title: Nodal: master and commander of the dorsal-ventral and left-right axes in the sea urchin embryo.
abstract: Recent studies suggest that specification of the dorsal-ventral and left-right axes of the sea urchin embryo relies on Nodal-expressing signalling centres located in the ventral ectoderm and in the archenteron that share striking similarities with vertebrate organising centres. Nodal and its downstream target BMP2/4 pattern all three germ layers along the dorsal-ventral axis, repress neural fates and control morphogenesis of the larva. Moreover, Nodal establishes left-right asymmetry by repressing formation of the adult rudiment and inhibiting germline cells differentiation on the right side, while BMP2/4 promotes expression of mesodermal genes on the left side. These findings provide a framework for future studies and raise new questions regarding the events upstream and downstream of Nodal and BMP signalling during axis formation.
authors.affiliation: LBDV, Laboratoire de Biologie du Développement de Villefranche-sur-Mer, Observatoire Océanologique, UMR 7009 CNRS, Université Pierre et Marie Curie, 06230 Villefranche sur Mer, France.
authors.forename: M Dolores
authors.initials: MD
authors.lastname: Molina
authors.forename: Noémie
authors.initials: N
authors.lastname: de Crozé
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Haillot
authors.forename: Thierry
authors.initials: T
authors.lastname: Lepage
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics*; D004625:Embryo, Nonmammalian; D018507:Gene Expression Regulation, Developmental; D055457:Nodal Protein / Q000235:genetics*; D012617:Sea Urchins / Q000196:embryology* / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics
chemical_list: D019485:Bone Morphogenetic Proteins; D055457:Nodal Protein