The neural crest and neural crest cells: discovery and significance for theories of embryonic organization

Abstract

The neural crest has long fascinated developmental biologists,and,increasingly over the past decades,evolutionary and evolutionary developmental biologists.The neural crest is the name given to the fold of ectoderm at the junction between neural and epidermal ectoderm in neurula-stage vertebrate embryos.In this sense,the neural crest is a morphological term akin to head fold or limb bud.This region of the dorsal neural tube consists of neural crest cells,a special population(s)of cell,that give rise to an astonishing number of cell types and to an equally astonishing number of tissues and organs.Neural crest cell contributions may be direct - providing cells - or indirect - providing a necessary, often inductive, environment in which other cells develop.The enormous range of cell types produced provides an important source of evidence of the neural crest as a germ layer, bringing the number of germ layers to four - ectoderm,endoderm,mesoderm,and neural crest. In this paper I provide a brief overview of the major phases of investigation into the neural crest and the major players involved,discuss how the origin of the neural crest relates to the origin of the nervous system in vertebrate embryos,discuss the impact on the germ-layer theory of the discovery of the neural crest and of secondary neurulation,and present evidence of the neural crest as the fourth germ layer.A companion paper (Hall, Evol. Biol.2008) deals with the evolutionary origins of the neural crest and neural crest cells.

Sulforaphane protects against ethanol‐induced oxidative stress and apoptosis in neural crest cells by the induction of Nrf2‐mediated antioxidant response

“…Activation of Nrf2 also protected against cell death in an in vitro model of ischaemia/reperfusion (Danilov et al, 2009). Studies have also shown that exposure to chromium (VI) and cadmium resulted in an increased ROS production and apoptosis in mouse embryonic fibroblast cells lacking Nrf2 (He et al, 2007;2008). Loss of Nrf2 function has also been found to be associated with increased susceptibility to chemical carcinogenesis, inhalation particles, ovarian toxicants and autoimmune disease (Ramos-Gomez et al, 2001;Li et al, 2004;Hu et al, 2006;Ma et al, 2006).…”

“…Among the vulnerable cell populations are neural crest cells (NCCs) (Sulik et al, 1981;Kotch and Sulik, 1992;Cartwright and Smith, 1995;Chen and Sulik, 1996;Chen and Sulik, 2000). The NCC is a multipotent progenitor cell population that can give rise to a diversity of neural and non-neural cell types, such as melanocytes, neurons, glial cells, endocrine cells, as well as mesenchymal cells that form craniofacial cartilages, bones, dermis, adipose tissue and vascular smooth muscle cells (Teng and Labosky, 2006;Hall, 2008). Studies have demonstrated that NCCs are vulnerable to ethanolinduced cytotoxicity.…”

Recapitulating cranial osteogenesis with neural crest cells in 3-D microenvironments

“…Often referred to as the "fourth embryonic germ layer" [10,11], neural crest is a transient, multipotent embryonic population of cells, which migrate from their site of origin at the dorsal neural tube and differentiate into a diverse array of specialized cell types during vertebrate development [12]. Cranial neural crest cells (CNCCs) can differentiate into chondrogenic and osteogenic cells that, in turn, generate most of the cranial skeletal tissues (both bones and cartilages) in the vertebrate head [12,13].…”

An embryological point of view on associated congenital anomalies of children with Hirschsprung disease

“…Neural crest cells originate in the dorsal parts of neural folds of developing neural tube, at the junction between neural ectoderm (the neural plate as the future brain and spinal cord) and non-neural ectoderm (future epidermis of the skin) (8). During the development of neural tube, the cells of neural crest origin underwent epithelial-to-mesenchymal transition (9) and migrate via different pathways into the whole embryo.…”