Search

The primary sequence of the long unique region L-DNA (L for low GC) of rhesus monkey rhadinovirus (RRV) isolate 26-95 was determined. The L-DNA consists of 130,733 bp that contain 84 open reading frames (ORFs). The overall organization of the RRV26-95 genome was found to be very similar to that of human Kaposi sarcoma-associated herpesvirus (KSHV). BLAST search analysis revealed that in almost all cases RRV26-95 coding sequences have a greater degree of similarity to corresponding KSHV sequences than to other herpesviruses. All of the ORFs present in KSHV have at least one homologue in RRV26-95 except K3 and K5 (bovine herpesvirus-4 immediate-early protein homologues), K7 (nut-1), and K12 (Kaposin). RRV26-95 contains one MIP-1 and eight interferon regulatory factor (vIRF) homologues compared to three MIP-1 and four vIRF homologues in KSHV. All homologues are correspondingly located in KSHV and RRV with the exception of dihydrofolate reductase (DHFR). DHFR is correspondingly located near the left end of the genome in RRV26-95 and herpesvirus saimiri (HVS), but in KSHV the DHFR gene is displaced 16,069 nucleotides in a rightward direction in the genome. DHFR is also unusual in that the RRV26-95 DHFR more closely resembles HVS DHFR (74% similarity) than KSHV DHFR (55% similarity). Of the 84 ORFs in RRV26-95, 83 contain sequences similar to the recently determined sequences of the independent RRV isolate 17577. RRV26-95 and RRV17577 sequences differ in that ORF 67.5 sequences contained in RRV26-95 were not found in RRV17577. In addition, ORF 4 is significantly shorter in RRV26-95 than was reported for RRV17577 (395 versus 645 amino acids). Only four of the corresponding ORFs between RRV26-95 and RRV17577 exhibited less than 95% sequence identity: glycoproteins H and L, uracil DNA glucosidase, and a tegument protein (ORF 67). Both RRV26-95 and RRV17577 have unique ORFs between positions 21444 to 21752 and 110910 to 114899 in a rightward direction and from positions 116524 to 111082 in a leftward direction that are not found in KSHV. Our analysis indicates that RRV26-95 and RRV17577 are clearly independent isolates of the same virus species and that both are closely related in structural organization and overall sequence to KSHV. The availability of detailed sequence information, the ability to grow RRV lytically in cell culture, and the ability to infect monkeys experimentally with RRV will facilitate the construction of mutant strains of virus for evaluating the contribution of individual genes to biological properties.

All members of the Herpesviridae family contain sequences for a highly conserved glycoprotein B (gB) gene. We investigated the phylogenetic relationships of gB sequences from eight independent rhadinovirus isolates obtained from three species: rhesus ( Macaca mulatta ), cynomologus ( Macaca fasicularis ), and pig-tailed ( Macaca nemestrina ) macaques. Samples were derived from monkeys housed at four separate facilities. Analysis of these eight independent gB sequences revealed five regions of heterogeneity within the 823- to 829-amino-acid polypeptides: residues 1 to 65, 120 to 185, 255 to 300, 352 to 393, and 412 to 457. The remaining regions of gB were highly conserved among the different macaque isolates. Overall divergence among these gene sequences ranged from 0.1 to 7.2% at the amino acid level. Phylogenetic trees constructed with our macaque rhadinovirus gB sequences and those derived from additional subfamilies or genera (alpha, beta, gamma-1, and gamma-2) revealed that the macaque gB sequences branched with other gamma-2 herpesvirus gB sequences and that within the gamma-2 genera, the macaque gB sequences clustered as a distinct branch. The eight macaque rhadinovirus gB sequences were all approximately equidistant from Kaposi sarcoma-associated herpesvirus (KSHV) gB sequences and had a shorter evolutionary distance to KSHV gB sequences than to any other herpesvirus, including the gamma-2 herpesvirus saimiri (HVS) of New World squirrel monkeys. The macaque gB sequences did not cluster according to the facility of origin, but did cluster according to the species of origin, displaying less intraspecies divergence (0.1 to 2.9%) than interspecies divergence (3.3 to 7.2%). These results demonstrate a close relatedness of rhadinovirus isolates from different macaque species.