FIGURE 6.2 Regulatory evolution and wing pigmentation pattern diversity. A suite of transcription factors control the development of the fly wing, each one being expressed in a particular pattern. Altogether, these expression patterns constitute a wing trans-regulatory landscape, conserved among Drosophila species (Top). The recruitment of a subset of the trans-regulatory landscape components by pigmentation genes results in the corresponding redeployment of these genes (Middle) and ultimately in a novel wing pigmentation pattern (Bottom). The recruitment of different combinations of trans-acting factors in different fly species yields distinct pigmentation patterns. In Middle, rectangles with motif represent binding sites for different trans-regulatory landscape components.