Analysis of the genome structure of influenza A virus strains isolated during the epidemics of 1977-1980.

The genome structure of different A(H1N1) and A(H3N2) influenza virus strains isolated from 1977 to 1980 was analysed by electrophoresis of single-stranded RNA and of the double-stranded RNA obtained by hybridization with complementary RNA of the A/Stavropol 188/79 (H3N2) strain. The differences in genome structure are insignificant within the A(H1N1) subtype, and considerable (involving almost all the 8 RNA fragments) between the two A(H3N2) strains (A/Texas 1/77 and A/Stavropol 188/79). The great differences between the genomes of A(H1N1) and A(H3N2) strains do not exclude certain genetic relationships between these viruses.