ISOLATION OF REPLICATIVE FORMS OF 3' TERMINAL SUBGENOMIC RNAS OF TOBACCO NECROSIS VIRUS

Three double-stranded RNAs of molecular weights 2.6 × 106, 1.05 × 106, and 0.94 × 106 are found to be synthesized during TNV infection of tobacco leaves. These double-stranded RNAs, isolated by LiCl fractionation and polyacrylamide gel electrophoresis, have been studied using RNA-RNA hybridization and RNase T1-resistant oligonucleotide finger-printing techniques. By these methods all three double-stranded RNAs are shown to be viral in origin and the smaller double-stranded RNA subsets of the larger RNAs. RNase T1 oligonucleotide mapping of the viral RNA shows that both smaller double-stranded RNAs are derived from the 3′ end of the viral genome. The possible role of these small double-stranded RNAs as replicative forms for mRNA synthesis and the organization and expression of the TNV genome is discussed. © 1979.