title: MicroRNAs regulate brain morphogenesis in zebrafish.
abstract: MicroRNAs (miRNAs) are small RNAs that regulate gene expression posttranscriptionally. To block all miRNA formation in zebrafish, we generated maternal-zygotic dicer (MZdicer) mutants that disrupt the Dicer ribonuclease III and double-stranded RNA-binding domains. Mutant embryos do not process precursor miRNAs into mature miRNAs, but injection of preprocessed miRNAs restores gene silencing, indicating that the disrupted domains are dispensable for later steps in silencing. MZdicer mutants undergo axis formation and differentiate multiple cell types but display abnormal morphogenesis during gastrulation, brain formation, somitogenesis, and heart development. Injection of miR-430 miRNAs rescues the brain defects in MZdicer mutants, revealing essential roles for miRNAs during morphogenesis.
authors.affiliation: Developmental Genetics Program, Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA. giraldez@saturn.med.nyu.edu
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Giraldez
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Cinalli
authors.forename: Margaret E
authors.initials: ME
authors.lastname: Glasner
authors.forename: Anton J
authors.initials: AJ
authors.lastname: Enright
authors.forename: J Michael
authors.initials: JM
authors.lastname: Thomson
authors.forename: Scott
authors.initials: S
authors.lastname: Baskerville
authors.forename: Scott M
authors.initials: SM
authors.lastname: Hammond
authors.forename: David P
authors.initials: DP
authors.lastname: Bartel
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Schier
mesh_terms: D000818:Animals; D019521:Body Patterning; D001921:Brain / Q000196:embryology*; D002454:Cell Differentiation; D002490:Central Nervous System / Q000196:embryology; D005775:Gastrula / Q000502:physiology; D020868:Gene Silencing; D006321:Heart / Q000196:embryology; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D009024:Morphogenesis; D009154:Mutation; D009474:Neurons / Q000166:cytology; D010641:Phenotype; D012323:RNA Processing, Post-Transcriptional; D012330:RNA, Double-Stranded / Q000378:metabolism; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D019170:Somites / Q000166:cytology / Q000502:physiology; D013116:Spinal Cord / Q000196:embryology; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics*
chemical_list: D035683:MicroRNAs; D012330:RNA, Double-Stranded; D043244:Ribonuclease III