Fig. 3. Expression of AP markers in the inner ear. Lateral or dorsolateral views of the otic vesicle (anterior towards the left). (A-D) pax5 expression at 24 h (A,B) and 30 h (C,D). Staining is limited to the anterior end of the otic vesicle in wild-type embryos (A,C) but is greatly expanded in val/val mutants (B,D). The midbrain-hindbrain border (mhb) is indicated. (E,F) Expression of nkx5.1 at 24 h in wild-type (E) and val/val (F) embryos. Expression is expanded posteriorly in val/val mutants. (G,H) Expression of zp23 at 24 h in wild-type (G) and val/val (H) embryos. No expression is detectable in the ear in val/val mutants. Relative positions of rhombomeres are indicated. Scale bar: 25 µm in A,B,G,H; 75 µm in C,D; 50 µm in E,F.