FIG. 1.

Phylogenetic tree of sequence similarity between lentiviruses. Sheep (S) and goat (G) lentiviral fragments sequenced in the study were compared with sequences from small ruminant, bovine, equine, feline, human, and simian lentiviruses available in the GenBank database (accession numbers are indicated in parentheses). The neighbor-joining tree was constructed by using MEGA. The bar indicates the amount of evolution (substitutions per site) along the horizontal branches. Statistical support for the internal branches was evaluated by the bootstrap test (values greater than 50 are shown). EIAV, equine infectious anemia virus; BIV, bovine immunodeficiency virus; FIV, feline immunodeficiency virus; HIV2, human immunodeficiency virus type 2; SIV, simian immunodeficiency virus.