Immunostaining for Rhodopsin protein (A, B), the cone protein GNAT2 (C, D), the bipolar protein PKCa (E, F), the Müller cell protein GFAP (G, H), and Calbindin (I, J), ChAT (K, L), and GABA (M, N) markers did not differ between Rai1+/- (B, D, F, H, J, L, N) and Rai1+/+ mice (A, C, E, G, I, K, M). As expected, rhodopsin was mainly localized in outer-segments of rods (A, B) and GNAT2 in cone cells (C, D). PKCa labeled whole ON bipolar cells with both dendrite and synapse structure (E, F). GFAP expression was restricted to the foot of Müller cells not extending to their cell bodies that show no activation in these retinal cells (G, H). Calbindin was expressed in horizontal cells (arrows) and some amacrine cells (arrowhead) as well as in ganglion cells located in the GCL (I, J). Three strata of connections (star) were well labeled by calbindin in both genotypes in the layer connecting the INL and GCL layers. Both ChAT (K, L) and GABA (M, N) labeled subpopulations of amacrine cells (arrowheads) and different strata of connections (star) in a pattern similar for Rai1+/- (L, N) and Rai1+/+ (K, M) mice. White horizontal bars represents 50 µm in A, B, E, F, G, and H and 100 µm in C, D, and I through M. OS: outer-segments; ONL: outer-nuclear layer; INL: inner-nuclear layer; GCL: ganglion cell layer; RHO: rhodopsin in green; GNAT2: G-protein subunit alpha transducin two in green; PKCa: Protein kinase C alpha in green; GFAP: gGlial fibrillary acidic protein in red; DAPI: 4',6-diamidino-2-phenylindole in blue; ChAT: choline acetyltransferase ChAT in green; GABA: γ-aminobutyric acid in green. (O) Quantitative RT-PCR showed that expression of M-opsin (Opn1mw; cones), melanopsin (Opn4, ipRGCs), rhodopsin (Rho; rods), and the retinal ganglion cell marker Thy1 was normal in Rai1+/- mice. Rai1 expression was decreased by 50% in Rai1+/- mice, as could have been expected.