Identification of candidate chemosensory genes by antennal transcriptome analysis in an ectoparasitoid wasp

Abstract

Iseropus (Gregopimpla) kuwanae Vlereck (Hymenoptera: Ichneumonidae) is an ectoparasitoid wasp that attacks the larvae of Rondotia menciana Moore (Lepidoptera: Bombycidae), which is a major pest harming mulberry trees in China. In this study, we obtained the antennal transcriptome dataset of I. kuwanae using RNA‐Seq technology. A total of 22,090,144 clean reads were generated, and 21,802 unigenes were assembled. Among them, 11,546 (52.96%) unigenes were matched in the NCBI non‐redundant protein database (E‐value of 10−5). Moreover, a total of 9,229 (42.33%) and 5,305 (24.33%) unigenes were annotated by Gene Ontology and Clusters of Orthologous Groups of the proteins database respectively. By antennal transcriptome analysis, a total of 122 candidate chemosensory genes were identified, including 11 odorant‐binding protein (OBP) genes, 6 chemosensory protein (CSP) genes, 87 olfactory receptor (OR) genes (including one odorant co‐receptor, Orco), 16 ionotropic receptor genes and two sensory neuron membrane protein genes. RT‐qPCR assays revealed that seven of the 11 IkuwOBPs were predominantly expressed in the antennae of I. kuwanae adults. IkuwOBP4 was highly expressed in the head. IkuwOBP7 and IkuwOBP8 had higher expression levels in the legs. Interestingly, IkuwOBP6 was significantly expressed in both female antennae and ovipositor. The present findings can provide the basis for the subsequent in‐depth exploration of chemosensory mechanisms in I. kuwanae.

Transcriptome Analysis and Identification of Chemosensory Genes in Baryscapus dioryctriae (Hymenoptera: Eulophidae)

“…The number of SNMPs in various species ranges from two (Drosophila melanogaster) [78] to sixteen (Onthophagus taurus) [79]. A total of eight SNMPs were identified in B. dioryctriae, which is much more than the number of SNMPs found in Iseropus kuwanae (2) [16] and M. mediator (2) [80], suggesting that BdioSNMPs have large species expansions among Hymenoptera [81]. In general, numerous studies have found that most insects have two types of SNMPs, namely SNMP1 and SNMP2 [50], and all identified BdioSNMPs belong to the SNMP1 subfamily (Figures 7 and S9).…”

“…High-throughput sequencing technologies have developed rapidly over the past decade [16], and have been widely used to identify chemosensory genes in many insects [17]. In Hymenoptera, an enormous number of chemosensory genes from various species have been reported, and most of them have been identified through antennal transcriptomes.…”

Odorant-Binding Protein 6 Contributes High Binding Affinity to Insecticides in a Parasitic Wasp Meteorus pulchricornis (Hymenoptera: Braconidae)

“…pulchricornis adults and collected with three replicates. Total RNA was isolated using the RNAiso Plus reagent (Takara, Dalian, China), and the reverse transcription was performed using the HiScript III 1st Strand cDNA Synthesis Kit (+gDNA wiper) (Vazyme Biotech Co., Ltd.) on the thermal cycler . The sequence analysis was performed using SignalP-6.0 server (), WebLogo online program (), and MEGA-X software .…”