Fig. 6

Inverse correlation between MG numbers and cone photoreceptor staining. Tg(gfap:gfp) embryos were injected with dye control (DIC; A), miR-216a (B), miR-216a^MOs (C), snx5^MOs (E), or snx5 mRNA (F) at the 1-cell stage, fixed at 65 hpf, and transverse sections of developing retinas were obtained. Immunohistochemistry was performed using antibodies to identify cone photoreceptors in the outer nuclear layer (Zpr-1) or amacrine/ganglion cells in the inner nuclear layer and the ganglion cell layer (HuC). Changes in Müller glia cell numbers led to consistent changes in cone photoreceptor numbers. Zpr-1 staining increased in embryos injected with mir-216a or snx5^MOs and decreased in embryos injected with mir-216a^MOs or snx5 compared to embryos injected with dye. Partial rescue of Zpr-1 levels is shown in (D) and (G) where embryos were co-injected with combinations of either snx5 and miR-216a (D) or snx5^MOs and miR-216a^MOs (G). Amacrine and ganglion cell numbers demonstrated similar, though less striking and less consistent changes compared to cone photoreceptors. Nuclei were marked by staining with To-Pro.