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Meeting Abstract
Immunity fundamentally relies on the host’s capacity to distinguish unwanted, potentially pathogenic microbes from a slurry of endogenous biological materials and other functionally inert molecules saturating the environment. To combat this colossal task, animals utilize various pattern-recognition receptors (PRRs) to identify and initiate immune responses against individual groups of pathogens. The patterns PRRs recognize, such as lipopolysaccharide (found in Gram-positive bacteria) or dsRNA (found in viruses), are often essential to the structure/biology of the potentially pathogenic agent on/in which they are found, and thus remain consistent/present over evolutionary time. Moreover, individual PRR proteins often only recognize a single classification of molecular pattern, like Gram-positive cell wall components or viral nucleotide polymers, suggesting an increase in the number of PRRs encoded in a single genome may represent increased immune capacity against a larger breadth of pathogens. In this study, we investigate the molecular conservation of the Nod-like receptors, Rig-1-like receptors, and Toll-like receptor PRR pathways among deuterostomes – a clade encompassing Echinodermata (e.g., sea stars, urchins, and sea cucumbers), Hemichordata (e.g., acorn worms and pterobranchs), and Chordata (e.g., sea squirts, lancelets, and vertebrates). In addition to findings on the ancestral repertoire of these pathways in the context of Deuterostomia and its composite clades, we will discuss novel domain architectures in close association with these core PRR pathways, and their potential role in immunity.