Meeting Abstract
Cnidarians are the only group of venomous animals that lack a centralized venom transmission system. Instead, they are equipped with stinging cells collectively known as cnidocysts. Cnidocysts vary in abundance and type across different tissues, often being attributed to tissue specific functions even though the venom composition in most species remains unknown. Within Cnidaria, sea anemones have been the best characterized group when it comes to venom diversity and function; however, previous studies have focused on venom isolated from cnidocysts or whole tentacle extracts from relatively few species. Depending on the tissue type, the venom composition may be vital for predation, defense, or digestion. To investigate tissue specific variation in venom we constructed partial transcriptomes for three different tissue types (tentacles, mesenterial filaments, and column) across three species of sea anemone (Anemonia sulcata, Heteractis crispa, and Megalactis griffiths). For each species we determined the tissues specific abundance of toxin-like sequences and investigated differential gene expression to identify non-venom transcripts outside expected expression levels. The species specific venom repertoire was similar across tissues, with notable differences in tissue specific abundance. When comparing across species, however, there were major differences in venom composition in addition to overall abundance estimates across similar tissue types. Our results show that evolutionary history may play a more significant role in sea anemone venom composition than the inferred functional roles of venom across different tissue types within a single polyp.
