Expression pattern analysis of odorant‐binding proteins in the pea aphid Acyrthosiphon pisum

Abstract

Odorant-binding proteins (OBPs) are soluble proteins mediating chemoreception in insects. In previous research, we investigated the molecular mechanisms adopted by aphids to detect the alarm pheromone (E)-β-farnesene and we found that the recognition of this and structurally related molecules is mediated by OBP3 and OBP7. Here, we show the differential expression patterns of 5 selected OBPs (OBP1, OBP3, OBP6, OBP7, OBP8) obtained performing quantitative RT-PCR and immunolocalization experiments in different body parts of adults and in the 5 developmental instars, including winged and unwinged morphs, of the pea aphid Acyrthosiphon pisum. The results provide an overall picture that allows us to speculate on the relationship between the differential expression of OBPs and their putative function. The expression of OBP3, OBP6, and OBP7 in the antennal sensilla suggests a chemosensory function for these proteins, whereas the constant expression level of OBP8 in all instars could suggest a conserved role. Moreover, OBP1 and OBP3 are also expressed in nonsensory organs. A light and scanning electron microscopy study of sensilla on different body parts of aphid, in particular antennae, legs, mouthparts, and cornicles-cauda, completes this research providing a guide to facilitate the mapping of OBP expression profiles.

Integrative transcriptomic and genomic analysis of odorant binding proteins and chemosensory proteins in aphids

“…The major alarm pheromone component E βf emitted from the cornicles of aphids (Edwards et al ., ) is recognized by large placoid sensillum neurons, which express OR5 on the sixth antennal segment in A. pisum (Zhang et al ., ); OBP3 and OBP7 are both expressed in the large placoid sensilla in M. persicae (Sun et al ., ) and in the type II trichoid sensilla in A. pisum in the antennae (Biasio et al ., ). OBP3 and/or OBP7 proteins in several aphid species ( A. pisum , S. avenae , M. viciae , N. ribisnigri and R. padi ) have high binding affinities with E βf (Qiao et al ., ; Vandermoten et al ., ; Zhong et al ., ; Fan et al ., ), but the cellular location of all M. persicae OBPs in the antennal sensilla and their binding abilities with E βf are still unknown.…”

“…Our data reveal that MperOBP7 is antennae specific and expressed at a level that is 8.7 times higher in the antennae than in the body ( p < 0.05) (Fig. ), consistent with previous reports of the high binding affinity of this OBP to E βf (Qiao et al ., ; Vandermoten et al ., ; Zhong et al ., ; Fan et al ., ) and its localization in antennal sensilla (Sun et al ., ; Biasio et al ., ). However, OBP3, which was also reported as the E βf binding protein in several aphid species ( A. pisum , S. avenae , M. viciae , N. ribisnigri and R. padi ), is neither antennae specific nor antennae enriched, but is highly expressed in the heads and body in M. persicae (Fig.…”

Identification and Expression Analysis of Candidate Odorant-Binding Protein and Chemosensory Protein Genes by Antennal Transcriptome of Sitobion avenae

“…pisum . SaveOBP6 , AgosOBP6 and ApisOBP6 clustered in a branch with sequences highly expressed in antennae, which strongly suggests that these genes have the same or similar function [21, 55]. The same phenomena can also be found in the branches of SaveOBP7 and ApisOBP7 , SaveOBP9 and AgosOBP9 , SaveOBP10 and AgosOBP10 [21].…”

Identification of pheromone-binding proteins of the maize stem borer, Chilo partellus (Swinhoe, 1885) (Lepidoptera: Crambidae)

“…OBPs are small, water-soluble, extracellular proteins that are located in the fluid surrounding the sensory dendrite and abundantly found in lymph of insect antennae and other sensory organs (De Biasio et al 2015). They are reflected to be vital in insect olfactory perception at various levels but the exact mechanism is still unknown.…”