Development and evolution of the neural crest: an overview

Abstract

The neural crest is a multipotent and migratory cell type that forms transiently in the developing vertebrate embryo. These cells emerge from the central nervous system, migrate extensively and give rise to diverse cell lineages including melanocytes, craniofacial cartilage and bone, peripheral and enteric neurons and glia, and smooth muscle. A vertebrate innovation, the gene regulatory network underlying neural crest formation appears to be highly conserved, even to the base of vertebrates. Here, we present an overview of important concepts in the neural crest field dating from its discovery 150 years ago to open questions that will motivate future research.

Figure 1

Schematic diagram illustrating the grafting technique whereby donor quail tissue is transplanted in place of a similar region of host chick tissue. This can be done at different axial levels and for different tissue; e.g. to transplant ectodermal placodes (a), cranial neural folds (b), and trunk neural tubes (c). (reprinted with permission).

Figure 2

Quail tissue can be recognized after transplantation into chick hosts. a) examples of hatchlings in which trunk quail neural tubes were grafted into white leghorn chick hosts, which lack melanocytes. Since neural crest cells give rise to melanocytes, the quail-derived donor cells have populated the feathers of the wings, which have quail pigmentation. b) a transverse section of an embryo into which a quail neural tube (NT) plus notochord (No) was transplanted. After staining for DNA, quail cells (arrows) can be recognized by the condensed heterochromatin and can be seen migrating away from the donor neural tube. (reprinted with permission).

Figure 3

Schematic diagram illustrating different levels of the body axis and the types of derivatives arising from neural crest at those levels. (reprinted with permission).