gamma -Herpesviruses closely related to the Epstein-Barr virus (EBV) are kn
own to naturally infect Old World non-human primates and are classified in
the same lymphocryptovirus (LCV) genera. LCV infecting humans and Old World
primates share similar biology, and recent studies have demonstrated that
these viruses share a similar repertoire of viral genes. Surprisingly, the
latent infection genes associated with cell growth transformation demonstra
te the most striking sequence divergence, but the functional mechanisms for
these genes are generally well conserved. The recent discovery of LVCs nat
urally infecting New World primates has rewritten tile old paradigm of LCV
host range restriction to humans and Old World non-human primates, so that
these viruses are more widespread than previously believed. However, the Ne
w World LCV genome has significant and interesting differences from EBV and
other Old World LCVs despite similar biological properties. Thus, tile sim
ian homologues of EBV can provide an important animal model for studying LC
V pathogenesis, and the similarities and differences that have evolved amon
g these related viruses can provide a unique perspective towards a better u
nderstanding of EBV.