Struhl G
Howard Hughes Medical Institute, Columbia University College of Physicians and Surgeons, New York, NY 10032.
Ciba Found Symp. 1989;144:65-86; discussion 86-91, 92-8. doi: 10.1002/9780470513798.ch5.
The basic body plan of insects is set up in response to determinants initially localized at the anterior and posterior poles of the egg. Early in development, these determinants give rise to a series of morphogen gradients which in turn trigger a cascade of molecular signals determining the body pattern. This signalling process is outlined and recent experiments testing the roles of these gradient systems in determining anterior and posterior pattern are described. The results of these experiments suggest that anterior pattern is controlled by a single instructive gradient, whereas posterior pattern depends on the overlap of several gradients, each providing only one or a few distinct responses.
昆虫的基本身体结构是在响应最初定位于卵的前端和后端的决定因素时建立的。在发育早期，这些决定因素产生一系列形态发生素梯度，进而触发一系列分子信号，决定身体模式。本文概述了这一信号传导过程，并描述了最近测试这些梯度系统在决定前后模式中作用的实验。这些实验结果表明，前部模式由单一的指导性梯度控制，而后部模式则取决于几个梯度的重叠，每个梯度仅提供一种或几种不同的反应。
