File:Melanocyte development cartoon.jpg

Overview of Melanocyte Development

A In mammals, melanoblasts are specified from neural crest cells (NCCs) via a SOX10-positive melanoblast/glial bipotent progenitor. SOX10 expression remains switched on in both of these lineages. Melanoblasts subsequently are specified and acquire MITF, DCT and KIT expression. After colonising the developing embryonic hair follicles, some melanoblasts differentiate into melanocytes and produce the pigment (melanin) that colours the first hair cycle. A subset of melanoblasts dedifferentiate (losing MITF and KIT expression but not DCT) to form melanocyte stem cells in the hair follicle bulge that replenish the differentiated melanocytes via a rapidly proliferating transit-amplifying cell in the subsequent hair cycles. The image on the far right is of a transgenic mouse embryo expressing lacZ under control of the melanoblast promoter Dct. X-Gal staining reveals blue-stained melanoblasts, in particular those migrating from the cervical neural crest and in the head. Also stained are the telencephalon, the dorsal root ganglia (DRG) and the retinal pigmented epithelium of the eye.

B In zebrafish, there are distinct embryonic and adult pigmentation patterns, as illustrated in the images on the far right. The melanoblasts that form both these patterns originate from a SOX10-positive neural crest-derived progenitor. The embryonic pattern is formed by melanocytes that develop directly from this progenitor via an MITF+ melanoblast. The melanoblasts that form the adult pattern are derived from a melanocyte stem cell population that resides at the dorsal route ganglia (DRG) and is specified by an ERB- and KIT-dependent pathway in the embryo.

Links: Melanocyte Development

Reference

<pubmed>25670789</pubmed>| Development

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© 2014. Published by The Company of Biologists Ltd This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.