The Bicoid Morphogen Papers (II): Account from Wolfgang Driever.

This article presents information on a gradient of bicoid (bcd) protein in drosophila embryos. According to the concept of positional information, the concentration of a morphogen instructs cells within an embryonic field of their position. The cells then interpret this information by an appropriate program of differentiation. Several models have been proposed that describe the generation of stable gradients of morphogens which could specify subregions of the embryo in a concentration-dependent manner.