Figure 4: PNPLA6 expression in the mouse and Drosophila retina.

(a) Section of a mouse retina superimposed with illustrations of the cell types found in the three different layers. onl, outer nuclear layer; inl, inner nuclear layer; gcl, ganglion cell layer; os, outer segment; is, inner segment; r, rod; c, cone; mu, Müller cell; rgc, retinal ganglion cell; bi, bipolar cell; h, horizontal cell; am, amacrine cell. (b) Illustration of a Drosophila retina along the longitudinal axis. ant, anterior; pos, posterior; re, retina; la, lamina. (c) Immunostaining for SWS in longitudinal sections of fly retina. SWS is expressed surrounding the nuclei and along the entire length of the photoreceptor (arrowheads). bm, basement membrane; c, cornea; re, retina. (d–f) Time course of PNPLA6 expression in the mouse retina, as indicated. PNPLA6 is expressed in cells of the inner and outer retina at all stages examined (arrowheads), as well as in the photoreceptor inner segment area (asterisk). Co-immunostaining of mouse retinal sections at P5 with PNPLA6 and the horizontal cell marker neurofilament-165 (NF-165; g–i), amacrine cell marker syntaxin (j–l) and the photoreceptor cell marker Na⁺/K⁺-ATPase (m–o). Arrowheads point to positive cells and asterisks point to area of positive staining. (p–r) Confocal z-stack projection of an adult mouse retinal sections (P30) co-immunostained with PNPLA6 and the photoreceptor inner segment plasma membrane marker Na^+/K⁺-ATPase. PNPLA6 localizes mostly to the plasma membrane, although some staining is detected inside the inner segment. (s–u) Co-immunostaining of PNPLA6 with the cone photoreceptor marker peanut agglutinin (PNA) showing expression of PNPLA6 in cones (arrow). Sections were counterstained with Hoechst (blue) to reveal nuclei.