Mating‐based regulation and ligand binding of an odorant‐binding protein support the inverse sexual communication of the greater wax moth, Galleria mellonella (Lepidoptera: Pyralidae)

Abstract

In moths, sex pheromones play a key role in mate finding. These chemicals are transported in the antennae by odorant-binding proteins (OBPs). Commonly, males encounter conspecific females; therefore, several OBPs are male-biased. Less is known, however, about how the olfactory system of moths has evolved toward inverse sexual communication, ie where females seek males. Therefore, the objective of this study was to identify the profile of OBPs and their expression patterns in the bee hive pest, Galleria mellonella, a moth that uses inverse sexual communication. Here, OBP-related transcripts were identified by an RNA Sequencing (RNA-Seq) approach and analysed through both Reverse Transcription Polymerase Chain Reaction (RT-PCR) in different tissues and quantitative real-time PCR for two states, virgin and postmating. Our results indicate that G. mellonella has 20 OBPs distributed amongst different tissues. Interestingly, 17 of the 20 OBPs were significantly down-regulated after mating in females, whereas only OBP7 was up-regulated. By contrast, 18 OBP transcripts were up-regulated in males after mating. Additionally, binding assays and structural simulations showed general odorant-binding protein 2 (GOBP2) was able to bind sex pheromone components and analogues. These findings suggest a possible role of OBPs, especially GOBPs, in the inverse sexual communication of G. mellonella, with gene expression regulated as a response to mating.

Identification and Expression Patterns of Chemosensory Genes in Male and Female Wax Moths, Galleria mellonella

“…More recently, Zhao et al (2019) performed transcriptome sequencing on G. mellonella antennae and identified several chemosensory genes (e.g., 46 ORs, 25 IRs, 22 OBPs, 20 CSPs and 2 SNMPs). Similarly, Lizana et al (2020) also identified 20 OBP genes from this moth species. However, the number of OBPs in G. mellonella is relatively lesser compared to other Pyralid moths, such as C. suppressalis, Ostrinia furnacalis, and Cnaphalocrocis medinalis, with 23, 26 and 26 OBP genes, respectively (Liu et al, 2017;Zhang et al, 2015b;Cao et al, 2014).…”

Analysis of glutathione-S-transferases from larvae of Galleria mellonella (Lepidoptera, Pyralidae) with potential alkaloid detoxification function

“…The greater wax moth, G. mellonella , is a global beehive pest that has remained without either effective or environmentally friendly control methods. Recent advances have focused on the olfactory system of G. mellonella adults to understand its chemical ecology ( Zhao et al, 2019 ; Lizana et al, 2020 ). However, less focus has been given to larval stages.…”

“…An antennal transcriptome reported by Zhao et al (2019) and retrieved from Bioproject PRJNA616199 (SRA study SRP254512) as well as larval transcriptome from 454 Sequencing data within the Bioproject PRJEB2452 (SRA study ERP000555) were used. Finally, an assembled adult head transcriptome from our laboratory and reported in Lizana et al (2020) was used. Homology searches were performed using a manually built amino acid database in FASTA format for GSTs from moths, such as B. mori , Helicoverpa assulta, and Amyelois transitella .…”

“…More recently, an aggregation pheromone (i.e., decanal) has been reported as a promising semiochemical to control G. mellonella larvae. However, these findings rely on olfactory mechanisms that have recently started to be revealed only for G. mellonella adults ( Zhao et al, 2019 ; Aburto et al, 2020 ; Lizana et al, 2020 ). Overall, none of the previous methods have resulted in the efficient control of G. mellonella .…”

Erratum: Mating‐based regulation and ligand binding of an odorant‐binding protein support the inverse sexual communication of the greater wax moth, Galleria mellonella (Lepidoptera: Pyralidae)

“…In the article by Lizana et al . (2020), a duplicated image was detected post‐publication. During the preparation of the article Fig.…”