Organization and evolution of the rat tyrosine hydroxylase gene

Abstract
This report describes the organization of the rat tyrosine hydroxylase (TH) gene and compares its structure with the human phenylalanine hydroxylase gene. Both genes are single copy and contain 13 exons separated by 12 introns. Remarkably, the positions of 10 out of 12 intron/exon boundaries are identical for the two genes. These results support the idea tha these hydroxylase genes are members of a gene family which has a common evolutionary origin. We predict that this ancestral gene would hav encoded exons similar, to those of TH prior to evolutionary drift to other members of this gene family.