Strategies for the sequence determination of viral dsRNA genomes.

The genetic study of viruses having dsRNA genomes is hampered by the technical difficulty of complete sequence determination of dsRNA. Optimised methods are described here for sequencing dsRNAs, which meet three different situations: (1) genomes that can be obtained in fairly high amounts (>20 ng per separated segment); (2) genomes with limited amounts of RNA that can be detected by electrophoretic gel separation and staining; (3) genomes that cannot be detected by electrophoretic gel separation and staining. These methods include improved Single Primer Amplification Technique protocols, an adaptation of the SMART methodology, and a new method permitting the selective enzymatic removal of dsRNA segments. Strategies permitting adaptation of these protocols to the full-length determination of dsRNA viral genomes are described. Each of the protocols is described for sequence determination of a chosen dsRNA virus.