The development of the mouse kidney--embryogenesis writ small.

Kidney development starts with an epithelial bud and a domain of committed mesenchyme inducing one another so that the former gives a bifurcating duct system and the latter nephrons. As these events take place in vitro, the mechanisms underpinning nephrogenesis can be investigated experimentally. Recent work has shown the diversity of regulatory molecules expressed during kidney development and begun to clarify the molecular basis of mesenchyme induction, but there is more to come.