Odorant-Binding Proteins and Chemosensory Proteins in Pheromone Detection and Release in the Silkmoth Bombyx mori

Abstract

The genome of the silkmoth Bombyx mori contains 44 genes encoding odorant-binding proteins (OBPs) and 20 encoding chemosensory proteins (CSPs). In this work, we used a proteomic approach to investigate the expression of proteins of both classes in the antennae of adults and in the female pheromone glands. The most abundant proteins found in the antennae were the 4 OBPs (PBP, GOBP1, GOBP2, and ABP) and the 2 CSPs (CSP1 and CSP2) previously identified and characterized. In addition, we could detect only 3 additional OBPs and 2 CSPs, with clearly different patterns of expression between the sexes. Particularly interesting, on the other hand, is the relatively large number of binding proteins (1 OBP and 7 CSPs) expressed in the female pheromone glands, some of them not present in the antennae. In the glands, these proteins could be likely involved in the solubilization of pheromonal components and their delivery in the environment.

Molecular Characterization and Differential Expression of Olfactory Genes in the Antennae of the Black Cutworm Moth Agrotis ipsilon

“…CSPs that are expressed in the pheromone gland of the cabbage armyworm M. brassicae can bind sex pheromone analogs, which suggests that these CSPs may play a role in pheromone capture [15]. In Heliothis virescens and B. mori, CSPs are all detected in the pheromone gland [66]–[68]. This observation suggests the possible involvement of these proteins in carrying and releasing sex pheromones, as demonstrated for the antennal OBPs and CSPs.…”

Antennal transcriptome analysis of the Asian longhorned beetle Anoplophora glabripennis

“…In addition, sex-biased expression of some CSPs was detected; for instance, GmmCSP2 was expressed at lower levels in male antennae than in female antennae50, and different sex-specific patterns of CSP1 and CSP2 expression have been observed in B. mori 48. In addition to the six olfactory tissues, CSPs are also expressed in female pheromone glands, e.g., 7 CSPs in B. mori , and this might reflect their role in the solubilization of pheromone components and their delivery to the environment48. In addition, CSP expression in different growth phases has also been investigated.…”

Identification of candidate chemosensory genes in the antennal transcriptome of Tenebrio molitor (Coleoptera: Tenebrionidae)

“…CSPs, unlike OBPs, contain four positionally conserved cysteine residues that form two disulfide bridges (Pelosi et al, 2014). Some CSPs are distributed in the antennae sensillar lymph where they bind host volatiles and pheromone constituents (Dani et al, 2011;Zhang et al, 2014). Other CSPs are highly expressed in non-olfactory tissues, including pheromone glands, legs and wings, suggesting they participate in other physiological processes (Jacquin-Joly et al, 2001;Pelletier and Leal, 2011).…”