2 anemone species were sequenced to determine tissue-specific differential expression and to find toxin composition in the two sea anemones. Sea anemone transcriptomics

Cnidarians are the simplest animals to have tissue level differentiation. They however do not have a centralized nervous system nor do they have a centralized venom delivery system. Snakes and spiders are known to have a centralized venom gland which ejects peptide and small molecule toxins into its prey.(Smith and Wheeler 2006; Fry et al. 2009; Castelin et al. 2012; Casewell et al. 2013). Cnidarians however lack a centralized venom delivery system instead having stinging cells called nematocysts which is used to deliver venom. The composition of the nematocysts vary various across different tissues of the animal(Mariscal 1974; Kass-Simon and Scappaticci 2002). The venom composition and expression of proteins in the nematocysts in different tissues of cnidarians is not well known. All metazoans with the exception of poriferans, cnidarians, and ctenophores have a centralized nervous system. Cnidarians have a diffuse nerve net with each neuron holding as much importance as any other neuron. The ion channel diversity and expression across different tissues of cnidarians is also not well known. In this study, we use a RNA-seq approach to characterize the expression patterns and composition of venom and ion channels across different tissues (tentacles and column) in two species of sea anemone: Entacmeae quadricolor(EQ) (common name: bubble tip anemone, Family:Actiniidae), and Condylactis gigantea (CG)(common name: condy anemone, family : actiniidae). These species vary in their symbiotic associations with clownfishes and in their morphology. Envenomation from either of these anemones is not painful to humans. EQ is known for hosting a wide range of fishes while CG is not known to host as many symbiots. These two specific species were also chosen for their ease of availablity from aquarium trade shops. We predicted that we would identify differentially expressed toxins and ion channels that would correlate with unique tissue specific functions and with variety of symbionts hosted by each species.