Phylogeny of RNA phages. The phylogenetic analysis was based on the complete genomic RNA sequences (left) and amino acid sequences of the replicase (right) which is the most conserved of all ssRNA phage proteins. Trees were constructed by unweighted pair group method with arithmetic mean (UPGMA) and tested using the bootstrap method with 500 replicates. The bootstrap values are expressed as percentages next to the nodes. RNA and protein sequences were aligned using MUSCLE  and the phylogenetic trees were constructed in program MEGA5 .