To adhere or not to adhere

The modulation of cell adhesion is fundamental to the morphogenesis that accompanies proper embryonic development. Cadherins are a large family of calcium-dependent cell adhesion molecules whose spatial and temporal expression is critical to the formation of the neural crest, a unique, multipotent cell type that contributes to the patterning of the vertebrate body plan. Neural crest cells arise from the embryonic ectoderm through inductive interactions and reside in the dorsal aspect of the neural tube. These cells under go an epithelial-to-mesenchymal transition and migrate to precise destinations in the embryo, where they go on to differentiate into such diverse structures as melanocytes, elements of the peripheral nervous system, and the craniofacial skeleton. Distinct cadherins are expressed during the induction, migration and differentiation of the neural crest. With the advent of genomic sequencing, assembly and annotation for various model organisms, it has become possible to elucidate the molecular mechanisms underlying cadherin expression, and how these cadherins function, during neural crest development. This review explores the known roles of cadherins and details, where relevant, how different cadherins are regulated during the formation of the neural crest.