Figure 5. Variability in mitochondrial mass and functionality can both contribute to noise in transcription rate.
Effects of changing variability in mitochondrial mass inheritance (
) and functionality (
) on overall transcription rate noise 
. This contour plot shows the value of 
for a given combination of 
. More stochasticity associated with inheritance of mitochondrial properties leads to higher transcription rate noise, and stochasticity in both mass and functional inheritance plays an important role in transcription rate noise. Contour lines on the bottom surface mark different values of 
. The ‘X’ mark denotes the default parameterisation of our model. Other contour lines show that this relationship remains essentially identical when variability due to cell cycle stage and volume inheritance is removed, suggesting that 
and 
are the key sources of transcription rate noise.