Viral dsRNAs extracted from transfected cultures, RT-PCR amplification and northern detection of ssRNA and dsRNA from A. fumigatus isolate NK125 following transfection with AfuTmV-1. (A) AfuTmV-1 dsRNAs extracted from transfected cultures (ATV-1 and ATR-1), wild-type (Af293) and virus-free (NK125) isolates. (B) RT-PCR amplification of a 337-bp segment from dsRNA 2. Lane M contains HyperLadder I kb DNA marker. (C) Amounts of viral ssRNA and dsRNA, equivalent to 10 mg of total nucleic acids before LiCl fractionation, were electrophoresed in 1.0% nondenaturing agarose gels and blotted onto nylon membranes. The samples were treated with DNase I (lanes 1, 3, 5, and 7) or DNase I and S1 nuclease (lanes 2, 4, 6, and 8). Hybridization was carried out using positive-strand specific and negative-strand specific riboprobes for all four dsRNAs. The positions of the single-stranded forms of each RNA are indicated on the blots by arrows. RT-PCR amplification of a 467-bp segment from dsRNA 1 (D) and a 337-bp segment from dsRNA 2 (E) from equal amounts of RNA extracted from transfected cultures (ATV-1, ATRS1
nuclease, and ATRRNase
III), wild-type (Af293) and virus-free (NK125) isolates. Lane M contains GeneRuler 100-bp DNA ladder.