Figure 7.

STIM expression in the mouse retina. A, Representative RT-PCR data demonstrating that the mouse retina expresses transcripts encoding Stim1, Stim2, Orai1–3, Trpc1, and Trpc3 genes. B, Dissociated cells labeled with STIM1 and STIM2 antibodies, together with the GS and DAPI (perikaryal) markers. STIM1 is expressed in the cell body, apical/distal stalks, and the end-foot. Weak STIM2-IR is observed in the cell body. Putative rods (asterisks) and amacrine cell (#) are also labeled. S, Soma; Ef, end-foot. Scale bar, 10 μm. C, Representative confocal images of vertical sections double labeled for STIM1, STIM2, and GS. STIM1-IR is observed across all retinal layers but is particularly strong in RGC somata and Müller end-feet (marked by GS–STIM1 colocalization, arrowheads). STIM2-IR is localized to the proximal INL, potentially corresponding to bipolar somata and dendritic processes (arrows). Insets 1 and 2 are magnified regions selected by corresponding rectangles in the merged images showing the presence of STIM1 and the absence of STIM2 in the end-foot. D, Representative retinal STIM immunoblots.