORs (accession numbers provided in additional file 6) (Figure 5). At least one lepidopteran orthologue could be assigned to the majority of the putative SlitORs, only five of them having no counterpart. Without surprise, the highly conserved SlitOR2 (EZ981047) clustered with other OR2 sequences (D. melanogaster OR83b orthologues) (Figure 5). In correlation with the BLAST results, the four candidate SlitPRs clustered in the lepidopteran PR clade, supporting their annotation.


An Expressed Sequence Tag collection from the male antennae of the Noctuid moth Spodoptera littoralis: a resource for olfactory and pheromone detection research.

Legeai F, Malpel S, Montagné N, Monsempes C, Cousserans F, Merlin C, François MC, Maïbèche-Coisné M, Gavory F, Poulain J, Jacquin-Joly E - BMC Genomics (2011)

Phylogenetic tree of candidate olfactory receptors (ORs) from S. littoralis, B. mori and other lepidopterans, including pheromone receptor (PR) and OR2 (D. melanogaster OR83b orthologue) clades. The S. littoralis translated unigenes are shown in bold. Accession numbers are given in additional file 6. The tree was constructed as in figure 4. Bmor, Bombyx mori; Dind, Diaphania indica; Epos, Epiphyas postvittana; Hvir, Heliothis virescens; Msep, Mythimna separata; Pxyl, Plutella xylostella.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3045336&req=5

Figure 5: Phylogenetic tree of candidate olfactory receptors (ORs) from S. littoralis, B. mori and other lepidopterans, including pheromone receptor (PR) and OR2 (D. melanogaster OR83b orthologue) clades. The S. littoralis translated unigenes are shown in bold. Accession numbers are given in additional file 6. The tree was constructed as in figure 4. Bmor, Bombyx mori; Dind, Diaphania indica; Epos, Epiphyas postvittana; Hvir, Heliothis virescens; Msep, Mythimna separata; Pxyl, Plutella xylostella.
Mentions: A phylogenetic analysis was conducted with the putative SlitORs and other lepidopteran OR sequences, including the annotated BmorORs (accession numbers provided in additional file 6) (Figure 5). At least one lepidopteran orthologue could be assigned to the majority of the putative SlitORs, only five of them having no counterpart. Without surprise, the highly conserved SlitOR2 (EZ981047) clustered with other OR2 sequences (D. melanogaster OR83b orthologues) (Figure 5). In correlation with the BLAST results, the four candidate SlitPRs clustered in the lepidopteran PR clade, supporting their annotation.

Bottom Line: 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.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.

View Article: PubMed Central - HTML - PubMed

Affiliation: 1IRISA, Equipe Symbiose, Campus Universitaire de Beaulieu, 35042 Rennes Cedex, France.

ABSTRACT

Background: 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.

Results: 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.

Conclusions: 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.

Show MeSH
Related in: MedlinePlus