Figure 4: Rapid evolution of norovirus GII.17 VP1. | Nature Communications

Figure 4: Rapid evolution of norovirus GII.17 VP1.

From: Rapid emergence and predominance of a broadly recognizing and fast-evolving norovirus GII.17 variant in late 2014

Figure 4

(a) Pairwise GII.17 VP1 nucleotide and amino-acid distance comparison. (b) Root-to-tip regression analysis to estimate GII.17 VP1 nucleotide substitution rates without a molecular clock assumption. Magenta circles indicate the novel GII.17 Kawasaki 2014. Green and blue dotted lines denote best fit lines for GII.17 from 1978 to 2002 and 2002 to 2015, respectively. Grey dotted lines denote best fit lines for both GII.4 and GII.17 from 1970s to 2015. Substitution rates are expressed as the number of nucleotide substitutions per site per year. Complete and near complete GII.17 VP1 sequences were used. GII.4 VP1 sequences used: CHDC5191/USA/1974 (GenBank accession number: JX023286; variant: ancestral); CHDC2094/USA/1974 (FJ537135; ancestral); calicivirus/USA/1995 (AJ004864; US-95/96); Farmington Hills/USA/2004 (JQ478408; Famington Hills 2002); Hunter 284E/AU/2004 (DQ078794; Hunter 2004); Yerseke38/NL/2006 (EF126963; Yerseke 2006); Sakai2/JP/2006 (AB447448; Asia 2003); Kumanoto4/JP/2006 (AB447462; Den Haag 2006); Apeldoorn317/NL/2007 (AB445395; Apeldoorn 2007); New Orleans/USA/2010 (JN595867; New Orleans 2009); NSW0514/AU/2012 (JX459908; Sydney 2012); CUHK-NS-264/HKG/2014 (JX459908; Sydney 2012); CUHK-NS-508/HKG/2015 (KT780371; Sydney 2012). (c) Upper panel. Number of accumulated VP1 nucleotide differences of local GII.17 Kawasaki 2014 compared with the first strain (magenta arrow) detected on 27 September 2014 in Hong Kong against time (in weeks) since first emergence. Lower panel. Number of accumulated VP1 nucleotide differences of local GII.4 Sydney 2012 collected between March 2014 and May 2015 compared with the earliest local strain NS-264 (purple arrow) collected on 23 March 2014 during the study period. Magenta and purple lines denote the LOWESS fit-lines for GII.17 Kawasaki 2014 and GII4 Sydney 2012, respectively. The earliest local GII.17 Kawasaki 2014 (NS-405) and GII.4 Sydney 2012 (NS-264) strains were excluded in LOWESS data fitting and Spearman’s correlation calculation.

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