Insights into arachnid venom evolution from a pseudoscorpion transcriptome

Of 11 orders of Arachnida, only 3 are known to possess venom: spiders, scorpions, and pseudoscorpions. Yet to date venom sequences have only been described from scorpions and spiders. We have obtained transcriptomic data from a neobisiid pseudoscorpion, including venom transcripts. By extracting RNA from the venom-containing pincer and the non-venom containing pedipalp arm, we were able to identify sequences that are very likely to be venom proteins in the pseudoscorpion. Comparing these sequences to other arachnid venoms, we make inferences about the evolution of venoms across Arachnida.