title: The out of Africa model of varicella-zoster virus evolution: single nucleotide polymorphisms and private alleles distinguish Asian clades from European/North American clades.
abstract: Until 1998, varicella-zoster virus (VZV) was generally considered sufficiently stable to allow the use of a single sequenced virus (VZV-Dumas) as a consensual representation of the world VZV genotype. But recent investigations have uncovered a gE mutant virus called VZV-MSP with a second genotype and a distinguishable accelerated cell spread phenotype. A subsequent study suggested that single nucleotide polymorphisms (SNPs) could be applied toward the genetic analysis of the VZV genome. To further assess the scope of genetic variation in the VZV genome on a worldwide basis, we carried out an extensive SNP analysis of structural glycoprotein genes gB, gE, gH, gI, gL, as well as the IE62 regulatory gene in viruses collected from Western Europe, North America and Asia, including the VZV vaccine strain. The SNP data showed segregation of viral isolates of Asian origin from those of Western ancestry into distinct phylogenetic clades. Unexpectedly, however, VZV from Thailand segregated with VZV from Iceland and the United States, i.e. it was more Western than Asian in nature. Further, SNP analysis disclosed strikingly unusual genotypes, e.g. gH genes with up to five missense mutations and gL genes with insertions of an in-frame methionine codon. In summary, these VZV genomic analyses have shown that individual VZV strains, like closely related human beings, have distinctive SNP profiles containing private alleles within just five VZV genes (gB, gH, gE, gL and IE62) that provide a fingerprint to localize ancestry of the viral strain.
authors.affiliation: Department of Microbiology, University of Iowa College of Medicine, University of Iowa Hospital/2501 JCP, 200 Hawkins Drive, Iowa City, IA 42242, USA.
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Wagenaar
authors.forename: Vincent T K
authors.initials: VT
authors.lastname: Chow
authors.forename: Chantanee
authors.initials: C
authors.lastname: Buranathai
authors.forename: Pranee
authors.initials: P
authors.lastname: Thawatsupha
authors.forename: Charles
authors.initials: C
authors.lastname: Grose
mesh_terms: D000349:Africa; D000483:Alleles; D000818:Animals; D001208:Asia; D005075:Biological Evolution; D005060:Europe; D019143:Evolution, Molecular; D016679:Genome, Viral; D014645:Herpesvirus 3, Human / Q000235:genetics / Q000502:physiology*; D015186:Hominidae / Q000821:virology; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics; D008562:Membrane Glycoproteins / Q000235:genetics; D009154:Mutation; D009656:North America; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D011323:Primates / Q000821:virology; D011995:Recombination, Genetic; D016415:Sequence Alignment; D015534:Trans-Activators / Q000235:genetics; D014759:Viral Envelope Proteins / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics
chemical_list: C074221:IE62 protein, Human herpesvirus 3; D017874:Immediate-Early Proteins; D008562:Membrane Glycoproteins; D015534:Trans-Activators; D014759:Viral Envelope Proteins; D014764:Viral Proteins; C090198:glycoprotein B, varicella-zoster virus; C056913:glycoprotein E, varicella-zoster virus; C094648:glycoprotein gL, varicella-zoster virus; C040496:gp 118 protein, Herpesvirus 3, Human