title: Molecular phylogeny and dissemination of human T-cell lymphotropic virus type I viewed within the context of primate evolution and human migration.
abstract: A renewed interest in the emergence and evolution of the primate T-cell lymphotropic viruses has followed the discovery of genetically distinct variants of human T-cell lymphotropic virus type I (HTLV-I) in Melanesia and Australia. Phylogenetic trees based on selected regions of the gag, pol, env and pX genes of HTLV-I from widely separated geographic regions and of simian T-cell lymphotropic virus type I (STLV-I) from African and Asian catarrhines, constructed using the neighbor-joining and maximum parsimony methods, indicated that the Australo-Melanesian and cosmopolitan strains of HTLV-I have evolved along separate geographically dependent lineages, with African STLV-I strains clustering with cosmopolitan HTLV-I strains and Asian STLV-I strains diverging from the common ancestral virus before the Australo-Melanesian HTLV-I strains. When viewed within the context of non-human primate evolution and human occupation of Australia and Melanesia, the rate of molecular change of HTLV-I and STLV-I is approximately 2.5-6.8 x 10(-7) substitutions per site per year. Overall, the sequence and phylogenetic analyses are in accord with interspecies virus transmission among non-human primates, as well as between non-human primates and humans, with independent evolution of HTLV-I in Southeast Asia and in Africa, and with dissemination of HTLV-I by forced or voluntary movements of human populations. The immunosuppressive and T-cell activation properties of HTLV-I places at added risk these Australian Aboriginal and Melanesian populations, some of which are in imminent threat of infection with human immunodeficiency virus type 1.
authors.affiliation: Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: R
authors.initials: R
authors.lastname: Yanagihara
authors.forename: N
authors.initials: N
authors.lastname: Saitou
authors.forename: V R
authors.initials: VR
authors.lastname: Nerurkar
authors.forename: K J
authors.initials: KJ
authors.lastname: Song
authors.forename: I
authors.initials: I
authors.lastname: Bastian
authors.forename: G
authors.initials: G
authors.lastname: Franchini
authors.forename: D C
authors.initials: DC
authors.lastname: Gajdusek
mesh_terms: D000349:Africa; D000569:Americas; D000595:Amino Acid Sequence; D000818:Animals; D001210:Asia, Southeastern; D001315:Australia; D001483:Base Sequence; D005075:Biological Evolution; D002460:Cell Line; D004279:DNA, Viral / Q000235:genetics; D006800:Deltaretrovirus Infections / Q000266:history / Q000662:veterinary / Q000821:virology; D004641:Emigration and Immigration; D000939:Epitopes / Q000235:genetics; D005260:Female; D005814:Genes, Viral; D015490:HTLV-I Infections / Q000453:epidemiology / Q000266:history / Q000821:virology*; D049669:History, 16th Century; D049672:History, 19th Century; D049673:History, 20th Century; D049690:History, Ancient; D049691:History, Medieval; D015186:Hominidae / Q000821:virology*; D015368:Human T-lymphotropic virus 1 / Q000145:classification* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008542:Melanesia; D008969:Molecular Sequence Data; D008992:Monkey Diseases / Q000266:history / Q000821:virology; D009154:Mutation; D010802:Phylogeny; D011323:Primates / Q000145:classification / Q000821:virology*; D011533:Proviruses / Q000235:genetics; D044469:Racial Groups / Q000266:history; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015303:Simian T-lymphotropic virus 1 / Q000145:classification* / Q000302:isolation & purification; D013045:Species Specificity; D015678:Viral Structural Proteins / Q000235:genetics
chemical_list: D004279:DNA, Viral; D000939:Epitopes; D015678:Viral Structural Proteins