Quo Vadis Venomics? A Roadmap to Neglected Venomous Invertebrates

Abstract

Venomics research is being revolutionized by the increased use of sensitive -omics techniques to identify venom toxins and their transcripts in both well studied and neglected venomous taxa. The study of neglected venomous taxa is necessary both for understanding the full diversity of venom systems that have evolved in the animal kingdom, and to robustly answer fundamental questions about the biology and evolution of venoms without the distorting effect that can result from the current bias introduced by some heavily studied taxa. In this review we draw the outlines of a roadmap into the diversity of poorly studied and understood venomous and putatively venomous invertebrates, which together represent tens of thousands of unique venoms. The main groups we discuss are crustaceans, flies, centipedes, non-spider and non-scorpion arachnids, annelids, molluscs, platyhelminths, nemerteans, and echinoderms. We review what is known about the morphology of the venom systems in these groups, the composition of their venoms, and the bioactivities of the venoms to provide researchers with an entry into a large and scattered literature. We conclude with a short discussion of some important methodological aspects that have come to light with the recent use of new -omics techniques in the study of venoms.

Melt With This Kiss: Paralyzing and Liquefying Venom of The Assassin Bug Pristhesancus plagipennis (Hemiptera: Reduviidae)

“…This study highlights the power of combining transcriptomic and proteomic approaches for providing a holistic overview of venom proteomes (72), and it further underscores the likelihood of finding novel protein families in poorly studied venomous taxa (73). Our results provide a solid foundation for understanding the role played by individual venom components in prey capture and liquefaction in predaceous assassin bugs and provide key insights into the different pathways of venom evolution in predaceous and hematophagous heteropterans.…”

Ancestral reconstruction of tick lineages

“…The definition to some extent, obscures meaning when a distinction between benign (those that does not cause debilitating toxicoses) and toxic arthropods is necessary, or when the evolutionary origins and causes of toxicoses are considered (Mans et al 2004). Irrespective of the definition, most authors recognize that convergent evolution of venoms occurred in all arthropod and arachnid lineages (Casewell et al 2013;Fry et al 2009;von Reumont et al 2014). …”

Latarcins: versatile spider venom peptides

“…Organisms that utilize venom for predation, defense, and competitor deterrence are believed to possess evolutionary advantages [1][2][3]. Among the venomous taxa (including cnidarians, echinoderms, mollusks, vertebrates, and arthropods, encompassing ants, bees, centipedes, scorpions, spiders, and wasps), spiders are arguably the most successful representing one of the most abundant terrestrial predators.…”

“…Spider genomes are similar in size to mammalian genomes and also feature a large amount of short exons and long introns [4]. Among the sources of the evolutionary advantage of spiders are the properties of their venom [5][6][7]: (1) they are fast acting; (2) minute dosages are enough to paralyze the victim or deter aggressors; (3) gene-encoded peptide neurotoxins are produced in the form of combinatorial libraries featuring hypermutations of essentially all residues, except for a few strictly conserved cysteines that stabilize the three-dimensional fold of the toxin; (4) there is functional synergy between the venom components. A combination of toxins, or toxin cabal (term coined by the Olivera laboratory to describe Conus venom [8]), acts synergistically, enhancing the venom potency.…”