Duplication of the CD8 beta-chain gene as a marker of the man-gorilla-chimpanzee clade.

In earlier studies we have found that the gene encoding the CD8 beta chain is duplicated in man. We demonstrate here that the duplicated genes are both located on chromosome 2. We have also studied the moment of the duplication event relative to the evolution of higher primates by using genomic DNA of a panel of primates. Our data strongly suggest that duplication occurred after the orangutan lineage had split and before the chimpanzee, gorilla, and man clade diverged, some 8-9.5 million years ago. This result makes the CD8 beta-chain gene duplication a convenient marker for the study of the evolution of higher primates. IMAGES: