AUTHOR=Takahashi Toshio 

TITLE=Comparative Aspects of Structure and Function of Cnidarian Neuropeptides

JOURNAL=Frontiers in Endocrinology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2020.00339

DOI=10.3389/fendo.2020.00339

ISSN=1664-2392

ABSTRACT=<p>Cnidarians are early-branching animals in the eukaryotic tree of life. The phylum Cnidaria are divided into five classes: Scyphozoa (true jellyfish), Cubozoa (box jellyfish), Hydrozoa (species, <italic>Hydra</italic> and <italic>Hydractinia</italic>), Anthozoa (sea anemone, corals, and sea pen), and Staurozoa (stalked jellyfish). Peptides play important roles as signaling molecules in development and differentiation in cnidaria. For example, cnidaria use peptides for cell-to cell communication. Recent discoveries show that <italic>Hydra</italic> neuropeptides control several biological processes including muscle contraction, neuron differentiation, and metamorphosis. Here, I describe the structure and functions of neuropeptides in <italic>Hydra</italic> and other cnidarian species. I also discuss that so-called primitive nervous system of <italic>Hydra</italic> is in more complex than generally believed. I also discuss how cnidaria use peptides for communication among cells rather than in higher animals.</p>