Unravelling the molecular evolution of spider venoms

Spiders as well as other venomous animals rely on the production of complex venoms mainly for predatory purposes but also for defence and competitor deterrence. The major components of most spider venoms are disulfide-rich peptides (DRPs) with mass 2–10 kDa along with proteins and enzymes with mass >15 kDa. Mass spectrometry analyses have shown that individual spiders can express hundreds to thousands of peptides in their venom. However, it is still poorly understood how spiders generate this extraordinary chemical diversity, as the venom of less than 0.25% of all spider species has been investigated. Here, we used a transcriptomic approach to investigate the venom profile of a taxonomically diverse range of spider species in order to understand, at the molecular level, how spider-venom proteomes evolved, expanded and diversified. We also investigated how adaptation to different predation strategies, ecological niches, and prey/predator taxa influences venom compositions.