Kobayakawa Y, Kubota H Y
J Embryol Exp Morphol. 1981 Apr;62:83-94.
Fertilized eggs of the Japanese newt, Cynops pyrrhogaster, were divided into two or four equal-sized parts with fine glass rods before the first cleavage. In such cases one of the egg fragments, at least, proceeds to cleavage and gastrulates. The temporal pattern of cell division and the onset of gastrulation in such half or quarter embryos were investigated and compared with normal development. The following results were obtained: (1) desynchronization starts two divisions earlier in quarter embryos and one division earlier in half embryos compared with whole embryos, (2) the time from the first cleavage to the onset of gastrulation does not widely vary among quarter, half and whole embryos and (3) the numbers of blastomeres which constitute embryos at the pigment stage decrease in proportion to the diminution of egg volume.
在日本蝾螈（Cynops pyrrhogaster）的受精卵第一次卵裂之前，用精细的玻璃棒将其分成两个或四个大小相等的部分。在这种情况下，至少有一个卵片段会继续进行卵裂并形成原肠胚。研究了这种半胚胎或四分之一胚胎中细胞分裂的时间模式和原肠胚形成的起始，并与正常发育进行了比较。得到了以下结果：（1）与完整胚胎相比，四分之一胚胎中去同步化在两个细胞周期之前开始，半胚胎中在一个细胞周期之前开始；（2）从第一次卵裂到原肠胚形成开始的时间在四分之一、半胚胎和完整胚胎之间没有很大差异；（3）在色素阶段构成胚胎的卵裂球数量随着卵体积的减小而成比例减少。
