Fig. 2. Blocking 5ß1 integrin induces molecular changes characteristic of joint formation. Forelimbs of E14.5 mouse embryos cultured for 4 days were injected at the wrist with 10 µg of an anti-5 integrin mAb (A-G,I,K,M,O). Control injected with 10 µg of an irrelevant IgG (H,J,L,N). (A) Histological sections of zeugopod region stained with Safranin O and Fast Green to show cartilage in red. In-situ hybridizations for Wnt14 (B), Gdf5 (C), chordin (D), autotaxin (E). Immunofluorescence for CD44 (F), type III collagen (G), type II collagen (H-I), type I collagen (J-K), type X collagen (L-M) and Indian hedgehog (N-O). Immunofluorescence staining for IHH and for type I, II, III and X collagen is green; cell nuclei were stained with propidium iodide (red).