title: Genetic analysis and molecular phylogeny of simian T-cell lymphotropic virus type I: evidence for independent virus evolution in Asia and Africa.
abstract: Type C retroviruses, designated simian T-cell lymphotropic virus type I (STLV-I), have been isolated from several genera of Old World monkeys and apes, but not from New World monkeys and prosimians. To determine the genomic diversity and molecular evolution of STLV-I and to clarify their genetic relationship to human T-cell lymphotropic virus type I (HTLV-I), we enzymatically amplified, then directly sequenced selected regions of the gag, pol, env, and pX genes of STLV-I strains from Asia and Africa. STLV-I strains Si-2, Matsu, and JM86 from Japanese macaques, which exhibited sequence similarities ranging from 98.5 to 99.8% among themselves, diverged by 12.9 to 13.3% from STLV-I strain MM39-83 from a naturally infected rhesus macaque, by 9.7 to 11.2% from STLV-I strains from Africa, and by 8.8 to 11.2% from HTLV-I strains originating in Japan, India, Africa, the Caribbean, the Americas, Polynesia, and Melanesia. By contrast, the interspecies nucleotide sequence similarity among African STLV-I strains from green monkey, yellow baboon, sooty mangabey, and common chimpanzee was remarkably high, ranging from 96.9 to 97.4%, and these STLV-I strains diverged by only 2.2 to 2.8% from HTLV-I strain EL from equatorial Zaire. Phylogenetic trees constructed by using the neighbor-joining and maximum parsimony methods indicated that the Asian STLV-I strains diverged from the common ancestral virus prior to African STLV-I and cosmopolitan and Melanesian HTLV-I strains. Thus, our data are consistent with an archaic presence of STLV-I in Asia, probably predating macaque speciation, with subsequent independent virus evolution in Asia and Africa.
authors.affiliation: Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: K J
authors.initials: KJ
authors.lastname: Song
authors.forename: V R
authors.initials: VR
authors.lastname: Nerurkar
authors.forename: N
authors.initials: N
authors.lastname: Saitou
authors.forename: A
authors.initials: A
authors.lastname: Lazo
authors.forename: J R
authors.initials: JR
authors.lastname: Blakeslee
authors.forename: I
authors.initials: I
authors.lastname: Miyoshi
authors.forename: R
authors.initials: R
authors.lastname: Yanagihara
mesh_terms: D000349:Africa; D000818:Animals; D001208:Asia; D001483:Base Sequence; D005075:Biological Evolution; D004279:DNA, Viral; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D011323:Primates; D012689:Sequence Homology, Nucleic Acid; D015303:Simian T-lymphotropic virus 1 / Q000145:classification / Q000235:genetics*
chemical_list: D004279:DNA, Viral