Wg expression starts after formation of the characteristic seven stripes of the pair-rule gene Even-skipped. (A, C, E) Early nuclear cycle 14, the seven stripes of Eve (red) are apparent; note that Wg is not yet expressed. (B, D, F) Mid nuclear cycle 14, Wg expression (in green) is detected in the posterior band. The posterior band of Wg is marked with an arrow. DAPI is used to mark nuclei (blue). Sequential staining with two mouse antibodies was used in this experiment (see Experimental Procedures).