Ikegami Susumu, Ozaki Yoshihiro, Ooe Yasunori, Itoh Noriyuki
Faculty of Applied Biological Sciences, Hiroshima University, Higashihiroshima-shi, Hiroshima 724, Japan.
Dev Growth Differ. 1991 Jun;33(3):193-200. doi: 10.1111/j.1440-169X.1991.00193.x.
Embryos of the starfish Asterina pectinifera were examined for their ability to undergo the early events of embryonic development in the presence of actinomycin D, a most widely used inhibitor of RNA synthesis. Fertilized eggs continued to divide eight or nine times in the presence of 25 μg ml actinomycin D, although delay of development was observed. Chromatin disintegrated in the blastomeres of actinomycin D-treated embryos specifically at the 32-cell stage and the nucleus was undetectable at later stages. Before the 32-cell stage, RNA synthesis was not affected by the presence of actinomycin D whereas DNA synthesis was severely inhibited. The stage when achromosomal divisions cease and embryos begin to die corresponds to the period just before onset of blastulation, suggesting that the presence of the nucleus and chromosomes is a prerequisite for blastula formation and development beyond the 512-cell stage in this species.
在存在放线菌素D（一种使用最广泛的RNA合成抑制剂）的情况下，对多棘海盘车的胚胎进行了研究，以考察其进行胚胎发育早期事件的能力。在含有25μg/ml放线菌素D的情况下，受精卵继续分裂了八九次，不过观察到发育有所延迟。在放线菌素D处理过的胚胎的卵裂球中，染色质在32细胞期特异性地解体，并且在后期无法检测到细胞核。在32细胞期之前，RNA合成不受放线菌素D的影响，而DNA合成则受到严重抑制。无染色体分裂停止且胚胎开始死亡的阶段与囊胚形成开始前的时期相对应，这表明细胞核和染色体的存在是该物种形成囊胚以及发育超过512细胞期的先决条件。
