Fig. 2. Light field (A,C,E) and corresponding dark field micrographs showing expression of Wnt4 (B,D) and Wnt5a (F) in the developing joints of the stage 28 wing (A,B), stage 37 wing (C,D) and stage 30 leg (E,F). Bars, 500 µm. h, humerus; j, joint interzone; m, mesenchyme; pc, perichondrium; r, radius; sc, synovial capsule; u, ulna. HE, haematoxylin and eosin-stained sections; TolB, toluidine blue-counterstained section.