Beta-catenin Translocation Into Nuclei Demarcates the Dorsalizing Centers in Frog and Fish Embryos

Mech Dev. 1996 Jul;57(2):191-8. doi: 10.1016/0925-4773(96)00546-1.

Abstract

The question of how dorsal-ventral polarity is established in vertebrates is central to our understanding of their early development. Several lines of evidence suggest that wnt-signaling is involved in the induction of dorsal-specific gene expression in the Spemann Organizer of amphibians. Here, we show that beta-catenin, acting as a component of the wnt-pathway, transiently accumulates in nuclei on the dorsal side of Xenopus and zebrafish blastulae. The spatially restricted nuclear translocation of beta-catenin precedes the expression of dorsal-specific genes. In experimentally ventralized frog embryos the dorsal ventral pattern of beta-catenin nuclear staining is abolished; in contrast, embryos hyperdorsalized by Li-ions or by injection of Xwnt8 mRNA exhibit an enhanced nuclear accumulation of beta-catenin. The results show that translocation of beta-catenin into nuclei in the wake of wnt-signaling is an early step in the establishment of the dorsal-ventral axis in frog and fish embryos.

MeSH terms

  • Animals
  • Body Patterning / physiology*
  • Cadherins / metabolism*
  • Cell Nucleus / chemistry
  • Cell Nucleus / metabolism
  • Cytoskeletal Proteins / genetics*
  • Cytoskeletal Proteins / metabolism
  • Gene Expression Regulation, Developmental / physiology
  • Lithium / pharmacology
  • Trans-Activators*
  • Xenopus / embryology*
  • Xenopus Proteins
  • Zebrafish / embryology*
  • Zebrafish Proteins
  • beta Catenin

Substances

  • CTNNB1 protein, Xenopus
  • Cadherins
  • Cytoskeletal Proteins
  • Trans-Activators
  • Xenopus Proteins
  • Zebrafish Proteins
  • beta Catenin
  • ctnnb1 protein, zebrafish
  • Lithium