Fig. 4 Ventral view of whole-mount immunostaining with RGC markers Isl-1 (A,D) and zn8 (B,E) in 48 hpf retinas. Less Isl-1 positive RGCs were found in the irx1a morphant retina (D) in comparison to the control (A). (B) Zn8 immunoreactivity was observed on the surface of RGC and axons in the optic nerve. However, zn8 staining was barely detectable (white arrow) in the irx1a morphant retina (E). (C, F) Dorsal view of DiI-(red) and DiO-(green) injected eyes at 48 hpf. The RGC axons were retrogradely labeled in the control retina (C). No RGC axon projection could be clearly detected in irx1a morphants (F). Expression of ath5 is altered in irx1a morphant retinas; (G,J) ventral view, (H,K) lateral view, anterior to the left, and (I,L) coronal section. At 48 hpf, ath5 is expressed in the ciliary margin (asterisks) of the control retina (G-I), whereas it is expressed near the optic stalk in the irx1a morphant retina (J–L).
Reprinted from Mechanisms of Development, 123(3), Cheng, C.W., Yan, C.H., Hui, C.C., Strähle, U., and Cheng, S.H., The homeobox gene irx1a is required for the propagation of the neurogenic waves in the zebrafish retina, 252-263, Copyright (2006) with permission from Elsevier. Full text @ Mech. Dev.