Figure 10.

Cross-species comparison of intrinsic and extrinsic noise. Based on a single-gene stochastic simulation at steady-state, the total coefficient of variation for protein abundance was measured. Using the estimation formula for intrinsic noise ${\eta }_{\text{int}}=\sqrt{\text{burst}/\text{prot}}$, where ‘burst’ is the burst parameter (given in the main text), and ‘prot’ is the mean protein abundance, we estimated the contribution of intrinsic noise to the total coefficient of variation. The remaining component of the noise is attributed to extrinsic noise (from the transcription factor concentration fluctuations).