Phylogenetic relationships in the Lymphocryptovirus genus of the Gammaherpesvirinae.

Complete DNA sequences were determined for the glycoprotein B (gB) genes of four viruses from the genus Lymphocryptovirus, whose hosts had been assigned as baboon, orangutan, chimpanzee and gorilla. Together with published sequences for the gB genes of three lymphocryptoviruses, namely the human pathogen Epstein-Barr virus (EBV), a rhesus monkey virus and a marmoset virus, the sequences were used to investigate evolutionary relationships in the genus. The chimpanzee and orangutan viruses' sequences were found to be so close that it is unlikely both represent natural infections in these hosts. Phylogenetic analyses showed that the New World marmoset virus lineage formed a sister clade to that of the Old World viruses, consistent with a cospeciational separation. Within the Old World virus group, resolution of branching pattern was incomplete, and suggestive of a complex history. In particular, it was inferred that separation of the EBV lineage from that of the gorilla virus plus the chimpanzee/orangutan virus may have predated separation of the present day host species.