Fig. 1

Identification of macque ERV-K provirus and a fully-spliced SERV-K1 Env mRNA. a Using human ERV-K sequences to search the rhesus macaque genome for ERV proviral insertions, we identified a proviral insertion of SERV-K1 on macaque chromosome 12. Genomic organization of this SERV-K1 provirus is shown. b Using mRNA capture, we identified a fully-spliced mRNA encoding the SERV-K1 Env protein. Predicted protein translation of the captured mRNA is shown with canonical Env structural features: leader sequence (light grey), R-X-K/R-R cleavage site (boxed), fusion domain (grey highlight), immunosuppressive domain (Bolded and underlined), conserved cysteine residues (white, underlined Cs), and transmembrane anchor domain (grey highlight). c Hydrophobicity plot of SERV-K1 Env protein with features highlighted as in part b. d Phylogram showing the relationship of the simian ERVs examined here to previously characterized HERV-K HML-2 insertions in chimpanzees and humans. The phylogram was generated using maximum likelihood as implemented in PHYML [27] with 1000 bootstrap replicates. The tree is rooted on HERV-K(OLD) proviruses previously determined to be ancestors of the HML-2 lineage in Old World primates [28]. The macaque locus examined here is indicated by background shading. Asterisks indicate nodes that were recovered in >95 % of bootstrap trees. OWM old world monkey, Chr chromosome