Figure 1
Molecular characteristics of L- and S-dsRNA in S. sclerotiorum strain Sunf-M. (A) Agarose gel electrophoresis of dsRNA isolated from mycelial extracts of Sunf-M. The nucleic acid preparation was fractionated on 1.0% agarose gel and stained with ethidium bromide. Lane M, DNA size markers generated by digestion of λDNA with HindIII. (B) Northern hybridization analysis of L- and S-dsRNA. dsRNAs were separated on a 1.0% agarose gel, transferred on to Hybond-N + membrane and hybridized with 32P-labelled probes prepared by random-primer labelling of cloned cDNA to L, S-1 and S-2 dsRNA, respectively. (C) Schematic representation of the genomic organization of L-dsRNA shows the presence of two ORFs. The dotted line box indicates a possible extension of ORF2 by frameshifting. The conserved domains of deduced proteins are shown: SIS, Sugar ISomerase domain; S7, Phytoreovirus S7 protein; RdRP_4, Viral RNA-dependent RNA-polymerase. (D) The pseudoknot structure immediately downstream of the putative frameshift site. The RNA secondary structure was predicted by KnotSeeker program [45] and drawn by VARNAv3-7 program [46]. (E) Schematic representation of predicted genome organization of S dsRNA.