Fig. 3

Fig. 3 Neural expression of zebrafish rar genes. ISH reveals distinct patterns of rar gene expression within and near the neural tube. Dorsal views of flatmounted embryos; rar gene expression is depicted in blue, and krox20, indicating r3 and r5, is shown in red. A: At the 5-somite stage, expression of raraa is adjacent to r5. B: At 24 hpf, raraa is expressed in the anterior spinal cord. C,D: Expression of rarab at the 5-somite stage and the 18-somite stage in the anterior spinal cord and hindbrain, with higher expression in r5and r6. E: Expression of rarga at the 5-somite stage in anterior mesendoderm (arrows) and r4 (arrowhead). F: At 24 hpf, expression of rarga has spread to the posterior hindbrain and anterior spinal cord. G: At the 10-somite stage, rargb is expressed in the lateral diencephalon (arrowhead) and the premigratory neural crest. H: At the 18-somite stage, rargb is expressed in the lateral diencephalon (arrowhead) and migrating neural crest. I: At 24 hpf, rargb is present in the pharyngeal neural crest. Numbers indicate the three streams of neural crest. Images A-F are the same magnification, and images G-I are the same magnification. Scale bar = 10 μm.