RT–PCR and qRT–PCR analyses

RT–PCR and qRT–PCR analyses were performed as described previously (Chaya et al, 2014; Okamoto et al, 2017). Total RNAs were extracted using TRIzol (Ambion) from tissues dissected from ICR mice at 4 weeks, retinas from Klhl18 ^+/+ and Klhl18 ^−/− mice at 1 M, and retinas from Pde6b ^+/+ and Pde6b ^rd1/rd1 mice at P14. Total RNA of 0.5 or 2 μg was reverse‐transcribed into cDNA with random hexamers using SuperscriptII (Invitrogen) or PrimeScriptII Reagent (TaKaRa). The cDNAs were used for PCR by rTaq polymerase (TaKaRa). Primer sequences used for amplification are listed in Table EV1. qRT–PCR was performed using SYBR Green ER Q‐PCR Super Mix (Invitrogen) and Thermal Cycler Dice Real Time System Single MRQ TP870 (Takara) according to the manufacturer's protocols. Quantification was performed by Thermal Cycler Dice Real Time System software ver. 2.0 (Takara). Primer sequences used for amplification are listed in Table EV1.