A, B. Plasmids encoding U6-sh-COUP-TFI or U6-sh-COUP-TFII with/without Crx expression plasmid were transfected into Y79 (A). Expression plasmid of COUP-TFII and/or TRß2 were transfected to HEK293T (B) cells. Transfected cells were harvested after two days. Then expression of COUP-TFI, COUP-TFII, red opsin, and blue opsin (A), and red opsin (B) was examined by semi-quantitative RT-PCR. G3PDH was used as a control (A, B). C, D. Human red opsin luciferase constructs, hRU0.3 (C) or hRD0.3/8.4–11 (D) was transfected into HEK293T with TRß2 expression plasmid or a control vector, and cultured for 12 hours, T3 (100 nM) was added half of samples and cultured additional 16 hours. p value; **<0.01, *<0.05, or actual value was calculated by Student’s t-test.