Fig. 6. The dap regulatory region contains a complex array of independent elements. Embryos with the lacZ reporter constructs dap-2l (A-C), dap-3l (D-F), dap-4l (G-I), dap-5l (J-L), dap-12l (M), dap-15l (N,Q), and dap-15l-A8 (O,R) at late stage 11 (A,B,D,E,G,H,J,K,M-R) or stage 14 (C,F,I,L) were labeled with anti-ß-galactosidase antibodies (A-O,Q,R, green in C,F,I,L) and double labeled with anti-Futsch/22C10 (red in C,F,I,L) to identify cells in the peripheral nervous system. The merged images (C,F,I,L) show a region from two abdominal segments with the lateral chordotonal organs (lch). The regulatory region present in dap-2l drives expression in the epidermis (A), in the anterior and posterior midgut (amg, pmg) and the interstitial cell progenitors (icp) (B, amg, pmg, icp) and in some cells of the peripheral nervous system (C, lch). The three subfragments of this region introduced into dap-3l, dap-4l and dap-5l drive different aspects of the dap-2l expression pattern. dap-3l is expressed in the peripheral nervous system (D,F), dap-4l primarily in the icp (H) and dap-5l in epidermis (J) and midgut (K). Global expression in the epidermis is driven by an element present in dap-12l (M). An element with ABD-B-binding sites (conserved A8 block, see Fig. 4) present in dap-15l (N) and deleted in dap-15l-A8 (O) results in early and high level expression in the prospective posterior spiracle region (ps, arrowheads in J,M-O) which is specified by Abd-B. prd-GAL4 driven ectopic expression of UAS-Abd-B does not induce dap-15l-A8 expression (R), while it readily induces ectopic expression of dap-15l (Q, stars) and of the endogenous dap gene (P, stars) as detected by in situ hybridization.
