meis1.1 and hoxa11b expression in zebrafish fins. a–f Dorsal, g, h anal and i–l pelvic fins. a–d, f, h, i–l WISH and e, g Alcian Blue staining followed by WISH. a–c, e, g, h Arrowheads indicate fin mesenchyme cells expressing meis1.1 and hoxa11b. c The white arrow indicates unsegmented radial; c the black arrows indicate WISH staining in dorsal somite cells. a–d, j, l The dashed lines indicate distal limit of endochondrogenic mesoderm below the finfold in a–d dorsal and j, l pelvic fins. e–h The solid lines indicate the boundary between proximal and distal radials in e, f dorsal and g, h anal fins. a–f, i–l Anterior to left, distal to top; g, h anterior to left, distal to bottom. Fish length is a–c 3.6–4.4 mm, d 4.0–5.2 mm, e–h 5.6–6.1 mm, i, k 4.1–5.3 mm, j, l 5.0–6.4 mm. Abbreviations: dr, distal radial; pr, proximal radial. Scale bars are 100 μm (a, b, f, g), 50 μm (c–e, h–l), and 70 μm (k–n)

meis1.1 expression and chondrogenesis in zebrafish pectoral fin. Dorsal view of Alcian Blue staining followed by WISH. meis1.1 transcript is restricted to proximal-posterior margin (arrow) during cartilage remodelling. Abbr.: s, scapulocoracoid; r, radial. Scale bar: 100 μm.