Regulation of the Hedgehog Morphogene Gradient

Abstract

The development of a multicellular organism is controlled by a genetic program that manifests itself in proliferation, cell differentiation, and apoptosis, leading to the formation of functional organs. A small number of secreted molecules work as “instructors” during these processes [1, 2]. Among them are the Hedgehog (Hh) family of proteins, which act from their source of production at short and long range. They trigger cell fate decisions by inducing a signaling cascade in the ligand-receiving tissues of invertebrates and vertebrates. Dramatic developmental abnormalities are observed in human embryos with compromised Hh signaling, and while great effort is being made to understand and man..