Molecular genetic analysis of Wnt signals in mouse development

A major advance in developmental biology has been the identification of signalling molecules responsible for mediating pattern formation. The Wnts, a large family of secreted glycoproteins, are involved in numerous fundamental patterning processes throughout vertebrate embryogenesis. In-situ hybridization and ectopic expression studies have implicated Wnts in the control of gastrulation, CNS patterning, organogenesis, and limb development. Mutations in various mouse Wnt genes which have been generated using gene targeting techniques have allowed a direct assessment of the role of Wnt signals in these processes. In conjuction with the identification of factors involved in the interpretation of Wnt signals, these data begin to present a glimpse of the mechanism by which Wnt signals regulate embryonic development.