title: Chibby functions in Xenopus ciliary assembly, embryonic development, and the regulation of gene expression.
abstract: Wnt signaling and ciliogenesis are core features of embryonic development in a range of metazoans. Chibby (Cby), a basal-body associated protein, regulates β-catenin-mediated Wnt signaling in the mouse but not Drosophila. Here we present an analysis of Cby's embryonic expression and morphant phenotypes in Xenopus laevis. Cby RNA is supplied maternally, negatively regulated by Snail2 but not Twist1, preferentially expressed in the neuroectoderm, and regulates β-catenin-mediated gene expression. Reducing Cby levels reduced the density of multiciliated cells, the number of basal bodies per multiciliated cell, and the numbers of neural tube primary cilia; it also led to abnormal development of the neural crest, central nervous system, and pronephros, all defects that were rescued by a Cby-GFP chimera. Reduction of Cby led to an increase in Wnt8a and decreases in Gli2, Gli3, and Shh RNA levels. Many, but not all, morphant phenotypes were significantly reversed by the Wnt inhibitor SFRP2. These observations extend our understanding of Cby's role in mediating the network of interactions between ciliogenesis, signaling systems and tissue patterning.
authors.affiliation: Molecular, Cellular, & Developmental Biology, University of Colorado, Boulder, CO 80309-347, USA.
authors.forename: Jianli
authors.initials: J
authors.lastname: Shi
authors.affiliation: Molecular, Cellular, & Developmental Biology, University of Colorado, Boulder, CO 80309-347, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Molecular, Cellular, & Developmental Biology, University of Colorado, Boulder, CO 80309-347, USA.
authors.forename: Domenico
authors.initials: D
authors.lastname: Galati
authors.affiliation: Molecular, Cellular, & Developmental Biology, University of Colorado, Boulder, CO 80309-347, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Winey
authors.affiliation: Molecular, Cellular, & Developmental Biology, University of Colorado, Boulder, CO 80309-347, USA. Electronic address: michael.klymkowsky@colorado.edu.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Klymkowsky
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002923:Cilia / Q000235:genetics* / Q000502:physiology; D017931:DNA Primers / Q000235:genetics; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics* / Q000502:physiology*; D015151:Immunoblotting; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D047908:Intracellular Signaling Peptides and Proteins; D018613:Microscopy, Confocal; D054258:Neural Plate / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis / Q000196:embryology* / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; C000594710:Cby1 protein, Xenopus; D017931:DNA Primers; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D029867:Xenopus Proteins
keywords: Chibby; Cilia; Hedgehog; Neural crest; Neural plate; Pronephros; Snail2; Wnt signaling; Xenopus laevis