YFP expression is correlated with noise strength.

<p>(<b>A</b>) For several different galactose concentrations (represented by different colors), shown is the YFP expression of each 3′ end library strain (x-axis) versus its noise (y-axis, expression variance divided by mean expression squared). Each point represents the noise computed from single cell flow cytometry measurements of the corresponding 3′ end strain. (<b>B</b>) Same as panel (A) only with noise strength (expression variance divided by mean expression) on the y-axis.