Electroretinographic analysis (ERG)

Treated C57BL/6 mice were dark-adapted (>12 hr) and anesthetized with a mixture of ketamine (72 mg/kg)/xylazine (4 mg/kg) by intraperitoneal injection, and ERG experiments were conducted at 2 months following subretinal injections with the AAV2 quad YF vector carrying the CLRN1-HA-tagged transgene as described above. For toxicity assays, one eye in each mouse received one microliter of either a full strength titer of approximately 10¹³ vector genome/ml (vg/mL) or serially diluted vectors of 10¹², 10¹¹, or 10¹⁰ vg/mL. Pupils were dilated with topical agents (1% atropine sulfate, 2.5% phenylephrine hydrochloride) under dim red light. Full-field ERGs were recorded as previously described [42], using a UTAS Visual Diagnostic System (LKC Technologies, Gaithersburg, MD). Dark-adapted ERGs were elicited with 0.02, 0.2 and 2 scot-cd·sec·m^–2 stimuli. Differences in maximum b-wave amplitudes between AAV CLRN1-HA -injected and uninjected contralateral left eyes were analyzed by Student t test (GraphPad Prism 6.0, GraphPad Software, San Diego, CA), and considered statistically significant if p<0.05. All ERG data are presented as mean ± SEM.