Kelley R O
J Embryol Exp Morphol. 1975 Aug;34(1):1-18.
Development of the human hand plate (stages 16-17) has been analyzed with emphasis on differentiation of elements within the extracellular matrix and the composition of the mesenchymal cell surface. The epithelial-mesenchymal interface contains a basal lamina and a sublaminar matrix exhibiting: (a) collagen fibrils with characteristic 63-64 nm banding: (b) non-banded filaments, 10-15 nm in diameter; (c) ruthenium red-positive particles, 12-15 nm in diameter; and (d) attenuated threads, 3-5-5-0 nm in diameter which inter-connect particles, fibrils, filaments and the basal lamina. Processes of mesenchymal cells penetrate this matrix network. In addition to staining with ruthenium red, components of basal laminae bind to ferritin-conjugated Concanavalin A, greatest binding being localized on the mesenchymal surface of the lamina. Asymmetry of binding is removed by incubation of exposed laminae with trypsin (5 mug/ml). Regional differences in these staining and binding characteristics within the subepithelial matrix have not been observed in the hand plate. However, precartilaginous extracellular zones deep within the plate are notably unstructured in comparison to the sublaminar region. Ruthenium red-positive materials at mesenchymal cell surfaces display sensitivity to testicular hyaluronidase, Pronase and trypsin but resist removal with neuraminidase and EDTA. These features of the substrate in situ may be important in the regulation of mesenchymal cell behavior during limb morphogenesis in man.
对人手部板（第16 - 17阶段）的发育进行了分析，重点关注细胞外基质内成分的分化以及间充质细胞表面的组成。上皮 - 间充质界面包含基膜和亚层基质，其表现为：（a）具有特征性63 - 64纳米条带的胶原纤维；（b）直径为10 - 15纳米的无条带细丝；（c）直径为12 - 15纳米的钌红阳性颗粒；以及（d）直径为3 - 5 - 5 - 0纳米的细弱丝，它们将颗粒、纤维、细丝和基膜相互连接。间充质细胞的突起穿透该基质网络。除了用钌红染色外，基膜成分还与铁蛋白偶联的伴刀豆球蛋白A结合，最大结合部位位于基膜的间充质表面。用胰蛋白酶（5微克/毫升）孵育暴露的基膜可消除结合的不对称性。在手板中未观察到上皮下基质内这些染色和结合特征的区域差异。然而，与亚层区域相比，板深部的软骨前细胞外区域明显缺乏结构。间充质细胞表面的钌红阳性物质对睾丸透明质酸酶、链霉蛋白酶和胰蛋白酶敏感，但对神经氨酸酶和乙二胺四乙酸有抗性。原位底物的这些特征可能对人类肢体形态发生过程中间充质细胞行为的调节很重要。
