Dan-Sohkawa M, Satoh N
J Embryol Exp Morphol. 1978 Aug;46:171-85.
Not only a whole denuded egg, but also blastomeres isolated from 2-, 4- and 8-cell starfish embryos developed into morphologically normal, but dwarf bipinnariae, the sizes of which were roughly proportionate to that of the respective original blastomeres. Some of the blastomeres isolated from the 16-cell stage were also capable of developing into the larval stage. All isolated blastomeres divided in good synchrony with the control embryos. Blastulae of all groups gastrulated within quite a short range of time, around 14-5 h after insemination at 20+/-1 degrees C, although one-third of the 1/8-blastula missed this chance but gastrulated by 19.5 h. The number of constituent cells of the 1/8-gastrula was counted to be about 560, which corresponds roughly to one-half that of the 1/4-, one-fourth of the 1/2- and one-eight of the 1/1-gastrula. This ratio also fitted roughly for the total cell volume. The results are compared with those of other invertebrate species, as well as of some vertebrates, and are discussed in connexion not only with the concepts of 'regulative' and 'mosaic' eggs, but also with a criterion that does not fit into either of these; the developmental system of the mammals.
不仅整个裸露的卵，而且从二细胞、四细胞和八细胞海星胚胎中分离出的卵裂球都发育成形态正常但体型较小的双羽幼虫，其大小与各自原来的卵裂球大致成比例。从十六细胞阶段分离出的一些卵裂球也能够发育到幼虫阶段。所有分离出的卵裂球与对照胚胎同步良好地分裂。所有组的囊胚在相当短的时间范围内开始原肠胚形成，在20±1摄氏度受精后约14 - 5小时，尽管八分之一囊胚中有三分之一错过了这个时机，但在19.5小时时开始原肠胚形成。八分之一原肠胚的组成细胞数量经计数约为560个，大致相当于四分之一原肠胚的一半、二分之一原肠胚的四分之一和完整原肠胚的八分之一。这个比例在总细胞体积方面也大致适用。将这些结果与其他无脊椎动物物种以及一些脊椎动物的结果进行了比较，并且不仅结合“调整型”和“镶嵌型”卵的概念进行了讨论，还结合了一个不属于这两者任何一种的标准进行了讨论；即哺乳动物的发育系统。
