GFP expression in the retina after the intravenous delivery of scAAV9-GFP in adult mice.

<p>Retinal cross sections were treated for GFP immunofluorescence (green) and counterstained with DAPI (blue), four weeks after the injection of 2×10¹² vg of scAAV9-GFP into the tail veins of eight-week-old mice. GFP was detected in all retina layers (A–D) and in the ciliary bodies (CB in A). Transduction efficiency was particularly high in the RGC layer (B–C) but GFP was also expressed in the various cell types of the inner nuclear layer (INL), including cells with the morphology of bipolar cells (arrowheads in C) and of Müller cells (arrows in D). Rare GFP-positive photoreceptors (asterisks in B and D) and RPE cells (arrowheads in D and F) were also detected. (E–G) High magnification of GFP-positive (E) Müller cells, (F) RPE cells and (G) photoreceptors. RPE: retinal pigment epithelium; ONL: outer nuclear layer; INL: inner nuclear layer; RGC: retinal ganglion cell layer. Scale bar: 200 µm in A and B; 70 µm in C; 50 µm in D; 20 µm in E–G. A, B and E–G are epifluorescence images; C and D are confocal images.