Richardson M K, Sieber-Blum M
Department of Cell Biology and Anatomy, Medical College of Wisconsin, Milwaukee 53226.
Dev Biol. 1993 Jun;157(2):348-58. doi: 10.1006/dbio.1993.1140.
The neural crest, a migratory population of embryonic cells, gives rise to a wide range of differentiated cell types in the mature vertebrate organism, including the melanocytes of the skin. Little is known about the developmental potentials of neural crest cells toward the end of their migratory phase. We have therefore used in vitro analysis to examine the developmental potential of mesenchymal cells derived from explants of trunk epidermal ectoderm of the quail embryo. Melanocytes which differentiated in the cultures could be identified by their content of melanin granules. To detect different neuronal cells, the cultures were stained with antibodies including anti-dopamine-beta-hydroxylase (anti-DBH), which characterizes sympathoadrenal cells, and AC4, an antibody which recognizes the stage-specific embryonic antigen-1 (SSEA-1) that is expressed by cells in the sensory neuron lineage of the quail embryo, but not by sympathoadrenal cells. Seventy-eight percent of the population of neural crest-derived cells seeding the ectoderm around stage 21 gave rise to colonies containing melanocytes only. Twenty percent, however, generated mixed colonies that contained melanocytes, DBH+ cells, SSEA-1+ cells, and unidentified, unpigmented cells. Small numbers of colonies containing fewer phenotypes were also seen. With increasing embryonic age, the number of colonies containing multiple phenotypes declined, until by stage 30 all neural crest colonies contained melanocytes only. Some colonies had been marked at the single-cell stage, and this provided additional confirmation that each colony-type could be generated from a single cell. Thus the significant finding in this study is that a substantial fraction of the neural crest cells arriving early in the ectoderm are pluripotent cells that are able to give rise to pigment cells, to sympathoadrenal cells, to primary sensory neuron precursors, and possibly to other cells which were not identified here. This observation may have implications for our understanding of the mechanisms that control neural crest cell migration and differentiation.
神经嵴是一群迁移的胚胎细胞，在成熟的脊椎动物机体中会产生多种分化的细胞类型，包括皮肤的黑素细胞。关于神经嵴细胞在其迁移阶段末期的发育潜能，人们了解甚少。因此，我们利用体外分析来研究源自鹌鹑胚胎躯干表皮外胚层外植体的间充质细胞的发育潜能。培养物中分化出的黑素细胞可通过其所含的黑素颗粒来识别。为了检测不同的神经元细胞，培养物用包括抗多巴胺-β-羟化酶（抗DBH）的抗体进行染色，抗DBH可鉴定交感肾上腺细胞，还有AC4，这是一种识别阶段特异性胚胎抗原-1（SSEA-1）的抗体，鹌鹑胚胎感觉神经元谱系中的细胞表达该抗原，但交感肾上腺细胞不表达。在约21期接种到外胚层的神经嵴来源细胞群体中，78%产生了仅含有黑素细胞的集落。然而，20%产生了混合集落，其中包含黑素细胞、DBH阳性细胞、SSEA-1阳性细胞以及未鉴定的无色素细胞。也观察到了含有较少表型的少量集落。随着胚胎年龄的增加，含有多种表型的集落数量减少，直到30期时所有神经嵴集落都仅含有黑素细胞。一些集落在单细胞阶段就已被标记，这进一步证实了每种集落类型都可由单个细胞产生。因此，本研究的重要发现是，在外胚层早期到达的相当一部分神经嵴细胞是多能细胞，能够产生色素细胞、交感肾上腺细胞、初级感觉神经元前体，可能还能产生此处未鉴定的其他细胞。这一观察结果可能对我们理解控制神经嵴细胞迁移和分化的机制具有启示意义。
