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Meeting Abstract
Innate immunity is an ancient physiological response critical for protecting metazoans from invading pathogens. It is the primary pathogen defense mechanism among invertebrates. While innate immunity has been studied in many different marine organisms including molluscs, crustaceans, and cnidarians, this important pathogen defense mechanism has not been characterized in ctenophores. The ctenophores comprise an exclusively marine, non-bilaterian lineage that diverged early during metazoan diversification. The phylogenetic position of ctenophore lineage suggests that characterization of the ctenophore innate immune system will reveal important features associated with the early evolution of the innate immune system. Here we present an analysis of genetic components of the ctenophore innate immunity pathway. We also have used cell biological approaches to identify and characterize ctenophore phagocytes that display macrophage-like behavior when challenged with a pathogen. We discuss the implications of these findings in ctenophores and how they inform our understanding of the evolution of the metazoan innate immune system.