Fig. 2. Northern blots (A) and analysis (B) of three mitochondrial encoded and two nuclear encoded genes whose protein products include subunits of complex IV (cytrochrome c oxidase) and V (ATP synthase) of the mitochondrial electron transport chain, in four tissues from euthermic and hibernating ground squirrels. Northern blots of total RNA (16 µg lane^-1) were scanned, then band intensities quantified and normalized to their corresponding 28S ribosomal bands. The ratios of normalized band intensities were then calculated. Values are mean ± S.E.M., N=3 separately run northern blots; each blot contained RNA prepared from separate animals.