Identification and Comparative Expression Profiles of Candidate Olfactory Receptors in the Transcriptomes of the Important Egg Parasitoid Wasp Anastatus japonicus Ashmead (Hymenoptera: Eupelmidae)

Anastatus japonicus Ashmead is an egg parasitoid wasp important for the biological control of fruit crop pests. The olfaction of parasitoids is crucial to searching for host pests in fruit crops. In this study, we sequenced and analyzed the antennal and abdominal transcriptomes of A. japonicus to better understand the olfactory mechanisms in this species. A total of 201 putative olfactory receptor genes were identified, including 184 odorant receptors (ORs) and 17 ionotropic receptors (IRs). Then, we assayed the tissue-specific and sex-biased expression profiles of those genes based on the transcriptional levels. In total, 165 ORs and 15 IRs had upregulated expression in the antennae. The expression levels of 133 ORs, including odorant receptor co-receptor (AjapORco), and 10 IRs, including AjapIR8a, were significantly different between the female and male antennae. Our results provide valuable information for further studies on the molecular mechanisms of the olfactory system in A. japonicus.

Automated summary

In this study, the antennal and abdominal transcriptomes of Anastatus japonicus Ashmead were sequenced and analyzed to understand the olfactory mechanisms in this species. A total of 201 putative olfactory receptor genes, including 184 odorant receptors (ORs) and 17 ionotropic receptors (IRs), were identified. Tissue-specific and sex-biased expression profiles of these genes were assayed, revealing significant differences in expression levels between female and male antennae. These findings provide valuable insights into the molecular mechanisms of the olfactory system in A. japonicus.