Fig 2. Progressive cone loss in adult cep290^fh297/fh297 mutants.

Methylene blue stained transverse histological sections of retinas from wild-type (top) and cep290^fh297/fh297 mutants (bottom) at 5 dpf (A); 3 months of age (B), 6 months of age (C), and 12 months of age (D). At 3 months, the cep290^fh297/fh297 mutants (bottom) had noticeably fewer cones (white arrows) and thinning of the cone outer segment (COS) layer. Few cones were observed at 12 months of age in cep290^fh297/fh297 mutants (black arrows). (E) Quantification of ONL thickness and (F) rows of nuclei in the ONL at different distances from the optic nerve in both the dorsal (negative numbers; left) and ventral (positive numbers; right) retina of cep290^fh297/fh297 mutants and wild-type sibling controls at 8 months of age. Data are shown as means ± SEM (n = 6, *P ≤ 0.05). ROS, rod outer segments; COS, cone outer segments; ONL, outer nuclear layer; OPL, outer plexiform layer; INL, inner nuclear layer; IPL, inner plexiform layer; GCL, ganglion cell layer. Scale bar: 100 μm.