(a) Histograms of the single cell fluorescence of populations of cells expressing either one (red) or two (blue) copies of pGal1-YFP. The mean of the two distributions are separated by one log2 unit.
(b) Total, intrinsic, and extrinsic noise plotted against log mean expression for seven levels of induction of pGal1-YFP. Noise was quantified as the Coefficient of Variation (CV=σ/μ) of the YFP distribution.
(c) Comparison of extrinsic noise values calculated using a two color (pGal1-YFP, pGal1-mCherry) or one color approach.
(d) Intrinsic (cyan) and extrinsic(black) noise plotted against log2 mean expression for 465 genes. Inset: log2(CV2) plotted against log2(mean), running means (smoothing window of 30) for intrinsic(cyan), extrinsic(black), total (dark blue) noise.