Figure 3. Differential expression of NGC mRNA isoforms in Rpe65^−/− mice. NGC-I (left bars) and NGC-III (right bars) mRNA expression was assessed by quantitative PCR on total RNA extracted from wild-type (wt) and Rpe65^−/− mice (ko) at 2, 6, and 12 months (n=3). Left panel shows retinal samples and right panel RPE cell samples. Retinal NGC-I mRNA expression (white bars) was compared to NGC-III mRNA levels (red bars). Similarly, RPE NGC-I mRNA expression (blue bars) was compared to NGC-III mRNA levels (green bars). Retinal NGC-I mRNA expression of 2-month-old wild-type mice was arbitrarily set to 1. For both panels, fold inductions±SEM are shown. By two-way ANOVA retinal NGC-I and NGC-III mRNA levels were significantly increased in Rpe65^−/− mice (p<0.01). Increase in NGC-III mRNA expression in the RPE was also significant at 6 and 12 months (p<0.05).