JC Virus Genotypes in Northwestern China: Implications for Its Population History.

Abstract

Genotyping of urinary JC virus (JCV) DNAs is a useful means of elucidating the origin of ethnic populations. We previously reported JCV genotypes in eastern China and Mongolia. To gain a comprehensive picture of JCV genotypes in China, we collected urine samples at three northwestern sites along the Silk Road: X'ian, Lanzhou and Urumqi. DNA was extracted from urine samples, and used to amplify the 610-base-pair region (IG region) of the viral genome. For each geographical site, we determined 16 to 24 IG sequences, from which a neighbor-joining phylogenetic tree was constructed to classify detected JCV isolates into distinct genotypes. (1) The northeastern-Asian genotype (CY) was mainly detected at X'ian and Lanzhou. This finding suggested that these two sites were colonized mainly by northeastern Asians. (2) The northeastern-Asian (CY) and central/western-Asian genotype (B1-b) were mainly detected at Urumqi. This suggested that Urumqi was colonized by both northeastern and central Asians. (3) In addition, several minor JCV genotypes were detected at these sites. These included a genotype (B1-c) prevalent in Europe and western Asia and a genotype (Af2) prevalent in Africa and western Asia. Significant admixture of human populations may have occurred in areas along the Silk Road that was used in ancient times to transport goods between China and Europe.