Fig. 1

(a and b) Phylogenetic trees of HIV-1 pol genes were constructed using MEGA 7 based on neighbor-joining methods. a (total tree) shows clusters of all the sequences, whereas b (subtree) indicates mainly clusters of different subtypes. The strain name of the reference sequences are shown in green. The bootstrap values greater than 70% based on 1000 replicates are shown on the major branches. The scale bar indicates 0.01 for the total tree and 0.005 for the subtree. The newly identified strains are named in “transmission route-subtypes-sample code”. Ho represents homosexual; He represents heterosexual; un represents unknown; IDU represents intravenous drug use. In front of strain name, newly identified unique recombinant forms (URFs) are color-coded in red dots