Cnidofest 2022: hot topics in cnidarian research

Abstract

The second annual Cnidarian Model Systems Meeting, aka "Cnidofest", took place in Davis, California from 7 to 10th of September, 2022. The meeting brought together scientists using cnidarians to study molecular and cellular biology, development and regeneration, evo-devo, neurobiology, symbiosis, physiology, and comparative genomics. The diversity of topics and species represented in presentations highlighted the importance and versatility of cnidarians in addressing a wide variety of biological questions. In keeping with the spirit of the first meeting (and its predecessor, Hydroidfest), almost 75% of oral presentations were given by early career researchers (i.e., graduate students and postdocs). In this review, we present research highlights from the meeting.

Keywords: Clytia; Cnidarians; Cnidofest; Conference; Hydra; Hydractinia; Nematostella.

Fig. 1

Cnidarian phylogeny. A A simplified phylogenetic tree showing the position of cnidarians as the sister group to the Bilateria and the relationship between major groups of cnidarians presented at the meeting [45]. The Cnidaria can be spilt into three groups; Anthozoa (Sea anemones, corals etc.); Medusozoa (hydroids, siphonophores, true jellyfish); Endocnidozoa (parasitic Myxozoa and Polypodium). B–D Examples of organisms presented at the meeting: the sea anemone Metridium senile (Anthozoa) (B), a polygastric colony of the siphonophore Chelophyes appendiculata (Hydrozoa) (C) and an adult medusa of the jellyfish Pelagia noctiluca (Scyphozoa). Image credits: Yareli Alvarez (A), Maciej Mańko (B) and Alexandre Jan (D). The silhouettes in A were obtained from phylopic (https://www.phylopic.org/) and all the images are available under a CC0 1.0 license except the siphonophore which was produced by Noah Schlottman (photo by Casey Dunn) and is available under a CC BY-SA 3.0 license (https://creativecommons.org/licenses/by-sa/3.0/)

Fig. 2

New technologies drive cnidarian research. A A whole Hydra polyp expressing GFP in all neurons imaged by confocal microscopy [46]. B Close up confocal section of the Nematostella vectensis gastrodermis from a line containing a CRISPR-Cas9 knock-in of GFP into the Piwi1 locus (Green) and the NvSoxB(2)::mOrange2 transgene [22, 47]. C A sexual polyp of transgenic Hydractinia symbiolongicarpus bearing the β-tubulin::mScarlet and Piwi1::GFP transgenes [48, 49]. All transgenic cells in the polyp are derived from a single transplanted stem cell (i-cell) [21]. Image credits: Ben Cox (A), Paula Miramon-Puertolas (B), Áine Varley (C). Scale bars: 250 µm (A), 50 µm (B), 200 (C)