Fig. 2

Phylogenetic tree analysis of EIAV proviral genomes and individual genes (gag, pol, env, tat, s2, rev and LTR). Sequence data were collected from 65 complete proviral genomes of seven viral strains. The phylogenetic trees were constructed using the neighbor-joining method and calculated with the Kimura 2 parameter in MEGA 5. Bootstrap values above 70 % are indicated. The virulent strains, including EIAV_LN40, EIAV_DV117, EIAV_DLV34 and EIAV_DLV62, are viruses that cause typical EIA symptoms (rectal temperature >39 °C, the platelet count <100,000/μL and the plasma viral load >10⁶ copies/mL)