Gardiner D M, Bryant S V
Developmental Biology Center, University of California, Irvine 92717.
J Exp Zool. 1989 Jul;251(1):47-55. doi: 10.1002/jez.1402510107.
We have used the phenomenon of position-dependent growth stimulation, brought about by the confrontation of cells with dissimilar positional values, to reveal the organization of positional information in the center of the upper and lower arms of axolotls. When either humerus or radius was transplanted into either dorsal or posterior positions, extra growth leading to the formation of supernumerary digits occurred following amputation through the graft. However, transplants of humerus or radius into anterior or ventral positions did not lead to the formation of any additional digits. The ulna by contrast was capable of stimulating supernumerary digit formation when transplanted into anterior, posterior, dorsal, or ventral positions. We interpret these results to indicate that the humerus and radius are surrounded by symmetrically arranged anterior and ventral positional values, whereas the ulna is surrounded by a complete asymmetrical set of angular positional values. We use our proposed arrangement for the positional information in the limb center to explain a number of previous experimental findings. In addition, we provide an explanation, in terms of the underlying positional information, for the structural and developmental relationships between the different skeletal elements of the vertebrate limb, and in particular for the anatomical pattern known as Gregory's pyramid.
我们利用细胞与不同位置值相对抗所引发的位置依赖性生长刺激现象，来揭示蝾螈上臂和下臂中心位置信息的组织方式。当将肱骨或桡骨移植到背侧或后侧位置时，通过移植部位截肢后会出现额外生长，导致多指形成。然而，将肱骨或桡骨移植到前侧或腹侧位置不会导致任何额外指的形成。相比之下，尺骨移植到前侧、后侧、背侧或腹侧位置时能够刺激多指形成。我们将这些结果解释为表明肱骨和桡骨被对称排列的前侧和腹侧位置值所包围，而尺骨被一组完全不对称的角位置值所包围。我们利用我们提出的肢体中心位置信息排列方式来解释一些先前的实验结果。此外，我们根据潜在的位置信息，对脊椎动物肢体不同骨骼元素之间的结构和发育关系，特别是对被称为格雷戈里金字塔的解剖模式，提供了解释。
