RT Journal Article SR Electronic T1 The chromatin-regulating CoREST complex is animal specific and essential for development in the cnidarian Nematostella vectensis JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.11.11.468220 DO 10.1101/2021.11.11.468220 A1 James M Gahan A1 Maria Hernandez-Valladares A1 Fabian Rentzsch YR 2021 UL http://biorxiv.org/content/early/2021/11/12/2021.11.11.468220.abstract AB Chromatin-modifying proteins are key players in the regulation of development and cell differentiation in animals. Many individual chromatin modifiers, however, predate the evolution of animal multicellularity and how they became integrated into the regulatory networks underlying development is unclear. Here we show that CoREST is an animal-specific protein that assembles a conserved, vertebrate-like histone-modifying complex including Lsd1 and HDAC1/2 in the sea anemone Nematostella vectensis. We further show that NvCoREST expression overlaps fully with that of NvLsd1 throughout development. NvCoREST mutants, generated using CRISPR-Cas9, reveal essential roles during development and for the differentiation of cnidocytes, thereby phenocopying NvLsd1 mutants. We also show that this requirement is cell autonomous using a cell-type-specific rescue approach. Together, this shows that the evolution of CoREST allowed the formation of a chromatin-modifying complex that was present before the last common cnidarian-bilaterian ancestor and thus represents an ancient component of the animal developmental toolkit.Competing Interest StatementThe authors have declared no competing interest.