Meeting Abstract
Cnidaria is the oldest venomous lineage in Metazoa and is characterized by the presence of stinging cells called nematocysts. These cells contain a number of toxin proteins that disrupt cellular homeostasis of predators and prey. Current research is lacking with regards to the venom expression or effect these proteins have on predator and prey. To elucidate the toxin activity and diversity within sea anemones, we used Nematostella vectensis and Exaiptasia pallida to characterize how specific toxin proteins interact with potential predators or prey. Sea anemones are bottom dwelling sessile predators with their mouth facing upwards surrounded by nematocysts packed tentacles. Of the two species, N. vectensis has the best characterized venom assemblage within sea anemones. The recent sequencing of E. pallida’s genome allowed us to identify toxin candidates and speculate about their potential function. However, likely due to their evolutionary histories and differing environments, these species differ significantly in venom composition, which may play a major role in how they interact with potential predators or prey. In both species, we examined the difference in naturally induced toxin production in the oral region when anemones were exposed to a predator (Palaemonetes pugio) and prey (Artemia salina). We found that of the genes we examined most N. vectensis toxins had higher levels of expression when nematocysts were manually discharged, but had no change when exposed to predators or prey. E. pallida was found to exhibit a predatory response evidenced by increased expression in several toxin genes when exposed to water used to grow A. salina, indicating a physiological response to a potential food source. These results allow for future proteomics work to be completed on these model sea anemones as well as an insight into venom function based on associated biotic communities and their evolutionary history.
