Figure 5. RNAi components are required for transgene-induced vegetative silencing.

A) Transgenic strain PPW22 and ago1Δ, rdp1Δ, dcr1Δ, or dcr2Δ mutant derivatives were grown on YPD medium without or with 100 µg/ml CsA, incubated at 30°C and 37°C for four days, and photographed. B) Expression of CPA1 and CPA2 was examined by northern blot analysis. The quantities of CPA1/2 were determined by phosphorimager analysis and Image Quantifier 5.2 software as described above. C) Expression of the Cpa1 and Cpa2 proteins was detected by immunoblotting with anti-Cpa1 antiserum. D) siRNAs were enriched (see Materials and Methods) from individual total RNAs and resolved in a 15% denaturing polyacrylamide TBE-urea gel. A ³²P-labeled in vitro transcribed CPA1 sense transcript was first hydrolyzed and then used to probe antisense CPA1 siRNAs.