engleski

Early evolution of human respiratory syncytial virus ON1 strains: analysis of the diversity in C-terminal hypervariable region of glycoprotein gene within the first 3.5 years since their detection

Objective was a characterization of phylogeny and diversity of human respiratory syncytial virus (HRSV) genotype ON1 that occurred during its early evolution (within the first 3.5 years since detection of the first ON1 strains). ON1 strains possess 72 nucleotides long in frame duplication within the second hypervariable domain of the glycoprotein gene (HVR2). All available HVR2 sequences of strains belonging to ON1 genotype published prior to June 20, 2014 were collected. Multiple sequence alignments, phylogeny, phylogeography, sequence clustering and putative protein analyses were performed. Worldwide spread and diversification of ON1 strains is presented. Only in minority of ON1 strains the two replicas remained identical and various ON1 strains possess common differences between the first and the second copy (segments A and B). Mutations of progenitor sequence were more frequent in segment B, higher overall diversity on protein level and more putative glycosylation sites exist in segment B, and unlike segment A, positive selection acts on that protein region. The fast spread of 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.

human respiratory syncytial virus ; molecular evolution ; ON1 genotype ; glycoprotein gene ; variability

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