Fig. 2. The major cell types develop normally in the Fz5^-/- retina at P30. (A) Amacrine cells, stained for calretinin, residing in the ganglion cell layer and inner nuclear layer show a characteristic trilamination of processes in the inner plexiform layer. (B) Nuclear localization of Islet1 in a subset of amacrine cells and retinal ganglion cells, and the distinctive inner plexiform layer stratification of processes of amacrine cells expressing glutamic acid decarboxylase (GAD). (C) Dopaminergic amacrine cells expressing tyrosine hydroxylase (TH) have processes that are confined to the outermost stratum of the inner plexiform layer. (D) Synaptophysin marks presynaptic terminals in the inner plexiform layer and outer plexiform layer, and glial fibrillary acidic protein (Gfap) marks astrocytes in the ganglion cell layer. (E) Glutamine synthetase (GS) in Müller glia and Gfap in astrocytes. (F) Similar extent of activation of Gfap expression in Müller glia of WT (Fz5^+/-) and Fz5^-/- mouse retinas following exposure to bright light. Note that the intense Gfap immunoreactivity in the innermost region of the Fz5^-/- retina is likely to reflect an excess of astrocytes (see Fig. 9). DAPI staining (blue) in A-E shows the three nuclear layers.