Schaller H C, Rau T, Bode H
Nature. 1980 Feb 7;283(5747):589-91. doi: 10.1038/283589a0.
It has been shown that hydra, consisting almost exclusively of epithelial cells, have normal morphogenetic properties. This means that they are able to reproduce asexually by budding and to regenerate head or foot with conservation of the original polarity. Such hydra have no interstitial cells and they lack nerves and nematocytes as differentiation produces of the interstitital stem cell. Consequently, they are unable to catch or ingest food and would not survive in ntaure. However, stocks can be maintained in the laboratory, if food is injected into the gastric cavity. The fact that nerve-free hydra would grow and regenerate normally raised some doubts as to the role of the nervous system in the control of differentiation and development in hydra. In particular, the significance of morphogenetic substances, such as the head activator, which is normally produced by nerve cells, seemed to need reassessment. We now show that epithelial cells, seemed toneed reassessment. We now show that epithelial cells in hydra have the potential to produce head activator and other morphogenetic factors, but that this property is repressed in the presence of nerves.
研究表明，几乎完全由上皮细胞组成的水螅具有正常的形态发生特性。这意味着它们能够通过出芽进行无性繁殖，并在保持原始极性的情况下再生头部或足部。这种水螅没有间质细胞，并且由于间质干细胞的分化产物，它们缺乏神经和刺细胞。因此，它们无法捕捉或摄取食物，在自然环境中无法生存。然而，如果将食物注入胃腔，水螅种群可以在实验室中维持。无神经的水螅能够正常生长和再生这一事实，引发了人们对神经系统在水螅分化和发育控制中的作用的一些质疑。特别是，形态发生物质的重要性，例如通常由神经细胞产生的头部激活因子，似乎需要重新评估。我们现在表明，水螅中的上皮细胞有产生头部激活因子和其他形态发生因子的潜力，但这种特性在有神经存在的情况下会受到抑制。
