title: Early Evolution of Human Respiratory Syncytial Virus ON1 Strains: Analysis of the Diversity in the C-Terminal Hypervariable Region of Glycoprotein Gene within the First 3.5 Years since Their Detection.
abstract: OBJECTIVE
  Characterization of the phylogeny and diversity of human respiratory syncytial virus (HRSV) genotype ON1 that occurred during its early evolution (within the first 3.5 years since the detection of the first ON1 strains). ON1 strains have a 72-nucleotide-long in-frame duplication within the second hypervariable domain of the glycoprotein gene (HVR2).
  
  
  METHODS
  All available HVR2 sequences of strains belonging to the ON1 genotype published prior to June 20, 2014 were collected. Multiple sequence alignments, phylogeny, phylogeography, sequence clustering and putative protein analyses were performed.
  
  
  RESULTS
  The worldwide spread and diversification of ON1 strains are presented. Only in a minority of ON1 strains do the two replicas remain identical, and various ON1 strains possess common differences between the first and the second copy (segments A and B). Mutations of the progenitor sequence were more frequent in segment B, a higher overall diversity on the protein level and more putative glycosylation sites exist in segment B, and, unlike in segment A, positive selection acts on that protein region.
  
  
  CONCLUSIONS
  The fast spread of the novel HRSV genotype ON1 has been accompanied by its rapid concurrent diversification. Differences in variability of the two replicas within HVR2 were detected, with C-terminal replica being more variable.
authors.affiliation: Centre for Research and Knowledge Transfer in Biotechnology, University of Zagreb, Zagreb, Croatia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Ivancic-Jelecki
authors.forename: Dubravko
authors.initials: D
authors.lastname: Forcic
authors.forename: Gordana
authors.initials: G
authors.lastname: Mlinaric-Galinovic
authors.forename: Goran
authors.initials: G
authors.lastname: Tesovic
authors.forename: Ana
authors.initials: A
authors.lastname: Nikic Hecer
mesh_terms: D000595:Amino Acid Sequence; D002675:Child, Preschool; D016000:Cluster Analysis; D019143:Evolution, Molecular; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009154:Mutation; D010802:Phylogeny; D058974:Phylogeography; D018357:Respiratory Syncytial Virus Infections / Q000821:virology*; D018113:Respiratory Syncytial Virus, Human / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013997:Time Factors; D014760:Viral Fusion Proteins / Q000737:chemistry* / Q000235:genetics*
chemical_list: C502275:G glycoprotein, Respiratory syncytial virus; D014760:Viral Fusion Proteins