Rb1-deficient embryos possess delayed retinotectal projection.

<p>Dorsal view of maximum intensity projection of confocal z-stacks of RGC axons in wild type or <i>rb1^te226; ath5:gfp^+/−</i> embryos. (A–C) RGC axons fail to exit <i>rb1^te226</i> retina at 36 hpf. (D–F) <i>rb1^te226</i> optic nerves are hypoplastic. Diameter measured upon retinal exit, marked by dashed rectangle. (G–L) Tectal innervation is reduced in <i>rb1^te226</i> at 72 (G–I) and 96 hpf (J–L). Innervation measured as a function of pixel intensity units per µm² from summation intensity projections of tectal area (not shown, see Experimental Procedures). Digitally excluded eyes (e) are outlined by dotted line. (C, F, I, L) Bar graphs represent the mean with error bars denoting SEM. *p<0.001; one-way ANOVA (F, I, L) or binomial z-test (C). N retinas, optic nerves, or tecta shown at base of bar graphs. Anterior to the top of panel, scale bar = 50 µm.