Plickert G, Kroiher M, Munck A
Zoologisches Institut Universität Heidelberg, FRG.
Development. 1988 Aug;103(4):795-803. doi: 10.1242/dev.103.4.795.
The early embryonic development of Hydractinia lasts about 2.5 days until the developing planula larva acquires competence for metamorphosis. Most embryonic cells stop cycling on reaching the larval stage. In older larvae of Hydractinia, cells that are still proliferating occur exclusively in the endoderm in a typical distribution along the longitudinal axis. During metamorphosis, proliferation activity begins again. The number of S-phase cells has increased by the 9th hour after induction of metamorphosis. Proliferative activity starts in the middle gastric region and in basal parts of primary polyps. Tentacles and stolon tips are always free of replicating cells.
水螅虫的早期胚胎发育持续约2.5天，直到发育中的浮浪幼虫获得变态能力。大多数胚胎细胞在进入幼虫阶段时停止循环。在水螅虫的老龄幼虫中，仍在增殖的细胞仅在内胚层中沿纵轴呈典型分布。在变态过程中，增殖活动再次开始。在诱导变态后的第9小时，S期细胞数量增加。增殖活动从中胃区域和初级息肉的基部开始。触手和匍匐茎顶端始终没有正在复制的细胞。
