High - frequency flicker ERG and step ERG of FAT3 ICD deficient mice. (A and B) Schematics of molecular structure of FAT3 WT and FAT^ΔICD-GFP proteins B. Immunostaining for GFP in WT retinal sections. The arrow points the OPL. Inset (yellow box) is seen in B′. (C) Immunostaining for GFP in Fat3^{∆ICD-GFP/∆ICD-GFP} retinal sections. The arrow points to the OPL. Inset (yellow box) is seen in C′. (D) Representative OCT images of Fat3^ΔICD-GFP/+ control and Fat3^{ΔICD-GFP/ΔICD-GFP} eyes. (E) Representative flicker ERG raw traces of Fat3^ΔICD-GFP/+ control and Fat3^{ΔICD-GFP/ΔICD-GFP} eyes elicited by 3.162 cd s/m² flashes at 20, 30, 40, and 50 Hz frequencies. (F) Flicker ERG amplitude at 0.5, 10, 20, 30, 40, and 50 Hz for Fat3^ΔICD-GFP/+ control (n = 10 eyes) and Fat3^{ΔICD-GFP/ΔICD-GFP} (n = 10) eyes. Unpaired two-tailed Student’s t test. Error bar: SEM. (G) Flicker ERG implicit time at 20 Hz for Fat3^ΔICD-GFP/+ control (37.4 ± 0.5 ms, n = 10 eyes) and Fat3^{ΔICD-GFP/ΔICD-GFP} (41.9 ± 0.8 ms, n = 10) eyes at 20 Hz. Unpaired two-tailed Student’s t test. Error bar: SEM. (H) Representative step ERG raw traces of Fat3^ΔICD/+ control (left) and Fat3^{ΔICD-GFP/ΔICD-GFP} (right) eyes elicited by a 3-s step light at 1,000 cd/m² intensity. (I) Quantification of step ERG d-wave amplitudes for Fat3^ΔICD-GFP/+ control (36.1 ± 3.7 µV, n = 10 eyes) and Fat3^{ΔICD-GFP/ΔICD-GFP} (14.4 ± 3.8 µV, n = 10) eyes elicited by a 3-s step of light at 1,000 cd/m² intensity. Unpaired two-tailed Student’s t test. Error bar: SEM.