Transcriptomic and proteomic approach for the identification of Torymus sinensis (Hymenoptera:Torymidae) venom gland proteins

Torymus sinensis Kamijo (Hymenoptera: Torymidae) is a hymenopteran wasp used for the biological control of the Asian chestnut gall wasp, Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae), a globally invasive pest of chestnut, Castanea spp. T. sinensis is a univoltine ectoparasitoid, sometimes exhibiting a prolonged diapause, with a life cycle synchronized with its host. It is the dominant parasitoid species reared from D. kuriphilus galls in its native China and has been introduced into many countries of Asia, North America, and Europe for the gall wasp populations management. We used high-throughput nucleic acid sequencing methods to describe the transcriptome of T. sinesis venom gland. From de novo assembly of all cDNA, 22,874 contigs were obtained and all the sequences were analysed by Blast2GO software for the functional annotation and for the analysis of genes or protein sequences. An overall picture of putative proteins present in the venom gland was provided by transcriptomic information which also gave information on molecular functions and biological processes. Venom components were also analysed by proteomic methodologies and fractionated by SDS-PAGE electrophoresis. Protein bands were excised from the gel and, after tryptic digestion, were identified by mass spectrometry (MALDI TOF/TOF and LC-MS/MS). The comparison between the protein sequences identified by the MaxQuant software and the transcriptomic data, allowed the identification of numerous putative proteins of T. sinensis venom. Molecular identification and subsequent characterization of these molecules will allow to understand the role played by venom in the induction and regulation of the pathological syndrome observed in parasitized hosts.