Positional Information and Positional Signalling in Hydra
Positional Information and Positional Signalling in Hydra
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Hydra 中的位置信息和位置信号
DOI：
10.1093/icb/14.2.647
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发表时间：
1974
影响因子：
2.6
通讯作者：
M. Clarke
中科院分区：
文献类型：
--
作者：
L. Wolpert;A. Hornbruch;M. Clarke
提出了一种基于位置信息的九头蛇头端调控再生模型，该模型包含两个梯度。一种是在头端制造的可扩散物质，它可以被认为是位置信号。另一种是更稳定的元胞参数，即位置值。首端形成的规则是可扩散物质的浓度下降到低于位置值的临界量。该模型提供了一些计算机模拟，可以解释各种移植物的头端形成。实验提供了可扩散信号的证据，在该实验中确定了嫁接磁头抑制磁头的时间/距离关系。调整过程中位置值的变化已被检测，并且远离边界的速度要慢得多。根据两个梯度之间的相互作用来解释极性。梯度的生化基础尚不清楚，但已经通过用各种化学试剂处理九头蛇来解决这个问题。
A model is proposed for regulation and regeneration of the head end of hydra in terms of positional information, which involves two gradients. One is a diffusible substance made at the head end, which may be regarded as a positional signal. The other is a more stable cellular parameter which is the positional value. The rule for head end formation is that the concentration of the diffusible substance falls a threshold amount below the positional value. This model, for which some computer simulation is provided, can account for head end formation in a wide variety of grafts. Evidence for a diffusable signal is provided by experiments in which the time/distance relationships for head inhibition by a grafted head are determined. Changes in positional value during regulation have been assayed and are much slower away from the boundary. Polarity is interpreted in terms of the interaction between the two gradients. The biochemical basis of the gradients is not known, but an approach to the problem has been made by treating hydra with a variety of chemical agents.