Schaller H C
Cell Differ. 1976 Apr;5(1):13-25. doi: 10.1016/0045-6039(76)90010-5.
In addition to its role as a growth hormone (preceding paper), at the cellular level the head activator functions as one of the substances which control the determination of uncommitted stem cells in hydra. In the presence of head activator the determination of interstitial stem cells to nerve cells is stimulated, the determination of interstitial cells to nematocytes is inhibited. The determination of interstitial cells to nerves occurs shortly before or in the very early S period of interstitial cells.
除了作为生长激素的作用（前文）外，在细胞水平上，头部激活因子作为控制水螅中未分化干细胞分化的物质之一发挥作用。在存在头部激活因子的情况下，间质干细胞向神经细胞的分化受到刺激，间质细胞向刺细胞的分化受到抑制。间质细胞向神经细胞的分化发生在间质细胞S期前不久或非常早期。
