Figure 6.—

Nuclear Exd is not equivalent to Hth. UAS transgenes were expressed in distal cells under the control of the Distalless-Gal4 (Dll-Gal4) driver. (A) The Dll-Gal4 expression domain is shown with expression of myc–GFP (A, green). Exd (B, white) is nuclear in proximal cells, marked with Hth in A (blue). Note that the Hth+ cells in the distal domain are peripoedal cells in the focal plane of A and B. The following were expressed using the Dll-Gal4 driver: myc–GFP (A–C), GFP–Hth (D and E), GFP–Hth^HM (F and G), myc–GFP–Exd⁺ (H and I), myc–GFP–Exd^NES (J and K), myc–GFP–Exd^ΔAla (L and M), and myc–GFP–Exd^NES,ΔAla (N and O). Antibody stains demonstrate similar levels of nuclear Exd (white in B, D, F, H, J, and N) with Hth–Exd dimers, Exd^NES, Exd^ΔAla, or Exd^NES,ΔAla. Adult female T1 legs lose distal fates when nuclear Hth–Exd or Hth^HM–Exd dimers are expressed (E and G), but are not affected by undimerized nuclear Exd (K, M, and O).