The gene even-skipped (eve) is expressed in 7 bands or stripes corresponding to 7 of Drosophila's 14 segments, skipping the even-numbered ones. It explains most important concepts concerning the spatial control of gene regulation in developing animals. Moreover, the distinct cis-acting regulatory elements of individual genes are controlled individually.
Each of the seven stripes that make up the expression patterns of the even-skipped and hairy pair-rule genes is controlled independently. If we consider the second stripe, it lies between the broad region of hunchback expression and on the edges of the region of expression of other two gap proteins called Giant and Kruppel.
In addition, within the area of future stripe, there will be large amounts of hunchback protein and small amounts of Giant and Kruppel protein and certain amount maternal effect bicoid protein. No other stripe in the embryo will contain these proteins in these proportions.
Therefore, the entire seven-stripe periodic pattern is the sum of different sets of inputs into separate cis-acting elements.