Sex- and tissue-specific expression of odorant-binding proteins and chemosensory proteins in adults of the scarab beetle Hylamorpha elegans (Burmeister) (Coleoptera: Scarabaeidae)

Abstract

In this study, we addressed the sex- and tissue-specific expression patterns of odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) in Hylamorpha elegans (Burmeister), an important native scarab beetle pest species from Chile. Similar to other members of its family, this scarab beetle exhibit habits that make difficult to control the pest by conventional methods. Hence, alternative ways to manage the pest populations based on chemical communication and signaling (such as disrupting mating or host finding process) are highly desirable. However, developing pest-control methods based on chemical communication requires to understand the molecular basis for pheromone recognition/chemical perception in this species. Thus, with the aim of discovering olfaction-related genes, we obtained the first reference transcriptome assembly of H. elegans. We used different tissues of adult beetles from males and females: antennae and maxillary palps, which are well known for embedded sensory organs. Then, the expression of predicted odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) was analyzed by qRT-PCR. In total, 165 transcripts related to chemoperception were predicted. Of these, 16 OBPs, including one pheromone-binding protein (PBP), and four CSPs were successfully amplified by qRT-PCR. All of these genes were differentially expressed in the sensory tissues with respect to the tibial tissue that was used as a control. The single predicted PBP found was highly expressed in the antennal tissues, particularly in males, while several OBPs and one CSP showed male-biased expression patterns, suggesting that these proteins may participate in sexual recognition process. In addition, a single CSP was expressed at higher levels in female palps than in any other studied condition, suggesting that this CSP would participate in oviposition process. Finally, all four CSPs exhibited palp-biased expression while mixed results were obtained for the expression of the OBPs, which were more abundant in the palps than in the antennae. These results suggest that these chemoperception proteins would be interesting novel targets for control of H. elegans, thus providing a theoretical basis for further studies involving new pest control methods.

Antennal Transcriptome Evaluation and Analysis for Odorant-Binding Proteins, Chemosensory Proteins, and Suitable Reference Genes in the Leaf Beetle Pest Diorhabda rybakowi Weise (Coleoptera: Chrysomelidae)

“…The number of OBPs in D. rybakowi was lower than previously reported, but eleven OBPs were found in Podabrus annulatus, which was the same as in previous reports [54]. Furthermore, upon comparing CSP numbers in D. rybakowi with those in other Coleoptera species, there were differences in twelve CSP genes in H. axyridis and C. bowringi, respectively [11,12], but similar CSP genes were found in Hylamorpha elegans (four CSPs), A. eugenii (six CSPs) [14], and C. maculatus (seven CSPs) [13,55]. The differences in the number of OBPs and CSPs may be due to the variation in the chemical environment of different species, where these species have evolved for a long time [56].…”

Revisiting trends in morphology of antennal sensilla in scarabaeoid beetles

“…Also, among other Pleurosticts (i.e., the paraphyletic "Melolonthinae", Cetoniinae, and Rutelinae), there are some quite speciespoor lineages and slowly diverging lineages with "modern" sensilla (Table 1). Hence, we see the here presented hypotheses and results as a starting point to refine our phylogenetical understanding of the Scarabaeoidea but most of all to open up for a molecular characterization of antennal sensilla functionality, regarding pheromones and odor binding proteins of sensilla (e.g., Leal 2001;Nikonov et al 2002;González-González et al 2019) to improve our understanding of their chemical communication, ecology and evolution.…”

Expression Pattern and Ligand Binding Characteristics Analysis of Chemosensory Protein SnitCSP2 from Sirex nitobei

“…Li et al found that PrapCSP20 was enriched in the testes of Pieris rapae and probably participated in the reproduction of insects [42]. A variety of CSPs were found in insects such as Hylamorpha elegans (HeleCSP3) [50], Ophraella ommuna Lesage (Ocom-CSP12) [51], and Scopula subpunctaria Herrich-Schaeffer (SubCSP1/16) [52] that may be involved in insect egg-laying behavior. Therefore, we cannot exclude that SnitCSP2 plays other roles in S. nitobei.…”