Solursh M
Cell Differ. 1984 Nov;15(1):17-24. doi: 10.1016/0045-6039(84)90025-3.
This review considers the hypothesis that the limb bud ectoderm establishes the initial pattern of the various mesodermal components within the limb bud. The evidence reviewed supports the hypothesis that the ectoderm establishes a peripheral, non-chondrogenic, avascular sleeve around the limb bud. The ectodermal influence is a diffusible factor that acts by altering the collagenous extracellular matrix so that cell flattening and fibrogenic differentiation are promoted. It is hypothesized that just within this sleeve is a vascular-rich zone where myogenic cells migrate in response to a chemotactic influence. In the center of the limb bud is the prechondrogenic core, whose size determines the number of skeletal elements which subsequently form. The dimensions of the developing limb bud are established during distal limb outgrowth by the reciprocal interaction between the apical ectodermal ridge, which has a mitogenic influence, and the underlying mesoderm.
本综述探讨了一个假说，即肢芽外胚层建立了肢芽内各种中胚层成分的初始模式。所综述的证据支持这样的假说：外胚层在肢芽周围建立起一个外周的、非软骨生成的、无血管的套层。外胚层的影响是一种可扩散因子，其作用方式是改变胶原细胞外基质，从而促进细胞扁平化和纤维生成分化。据推测，就在这个套层内是一个血管丰富的区域，成肌细胞在趋化作用的影响下迁移至此。在肢芽的中心是软骨前体核心，其大小决定了随后形成的骨骼元素的数量。在远端肢体生长过程中，具有促有丝分裂作用的顶端外胚层嵴与下方的中胚层之间的相互作用确定了发育中肢芽的尺寸。
