Fig. 1

tcf3 expression in medaka embryonic development. Whole mount in situ hybridization experiments were performed in wild type embryos at the indicated stages, using a digoxigenin-labelled RNA probe against tcf3. Embryos are shown in dorsal view, anterior at the top. (f-h) Flat mounts; (f'-h') tail view. During gastrulation (a-c) tcf3 is expressed throughout the epiblast and the embryonic body (c-d). In neurula the expression becomes restricted to the head (d,d') from where it spreads caudally and divides into a forebrain, midbrain, and hindbrain section (e;e'). A gap in expression at the mid-hindbrain boundary (f-h, arrowhead) is closed at later stages (h). In later stages, expression is observed throughout the entire body (g-h'). Scale bars 100 μm; a, a-c; f, f-f′; g, g-h′. Abbreviations: st, stage