Identification and motif analyses of candidate nonreceptor olfactory genes of Dendroctonus adjunctus Blandford (Coleoptera: Curculionidae) from the head transcriptome

Abstract

The round-headed pine beetle Dendroctonus adjunctus, whose dispersion and colonization behaviors are linked to a communication system mediated by semiochemicals, is one of the five most critical primary pests in forest ecosystems in Mexico. This study provides the first head transcriptome analysis of D. adjunctus and the identification of the nonreceptor olfactory genes involved in the perception of odors. De novo assembly yielded 44,420 unigenes, and GO annotations were similar to those of antennal transcriptomes of other beetle species, which reflect metabolic processes related to smell and signal transduction. A total of 36 new transcripts of nonreceptor olfactory genes were identified, of which 27 encode OBPs, 7 encode CSPs, and 2 encode SNMP candidates, which were subsequently compared to homologous proteins from other bark beetles and Coleoptera species by searching for sequence motifs and performing phylogenetic analyses. Our study provides information on genes encoding nonreceptor proteins in D. adjunctus and broadens the knowledge of olfactory genes in Coleoptera and bark beetle species, and will help to understand colonization and aggregation behaviors for the development of tools that complement management strategies.

Odorant-Binding and Chemosensory Proteins in Anthonomus eugenii (Coleoptera: Curculionidae) and Their Tissue Expression

“…Transcripts were predominantly annotated with sequences from D. ponderosae , T. castaneum and other related Coleopteran species due to their close evolutionary relationship with A. eugenii and the access to their genomic data [ 24 ]. Similar results have been obtained in other coleopterans studies, where antennae or complete head tissues were sequenced [ 25 , 26 ].…”

“…Transcriptome analyses have been used to identify and functionally characterize non-receptor proteins in other Coleopteran insects [ 26 , 30 , 31 ]. The conserved protein domains represent stable evolutionary units directly related to their tertiary structure, and the function in a protein family [ 32 ].…”

“…The conserved protein domains represent stable evolutionary units directly related to their tertiary structure, and the function in a protein family [ 32 ]. Hence, the criterion to identify AeugOBP and AeugCSP transcripts was through homology search, functional annotation domains, and phylogeny analysis, criteria that have already been used in another research [ 26 , 33 ].…”

“…In each group, motif 4 was highly conserved; however, in two of the eleven architectures, it took up different positions ( Figure S2 ). These architectural changes in highly conserved motifs are also present in Classic and Minus OBP in Dendroctonus adjunctus [ 26 ].…”

Candidate Chemosensory Genes Identified in the Adult Antennae of Sympiezomias velatus and Binding Property of Odorant-Binding Protein 15

“…It is the homolog of D. ponderosae OBP4 which is a Minus-C OBP “tetramer” ( Andersson et al, 2019 ). This novel type of OBP was also identified in three other Curculionidae species: the red palm weevil R. ferrugineus ( Antony et al, 2016 ), the round-headed pine beetle Dendroctonus adjunctus ( Torres-Huerta et al, 2020 ) and the Yunnan pine shoot beetle Tomicus yunnanensis (GFJU01117056) .…”