動物身體上復(fù)雜彩色圖案（如貝殼、熱帶魚和豹子身上的圖案）的形成,，對發(fā)育生物學(xué)家來說是一個經(jīng)典謎題,。
大多數(shù)試圖解釋圖案信息的工作都是理論上的，著重于反應(yīng)-擴(kuò)散機(jī)制,，按照這樣的機(jī)制，可擴(kuò)散性本地激發(fā)因子（形態(tài)發(fā)生素）與長距離抑制因子之間的互動被假設(shè)產(chǎn)生穩(wěn)定的圖案,。但此前一直沒有形態(tài)發(fā)生素或抑制因子的候選對象被識別出來,。
現(xiàn)在，Sean Carroll及其同事以果蠅Drosophila guttifera翅膀上的圓點(diǎn)圖案為模型發(fā)現(xiàn),，翅膀上的斑點(diǎn)是由無翼形態(tài)發(fā)生素誘導(dǎo)的,，這種果蠅翅膀上精致的斑點(diǎn)圖案很可能是通過在新的地方選擇無翼形態(tài)發(fā)生素的表達(dá)而從更簡單的圖案形成的。
在本期封面的合成圖片中,，左翼所示為這種果蠅16個與條紋相關(guān)的點(diǎn)及4個條紋間的陰影,；右側(cè)圖案將條紋點(diǎn)與條紋間陰影順勢調(diào)控元素的活性融合在這種果蠅一只雙轉(zhuǎn)基因個體蛹期翅膀中。(生物谷Bioon.com)
生物谷推薦原文出處：
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.
