title: Unexpected repertoire of metazoan transcription factors in the unicellular holozoan Capsaspora owczarzaki.
abstract: How animals (metazoans) originated from their single-celled ancestors remains a major question in biology. As transcriptional regulation is crucial to animal development, deciphering the early evolution of associated transcription factors (TFs) is critical to understanding metazoan origins. In this study, we uncovered the repertoire of 17 metazoan TFs in the amoeboid holozoan Capsaspora owczarzaki, a representative of a unicellular lineage that is closely related to choanoflagellates and metazoans. Phylogenetic and comparative genomic analyses with the broadest possible taxonomic sampling allowed us to formulate new hypotheses regarding the origin and evolution of developmental metazoan TFs. We show that the complexity of the TF repertoire in C. owczarzaki is strikingly high, pushing back further the origin of some TFs formerly thought to be metazoan specific, such as T-box or Runx. Nonetheless, TF families whose beginnings antedate the origin of the animal kingdom, such as homeodomain or basic helix-loop-helix, underwent significant expansion and diversification along metazoan and eumetazoan stems.
authors.affiliation: Departament de Genètica & Institut de Recerca en Biodiversitat (Irbio), Universitat de Barcelona, Barcelona, Spain.
authors.forename: Arnau
authors.initials: A
authors.lastname: Sebé-Pedrós
authors.affiliation: Departament de Genètica & Institut de Recerca en Biodiversitat (Irbio), Universitat de Barcelona, Barcelona, Spain.
authors.forename: Alex
authors.initials: A
authors.lastname: de Mendoza
authors.affiliation: Department of Biochemistry, Université de Montréal, H3C 3J7 Montréal, Canada.
authors.forename: B Franz
authors.initials: BF
authors.lastname: Lang
authors.affiliation: School of Biological Sciences, The University of Queensland, Brisbane Queensland 4072, Australia.
authors.forename: Bernard M
authors.initials: BM
authors.lastname: Degnan
authors.affiliation: Departament de Genètica & Institut de Recerca en Biodiversitat (Irbio), Universitat de Barcelona, Barcelona, Spain.|Institució Catalana per a la Recerca i Estudis Avançats (ICREA); Passeig Lluís Companys, 23, 08010 Barcelona, Spain.
authors.forename: Iñaki
authors.initials: I
authors.lastname: Ruiz-Trillo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D056897:Choanoflagellata / Q000145:classification / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000145:classification / Q000235:genetics*; D019143:Evolution, Molecular; D023281:Genomics; D008969:Molecular Sequence Data; D010802:Phylogeny; D014157:Transcription Factors / Q000145:classification / Q000235:genetics*
chemical_list: D004268:DNA-Binding Proteins; D014157:Transcription Factors