Figure 4.

Sisters machine data separates internal from environmental contributions to variance

(A) Two neighboring lineages of E. coli cells grow at the V-shaped bottom of the sisters machine trap, such that they share the same environment but have different lineage histories.

(B) Initial cell size vs generation number for two neighbor cells growing in the same trap (marked red and green in (A)).

(C) Collecting data along the green and red traces results in corresponding initial cell size distribution; pooling all data from the experiment results in the gray pooled ensemble distribution.

(D) Variance decomposition conditioned on trap microenvironment (orange) and on lineage identity (blue), computed from a set of sisters machine experiments. The remaining fraction complementing to 1 represents the contribution of temporal fluctuations. The gray vertical bar is the noise level (finite size sampling effect) estimated by running the same analysis on artificial lineages drawn at random from the pooled ensemble (see STAR Methods).