Fig. 3

hoxa11 expression in Neoceratodus lobed fins. WISH in pectoral lobed fins from early budding to early chondrogenesis. a Distribution of hoxa11 transcript in the posterior bud. b–d The arrowheads indicate expression in anterior cells at the distal margin of the lungfish pectoral fin. b–d The arrows indicate a PD discontinuity of low, if any, expression in the early phase of hoxa11 activity. e, f Comparison of single WISH and Alcian Blue staining indicates that transcription is depleted in those cells that will ultimately build the humerus (below dashed line). Abbreviations: h, humerus; r, radius; u, ulna. Distal to top, anterior to left. Scale bars are 100 µm (a–d) and 50 µm (e, f)