National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA.
Cold Spring Harb Perspect Biol. 2009 Jul;1(1):a002477. doi: 10.1101/cshperspect.a002477.
The amphibian embryo provides a powerful model system to study morphogen gradients because of the ease with which it is possible to manipulate the early embryo. In particular, it is possible to introduce exogenous sources of morphogen, to follow the progression of the signal, to monitor the cellular response to induction, and to up- or down-regulate molecules that are involved in all aspects of long-range signaling. In this article, I discuss the evidence that gradients exist in the early amphibian embryo, the way in which morphogens might traverse a field of cells, and the way in which different concentrations of morphogens might be interpreted to activate the expression of different genes.
两栖动物胚胎是研究形态发生梯度的有力模型系统,因为很容易对早期胚胎进行操作。特别是,有可能引入外源性形态发生源,跟踪信号的进展,监测细胞对诱导的反应,并上调或下调参与长距离信号传导各个方面的分子。在本文中,我将讨论在早期两栖动物胚胎中存在梯度的证据,形态发生素可能穿越细胞场的方式,以及不同浓度的形态发生素如何被解释为激活不同基因的表达。