Fig. 7

Nile Blue staining for cell death during autopodial morphogenesis. During autopodial morphogenesis, Nile Blue granules are concentrated along the distal periphery of the developing limb within the mesenchyme as well as delimiting the Apical Ectodermal Ridge in both the hands and feet (a-j). The AER is also highlighted as ventrally arched in distal view (b, d) and is also clearly dorsoventrally thinner at stages when cleft formation is underway (h, j). During final stages of cleft morphogenesis, nile blue staining is concentrated within the interdigital mesenchyme (k-n), with a significantly greater concentration in the interdigital mesenchyme between digits III and IV in the hand (k, l) and II and III in the foot (m, n). Reduced Nile Blue is present in the tissue within syndactylous digits. Nile Blue is visible in the AER on the anterior and posterior regions of the limb while absent in the cleft domain in the hand (k, l)