Figure 3. RetGC activity and AAV-mediated GUCY2D expression in GCdKO retinas. A: RetGC1 activity (mean ± standard deviation, SD) in retinal homogenates extracted from non-injected (-) eyes compared to those injected (+) with adenoassociated virus (AAV) vectors harboring wild-type (hWT), S248W, or R1091x GUCY2D cDNA. Results are the average of two independent experiments, each using two different mouse eyes. The difference in retinal membrane guanylyl cyclase 1 (RetGC1) activity between the eyes treated with AAV-S248W and the two other groups was highly statistically significant (p≤0.0002). There was no statistically significant difference between the hWT and R1091x-injected mice (p = 0.126). B: Western immunoblotting of the retinal proteins extracted from the injected and non-injected eyes probed with anti-RetGC1 antibody. Note the faint signal in the S248W lane compared to the two other GUCY2D variants. C: Quantitative real-time (QRT) PCR detection of GUCY2D-specific transcripts in the retinas from three wild-type (hWT) and two S248W GUCY2D-injected Gucy2e^−/−Gucy2f^−/− knockout (GCdKO) eyes plotted as fold-increase (mean ± standard error, SE) in the GUCY2D transcript signal relative to the non-injected (Log 0) GCdKO retinas.