β-Catenin regulates Cripto- and Wnt3-dependent gene expression programs in mouse axis and mesoderm formation

Gene expression profiling of β-catenin, Cripto and Wnt3 mutant mouse embryos has been used to characterise the genetic networks that regulate early embryonic development. We have defined genes whose expression is regulated by β-catenin during formation of the anteroposterior axis and the mesoderm, and have identified Cripto, which encodes a Nodal co-receptor, as a primary target of β-catenin signals both in embryogenesis as well as in colon carcinoma cell lines and tissues. We have also defined groups of genes regulated by Wnt3/β-catenin signalling during primitive streak and mesoderm formation. Our data assign a key role to β-catenin upstream of two distinct gene expression programs during anteroposterior axis and mesoderm formation.