Figure 4.

Phylogeny of TMUV-TP1906, Tembusu virus strains (TMUVs), and duck Tembusu virus strains (DTMUVs) based on the polyprotein amino acid sequences (3425 aa). The evolutionary history was inferred by using the maximum likelihood method based on the JTT matrix-based model [23]. The tree with the highest log likelihood is shown. Initial tree(s) for the heuristic search were obtained automatically by applying Neighbor-Join and BioNJ algorithms to a matrix of pairwise distances estimated using a JTT model, and then selecting the topology with superior log likelihood value. The tree is drawn to scale, with branch lengths measured in the number of substitutions per site. The analysis involved 40 amino acid sequences. All positions containing gaps and missing data were eliminated. Evolutionary analyses were conducted in MEGA7 [21]. The reliability of the analysis was calculated using 1000 bootstrap replication. Bootstrap support values >75 are shown. The scale bar indicates amino acid substitutions per site. The unique amino acid residues in TP1906, Sitiawan virus, MM1775, SD14, and DTMUV cluster 1 compared to other TMUV strains were colored in blue, brown, gray, green, and yellow, respectively. The unique amino acid residues in DTMUV cluster 1 and 2, TMUV lineage, and TP1906 and STWV compared to other TMUV strains were colored in black, purple, and red, respectively.