Abstract

Normal development of the nervous system is achieved through an elaborate program of guided neuronal migration and axonal growth. In the last few years, a flood of research has dissected the molecular bases of these phenomena, and several cell‐surface and extracellular matrix molecules, which are implicated in neuronal and axonal targeting processes, have been recognized. Taking this knowledge a step further, a recent paper by Tom Curran's group(1) reports the molecular cloning of the gene deleted in the autosomal recessive mouse mutation reeler, affecting cortical neuronal migration. This gene encodes reelin, a novel extracellular matrix protein.