Characterization and expression profiling of odorant-binding proteins in Anoplophora glabripennis Motsch.

Abstract In insects, olfaction plays a critical role in locating hosts, recognizing mates, and selecting oviposition sites. The Asian long-horned beetle (Anoplophora glabripennis Motschulsky) feeds on 43 species of trees in 15 families, but its chemosensory mechanisms are poorly understood. Herein, genes encoding 61 odorant-binding proteins (OBPs) were identified from the published genome and our previous A. glabripennis transcriptomic data. To investigate their physiological functions, we performed expression profiling of all Agla OBPs in the antennae, legs, and maxillary palps of both sexes. Phylogenetic analysis clustered A. glabripennis OBPs into four subgroups, comprising 29 Minus-C OBPs, 15 Antennae-binding proteins (ABPIIs), 10 Classic OBPs, and one Plus-C OBP. 12 Agla OBP genes were expressed specifically in antennae, and Agla OBP3, Agla OBP18, Agla OBP21, Agla OBP33, Agla OBP41, Agla OBP45, and Agla OBP47 were particularly highly expressed in male antennae. These proteins may function in the detection of female sex pheromones. Agla OBP23 and Agla OBP44 were preferentially expressed in maxillary palps. Expression profiling suggests that many OBPs may be involved in olfaction and gustation, in addition to carrying hydrophobic molecules. The Agla OBPs family has acquired functional diversity concurrently with functional constraints, and further investigation could provide insight into the roles of OBPs in chemoreception. Highlights • glabripennis OPBs were identified and revised from the genome and previous transcriptomic data. • Phylogenetic analysis clustered A. glabripennis OBPs into four subgroups. • Expression profiling revealed numerous antennae-specific OBPs, especially in males. • OBPs may function in olfaction and gustation, besides carrying hydrophobic molecules. [ABSTRACT FROM AUTHOR]