title: The increase in maternal expression of axin1 and axin2 contribute to the zebrafish mutant ichabod ventralized phenotype.
abstract: β-Catenin is a central effector of the Wnt pathway and one of the players in Ca(+)-dependent cell-cell adhesion. While many wnts are present and expressed in vertebrates, only one β-catenin exists in the majority of the organisms. One intriguing exception is zebrafish that carries two genes for β-catenin. The maternal recessive mutation ichabod presents very low levels of β-catenin2 that in turn affects dorsal axis formation, suggesting that β-catenin1 is incapable to compensate for β-catenin2 loss and raising the question of whether these two β-catenins may have differential roles during early axis specification. Here we identify a specific antibody that can discriminate selectively for β-catenin1. By confocal co-immunofluorescent analysis and low concentration gain-of-function experiments, we show that β-catenin1 and 2 behave in similar modes in dorsal axis induction and cellular localization. Surprisingly, we also found that in the ich embryo the mRNAs of the components of β-catenin regulatory pathway, including β-catenin1, are more abundant than in the Wt embryo. Increased levels of β-catenin1 are found at the membrane level but not in the nuclei till high stage. Finally, we present evidence that β-catenin1 cannot revert the ich phenotype because it may be under the control of a GSK3β-independent mechanism that required Axin's RGS domain function.
authors.affiliation: Sbarro Institute for Cancer Research and Molecular Medicine, College of Science and Technology, Temple University, Philadelphia, 19122, Pennsylvania; Department of Biology, College of Science and Technology, Temple University, Philadelphia, 19122, Pennsylvania.
authors.forename: Fabio
authors.initials: F
authors.lastname: Valenti
authors.forename: Jessica
authors.initials: J
authors.lastname: Ibetti
authors.forename: Yuko
authors.initials: Y
authors.lastname: Komiya
authors.forename: Melissa
authors.initials: M
authors.lastname: Baxter
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Lucchese
authors.forename: Lauren
authors.initials: L
authors.lastname: Derstine
authors.forename: Claudia
authors.initials: C
authors.lastname: Covaciu
authors.forename: Valeria
authors.initials: V
authors.lastname: Rizzo
authors.forename: Renza
authors.initials: R
authors.lastname: Vento
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Russo
authors.forename: Marcella
authors.initials: M
authors.lastname: Macaluso
authors.forename: Franco
authors.initials: F
authors.lastname: Cotelli
authors.forename: Daniele
authors.initials: D
authors.lastname: Castiglia
authors.forename: Cara J
authors.initials: CJ
authors.lastname: Gottardi
authors.forename: Raymond
authors.initials: R
authors.lastname: Habas
authors.forename: Antonio
authors.initials: A
authors.lastname: Giordano
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Bellipanni
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D060466:Axin Protein / Q000235:genetics / Q000378:metabolism*; D036703:Blastula / Q000187:drug effects / Q000378:metabolism; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D047108:Embryonic Development / Q000187:drug effects / Q000235:genetics; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D005799:Genes, Dominant; D007150:Immunohistochemistry; D018021:Lithium Chloride / Q000494:pharmacology; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D055550:Protein Stability / Q000187:drug effects; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics; D015027:Zebrafish / Q000196:embryology / Q000235:genetics*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism
chemical_list: D060466:Axin Protein; C000601280:Axin1 protein, zebrafish; D012333:RNA, Messenger; D029961:Zebrafish Proteins; C000601281:axin2 protein, zebrafish; D051176:beta Catenin; D018021:Lithium Chloride
keywords: AXIS FORMATION; Axin2-RGS DOMAIN; BETA-CATENIN; Wnt signaling; ZEBRAFISH