Hypothetical polyprotein cleavage sites of the viruses were predicted by multiple alignments with other BEVs and confirmed by the NetPicoRNA . Nucleotide (nt) sequences or amino acid (aa) sequences were aligned using ClustalW. Phylogenetic trees were constructed by maximum likelihood (ML) methods on MEGA5.2.2 . The mtREV24 + G + F model (5′UTR), rtREV + F model (3′UTR), rtREV + G + F model (P1), rtREV + G + I (P2 and P3), and WAG + G + I (VP1) were employed as evolutionary models for ML method. Pairwise identity was analyzed on CLC Genomics Workbench and the secondary RNA structure of the 5′UTR was predicted by Mfold .