Comparison of the structural organizations in the 3'-terminal regions of five avian retrovirus strains: RAV 7, RAV 50, B77, PR-B, and SR-B.

In order to obtain information on the phylogenies of viral strains which belong to RSV (Rous sarcoma virus) and ALV (avian leukosis virus), the nucleotide sequences of noncoding regions adjacent to the U3 region in two ALV strains, Rous-associated virus 7 (RAV 7) and RAV 50, and three RSV strains, Bratislava 77 (B77), Prague:subgroup B (PR-B), and Schmidt-Ruppin:subgroup B (SR-B) were determined by extension from a common primer. The sequences thus deduced were compared with known sequences of other RSV and ALV strains and the structural features of the newly determined viral genomes were discussed.