Fig. 2

Fig. 2 Identification of the olt gene as zebrafish frizzled3a gene. (A) Genetic map of the olt locus. (B) Genomic structure of the zebrafish fz3a gene. The nucleotide substitution resulting from the olt^rw689 mutation is indicated. (C) Schematic drawings for the mouse Fz3 and zebrafish Fz3a proteins. Amino acid sequence similarity (%) is shown for each domain. The mis-sense amino acid substitution in the Fz3a^rw689 protein is indicated. (D) The phylogenetic tree for fz3-family genes. (E) Lateral view of a wild-type embryo reacted with the fz3a RNA probe at 24 hpf. (E') Cross section of E at r5. (F-H) Wild-type Isl1-GFP embryo injected with fz3a-MO (H) showing the same neuronal migration defects as those observed in an olt embryo (G). The embryos are shown in dorsal view and the images are composite stacks of serial optical sections. (I,I') Wild-type Isl1-GFP embryo injected with fz3a-ΔC mRNA. Migration of the nVII motor neurons was specifically impaired (arrow in I'). Lateral views. Scale bars: 50 μm.