Differences in RNA patterns of influenza A viruses

Analysis of the segmented RNAs of influenza A viruses by electrophoresis on polyacrylamide urea slab gels has provided a method for sharper resolution of the number and migration rates of different segments than previously has been possible. Using this system, the RNA genome of influenza A/WSN (HON1) virus can be separated into seven to nine separate bands, depending on whether virus is obtained after high or low multiplicity of infection, and the genome of influenza A/PR/8 (HON1) virus can be resolved into eight bands, six of which migrate differently from comparable RNA bands of WSN virus. Comparison of the RNA patterns produced by influenza A/PR/8 (HON1) and A/England/42/72 (H3N2) viruses also reveals major differences in migration speeds of different bands, and analysis of the RNAs of an HON2 recombinant virus derived from these two strains permits the identification of RNA segments which have been derived from one particular parent. By extension of these techniques, it may be possible to define which RNA segment codes for each viral protein and to analyze recombinant strains to identify which genes have been derived from each of its parents.