Figure 4. Expression of dscam genes in developing zebrafish retina. In situ hybridization using cryosections derived from 48, 72 and 96 hpf zebrafish retina is shown for A–C) dscama, D–F) dscamb, and G–I) dscaml1. Consistent labeling for all dscam genes was found in the INL and GCL (arrows in all panels); however, strong expression in the ONL was observed for dscamb (arrowheads in F versus C). D–F: Expression in the CMZ was also observed for (A)dscama at 48 hpf, (F) dscamb at 96 hpf, and (H; asterisk) dscaml1 at 72 hpf. All images displayed are of sections processed with antisense probe. Abbreviations: hpf=hours post fertilization; Dscam=Down syndrome cell adhesion molecule; INL=inner nuclear layer; GCL=ganglion cell layer; IPL=inner plexiform layer; CMZ=ciliary marginal zone (asterisk). Scale bar in A=50 μm (applies to all).