Saha M S, Grainger R M
Department of Biology, University of Virginia, Charlottesville 22901.
Neuron. 1992 Jun;8(6):1003-14. doi: 10.1016/0896-6273(92)90123-u.
The process by which the vertebrate central nervous system acquires its regional properties remains a central problem in developmental biology. It is generally argued that at early gastrula stages the dorsal mesoderm possesses precise anterior-posterior positional information, which is subsequently imparted to the overlying ectoderm. However, using regionally specific gene probes to monitor regional responses in Xenopus embryos, we find that anterior-posterior properties are not fixed until early neurula stages. During gastrulation the regional inducing capacities of the dorsal mesoderm as well as the regional responses of the presumptive neural ectoderm are activated along the entire anterior-posterior axis when these properties are assayed in recombinant and explant experiments, respectively. Restriction of regional inducing capacity in the mesoderm and responsiveness in the neural ectoderm occur only at neural plate stages.
脊椎动物中枢神经系统获得其区域特性的过程仍然是发育生物学中的一个核心问题。一般认为，在原肠胚早期阶段，背侧中胚层拥有精确的前后位置信息，随后该信息被传递给上方的外胚层。然而，使用区域特异性基因探针监测非洲爪蟾胚胎中的区域反应时，我们发现前后特性直到神经胚早期阶段才固定下来。在原肠胚形成期间，当分别在重组实验和外植体实验中检测这些特性时，背侧中胚层的区域诱导能力以及假定神经外胚层的区域反应沿着整个前后轴被激活。中胚层区域诱导能力和神经外胚层反应性的限制仅发生在神经板阶段。
