McMahon D
Science. 1974 Sep 20;185(4156):1012-21. doi: 10.1126/science.185.4156.1012.
The hypothesis that physiological and developmental regulatory mechanisms are similar has been presented. Well-known developmental systems chosen illustrate the capability of the model to suggest a simple mechanism underlying the effects on development of a diverse group of chemicals. This hypothesis might be applied to other systems including the induction of the lens, limb regeneration, and the induction of the head of hydra (124). I have proposed this hypothesis not only because it permits consideration of a complex and varied array of experimental observations as reflections of a simple basic biochemical mechanism, but because recent technical advances in instrumentation and methods allow it to be directly tested. The fluorescent antibody method for the cytochemical measurement of cyclic nucleotides provides a means for investigating changes in the concentrations of cyclic nucleotides in developing cells and could also be used to detect neurotransmitters in developing cells. Similarly, the scanning electron microscope in the emitted x-ray mode provides a method for measuring changes in the content and distribution of cations within developing cells. The hypothesis presented here suggests pleasing asceticism on the part of eukaryotes. It suggests that simple derivatives of metabolites, including neurotransmitters and cyclic nucleotides, are linked together as regulatory molecules throughout the eukaryotes. The neurotransmitters are suggested to have a more general role in information transmission in eukaryotes than is generally accepted. They are hypothesized to have progressed during evolution from being intracellular messengers to a role as intercellular messengers for the relatively slow communication of developmental informatbn; and, finally, this process has culminated with their participation in the rapid intercellular communication mediated by nerves. The thought that the complex pictures of physiological regulation and of the construction of a complex multicellular organism like man might be painted with so few colors is quite satisfying.
生理和发育调节机制相似的假说已经提出。所选用的著名发育系统说明了该模型能够提出一种简单机制，这种机制是多种化学物质对发育产生影响的基础。这个假说可能适用于其他系统，包括晶状体的诱导、肢体再生以及水螅头部的诱导（124）。我提出这个假说，不仅是因为它能将一系列复杂多样的实验观察结果视为一种简单基本生化机制的反映，还因为仪器和方法方面最近的技术进展使其能够得到直接验证。用于细胞化学测量环核苷酸的荧光抗体方法为研究发育中细胞内环核苷酸浓度的变化提供了一种手段，也可用于检测发育中细胞内的神经递质。同样，发射X射线模式的扫描电子显微镜提供了一种测量发育中细胞内阳离子含量和分布变化的方法。这里提出的假说表明真核生物具有令人愉悦的简约性。它表明包括神经递质和环核苷酸在内的代谢物简单衍生物在整个真核生物中作为调节分子相互联系。有人提出神经递质在真核生物信息传递中的作用比一般认为的更为普遍。据推测，它们在进化过程中从细胞内信使发展到作为细胞间信使发挥作用，用于相对缓慢地传递发育信息；最后，这一过程以它们参与由神经介导的快速细胞间通讯而告终。想到用如此少的元素就能描绘出生理调节以及像人类这样复杂多细胞生物构建的复杂图景，实在令人满意。
