Fig. 3.

—Confirmation of the presence of 2b in the evolved viral lineages. Agarose gels (1%) with conventional RT-PCR products of the region encompassing the 2b inserted into the TEV genome. Expected amplicon sizes are indicated on the right panels with arrows: 298 bp for wild-type TEV and 651 bp for TEV/2b. No deletions or reorganizations were observed in any lineage or passage. (A) Amplicons of all virus lineages from the first (P1) passage. (B) Amplicons from the fifth (P5) passage. Healthy (H), buffer-inoculated (B) plant extracts and water (RT-PCR−) were used as negative RT-PCR controls. PCR products obtained from the original full-length cDNA virus clones of TEV (pTEV) and TEV/2b (pTEV2b) are included as positive controls of insertion size. RT-PCR −: negative RT-PCR control.