Meeting Abstract
Ctenophores, or comb jellies, are likely the earliest-diverging extant animal lineage. Given the group’s apparent physiological complexity, this recent finding was unexpected and remains difficult to contextualize. Part of this difficulty arises from the various poorly understood aspects of ctenophore biology. For example, an enduring source of mystery within the phylum is the colloblast, a cell type unique to ctenophores. Colloblasts are destructible cells found in these animals’ tentacles that release a fast-acting adhesive on contact with prey, ensnaring it. To date, little is known about this adhesive or its biochemistry. In this study, we present new evidence that the colloblast adhesive of the ctenophore Pleurobrachia bachei contains proteins that incorporate derivatives of the amino acid DOPA, suggesting a parallel with the adhesive foot proteins of mussels. We also find immunohistochemical evidence suggesting the presence of similar DOPA derivatives in the Pleurobrachia subepithelial nerve net. This latter finding is notable given ctenophores’ reported lack of the enzymatic machinery to produce or utilize catecholamine neurotransmitters such as dopamine. Our data point to a structural role for DOPA-like compounds in ctenophores, which in turn suggests that this noncanonical role for these molecules may be a deeply-rooted animal trait that arose independently of catecholamine neurotransimission.
