Species specificity of macaque rhadinovirus glycoprotein B sequences

All members of the Herpesviridae family contain sequences for a highly cons erved glycoprotein B (gB) gene. We investigated the phylogenetic relationsh ips of gB sequences from eight independent rhadinovirus isolates obtained f rom three species: rhesus (Macaca mulatta), cynomologus (Macaca fasicularis ), and pig-tailed (Macaca nemestrina) macaques. Samples were derived from m onkeys housed at four separate facilities. Analysis of these eight independ ent 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 a mong the different macaque isolates. Overall divergence among these gene se quences ranged from 0.1 to 7.2% at the amino acid level. Phylogenetic trees constructed with our macaque rhadinovirus gB sequences and those derived f rom additional subfamilies or genera (alpha, beta, gamma-1, and gamma-2) re vealed that the macaque gB sequences brandied with other gamma-2 herpesviru s gB sequences and that within the gamma-2 genera, the macaque gB sequences clustered as a distinct branch. The eight macaque rhadinovirus gB sequence s were all approximately equidistant from Kaposi sarcoma-associated herpesv irus (KSHV) gB sequences and had a shorter evolutionary distance to KSHV gB sequences than to any other herpesvirus, including the gamma-2 herpesvirus saimiri (RVS) 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 .