Hama Tadao, Tsujimura Hidenobu, Kanéda Teruo, Takata Kenzo, Ohara Akito
Biological Institute, Faculty of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464, Japan.
Dev Growth Differ. 1985;27(4):419-433. doi: 10.1111/j.1440-169X.1985.00419.x.
The organization center of Cynops pyrrhogaster was divided into Parts 1, 2 and 3 of equal size (0.3×0.4 mm ) with presumptive fates as pharyngeal, pharyngeal+prechordal+trunk notochord, and trunk-tail notochord, respectively. Movements and changes in size and shape of each part were followed through gastrulation. Differentiation tendencies of each part were examined under three conditions: I, isolated; II, sandwiched with presumptive ectoderm; 111, sandwiched with presumptive ectoderm after preculture in isolation for various times. In I, Parts 2 and 3 differentiated into dorsal mesoderm. In II, each part induced dorsal mesoderm and neural tissues, the frequency being highest in Part 2 and lowest in Part 3. In III, Parts 1 and 2 realized their presumptive fates, through changes in inductive capacities from trunk-tail to head. This change progressed rapidly in Part 1, and slowly in Part 2. Part 3 required induction by neighbouring Part 2 to realize its presumptive fate. Changes of inductive capacity of Parts 1 and 2 respectively, were chronologically similar in normal development and in preculture experiments. Lastly, the primary presumptive pharyngeal zone at blastula was proposed to act as an initiator of the organization center, its programmed information being transmitted to Part 2, and then to Part 3.
将日本林蛙的组织中心等分为大小相等的1、2、3部分（0.3×0.4毫米），其预定命运分别为咽部、咽部+前索+躯干脊索和躯干-尾部脊索。在原肠胚形成过程中观察各部分的运动以及大小和形状的变化。在三种条件下研究各部分的分化倾向：I，分离；II，与预定外胚层夹在一起；III，在分离预培养不同时间后与预定外胚层夹在一起。在条件I下，2和3部分分化为背侧中胚层。在条件II下，各部分诱导背侧中胚层和神经组织，频率在2部分最高，在3部分最低。在条件III下，1和2部分通过诱导能力从躯干-尾部向头部的变化实现其预定命运。这种变化在1部分进展迅速，在2部分进展缓慢。3部分需要相邻的2部分诱导才能实现其预定命运。在正常发育和预培养实验中，1和2部分诱导能力的变化在时间顺序上相似。最后，提出囊胚期的初级预定咽部区域作为组织中心的启动器，其程序化信息传递给2部分，然后传递给3部分。
