Thank you!

Thanks a lot Uli!

Thank you! 😁

Thanks a lot Pedro!! 😁

Thank you Alison!

and in collaboration with @mfnberlin.bsky.social, Jack Ullrich-Lüter, Jil Carl, Maria Schauer, Anne-C. Zakrzewski, Berit Zemann, Carsten Lüter, @biodev-vlfr.bsky.social @croce-urchin.bsky.social, Tiphaine Sancerni, Oğuz Akar, @igflyon.bsky.social, @almazan.bsky.social #ScienceAdvancesResearch

With @szndohrn.bsky.social @danivoronov.bsky.social , @mlrusciano.bsky.social , @mariacocurullo.bsky.social, Filomena Caccavale, Giovanna Benvenuto

Long considered brainless creatures, our results provide evidence that sea urchins possess a highly photosensitive nervous system organized in an “all-brain” manner instead.

Adding to this complexity, we discovered a vast array of photoreceptor cells with a conserved retinal molecular fingerprint, as well as a population expressing a rare combination of opsins that we hypothesize is an ideal candidate for non-ocular sea urchin vision.

Moreover, we found that the postmetamorphic nervous system, remarkable for its cell type diversity and complexity, also exhibits a head-like molecular signature and expresses vertebrate brain gene homologs.

Based on our findings, we report that the sea urchin juvenile body plan is head-like, similar to what has previously been demonstrated in sea stars and brittle stars, suggesting that echinoderms in general are predominantly head-like organisms.

By comparing juvenile and larval cell types, we identified those that retain developmental molecular signatures and gene regulatory fingerprints, as well as juvenile-specific ones.

With this project, funded by @hfspo.bsky.social, we identified the cell type repertoire of the postmetamorphic sea urchin juvenile at a single nucleus level.

We discuss new research on sea urchins, how echinoderms remain relevant experimental systems in the multiomics era, and the future of the cell type evolution and development field.