FIG. 2.

Five P element insertions were recovered within the BX-C. Transcription units are marked for the three homeotic genes, Ubx, abd-A, and Abd-B. Coordinates from the published sequence are shown (in kilobases). Above the map, control regions for each of the genes are denoted by brackets, and the large arrows point to the most anterior parasegments that they regulate in the fly embryo (displayed with the anterior portion to the left). The sites of insertion of the five P elements are indicated below the map as triangles. The location of the original 4× T7 promoters in the bx region (29) is indicated above the map as a black rectangle. Arrows denote the orientation of the T7 promoters.