title: MicroRNA control of Nodal signalling.
abstract: MicroRNAs are crucial modulators of gene expression, yet their involvement as effectors of growth factor signalling is largely unknown. Ligands of the transforming growth factor-beta superfamily are essential for development and adult tissue homeostasis. In early Xenopus embryos, signalling by the transforming growth factor-beta ligand Nodal is crucial for the dorsal induction of the Spemann's organizer. Here we report that Xenopus laevis microRNAs miR-15 and miR-16 restrict the size of the organizer by targeting the Nodal type II receptor Acvr2a. Endogenous miR-15 and miR-16 are ventrally enriched as they are negatively regulated by the dorsal Wnt/beta-catenin pathway. These findings exemplify the relevance of microRNAs as regulators of early embryonic patterning acting at the crossroads of fundamental signalling cascades.
authors.affiliation: Department of Histology, Microbiology and Medical Biotechnologies, Section of Histology and Embryology, University of Padua, viale Colombo 3, 35126 Padua, Italy.
authors.forename: Graziano
authors.initials: G
authors.lastname: Martello
authors.forename: Luca
authors.initials: L
authors.lastname: Zacchigna
authors.forename: Masafumi
authors.initials: M
authors.lastname: Inui
authors.forename: Marco
authors.initials: M
authors.lastname: Montagner
authors.forename: Maddalena
authors.initials: M
authors.lastname: Adorno
authors.forename: Anant
authors.initials: A
authors.lastname: Mamidi
authors.forename: Leonardo
authors.initials: L
authors.lastname: Morsut
authors.forename: Sandra
authors.initials: S
authors.lastname: Soligo
authors.forename: Uyen
authors.initials: U
authors.lastname: Tran
authors.forename: Sirio
authors.initials: S
authors.lastname: Dupont
authors.forename: Michelangelo
authors.initials: M
authors.lastname: Cordenonsi
authors.forename: Oliver
authors.initials: O
authors.lastname: Wessely
authors.forename: Stefano
authors.initials: S
authors.lastname: Piccolo
mesh_terms: D030301:Activin Receptors, Type II / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D028341:Activins / Q000378:metabolism; D000818:Animals; D019521:Body Patterning; D018507:Gene Expression Regulation, Developmental; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D055457:Nodal Protein; D020897:Organizers, Embryonic / Q000196:embryology / Q000378:metabolism; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D051153:Wnt Proteins / Q000378:metabolism; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
chemical_list: C000609088:MIRN15 microRNA, Xenopus; D035683:MicroRNAs; D055457:Nodal Protein; D016212:Transforming Growth Factor beta; D051153:Wnt Proteins; D051176:beta Catenin; D028341:Activins; D030301:Activin Receptors, Type II