Identification and Characterization of Chemosensory Receptors in the Pheromone Gland-Ovipositor of Spodoptera frugiperda (J. E. Smith)

Abstract

Chemoreception by moth ovipositors has long been suggested, but underlying molecular mechanisms are mostly unknown. To reveal such chemosensory systems in the current study, we sequenced and assembled the pheromone gland-ovipositor (PG-OV) transcriptome of females of the fall armyworm, Spodoptera frugiperda, a pest of many crops. We annotated a total of 26 candidate chemosensory receptor genes, including 12 odorant receptors (ORs), 4 gustatory receptors (GRs), and 10 ionotropic receptors (IRs). The relatedness of these chemosensory receptors with those from other insect species was predicted by phylogenetic analyses, and specific genes, including pheromone receptors, ORco, CO2 receptors, sugar receptors, and IR co-receptors, were reported. Although real-time quantitative-PCR analyses of annotated genes revealed that OR and IR genes were mainly expressed in S. frugiperda antennae, two ORs and two IRs expressed in antennae were also highly expressed in the PG-OV. Similarly, GR genes were mainly expressed in the proboscis, but two were also highly expressed in the PG-OV. Our study provides the first large-scale description of chemosensory receptors in the PG-OV of S. frugiperda and provides a foundation for exploring the chemoreception mechanisms of PG-OV in S. frugiperda and in other moth species.

Molecule characterization of chemosensory and metabolism-related genes in the proboscis of Athetis lepigone

“…Normally, odor signals are primarily detected by cephalic organs, including the antennae, proboscises, maxillary palps, and abdominal organs comprised of wings and legs. Similar results have also been reported for Spodoptera frugiperda (Sun et al, 2022).…”

“…Sensory sensilla neurons located on the proboscis and maxillary palps of both larvae and adults play a crucial role in detecting volatile and nonvolatile sensory cues. These neurons directly interact with odors or saccharides, facilitating activities such as locating host plants, feeding, egg-laying and mating, or identifying suitable oviposition sites (Shankar et al, 2016;Guo P. et al, 2018;Sun et al, 2022;Guo et al, 2023). This sensory characteristic frequently employed in the surveillance and management of varies of crop pests.…”

Chemosensory Receptor Expression in the Abdomen Tip of the Female Codling Moth, Cydia pomonella L. (Lepidoptera: Tortricidae)

“…Utilizing RNA-sequencing and transcriptomic analyses, some ORs plus the odorant receptor co-receptor (Orco), which functions as an OR trafficking chaperone and ion channel [23,24] were identified in ovipositor tissue of Sesamia nonagrioides [20]; two ORs, but not Orco, were identified in PG-OV tissue of Chilo suppressalis [21]; two ORs plus Orco, as well as two GRs and nine IRs, were identified in ovipositor tissue of M. sexta [17]. More recently, 12 ORs, 4 GRs, and 10 IRs have been found expressed in the PG-OV tissues of Spodoptera littoralis, including PRs, Orco, CO 2 receptors, sugar receptors, and IR co-receptors [25], and a complex pattern of all these chemosensory receptors, along with other gene families known to function in chemosensory processes, was found expressed in the PG-OV of Helicoverpa zea [26]. In another report, the PG-OV tissue of H. assulta unveiled 22 ORs, 6 GRs, and 13 IRs [18].…”

Odorant receptors for floral- and plant-derived volatiles in the yellow fever mosquito, Aedes aegypti (Diptera: Culicidae)

“…Arguably, olfaction is the most important sensory modality, conveying the ability to sense volatile chemical cues over large distances [1][2][3]. Olfaction is responsible for many arthropod behaviors, including host-seeking [4,5], oviposition [6,7], mate selection [8,9], and nectar foraging [10,11]. Odorant receptors (ORs) comprise the most prominent family of volatile odor detectors encoded in mosquito genomes [12].…”