Figure 5.

(A) Analysis of the steady state mtRNA levels in the Δppr mutants in the intron-less background. Total RNA from the intron-less P3 wild-type and isogenic Δppr mutants were hybridized to different probes as indicated. Three representative membranes are presented with the UV photograph of the cytoplasmic large rRNA and a control hybridization with the 21S large mitochondrial RNA. All hybridizations have been repeated two or three times and only the changes consistently observed in all experiments are described in the text. For unknown reasons, there is slightly less 21S RNA in the mutants Δppr1, 2 and 3. The same RNA sample was used in preparation for each membrane, but in membrane 1, the wild-type sample appears to have transferred less efficiently. (B) Northern blot of the mosaic genes cox1 and cytb in the Δppr4 and Δppr8 mutants in an intron-containing background. Total RNA from the intron-containing NB205-6A wild-type and isogenic Δppr4 and Δppr8 mutants and hybridized to the intron-containing cox1 and cytb probes as indicated. Precursor and mature RNAs are marked. The membranes are presented with the UV photograph of the cytoplasmic large rRNAs and a control hybridization with the 21S large mitochondrial RNA.