Project description:Assassin bugs (Hemiptera: Heteroptera: Reduviidae) are venomous insects that prey on invertebrates. Assassin bug venom has features in common with venoms from other animals, such as paralysing and lethal activity when injected, and a molecular composition that includes disulfide-rich peptide neurotoxins. Uniquely, this venom also has strong liquefying activity that has been hypothesised to facilitate feeding through the narrow channel of the proboscis—a structure inherited from sap- and phloem-feeding phytophagous hemipterans and adapted during the evolution of Heteroptera into a fang and feeding structure. However, further understanding of the function of assassin bug venom is impeded by the lack of proteomic studies detailing its molecular composition. In addition, the lack of knowledge regarding venoms of predaceous reduviids limits our understanding of how the venoms of the blood-feeding kissing bugs (Reduviidae: Triatominae) evolved to facilitate hematophagy. By using a combined transcriptomic/proteomic approach we show that the venom proteome of the harpactorine assassin bug Pristhesancus plagipennis includes a complex suite of >100 proteins comprising disulfide-rich peptides, CUB-domain proteins, cystatins, putative cytolytic toxins, triabin-like protein, odorant binding protein, serine proteases, catabolic enzymes, putative nutrient-binding proteins, plus eight families of proteins without homology to characterised proteins. Serine proteases, CUB domain proteins and other novel proteins in the 10–16 kDa mass range, as well as putative cytolytic toxins, were the most abundant venom components. Thus, in addition to putative neurotoxins, assassin bug venom includes a high proportion of enzymatic and cytolytic venom components well suited to tissue liquefaction. While some protein families such as lipocalin/triabins occur in the venoms of both predaceous and blood-feeding reduviids, the composition of venoms in these two groups differs markedly. These results provide insights into the venom evolution in the insect suborder Heteroptera.
2017-11-14 | PXD004804 | Pride
Project description:Historical biogeography and plastome evolution of Commelinaceae Mirb.
