Polymorphic tandem repeats in dopamine D4 receptor are spread over primate species

Abstract

The human dopamine D4 receptor has polymorphic tandem repeats in the third cytoplasmic loop. However, these repeats are not present in the rat counterpart. To determine whether the tandem repeats are specific to humans or not, we analyzed genomic DNA sequences for the D4 receptor of six primate species (human, chimpanzee, gorilla, orangutan, macaque, marmoset). Sequencing data revealed that all primates have the 48-bp tandem repeats in the D4 receptor gene. This finding suggests that these repeats originated before the separation of the New World monkey lineage from the Old World monkey and ape-human lineages.