Effect of p22 down-regulation on mitochondrial RNA levels. Quantitative RT-PCR analysis of different RNAs from PF p22 RNAi cells at 3 days post induction. RNA levels represent the mean of at least six determinations for each mRNA set with error bars representing the standard error mean. A value of 1 indicates no change in RNA levels in induced cells relative to uninduced cells. P, pre-edited; E, edited; CYb, apocytochrome b; COI, COII, and COIII, cytochrome oxidase subunits I–III; NDI, ND4, and ND7, NADH dehydrogenase subunits I, 4, and 7; A6, ATPase subunit 6; RPS12, ribosomal protein S12; and MURF1 and -2, mitochondrial unknown reading frames 1 and 2. Mitochondrial RNA levels were standardized to both β-tubulin and 18 S rRNA.