title: Retinoic acid controls proper head-to-trunk linkage in zebrafish by regulating an anteroposterior somitogenetic rate difference.
abstract: During vertebrate development, the primary body axis elongates towards the posterior and is periodically divided into somites, which give rise to the vertebrae, skeletal muscles and dermis. Somites form periodically from anterior to posterior, and the anterior somites form in a more rapid cycle than the posterior somites. However, how this anteroposterior (AP) difference in somitogenesis is generated and how it contributes to the vertebrate body plan remain unclear. Here, we show that the AP difference in zebrafish somitogenesis originates from a variable overlapping segmentation period between one somite and the next. The AP difference is attributable to spatiotemporal inhibition of the clock gene her1 via retinoic acid (RA) regulation of the transcriptional repressor ripply1. RA depletion thus disrupts timely somite formation at the transition, eventually leading to the loss of one somite and the resultant cervical vertebra. Overall, our results indicate that RA regulation of the AP difference is crucial for proper linkage between the head and trunk in the vertebrate body plan.
authors.affiliation: Gene Regulation Research, Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Nara 630-0101, Japan.
authors.forename: Bambang
authors.initials: B
authors.lastname: Retnoaji
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Akiyama
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Matta
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Bessho
authors.forename: Takaaki
authors.initials: T
authors.lastname: Matsui
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism*; D019521:Body Patterning / Q000235:genetics / Q000502:physiology*; D002574:Cervical Vertebrae / Q000196:embryology; D055785:Gene Knockdown Techniques; D060172:Morpholinos / Q000235:genetics; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000378:metabolism*; D050697:Retinal Dehydrogenase / Q000235:genetics; D015398:Signal Transduction; D019170:Somites / Q000196:embryology*; D014158:Transcription, Genetic; D014212:Tretinoin / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D060172:Morpholinos; D009687:Nuclear Proteins; D050697:Retinal Dehydrogenase; D014212:Tretinoin; D029961:Zebrafish Proteins; C491619:her1 protein, zebrafish; C507062:ripply1 protein, zebrafish; C518907:Aldh1a2 protein, zebrafish
keywords: Axis elongation; Live imaging; Somitogenesis; Zebrafish