Viral genome sequences were obtained using strategies we had previously used for other RNA viruses [50] [51] [52] . RNA extraction and cDNA generation were performed as described above. PCR primers were designed by targeting conserved regions, which were identified from the multiple alignment of genomes of related SaVs, as primer-binding sites. Additional primers for subsequent rounds of PCR were designed based on the results of earlier rounds of genome sequencing. The complete set of primer sequences is available from the authors upon request. The 59 and 39 ends of the viral genomes were sequenced following amplification of the segments by rapid amplification of cDNA ends, which was performed using the SMARTer RACE cDNA Amplification kit (Clontech) according to the manufacturer's instructions.