Southern blot analysis of wild-type and transgenic CalCuV-infected plants. Total DNA was extracted from a mix of 5 rosettes and loaded in each well of an agarose gel. A fragment of viral component A was used as probe. (W) Wild-type plants, (O) CaMV35S-CRL T2-1 plants, (S) CRL-RNAi T2-5 plants, (SS) CRL-RNAi T2-5 symptomatic plants, (V) viral DNA-A cloned into Bluescript plasmid. Viral forms (open circular viral-DNA, oc; closed circular viral-DNA, cc; single stranded, ss) are indicated. Ethidium bromide staining of genomic DNA is shown as a loading control.