Emergence of the A188V substitution at NS1 protein during Zika virus (ZIKV) Asian genotype evolution. (A) Correlation between the sampling date of each ZIKV sequence (n = 65) and the genetic distance of that sequence from the root of a maximum likelihood (ML) phylogenetic tree. Colours indicate the geographic region of sampling. (B) Bayesian time-scale maximum clade credibility (MCC) phylogenetic tree estimated from ZIKV Asian genotype genomic sequences (n = 65). Branches are coloured according to the most probable location state (geographic region) of their descendent nodes as indicated at the legend on the lower left. Reconstructed ancestral key nodes and terminal nodes are highlighted with circles colored according to the location (colour) and the amino acid at NS1 188 residue (fill or empty), as indicated at the legend on the lower left. Numbers at key selected nodes represent the posterior probability supports of the clades. All horizontal branch lengths are drawn to a scale of years. Taxon labels include information of GenBank accession number, country of origin, region of origin (AM = Americas; AS = Asia; PA = Pacific) and year of isolation. Countries represented are: American Samoa (AS), Brazil (BR), Cambodia (KH), Colombia (CO), Federated States of Micronesia (FM), Fiji (FJ), French Guiana (GF), French Polynesia (PF), Guatemala (GT), Haiti (HT), Honduras (HN), Malaysia (MY), Martinique (MQ), Mexico (MX), Panama (PA), Philippines (PH), Puerto Rico (PR), Samoa (WS), Singapore (SG), Suriname (SR), Thailand (TH), Tonga (TO), and Vietnam (VN).