Molecular genetics of early liver development

The control of liver development was originally defined by classical histology and tissue transplantation studies twenty to thirty years ago. In the past ten years, molecular biology studies have revealed numerous transcription factors important for adult liver differentiation. Recent work in which genes encoding regulatory proteins are inactivated in transgenic mice is evaluated in order to assess the consequences on liver development. The transgenic studies emphasize the roles of growth factors and signal transducers and the conservation of the basic components of signaling pathways in evolution.