Fig. 6
From: Size control in mammalian cells involves modulation of both growth rate and cell cycle duration
Size correction by growth-rate modulation in control and abnormal large Hela cells. a Examples of single-cell growth trajectories for HeLa-hgem cells, either control (‘ctrl’), or after washout from Roscovitine treatment (‘rosco’) as a function of time from birth. b Duration of G1, ΔtG1 as a function of the logarithm of volume at birth (Vbirth) for HeLa-hgem cells. Results from the linear fit: control: a = −4 ± 0.1, p = 1*10−90, R2 = 0.888, n = 199, N = 2; Roscovitine: a = 0 ± 0.2, R2 = 0.019, p = 1, n = 120, N = 3. Red dashed line and gray area are a visual guide for minimum G1 duration. Top: kernel estimates of volume at birth; control: 〈log Vbirth〉=7.37, n = 231, N = 2; Roscovitine: 〈log Vbirth〉=7.86, n = 136; Welch t test comparing the means: p = 2.2×10−16. Right: kernel estimates of ΔtG1; control: 〈ΔtG1〉=7.0 h., n = 201, N = 2; Roscovitine: 〈ΔtG1〉=6.1 h, n=124, N=3; Welch t test comparing the means: p=6.5×10−7. c Added volume in G1 (ΔVG1) vs. volume at birth for HeLa-hgem cells. Results from the linear fit: control: a = −0.25 ± 0.01, p = 1×10−46, R2 = 0.706, n = 178, N = 2; Roscovitine (red line): a = 0.1 ± 0.02, p = 0.1, R2 = 0.046, n = 108, N = 3. Dashed lines represent the median added volume in G1 for the control (〈ΔVG1〉=350 µm3, n = 178) and the Roscovitine (〈ΔVG1〉=390 µm3, n = 108) condition. Right: kernel estimates of ΔVG1. Welch’s t test comparing the mean added volume: p = 0.2423. d Instantaneous growth speed dv/dt in G1 as a function of volume, with bivariate kernel densities (concentric circles) and average bins for control (n = 119, N = 1) and Roscovitine (n = 49, N=2) conditions. Results from the linear fits, control: a=0.0489 ± 0.0005, p≈0, R2 = 0.78; Roscovitine: a = 0.047 ± 0.002, p = 1×10−137, R2 = 0.49. e Top: kernel density of volume at birth for control and Roscovitine treated HeLa-hgem cells grouped together. Bars represent the 20 and 80% percentiles and define three groups: cells within the 0–20% percentile (blue), 20–80% percentile (orange) and 80–100% percentile (green). Bottom: Same data as d but for the three groups analyzed separately. Results from the linear fits (lines) on the average bins (dots) for each group with nc (number of control cells) and nr (number of Rocovitine-treated cells): 0–20%: a = 0.119 ± 0.008, p = 4.1×10−5, R2 = 0.98, nc = 24, nr = 0; 20–80%: a = 0.072 ± 0.009, p = 4.88×10−5, R2 = 0.90, nc = 60, nr = 15; 80–100%: a = 0.05 ± 0.01, p = 0.00192, R2 = 0.43, nc = 3, nr = 24. For b–d, control condition (‘ctrl’) is in gray and Roscovitine-treated condition (‘rosco’) is in red. Individual cell measures (dots) as well as median (c, d) or average (d) bins (ctrl: squares, rosco: triangles) and s.d. (bars) are shown. Solid lines shows linear regression on the bins weighted by the number of event in each bin. a is alsways given as slope ± standard error. See also Supplementary Figures 6 and 7, Supplementary Movie 4
