In vertebrates, the Wnt/β-catenin pathway is the core of a conserved mechanism that establishes the main body axis during early development. Now, on p. 2567, Andrés Carrasco and colleagues report that Notch restricts dorsal-anterior development in Xenopus by destabilising maternal β-catenin. The blastula chordin- and noggin-expressing centre (BCNE) is a signalling centre in early Xenopus embryos that precedes the Spemann-Mangold's organiser and that contains brain precursors. BCNE specification depends on the dorsal accumulation of nuclear β-catenin. By injecting early embryos with Notch mRNA and morpholino constructs, the researchers show that Notch antagonises Wnt signalling by degrading β-catenin in the ventral region of the embryo. This degradation process, they report, does not require β-catenin phosphorylation by GSK3, a process that usually marks β-catenin for degradation. The researchers suggest that this interaction between Notch and β-catenin, which has not previously been recognised in vertebrates, restricts the size of the BCNE and controls the size of the brain.