Electroretinogram (ERG) measurements from control Clrn2clarinet/+ (grey) and mutant Clrn2clarinet/clarinet (red) mice. Each trace in B and C is representative of an ERG response from the eye of age-matched Clrn2clarinet/+ and Clrn2clarinet/clarinet mice, showing no significant difference in a- or b-wave amplitudes. (D-F) The lack of change in ERG amplitude responses in Clrn2clarinet/clarinet mice (aged 3 or 6-7 months), regardless of the test conditions: scotopic (D,E), or photopic (F), indicate normal photoreceptor kinetics and no change in the sensitivity of photoreceptor cells. 