Identification of Male- and Female-Specific Olfaction Genes in Antennae of the Oriental Fruit Fly (Bactrocera dorsalis)

Abstract

The oriental fruit fly (Bactrocera dorsalis) is a species of tephritid fruit fly, endemic to Southeast Asia but also introduced to many regions of the US, and it is one of the major pest species with a broad host range of cultivated and wild fruits. Although males of B. dorsalis respond strongly to methyl eugenol and this is used for monitoring and estimating populations, the molecular mechanism of the oriental fruit fly olfaction has not been elucidated yet. Therefore, in this project, using next generation sequencing technologies, we sequenced the transcriptome of the antennae of male and female adults of B. dorsalis. We identified a total of 20 candidate odorant binding proteins (OBPs), 5 candidate chemosensory proteins (CSPs), 35 candidate odorant receptors (ORs), 12 candidate ionotropic receptors (IRs) and 4 candidate sensory neuron membrane proteins (SNMPs). The sex-specific expression of these genes was determined and a subset of 9 OR genes was further characterized by qPCR with male and female antenna, head, thorax, abdomen, leg and wing samples. In the male antennae, 595 genes showed a higher expression, while 128 genes demonstrated a higher expression in the female antennae. Interestingly, 2 ORs (BdorOR13 and BdorOR14) were highly and specifically expressed in the antennae of males, and 4 ORs (BdorOR13, BdorOR16, BdorOR18 and BdorOR35) clustered with DmOR677, suggesting pheromone reception. We believe this study with these antennae-enriched OBPs, CSPs, ORs, IRs and SNMPs can play an important role in the detection of pheromones and general odorants, and so in turn our data improve our current understanding of insect olfaction at the molecular level and provide important information for disrupting the behavior of the oriental fruit fly using chemical communication methods.

Identification and expression profiles of novel odorant binding proteins and functional analysis of OBP99a in Bactrocera dorsalis

“…Additionally, the host regulation of OBPs at the transcription level was analyzed, and the possible roles of OBP99a in host location and mating behavior were investigated using RNAi approaches. Notably, the qRT‐PCR results revealed that these genes were abundantly expressed in nonantenna organs, which contrasts previous studies in B. dorsalis that focused on OBP identification and expression profiles to identify the antennae‐enriched OBPs (Liu, Smagghe, Lei, & Wang, ; Wu et al., ).…”

Identification and characterization of the distinct expression profiles of candidate chemosensory membrane proteins in the antennal transcriptome of Adelphocoris lineolatus (Goeze)

“…Generally, there are two conserved groups of SNMP1 and SNMP2 in Lepidoptera and Diptera. In recent years, three SNMPs have been identified in Spodoptera exigua (Liu et al ., ) and four SNMPs in Bactrocera dorsalis (Liu et al ., ), suggesting that there were distinct evolutionary strategies in gene duplication events of SNMP subfamilies, and resulting in the loss of SNMPs in some insect species.…”

“…Generally, there are two conserved groups of SNMP1 and SNMP2 in Lepidoptera and Diptera. In recent years, three SNMPs have been identified in Spodoptera exigua and four SNMPs in Bactrocera dorsalis (Liu et al, 2016), suggesting that there were distinct evolutionary strategies in gene duplication events of SNMP subfamilies, and resulting in the loss of SNMPs in some insect species. Odorant receptors are always expressed in the dendrites of antennal sensilla and, as biotransducers, facilitate the conversion of the chemical message to an electrical signal (Zhang & L€ ofstedt, 2015).…”

Identification of odorant-binding proteins in the reproductive system of Athetis dissimilis using transcriptome analysis

“…OBPs are more accessible targets for research, considering they are small, soluble, stable and easier to manipulate and modify. About exact functions of the OBPs are unclear, but it is widely believed that their function is to capture and transfer outside odorants to ORs located on the membranes of ORNs [8,11,32]. 8,11,38 Insect OBPs are present on the antennae where they execute odorant functions [11,[33][34][35][36].…”