Fig. 1.
Expression of TPH1, TPH2, AANAT, and HIOMT genes in human retinal pigment epithelium (RPE) cells. (A) Exonal organization of genes. Coding exons are identified by numbers. Arrows represent PCR primers. Dashed line encompasses PCR fragments. (B) Tryptophan hydroxylase I (TPH1), (C) tryptophan hydroxylase II (TPH2), (D) arylalkylamine N-acetyltransferase (AANAT), (E) hydroxyindole-O-methyltransferase (HIOMT). RT-PCR lane M—DNA ladder; p24, p26, p31 indicate RPE passages, B—human brain cDNA. RT-PCR was performed as previously described (Slominski et al., 2002a,b) except for TPH2 (see Section 2 for details).