Protein Discovery: Combined Transcriptomic and Proteomic Analyses of Venom from the Endoparasitoid Cotesia chilonis (Hymenoptera: Braconidae).

David Stanley,Zhi-Chao Yan,Shi-Jiao Xiong,Qi Fang,Shi-Yu Gan,Zi-Wen Teng,Xuan Chen,Gong-Yin Ye,Gang Xu

doi:10.3390/toxins9040135

Abstract

Many species of endoparasitoid wasps provide biological control services in agroecosystems. Although there is a great deal of information on the ecology and physiology of host/parasitoid interactions, relatively little is known about the protein composition of venom and how specific venom proteins influence physiological systems within host insects. This is a crucial gap in our knowledge because venom proteins act in modulating host physiology in ways that favor parasitoid development. Here, we identified 37 possible venom proteins from the polydnavirus-carrying endoparasitoid Cotesia chilonis by combining transcriptomic and proteomic analyses. The most abundant proteins were hydrolases, such as proteases, peptidases, esterases, glycosyl hydrolase, and endonucleases. Some components are classical parasitoid venom proteins with known functions, including extracellular superoxide dismutase 3, serine protease inhibitor and calreticulin. The venom contains novel proteins, not recorded from any other parasitoid species, including tolloid-like proteins, chitooligosaccharidolytic β-N-acetylglucosaminidase, FK506-binding protein 14, corticotropin-releasing factor-binding protein and vascular endothelial growth factor receptor 2. These new data generate hypotheses and provide a platform for functional analysis of venom components.

Highlights

Most hymenopteran parasitoids are very small insects that produce minute quantities of venom, which helps explain why research in this area is limited to about 70 of the approximately 300,000 venom-producing species, mainly stinging wasps, bees, and ants [1,2]
We found that Cotesia chilonis venom inhibits host humoral immunity and it synergizes the immunosuppressive effects of calyx fluid [42]
Transcriptome sequence data were generated from two cDNA libraries, a venom gland library (VG) and an adult female carcass library (FAC)

Summary

Introduction

Most hymenopteran parasitoids are very small insects that produce minute quantities of venom, which helps explain why research in this area is limited to about 70 of the approximately 300,000 venom-producing species, mainly stinging wasps, bees, and ants [1,2]. Beyond understanding the mechanisms of host/parasitoid relationships, research into parasitoid venom has the potential to uncover a wealth of biomolecules of value in agriculture and pharmacology [1,3,4]. Parasitoid venoms are highly diverse among species [2]. Venoms from ectoparasitoids result in short- to long-term paralysis/lethargy in hosts [5,6]. Ectoparasitoid venoms alter host biology, including immunosuppression, developmental arrest, apoptosis, stress response, and regulating metabolism [7,8]. Endoparasitoid venoms induce transient paralysis, as seen in two ichneumonids, Pimpla hypochondriaca (Hymenoptera: Ichneumonidae) [9], and Pimpla turionellae (Hymenoptera: Ichneumonidae) [10], as well as in four braconid wasps, including Asobara tabida (Hymenoptera: Braconidae) [11], two Binodoxys species (Hymenoptera: Braconidae) [12], and Chelonus inanitus (Hymenoptera: Braconidae) [13]

Methods

Results

Conclusion