Regulation of interstitial cell differentiation in Hydra attenuata. I. Homeostatic control of interstitial cell population size.
Regulation of interstitial cell differentiation in Hydra attenuata. I. Homeostatic control of interstitial cell population size.
复制标题
衰减水螅间质细胞分化的调节。
作者：
H. Bode;K. Flick;G. Smith
本文对水螅多能间质细胞（i-cell）群体大小的调控机制进行了研究。在10-2 M羟基脲（HU）中24 h与在培养基中12 h交替的3个周期的治疗方案选择性地杀死了95-99%的i细胞，但对上皮细胞几乎没有影响。i细胞群在35天内恢复到正常的i细胞：上皮细胞比I：I。[3 H]胸苷的连续标记实验表明，i-细胞群体的恢复不是由于上皮细胞或间质细胞的细胞周期长度的变化。在对照动物中，60%的i细胞群体每天进行分裂，而40%进行分化。HU处理的动物的细胞类型的定量表明，在HU处理后恢复的前2周期间，较大部分的i-细胞正在分裂，并且较少分化成巨噬细胞。因此，恢复的机制涉及i细胞的60：40分裂：分化比向更高的分裂分数的转变，直到i细胞的正常群体大小被恢复。这种稳态机制代表了影响i细胞分化的影响之一。
Mechanisms regulating the population size of the multipotent interstitial cell (i-cell) in Hydra attenuata were investigated. Treatment of animals with 3 cycles of a regime of 24 h in 10-2 M hydroxyurea (HU) alternated with 12 h in culture medium selectively killed 95-99% of the i-cells, but had little effect on the epithelial cells. The i-cell population recovered to the normal i-cell:epithelial cell ratio of I:I within 35 days. Continuous labelling experiments with [3H]thymidine indicate that the recovery of the i-cell population is not due to a change in the length of the cell cycle of either the epithelial cells or the interstitial cells. In control animals 60% of the i-cell population undergo division daily while 40% undergo differentiation. Quantification of the cell types of HU-treated animals indicates that a greater fraction of the i-cells were dividing and fewer differentiating into nematocytes during the first 2 weeks of the recovery after HU treatment. Therefore, the mechanism for recovery involves a shift of the 60:40 division:differentiation ratio of i-cells towards a higher fraction in division until the normal population size of the i-cells is regained. This homeostatic mechanism represents one of the influences affecting i-cell differentiation.