Figure 5.

Covariation of sloppy homeostatic set points

(A and B) Sloppy variables α, τ display a range of homeostatic set points (time averages). Scatter plots for two neighboring lineages in the same microfluidic trap: (A) Exponential growth-rate α, Pearson $\rho =0.74$; (B) generation time τ, $\rho =0.8$. The set points are primarily sensitive to the environment (diagonal spread), and less so to lineage history (off-diagonal spread). Black lines are standard deviations in the two directions.

(C) Within each lineage, set points strongly covary (blue circles; $\rho =-0.9$) and lie close to the line $\overline{\alpha }\overline{\tau }=\text{ln}2$ (dashed black). Orange circles show averages of per-cycle variables over arbitrary groups of the same sizes as lineages (artificial lineages; $\rho =-0.42$).

(D) Scatter plot of fold-growth set points ϕ for neighbor cells, Pearson $\rho =0.43$.

(E) Scatter plot of division fraction set points $\overline{f}$ for neighbor cells, Pearson $\rho =0.33$.

(F) Same presentation as in C, for the variables $\overline{f}$ and $\overline{e^{\varphi }}$. The dashed black line is $\overline{f}\overline{e^{\varphi }}=1$; $\rho =-0.84$ for temporal averages, $\rho =-0.38$ for artificial averages. For a full matrix of set point scatter plots for pairs of variables between neighbor lineages, see Figure S7