FIG 4.

LMP1 phylogenetic tree classified by LMP1 type. Maximum-likelihood phylogenetic tree of LMP1 nucleotide sequence from 83 EBV strains (71 new strains and 12 published strains, annotated with a “P”). Bootstrap values above 60 are shown, and the scale bar represents 0.01 nucleotide substitution per site. All strains could be classified into one of the 7 LMP1 types (as defined in reference 16; see the key for colors), and these define the major clades of the tree, except China 1 strains, which are split across several clades. Strains with type 2 EBNA2 and EBNA3 (empty red bars) are present in multiple LMP1 types but absent from the NC and Med LMP1 types. Geographic origin (shown by the color of the sample name: blue, Asia; green, Africa; red, Europe; yellow, USA; purple, Australia; dark red, Papua New Guinea) shows that many of the LMP1 types, including Med and NC, are found in strains from a wide geographic area.