NUCLEOTIDE-SEQUENCE OF FELINE IMMUNODEFICIENCY VIRUS - CLASSIFICATIONOF JAPANESE ISOLATES INTO 2 SUBTYPES WHICH ATE DISTINCT FROM NON-JAPANESE SUBTYPES

Seven isolates of feline immunodeficiency virus (FIV), Shizuoka, Yokoh ama, Sendai-1, Sendai-2, Fukuoka, Aomori-1, and Aomori-2, were isolate d from FIV-seropositive domestic cats in Japan, and their proviral DNA s were amplified by PCR, The nucleotide sequences of their env and gag genes were determined and compared with those of previously described isolates: U.S. and European isolates and one Japanese isolate, TM2, P hylogenetic analyses of complete env gene sequences demonstrate that w orldwide isolates are classified into three subtypes: Japanese TM2, Ja panese Shizuoka, and non-Japanese subtypes (U.S. and European isolates ), with 20% amino acid distances from each other. This pattern indicat es that an evolutionary radiation of these three subtypes of FIV occur red at approximately the same time, The sequence data of gag genes als o confirmed these results. Furthermore, the Sendai-1 isolate was ident ified as an imported FIV isolate.