Fig. 4. Abnormal pigmentation in mob^m610 mutant embryos. (A,B) Wild-type (A) and mob^m610 (B) live embryos at 36 hpf. Pigmentation is reduced in a mob^m610 embryo, with melanophores missing in the head and in the tail. (C,D) Wild-type (C) and mob^m610 (D) live embryos at 48 hpf. The defect in pigment cell distribution is still visible in the distal part of the tail, but less evident than at earlier stages. (E,F) Development of iridophores is severely affected in mob^m610 embryos. Iridophores (indicated by arrowheads) in the tail were photographed under incident light at 3 dpf in wild-type (E) and mob^m610 (F) embryos. (G,H) Expression of dopachrome tautomerase (dct) at 22 hpf in wild-type (G) and mob^m610 (H) embryos. (I,J) Expression of kit tyrosine kinase receptor at 22 hpf in wild-type (I) and mob^m610 (J) embryos. Arrowheads indicate migrating pigment cell precursors. (K,L) Expression of the xanthine dehydrogenase (xdh) gene in xanthophore precursors at 25 hpf in wild-type (K) and mob^m610 (L) embryos (arrowheads indicate the posterior end of the otic vesicle).