Figure 3.

Wnt6 is expressed in the maxillary palp anlage, and not wingless. (A-A’) Staining of control eye-antenna discs (A) with anti-wingless antibody (clone 4D4) gives a signal in the maxillary palp anlage (arrowhead) which is not visible in Wnt6^KO discs (A’). (B) Wingless and Wnt6 do not induce expression of each other, detected by mRNA in situ hybridization. Expression of Wnt6 in the patched domain along the A/P boundary, perpendicular to the endogenous wingless and Wnt6 expression domains, does not ectopically induce wingless, and vice-versa. (C) Anti-wingless monoclonal antibody clone 4D4 cross-reacts with Wnt6 on immuno-blots. Lysates from control S2 cells or S2 cells transfected to express wingless or Wnt6 were probed with anti-wg antibody. The upper band is a non-specific band also present in untransfected S2 cells. (D-D’)In situ hybridization detecting wingless mRNA (D) and Wnt6 mRNA (D’) in eye-antenna discs reveals Wnt6 expression but not wingless expression in the maxillary palp anlage (arrow). Wnt6^KO, Wnt6 knockout.