title: Regional distribution of two related Northeast Asian genotypes of JC virus, CY-a and -b: implications for the dispersal of Northeast Asians.
abstract: JC virus (JCV) is a useful marker to trace human dispersal. Two genotypes of JCV (MY and CY) are mainly distributed in Northeast Asia. The population history of people carrying MY has been studied in some detail but that of people carrying CY remains poorly understood. To gain insights into the population history of Northeast Asians carrying CY we analyzed the genetic variation in CY isolates. We constructed a neighbor-joining phylogenetic tree from 28 complete CY DNA sequences: on the resultant tree the CY DNA sequences diverged into two clades, designated CY-a and -b, each clustered with a high bootstrap probability. The split into CY-a and -b was estimated to have occurred about 10 000 years ago, based on K(s) values (synonymous substitutions per synonymous site) and the suggested rate of synonymous nucleotide substitutions. Comparison of the 28 complete CY sequences revealed six nucleotide mismatches between CY-a and -b, one of which showed a restriction fragment length polymorphism (RFLP). We then PCR-amplified a region of the genome containing this polymorphic site from many CY isolates in various Northeast Asian populations and classified the isolates into CY-a or -b according to the RFLP analysis. CY-a was more abundant than CY-b in various Chinese and Japanese populations but CY-b was more abundant than CY-a in South Koreans. On the basis of the present findings we inferred the population history in East Asians carrying CY.
authors.affiliation: Department of Urology, Faculty of Medicine, The University of Tokyo, Hongo 7-3-1, Tokyo 113-8655, Japan. teizhy-tky@umin.ac.jp
authors.forename: Huai-Ying
authors.initials: HY
authors.lastname: Zheng
authors.forename: Pengyun
authors.initials: P
authors.lastname: Zhao
authors.forename: Hideki
authors.initials: H
authors.lastname: Suganami
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ohasi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ikegaya
authors.forename: Jung-Chul
authors.initials: JC
authors.lastname: Kim
authors.forename: Chie
authors.initials: C
authors.lastname: Sugimoto
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Takasaka
authors.forename: Tadaichi
authors.initials: T
authors.lastname: Kitamura
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Yogo
mesh_terms: D001208:Asia; D044466:Asian People / Q000235:genetics*; D004279:DNA, Viral / Q000737:chemistry / Q000302:isolation & purification; D004641:Emigration and Immigration; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007577:JC Virus / Q000235:genetics* / Q000302:isolation & purification*; D010802:Phylogeny; D017354:Point Mutation; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
chemical_list: D004279:DNA, Viral