Fig. 3. Expression of 6 and ß1 integrins and laminin 1 in axolotl embryos. (A) A stage 24 albino embryo was treated as described in Materials and Methods, with an anti-6 integrin antibody (GoH3) followed by antibody detection (top). Antibody staining is evident along the somites, the pronephros (arrow) and the migrating PND. A control embryo to which no GoH3 antibody was added (bottom) did not show staining. (B) A stage 26 albino embryo was fixed and the epidermis overlying the lateral flank was removed. The embryo was then treated with an anti-ß1 integrin primary antibody as described in Materials and Methods. Staining was evident throughout the lateral mesoderm, including the somites, the pronephros and the PND (arrow), indicating broad expression of ß1-containing integrins. (C) The extracellular localization of laminin was observed following transverse sectioning through an axolotl embryo that had been previously treated with an anti-laminin-1 antibody. Strong staining was evident within the outermost epidermal layers (arrow and bracket) and highlights its expected localization to the basal lamina.