Fig. 4. Expression patterns of developmental landmark genes in wild-type (wt, upper panels) and ntn mutant (lower panels) embryos at 30 hpf. Lateral views of embryos stained by in situ hybridization with (A) antisense zash1a probe; (B) antisense zash1b probe; (C, left) antisense hlx1 probe; (D) antisense dlx2 probe; (E) antisense krox20 probe; (F) antisense shh probe; (G) antisense pax2a probe; (H) antisense ntl probe. (I) antisense myod probe. (C, right) Dorsal view of embryo stained by in situ hybridization with antisense hlx1 probe. Arrowheads in D indicate pharyngeal arches; arrowheads in G indicate pronephric ducts. Scale bars: 100 µm in A-D,F; 50 µm in E,G-I.