1. ) The first venomous crustacean
We recently described the first venomous crustacean, a blind cave dwelling remipede species of the crustacean class Remipedia. The project is still proceeding, first results show that remipedes evolved a unique venom within arthropods and inject a rattle snake like proteinaceous cocktail including several smaller neurotoxin components. We approach our questions applying methods from three different scientific fields, molecular transcriptomics, functional morphology and recently also proteomics characterizing single proteins.
Molecular transcriptomics: we use Next Generation Sequencing platforms (454 titanium and Illumina) to identify putative toxin transcripts and to analyse the venom composition and expression patterns.
Functional Morphology: Synchrotron µ-Computer Tomography was used to reconstruct three-dimensionally the venom delivery system.
Proteomics: Currently protein data is generated including spectrometry and activity analyses.
The graphics show the cephalothorax synchrotron scan of the remipede Speleonectes tulumensis (A + B) and the muscle arrangement to facilitate the injection of the venom (C). The venom composition and toxin components are shown in the pie chart based on 454 Titanium data (D). mxu = maxillula, cep = cephalothorax, rv = venom reservoir, dc = venom ductus, gl = venom gland.
2.) Comparative studies on toxins of neglected venomous taxa
Venoms are composed of highly specific components referred to as toxins, which are mainly recruited by duplication events of proteins that are non-venomous. Consequently, venoms are composed of proteins that evolved highly convergent.
Including studies of new toxins of neglected venomous taxa like remiepeds, centipedes, polychaetes and several insect groups into comparative analyeses improves our understanding of the process and mechanism of venom evolution in general. However, every unknown toxin, in partidular neurotoxins, bear the potential for innovative, applied approaches, such as insecticide or drug development.
Polychaete venoms: One major result is a first study on the venom of the polychaete Glycera, a bloodworm, which revealed a highly complex toxin cocktail including several neurotoxins. The graphics show such an animal (A) and the final part of its proboscis with the four jaws that grap the prey (B).
Further, remipede crustaceans play a key role as the most likely taxon that is closest related to hexapods within pancrustaceans. To understand the evolution of venom proteins in hexapods, like e.g. venom allergen 5 (CRISP family), the venom toxins identified in remipedes are crucial. Interestingly toxins and venom composition of many insect species that are known to be venomous are understudied or unknown.
3.) Fly venom evolution
Robber flies inhabit many vicious predatory species on other venomous insects or even potent predators like dragonflies and known since over a century to paralyze such prey immideately. Their venom and toxins are still unknown.
4.) Improving methods and analyses in Venomics focused on transcriptomics
That also includes how to combine new insights of assembly and toxin identification strategies in new pipelines. Important is the synergistic and comparatice aspect in which transcriptomics, if possible genomics (genome data of species) and proteomics are combined to understand toxin evolution and venom compositions.
Lat but not least, maybe most important of all, is to understand the ecology and morphology of the studied species. In most cases these are often not known or knowledge sparse. However, these insights finally result in the more complete picture and also help to understand venoms and their complex, convergent evolution.
Link to the NHM project pages: