Identification of the main components of Torymus sinensis venom by an integrated transcriptomic and proteomic approach

Torymus sinensis Kamijo (Hymenoptera: Torymidae) is a hymenopteran wasp utilized 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 perfectly 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 management of the gall wasp populations. We used high-throughput nucleic acid sequencing methods to describe the transcriptome of T. sinesis venom gland. From de novo assembly of all cDNA 22874 contigs were obtained, all sequences were analysed using Blast2GO software, a bioinformatic "tool" used for the annotation and functional analysis of genes or protein sequences. The transcriptomic information provided an overall picture of the putative proteins present in the venom gland and information on molecular functions, biological processes and putative cellular compartments. The proteomic analysis was carried out on the components of the venom, 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 using the MASCOT software and the transcriptomic data, allowed to identify numerous putative proteins of T. sinensis venom. Molecular identification and subsequent characterization of these molecules will be essential to understand the role played by venom in the induction and regulation of the pathological syndrome observed in parasitized hosts.