Induction of the retrograde response in Top1mt−/− cells.

<p>(<b>A</b>) Gene expression of nuclear-encoded TFAM, PGC-1α, NRF-1 and POLG by RT-PCR in WT and Top1mt−/− cells (means ± standard deviations of 3 experiments). Gene expression was normalized to β2-microglobulin (β2M). Right panels show representative Western blots for Top1mt, PGC-1α, TFAM, POLG and actin protein levels in WT and Top1mt−/− cells. (<b>B</b>) Myc gene expression by RT-PCR normalized to β2M (mean ± standard deviation of 3 experiments) and c-myc protein level by Western blotting in WT and Top1mt−/− cells. (<b>C</b>) ND2, Cox1, Cox2; Cox3; ND4; ND5 and CytB expression by RT-PCR in WT and Top1mt−/− cells (means ± standard deviations of 3 experiments). (<b>D</b>) Determination of mitochondrial mass by Mitotracker Green staining. Representative histogram corresponding to Mitotracker Green fluorescence (x axis) plotted against cells numbers (count) and quantification of Mitotracker Green mean fluorescence intensity in cell population referred as percentage of WT values.