Comparison of the complete sequence of feline spumavirus with those of the primate spumaviruses reveals a shorter gag gene.

The complete nucleotide sequence of the provirus of feline foamy virus (FeFV), strain F-17, was determined, and compared to the available data for human and simian spumaviruses. In addition to the usual retroviral gag, pol and env genes, two open reading frames are present between the env gene and the 3'-LTR, as in the simian spumaviruses, the first being the putative transactivator. The gag gene is predicted to encode a precursor protein of only 53 kDa compared to 70 kDa for simian spumaviruses and a doublet of 70/74 kDa for human spumavirus. The gag gene contains conserved splice acceptor and donor sites suggesting that, like human foamy virus, FeFV expresses its pol gene using a spliced mRNA. The poland envgenes showed greater sequence similarity to their counterparts in the primate spumaviruses than the gag gene and additional open reading frames.