title: Medaka simplet (FAM53B) belongs to a family of novel vertebrate genes controlling cell proliferation.
abstract: The identification of genes that regulate proliferation is of great importance to developmental biology, regenerative medicine and cancer research. Using an in situ screen on a cortical structure of the medaka fish brain, we identified the simplet gene (smp), which is homologous to the human FAM53B gene. smp was expressed in actively proliferating cells of the CNS throughout embryogenesis. It belongs to a family of vertebrate-specific genes with no characterized biochemical domains. We showed that FAM53B bound 14-3-3 chaperones, as well as SKIIP proteins, adaptor proteins connecting DNA-binding proteins to modulators of transcription. smp inactivation with morpholinos led to delayed epiboly and reduced embryonic size. Absence of Smp activity did not induce apoptosis, but resulted in a reduced cell proliferation rate and enlarged blastomeres. Moreover, smp was shown to control the expression of the pluripotency-associated oct4/pou5f1 gene. We propose that smp is a novel vertebrate-specific gene needed for cell proliferation and that it is probably associated with the maintenance of a pluripotent state.
authors.affiliation: INRA MSNC Group, DEPSN, Institut A. Fessard, CNRS, 1 avenue de la Terrasse, 91198 Gif-sur-Yvette, France.
authors.forename: Violette
authors.initials: V
authors.lastname: Thermes
authors.forename: Eva
authors.initials: E
authors.lastname: Candal
authors.forename: Alessandro
authors.initials: A
authors.lastname: Alunni
authors.forename: Guillaume
authors.initials: G
authors.lastname: Serin
authors.forename: Franck
authors.initials: F
authors.lastname: Bourrat
authors.forename: Jean-Stéphane
authors.initials: JS
authors.lastname: Joly
mesh_terms: D048948:14-3-3 Proteins / Q000378:metabolism; D000818:Animals; D049109:Cell Proliferation; D002490:Central Nervous System / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian; D018507:Gene Expression Regulation, Developmental; D008845:Microinjections; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D009990:Oryzias / Q000196:embryology / Q000235:genetics*; D010802:Phylogeny; D014714:Vertebrates / Q000235:genetics*
chemical_list: D048948:14-3-3 Proteins; D004268:DNA-Binding Proteins; D050814:Octamer Transcription Factor-3; D016376:Oligonucleotides, Antisense