Figure 1: Widespread preferential glial transduction of mouse brains after intracardiac injections of tyrosine-mutant AAV9/3 vectors containing a ubiquitous promoter. The tyrosine-mutant AAV9/3 vector expressed green fluorescent protein (GFP) under control of the cytomegalovirus immediate-early enhancer and chicken -actin (CAG) promoter. ((a)–(d)) Representative images of coronal sections stained with an anti-GFP antibody following virus administration. Section locations relative to the Bregma: (a) +1.34 mm; (b) +0.14 mm; (c) –1.70 mm; and (d) –6.24 mm. ((e), (f)) Merged images showing results of double immunostaining experiments. Most transduced cells showed glial morphologies and were immunoreactive for glial fibrillary acidic protein (GFAP) but not NeuN. (e) GFP (green), NeuN (red); and (f) GFP (green), GFAP (red). Analysis of GFP expression in peripheral organs revealed robust transduction of the heart, liver, and kidney (g–i). Scale bars: ((a)–(d)) 2 mm; ((e), (f), insets of (g)–(i)) 30 μm; ((g)–(i)) 1 mm.