Silent delta-globin gene in Old World monkeys.

The delta polypeptide chain is present in the adult hemoglobin of all higher primates except Old World monkeys. Because Old World monkeys have evolved from higher primate ancestors, it can be concluded that the ability to synthesize this polypeptide has been lost relatively recently. It is shown here that the gene for delta globin exists in two of these species, the rhesus monkey (Macaca mulatta) and the baboon (Papio papio). Restriction endonuclease fragments of monkey genomic DNA bearing the delta- and beta-globin genes were detected after hybridization of human globin cDNA probes to filter-bound primate DNAs according to the Southern method. A restriction map prepared for rhesus DNA was identical in overall organization to the map of the human region. This indicates that large deletions or additions of DNA are not responsible for the Old World monkeys' lack of delta globin.