Origin of TMUV in China
To trace the origin of TMUV, we constructed an ML tree based on the ORF gene sequence (Fig. 1a). We found that all the avian TMUV strains were closely related to the mosquito TMUV with high confidence. The West Nile virus lineage 2 (NC001563) was selected as outgroup of the mosquito TMUV and avian TMUV strains, which might indicate a potential mosquito TMUV origin. To further verify this result, an MCC tree was constructed (Fig. 1b). The MCC tree showed a topology similar to that of the ML tree. Although this provides evidence that a close relationship exists between avian TMUV and mosquito TMUV, it is worth noting that only 3 strains of mosquito TMUV could be obtained from GenBank; we will update the analysis once more mosquito TMUV is available.