Shank 1A immunoreactivity is co-localized with the lectin PNA (peanut agglutinin) in photoreceptor terminals.

<p><b>A–D</b>: Combined labeling of Shank 1A, PNA, and YFP in the mouse thy-1.2 YFP 16 line vertical retinal section. A. Shank 1A labels both the OPL and IPL. The immunoreactive puncta in the OPL are indicative of cone photoreceptor labeling. B. PNA conjugated rhodamine labels the inner and outer segments of cone photoreceptors, and cone photoreceptor terminals in the OPL. C. YFP fluorescence is present in bipolar, amacrine, and ganglion cells. D. Combined triple fluorescence channel image of PNA (red), Shank 1A (blue), and YFP (yellow). A box is drawn of a region in the OPL and high magnification images are shown in E–H. <b>E–H</b>: High magnification zoom of a region in the OPL from D. E. Shank 1A (blue). F. PNA (red). G. YFP labeled cone bipolar cells and their dendrites (yellow). H. A combined triple labeled fluorescent image showing that Shank 1A (blue) is expressed at the same site as PNA (red) above the YFP cone bipolar cell dendrites (yellow). OS = outer segment, IS = inner segment, ONL = outer nuclear layer, OPL = outer plexiform layer, INL = inner nuclear layer, IPL = inner plexiform layer, and GCL = ganglion cell layer. Scale bars is 10 µm.