Wnt/β-Catenin dependent roles of the Pygopus family of nuclear factors during Zebrafish early dorso-ventral specification

The Increase in Maternal Expression ofaxin1andaxin2Contribute to the Zebrafish MutantIchabodVentralized Phenotype

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-ca…