title: Involvement of the Wnt/β-catenin pathway in neurectoderm architecture in Platynereis dumerilii.
abstract: Signalling pathways are essential for the correct development of the central nervous system (CNS) in bilaterian animals. Here we show that in the CNS of the annelid Platynereis dumerilii, neural progenitor cells (NPCs) are located close to the ventral midline and express axin, a negative regulator of the Wnt/β-catenin pathway. Using pharmacological inhibitors, we observe that Wnt/β-catenin is required for the transition between proliferating NPCs and differentiating neurons. We also show that the Rho-associated kinase (Rok) is necessary for neurectoderm morphogenesis and ventral midline formation, and indirectly affects the distribution of the NPCs and the development of axonal scaffolds. Moreover, seven genes belonging to the planar cell polarity (PCP) pathway are expressed in the developing Platynereis neurectoderm, suggesting an involvement in its morphogenesis. When compared with previous studies in vertebrates, our data suggest that the involvement of the Wnt/β-catenin pathway in the control of neural cell proliferation/differentiation is ancestral to bilaterians.
authors.affiliation: Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot, Sorbonne Paris Cité, F-75205 Paris, France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Demilly
authors.forename: Patrick
authors.initials: P
authors.lastname: Steinmetz
authors.forename: Eve
authors.initials: E
authors.lastname: Gazave
authors.forename: Lauriane
authors.initials: L
authors.lastname: Marchand
authors.forename: Michel
authors.initials: M
authors.lastname: Vervoort
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D016764:Cell Polarity; D049109:Cell Proliferation; D002490:Central Nervous System / Q000196:embryology / Q000378:metabolism / Q000473:pathology; D004625:Embryo, Nonmammalian / Q000166:cytology; D018507:Gene Expression Regulation, Developmental; D007814:Larva / Q000033:anatomy & histology / Q000166:cytology; D008969:Molecular Sequence Data; D054258:Neural Plate / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D058953:Neural Stem Cells / Q000166:cytology / Q000378:metabolism; D011077:Polychaeta / Q000033:anatomy & histology* / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D060449:Wnt Signaling Pathway / Q000235:genetics; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D054460:rho-Associated Kinases