Fig. S1

ath5 MO does not grossly affect the lamination, position of presumptive optic nerve or neurogenesis of non-RGCs in the retina. Coronal sections through 6 dpf isl2b:GFP eyes after double-staining for GFP (B,E,H) and parvalbumin (Pv; C,F,I). (A-C) Uninjected wild type; (D-F) larva injected with control MO; (G-I) larva injected with high dose of ath5 TMO. (A′-I′) High-power views of A-I (see boxed areas in A,D,G). (A,D,G) DIC images show that retinal lamination is not affected in ath5 morphants, with the exception of a severely reduced RGC layer. (A′,D′,G′) The location of the presumptive optic nerve (on) and optic nerve head (onh, arrows), as well as a break in the RPE that represents the normal exit point for retinal axons, are clearly identifiable in ath5 morphants. (B,E,H) In controls, isl2b:GFP staining shows RGCs throughout the entire RGC layer (rgc, arrows) and their axons exiting the eye in the optic nerve (on, arrowhead). However, in ath5 morphants (H), central RGCs do not differentiate, although later-born RGCs in the periphery differentiate normally (arrow). In addition, no axons exit the eye (open arrowhead). Staining in central retina represents axons from peripheral RGCs (open arrow). GFP+ photoreceptors labeled by isl2b:gfp differentiate normally in ath5 morphants (B,E,H; small arrows). (C,F,I) Differentiation of Pv+ amacrine cells in the inner nuclear layer (a, arrows) and displaced amacrine cells in the RGC layer (da, arrowheads) appears unaffected in ath5 morphants. Scale bar: 100 μm.