Figure 1. Induction of Cre expression in inducible RPE-specific Cre mice. A: cre mRNA induction was detected with intravitreally delivered doxycycline (Dox; 4 µg in 1 µl) with reverse transcription (RT)–PCR. Expression of cre mRNA was detected 7 days (7D) after induction and was diminished 60 days (60D) after induction. B: Western blot analysis shows relative amounts of Cre protein after induction by Dox feeding (daily gavage at a dose of 0.4 mg/g bodyweight for 2 days) or intravitreal Dox injection. Cre expression was robustly elevated 15 days after intravitreal injection, compared with that induced by feeding. Cre accumulation was reduced and diminished, 60 days or 180 days after intravitreal Dox induction, respectively. Error bar: standard deviation (SD); n = 3. *: p<0.01.