Diurnal rhythms of tryptophan hydroxylase 1 and 2 mRNA expression in the rat retina

J Liang, JH Wessel III, PM Iuvone, G Tosini… - …, 2004 - journals.lww.com
Tryptophan hydroxylase is the first of four enzymes in the melatonin biosynthetic pathway.
Recent studies have shown that there are two genes, Tph1 and Tph2, that encode
tryptophan hydroxylase in mammals. In this study, we investigated which of the two genes is
expressed in the rat retina. To that end, we measured Tph1 (classical Tph) and Tph2 mRNA
levels using real-time quantitative RT-PCR in the retina. Our data demonstrate that Tph1
mRNA is the prevalent form expressed in the retina; Tph2 mRNA is also present but the level …