Fig. 3

Dlx expression expands ventrally in hand2 mutants. Images are projections from confocal stacks of 36 hpf RNA in situ, with anterior leftwards, dorsal upwards. For context, dlx2a (blue lines) or dlx5a expression (white lines) is outlined in the first two arches. (A) In wild-type fish, dlx4b is expressed dorsal to the edn1-expressing mesoderm and ectoderm. However, in hand2^S6 fish (B), dlx4a is expressed both within the ventral edn1 expressing region and in the intermediate mesenchyme. Although expanded, dlx4a expression remains ventral to the. Similarly, compared with wild type (C), dlx3b and dlx4b expression expands into ventral regions of hand2^S6 (D), while remaining ventral to stomodeum and first pouch. (E-T) Separated confocal channels from A-D. Scale bar: 50 μm. Arrows indicate stomodeum; asterisks indicate the first pouch.