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Neural crest cells are a temporary group of cells unique to vertebrates that arise from the embryonic ectoderm cell layer, and in turn give rise to a diverse cell lineage -- including melanocytes, craniofacial cartilage and bone, smooth muscle, peripheral and enteric neurons and glia.〔Huang, X., and Saint-Jeannet, J.P. (2004). "Induction of the neural crest and the opportunities of life on the edge". Dev. Biol. 275, 1-11. 〕 After gastrulation, neural crest cells are specified at the border of the neural plate and the non-neural ectoderm. During neurulation, the borders of the neural plate, also known as the neural folds, converge at the dorsal midline to form the neural tube. Subsequently, neural crest cells from the roof plate of the neural tube undergo an epithelial to mesenchymal transition, delaminating from the neuroepithelium and migrating through the periphery where they differentiate into varied cell types.〔 The emergence of neural crest was important in vertebrate evolution because many of its structural derivatives are defining features of the vertebrate clade.〔Meulemans, D., and Bronner-Fraser, M. (2004). "Gene-regulatory interactions in neural crest evolution and development". Dev Cell. 7, 291-9. 〕 Underlying the development of neural crest is a gene regulatory network, described as a set of interacting signals, transcription factors, and downstream effector genes that confer cell characteristics such as multipotency and migratory capabilities.〔Sauka-Spengler, T., Meulemans, D., Jones, M., and Bronner-Fraser, M. (2007). "Ancient evolutionary origin of the neural crest gene regulatory network". Dev Cell. 13, 405-20. PMID 17765683〕 Understanding the molecular mechanisms of neural crest formation is important for our knowledge of human disease because of its contributions to multiple cell lineages. Abnormalities in neural crest development cause neurocristopathies, which include conditions such as frontonasal dysplasia, Waardenburg-Shah syndrome, and DiGeorge syndrome.〔 Therefore, defining the mechanisms of neural crest development may reveal key insights into vertebrate evolution and neurocristopathies. ==History== Neural crest was first described in the chick embryo by Wilhelm His in 1868 as "the cord in between" (Zwischenstrang) because of its origin between the neural plate and non-neural ectoderm.〔 He named the tissue ganglionic crest since its final destination was each lateral side of the neural tube where it differentiated into spinal ganglia.〔Le Douarin, N.M. (2004). "The avian embryo as a model to study the development of the neural crest: a long and still ongoing story". Mech Dev. 121, 1089-102. 〕 During the first half of the 20th century the majority of research on neural crest was done using amphibian embryos which was reviewed by Hörstadius (1950) in a well known monograph.〔Hörstadius, S. (1950). ''The Neural Crest: Its Properties and Derivatives in the Light of Experimental Research''. Oxford University Press, London, 111 p.〕 Cell labeling techniques advanced the field of neural crest because they allowed researchers to visualize the migration of the tissue throughout the developing embryos. In the 1960s Weston and Chibon utilized radioisotopic labeling of the nucleus with tritiated thymidine in chick and amphibian embryo respectively. However, this method suffers from drawbacks of stability, since every time the labeled cell divides the signal is diluted. Modern cell labeling techniques such as rhodamine-lysinated dextran and the vital dye diI have also been developed to transiently mark neural crest lineages.〔 The quail-chick marking system, devised by Nicole Le Douarin in 1969, was another instrumental technique used to track neural crest cells.〔Le Douarin, N.M. (1969). "Particularités du noyau interphasique chez la Caille japonaise (Coturnix coturnix japonica). Utilisation de ces particularités comme «marquage biologique» dans les recherches sur les interactions tissulaires et les migrations cellulaires au cours de l'ontogenèse". Bull biol Fr Belg 103 : 435-52.〕〔Le Douarin, N.M. (1973). "A biological cell labeling technique and its use in experimental embryology". Dev Biol. 30 217-22. 〕 Chimeras, generated through transplantation, enabled researchers to distinguish neural crest cells of one species from the surrounding tissue of another species. With this technique, generations of scientists were able to reliably mark and study the ontogeny of neural crest cells. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Neural crest」の詳細全文を読む スポンサード リンク
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