FIG. 2.

Env phylogenetic tree constructed by the neighbor-joining method with a fragment of 522 bp encompassing the end of the carboxy terminus of the gene for gp46 and most of the gene for gp21 in 66 HTLV-1 strains, including 6 new strains from Guyana (with the prefix Gya, in bold), 4 new strains from Suriname (with the prefix Sur, in bold), and 14 previously published strains from French Guiana (F. Guiana; with the prefixes AM, CR, and NM, in bold). Strain PTM3 (an STLV-1 strain) was used to root the tree. The numbers along the ancestral segments indicate the robustness of each node, as estimated from 1,000 bootstrap samplings of the data. The geographical origins of the strains other than those from Guyana, Suriname, and French Guiana reported in the cosmopolitan HTLV-1 subtype A are as follows, from top to bottom: PT12, PT3, and PT5, Brazil; PT1 and PT18, Caribbean; Abel2, Reunion Island; PH121, Senegal; CH, Caribbean; ARGMF, Argentina; TSP1, MEL, ATK, H5, OUL, AKR, AKE, MAP, BAT, and MT2, Japanese group; HS35, Caribbean; SIE and SIK, Ivory Coast; PH122, Senegal; and PH333, Mauritania. The sequences in the phylogenetic tree are reported elsewhere (12, 13, 23, 24, 46, 49, 50).