Generation of CD11c-Rac1(N17) Tg⁺ mice and selective Tg expression in DCs. To inhibit Rac1 function selectively in DCs, the DN form of the GTPase, Rac1(N17), was expressed under the control of the murine CD11c promoter in Tg mice. (A) Restriction map of the Tg construct (B indicates BamHI; Bs, BspHI; E, EcoRI; N, NotI; S, SstI; X, XhoI). Restriction sites (in parentheses) were destroyed by blunt-end cloning. (B) Splenocytes from Tg⁺ mice (black) and WT controls (gray) were stained to distinguish different cell types, followed by intracellular staining to detect the c-myc tag contained within the Rac1(N17) construct (x-axis). Histograms are gated on cell populations positive for the cell surface markers specified in parenthesis. (C) In vitro–cultured DCs from Tg⁺ mice and WT controls were analyzed for Rac1 and c-myc expression by Western blot. Lysates of purified CD11c⁺ cells were probed with anti-Rac1 (upper panel) and, after stripping of the membrane, anti–c-myc mAb (lower panel). The 25- and 20-kDa molecular weight markers are shown. Blots are representative of 7 WT and 8 Tg⁺ mice tested.