Niswander L, Tickle C, Vogel A, Booth I, Martin G R
Department of Anatomy, School of Medicine, University of California, San Francisco 94143.
Cell. 1993 Nov 5;75(3):579-87. doi: 10.1016/0092-8674(93)90391-3.
The apical ectodermal ridge plays a key role in limb development. We show that recombinant FGF-4 can substitute for the ridge to provide all the signals necessary for virtually complete outgrowth and patterning of the chick limb. FGF-4 stimulates proliferation of cells in the distal mesenchyme and maintains a signal from the posterior to the distal mesenchyme that appears to be required for elaboration of skeletal elements in the normal proximodistal sequence. Moreover, retinoic acid, which is capable of providing polarizing activity, can supply this signal. This suggests that polarizing activity plays a role in patterning along the proximodistal axis, in addition to its well-established role in anteroposterior patterning. Taken together, the data suggest a simple mechanism whereby FGF-4 links growth and pattern formation during limb development.
顶端外胚层嵴在肢体发育中起关键作用。我们发现重组FGF-4可以替代嵴，为鸡胚肢体几乎完全的生长和模式形成提供所有必要信号。FGF-4刺激远端间充质细胞的增殖，并维持从后部到远端间充质的信号，这一信号似乎是按照正常的近端到远端顺序形成骨骼元件所必需的。此外，能够提供极化活性的视黄酸也可以提供这一信号。这表明极化活性除了在前后模式形成中已确立的作用外，在沿近端到远端轴的模式形成中也发挥作用。综上所述，这些数据提示了一种简单的机制，即FGF-4在肢体发育过程中连接生长和模式形成。
