动物身体上复杂彩色图案（如贝壳、热带鱼和豹子身上的图案）的形成，对发育生物学家来说是一个经典谜题。
大多数试图解释图案信息的工作都是理论上的，着重于反应-扩散机制，按照这样的机制，可扩散性本地激发因子（形态发生素）与长距离抑制因子之间的互动被假设产生稳定的图案。但此前一直没有形态发生素或抑制因子的候选对象被识别出来。
现在，Sean Carroll及其同事以果蝇Drosophila guttifera翅膀上的圆点图案为模型发现，翅膀上的斑点是由无翼形态发生素诱导的，这种果蝇翅膀上精致的斑点图案很可能是通过在新的地方选择无翼形态发生素的表达而从更简单的图案形成的。
在本期封面的合成图片中，左翼所示为这种果蝇16个与条纹相关的点及4个条纹间的阴影；右侧图案将条纹点与条纹间阴影顺势调控元素的活性融合在这种果蝇一只双转基因个体蛹期翅膀中。(生物谷Bioon.com)
生物谷推荐原文出处：
Nature doi:10.1038/nature08896
Generation of a novel wing colour pattern by the Wingless morphogen
Thomas Werner1,2, Shigeyuki Koshikawa1,2, Thomas M. Williams1,3 & Sean B. Carroll1
Howard Hughes Medical Institute and Laboratory of Molecular Biology, University of Wisconsin, 1525 Linden Drive, Madison, Wisconsin 53706, USA
These authors contributed equally to this work.
Present address: Department of Biology, University of Dayton, 300 College Park, Dayton, Ohio 45469, USA.
The complex, geometric colour patterns of many animal bodies have important roles in behaviour and ecology. The generation of certain patterns has been the subject of considerable theoretical exploration, however, very little is known about the actual mechanisms underlying colour pattern formation or evolution. Here we have investigated the generation and evolution of the complex, spotted wing pattern of Drosophila guttifera. We show that wing spots are induced by the Wingless morphogen, which is expressed at many discrete sites that are specified by pre-existing positional information that governs the development of wing structures. Furthermore, we demonstrate that the elaborate spot pattern evolved from simpler schemes by co-option of Wingless expression at new sites. This example of a complex design developing and evolving by the layering of new patterns on pre-patterns is likely to be a general theme in other animals.
