Identification and Expression Patterns of Anoplophora chinensis (Forster) Chemosensory Receptor Genes from the Antennal Transcriptome

Abstract

The citrus long-horned beetle (CLB), Anoplophora chinensis (Forster) is a destructive native pest in China. Chemosensory receptors including odorant receptors (ORs), gustatory receptors (GRs), and ionotropic receptors (IRs) function to interface the insect with its chemical environment. In the current study, we assembled the antennal transcriptome of A. chinensis by next-generation sequencing. We assembled 44,938 unigenes from 64,787,784 clean reads and annotated their putative gene functions based on gene ontology (GO) and Clusters of Orthologous Groups of proteins (COG). Overall, 74 putative receptor genes from chemosensory receptor gene families, including 53 ORs, 17 GRs, and 4 IRs were identified. Expression patterns of these receptors on the antennae, maxillary and labial palps, and remaining body segments of both male and female A. chinensis were performed using quantitative real time-PCR (RT-qPCR). The results revealed that 23 ORs, 6 GRs, and 1 IR showed male-biased expression profiles, suggesting that they may play a significant role in sensing female-produced sex pheromones; whereas 8 ORs, 5 GRs, and 1 IR showed female-biased expression profiles, indicating that these receptors may be involved in some female-specific behaviors such as oviposition site seeking. These results lay a solid foundation for deeply understanding CLB olfactory processing mechanisms. Moreover, by comparing our results with those from chemosensory receptor studies in other cerambycid species, several highly probable pheromone receptor candidates were highlighted, which may facilitate the identification of additional pheromone and/or host attractants in CLB.

Identification and Expression Profile of Olfactory Receptor Genes Based on Apriona germari (Hope) Antennal Transcriptome

“…In a recent study, 45 ORs were identified from the transcriptome of A. chinensis antennae. The qRT-PCR analysis showed that 41 ORs were highly expressed in the antennae; however, one OR was found to be highly expressed in the maxillary palp and the other three ORs were found to be highly expressed in the male body (Sun et al, 2018). Among the transcriptome of Adelphocoris lineolatus antennae with 57 randomly selected ORs, 26 ORs were found to be specifically expressed in male antennae, 16 ORs were found to be specifically expressed in female antennae, and the other ORs showed complex expression patterns, such as high expression in the body except the head or equal expression in male and female antennae (Xiao et al, 2017).…”

“…The RNA samples were sent to Novogene Co., Ltd. (Beijing, China) for non-reference transcriptome sequencing. cDNA library construction and next-generation sequencing were performed as previously described ( Sun et al, 2018 ). In brief, RNA purity was checked using a NanoPhotometer spectrophotometer (IMPLEN, CA, United States).…”

“…Isolated RNA was reverse-transcribed into cDNA using PrimeScriptTMRT reagent kit with gDNA Eraser (Perfect Real Time, TaKaRa, Beijing, China). qRT-PCR validation was carried out as described in Sun et al (2018) but using different primers ( Supplementary Table S1 ). Three biological replications were carried out for each sample and measured in three technique replications.…”

“…Then, MEGA5 was used to make phylogenetic trees by neighbor-joining method and bootstrap with 1,000 replicates (Saitou and Nei, 1987). The evolutionary tree of candidate ORs was constructed from the protein sequences of Anoplophora chinensis (Sun et al, 2018), Anoplophora glabripennis (Mitchell et al, 2017), Agrilus planipennis (Mitchell et al, 2020), Dendroctonus ponderosae (Andersson et al, 2013), Tribolium castaneum (Engsontia et al, 2008), Anomala corpulenta , Monochamus alternates (Wang et al, 2014), Megacyllene caryae (Mitchell et al, 2012), and Tenebrio molitor (Liu et al, 2015). The evolutionary tree of candidate IRs was built with the aligned protein sequences from A. chinensis, I. typographus, A. glabripennis, D. ponderosae, D. melanogaster (Benton et al, 2009), Phyllotreta striolata (Wu et al, 2016), T. castaneum (Croset et al, 2010), A. corpulenta, M. alternates, and T. molitor.…”

Peer Review #2 of "Sex- and tissue-specific expression of odorant-binding proteins and chemosensory proteins in adults of the scarab beetle Hylamorpha elegans (Burmeister) (Coleoptera: Scarabaeidae) (v0.1)"

“…Manuscript to be reviewed Holotrichia parallela and Anomala corpulenta, other agriculturally important scarab beetle pests (Ju et al, 2014;Yi et al, 2018). These numbers also resembled those obtained from the transcriptomes of other beetle species, such as Tomicus yunnanensis (Zhu, Zhao & Yang, 2012), Ips typographus, Dendroctonus ponderosae (Andersson et al, 2013), Tenebrio molitor (Liu et al, 2015), Brontispa longissima (Bin et al, 2017), Callosobruchus chinensis (Zhang et al, 2017) and Anoplophora chinensis (Sun et al, 2018). Furthermore, BUSCO completeness analysis showed that 98.7% conserved genes were found in this assembly, while the fraction of missing BUSCOs are quite low (1.3%).…”