title: The ancestral gene repertoire of animal stem cells.
abstract: Stem cells are pivotal for development and tissue homeostasis of multicellular animals, and the quest for a gene toolkit associated with the emergence of stem cells in a common ancestor of all metazoans remains a major challenge for evolutionary biology. We reconstructed the conserved gene repertoire of animal stem cells by transcriptomic profiling of totipotent archeocytes in the demosponge Ephydatia fluviatilis and by tracing shared molecular signatures with flatworm and Hydra stem cells. Phylostratigraphy analyses indicated that most of these stem-cell genes predate animal origin, with only few metazoan innovations, notably including several partners of the Piwi machinery known to promote genome stability. The ancestral stem-cell transcriptome is strikingly poor in transcription factors. Instead, it is rich in RNA regulatory actors, including components of the "germ-line multipotency program" and many RNA-binding proteins known as critical regulators of mammalian embryonic stem cells.
authors.affiliation: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan; alexandre.alie@inaf.cnrs-gif.fr funayama@mdb.biophys.kyoto-u.ac.jp.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Alié
authors.affiliation: Genome Resource and Analyzing Unit, RIKEN Center for Developmental Biology, Kobe, Hyogo 650-0047, Japan;
authors.forename: Tetsutaro
authors.initials: T
authors.lastname: Hayashi
authors.affiliation: HSS: Hokkaido System Science Co., Ltd., Kitaku Sapporo 001-0932, Japan;
authors.forename: Itsuro
authors.initials: I
authors.lastname: Sugimura
authors.affiliation: Université Pierre et Marie Curie-Paris 6, UMR 7138 Université Pierre et Marie Curie CNRS, Institut de Biologie Paris-Seine, Paris 75005, France;
authors.forename: Michaël
authors.initials: M
authors.lastname: Manuel
authors.affiliation: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan;
authors.forename: Wakana
authors.initials: W
authors.lastname: Sugano
authors.affiliation: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan;
authors.forename: Akira
authors.initials: A
authors.lastname: Mano
authors.affiliation: Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa 904-0495, Japan.
authors.forename: Nori
authors.initials: N
authors.lastname: Satoh
authors.affiliation: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan;
authors.forename: Kiyokazu
authors.initials: K
authors.lastname: Agata
authors.affiliation: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan; alexandre.alie@inaf.cnrs-gif.fr funayama@mdb.biophys.kyoto-u.ac.jp.
authors.forename: Noriko
authors.initials: N
authors.lastname: Funayama
mesh_terms: D000818:Animals; D019143:Evolution, Molecular; D042822:Genomic Instability; D006829:Hydra / Q000166:cytology / Q000235:genetics; D008322:Mammals; D010802:Phylogeny; D011161:Porifera / Q000166:cytology / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics; D013234:Stem Cells / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics; D059467:Transcriptome
chemical_list: D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; D014157:Transcription Factors
keywords: Porifera; RNA binding; evolution; stem cells; uPriSCs