Figure 4

Wnt pathway members are expressed in the episphere and hyposphere during early development. The prototroch is marked with a dashed line. The tip of the apical plate is marked with an asterisk. Arrows indicate dorsal (D), ventral (V), anterior (A) and posterior (P). (A) Frizzled5/8 across the apical plate, 16 hours post-fertilization (hpf) apical view and a (A’) 20 hpf ventral view (inset shows a surface ventral view). (B) Wnt4 along the blastopore, 16 hpf lateral view. (B’) Confocal image of ventral view of Wnt4 expression in which antibody staining to acetylated tubulin is visible with a green secondary antibody, reflection signal of in situ hybridization is red and nuclei are visible, stained with DAPI, in blue. (C) Apical view of sfrp1/5 expression at 24 hpf and at (C’) 48 hpf. (A”, B” and C”) Schematic representations of the expression patterns in (A) and (B) and (C) and (A’) and (B’) and (C’).