Robertson, Helen E.Sebé-Pedrós, ArnauSaudemont, BaptisteLoe-Mie, YannZakrzewski, Anne-C.Grau Bové, XavierMailhe, Marie-PierreSchiffer, Philipp H.Telford, Maximilian J.Marlow, Heather2024-07-312024-07-312024Robertson HE, Sebé-Pedrós A, Saudemont B, Loe-Mie Y, Zakrzewski AC, Grau-Bové X, et al. Single cell atlas of Xenoturbella bocki highlights limited cell-type complexity. Nat Commun. 2024 Mar 19;15(1):2469. DOI: 10.1038/s41467-024-45956-y2041-1723http://hdl.handle.net/10230/60871Phylogenetic analyses over the last two decades have united a few small, and previously orphan clades, the nematodermatids, acoels and xenoturbelids, into the phylum Xenacoelomorpha. Some phylogenetic analyses support a sister relationship between Xenacoelomorpha and Ambulacraria (Xenambulacraria), while others suggest that Xenacoelomorpha may be sister to the rest of the Bilateria (Nephrozoa). An understanding of the cell type complements of Xenacoelomorphs is essential to assessing these alternatives as well as to our broader understanding of bilaterian cell type evolution. Employing whole organism single-cell RNA-seq in the marine xenacoelomorph worm Xenoturbella bocki, we show that Xenambulacrarian nerve nets share regulatory features and a peptidergic identity with those found in cnidarians and protostomes and more broadly share muscle and gland cell similarities with other metazoans. Taken together, these data are consistent with broad homologies of animal gland, muscle, and neurons as well as more specific affinities between Xenoturbella and acoel gut and epidermal tissues, consistent with the monophyly of Xenacoelomorpha.application/pdfeng© The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.info:eu-repo/semantics/articlehttp://dx.doi.org/10.1038/s41467-024-45956-yCell type diversityEvolutionary developmental biologyMusculoskeletal developmentNon-model organismsinfo:eu-repo/semantics/openAccess