CLONING OF A NEW MURINE ENDOGENOUS RETROVIRUS, MUERV-L, WITH STRONG SIMILARITY TO THE HUMAN HERV-L ELEMENT AND WITH A GAG CODING SEQUENCE CLOSELY-RELATED TO THE FV1 RESTRICTION GENE

We had previously identified a new family of human endogenous retrovir us-like elements, the HERV-L elements (human endogenous retrovirus wit h leucine tRNA primer), whose pol gene was most closely related to tha t of the foamy viruses, HERV-Lpol-related sequences were also detected in other mammalian species. The recent cloning of the mouse Fv1 gene (S, Best, P, Le Tissier, G, Towers, and J, P, Stoye, Nature 382:826-82 9, 1996) has shed light on another HERV-L domain-identified as a gag g ene based on its location within the provirus-which was found to be 60 % identical, at the nucleotide level, to the Fv1 open reading frame (O RF), We have now cloned the murine homolog of NERV-L which, in contras t to HERV-L, displays fully open reading frames in the gag and pal gen es. Its predicted Gag protein shares 43% identity with the Fv1 ORF pro duct, Moreover, the characteristic major homology region of the capsid subdomain can be identified within both proteins, thus strongly empha sizing the gag-like origin of Fv1.