Evolution of two types of rhesus lymphocryptovirus similar to type 1 and type 2 Epstein-Barr virus

Rhesus monkeys and other nonhuman Old World primates are naturally infected with lymphocryptoviruses (LCV) that are closely related to Epstein-Barr vi rus (EBV). A rhesus LCV isolate (208-95) was derived from a B-cell lymphoma in a simian immunodeficiency virus-infected rhesus macaque. The EBNA-2 hom ologues from 208-95 and a previous rhesus LCV isolate (LCL8664) were polymo rphic on immunoblotting, so the EBNA-2 genes from these two rhesus LCV were cloned, sequenced, and compared. The EBNA-2 genes have 40% nucleotide and 41% amino acid identities, and the differences are similar to those between the type 1 and type 2 EBV EBNA-2, Sequence from a portion of the LMP1 gene which is extremely divergent among different LCV was virtually identical b etween the 208-95 and LCL8664 strains, confirming a common rhesus LCV backg round. Thus, the EBNA-2 polymorphism defines the presence of two different rhesus LCV types, and both rhesus LCV types were found to be prevalent in t he rhesus monkey population at the New England Regional Primate Research Ce nter. The existence of two rhesus LCV types suggests that the selective pre ssure for the evolution of two LCV types is shared by human and nonhuman pr imate hosts.