A truncated immunoglobulin epsilon pseudogene is found in gorilla and man but not in chimpanzee.

Molecular genetic analyses of the young pseudogenes of the immunoglobulin C epsilon genes were carried out to obtain qualitative evidence for the phylogenetic branching pattern of hominoid primates. We found that Old World monkeys had two C epsilon genes, one of which was processed. Among the hominoids examined only the gorilla and human genomes contained three C epsilon genes: an active, a truncated, and a processed gene. Other hominoids so far examined, including chimpanzee, contained two C epsilon genes: one active and the other processed. These results suggest that the processed C epsilon pseudogene was generated before the divergence between Old World monkeys and hominoids and that the gorilla is more closely related to man than the chimpanzee is, unless the chimpanzee has lost the C epsilon 2 gene after the divergence of this species.