Figure 2: Detection of (-) and (+) forms of ASBVd in Nostoc using strand-specific RT-PCR. A. Strand-specific RT-PCR performed with RNAs extracted from pRLASBVd(-) or pRLASBVd(+) recombinant strains. For each reaction, the primer used in the reverse transcription step and the polarity of the corresponding amplified cDNAs are indicated at the bottom of the image. The “size control” line corresponds to the result of a PCR amplification step in which the ASBV-O1 and ASBV-O2 primers and the pCRII-topo ASBVd (-) plasmid were used. B. Amplification of the rnpB gene using RNAs extracted from pRLASBVd(-) versus pRLASBVd(+) recombinant strains. C. RT-PCR reactions performed using the LKASBV-O1 and LKASBV-O2 primers and RNAs extracted from a Nostoc strain harboring the empty pRL25 plasmid. This experiment was performed with five recombinant Nostoc strains obtained by performing five independent conjugations and similar results were obtained.