Growing cells adjust their division time with biomass accumulation to maintain growth homeostasis. Size control mechanisms, such as the size checkpoint, provide an inherent coupling of growth and division by gating certain cell cycle transitions based on cell size. We describe genetic manipulations that decouple cell division from cell size, leading to the loss of growth homeostasis, with cells becoming progressively smaller or progressively larger until arresting. This was achieved by modulating glucose influx independently of external glucose. Division rate followed glucose influx, while volume growth was largely defined by external glucose. Therefore, the coordination of size and division observed in wild‐type cells reflects tuning of two parallel processes, which is only refined by an inherent feedback‐dependent coupling. We present a class of size control models explaining the observed breakdowns of growth homeostasis.
wildtype cells grown in 0%, 0.01%, 0.1% or 0.2% glucose
This .nd2 file can be viewed with the Nikon Viewer, available at http://www.nikoninstruments.com/Products/Software/NIS-Elements-Advanced-Research/NIS-Elements-Viewer. The file contains 80 fields of view (FOVs), images were taken every 10 minutes. The data corresponds to figures 1A, 1B and 1C. Wildtype cells were grown in SC media supplemented with either no glucose (FOV 1 to 20, up to timepoint 144), 0.01% glucose (FOV 21 to 40), 0.1% glucose (FOV 41 to 60) or 0.2% glucose (FOV 61 to 80).
121205_WT.nd2
wildtype cells grown 2% glucose
Wildtype cells grown in SC with 2% glucose. Fields of view 27 to 41. Images were taken every 10 minutes. Corresponds to figure 1B, 1C.
ma10_WT_KD_1condition001.nd2
Transporterless cells with sensors in 0% glucose
Transporterless cells with sensors were grown in 0% glucose. Fields of view 1 to 20. Images were taken every 10 minutes.
121017_sys_D1_Dox0.nd2
Transporterless cells without sensors in 0% or 2% glucose
Transporterless cells without sensors were grown in 0% (Fields of view 1 to 20) or 2% (Fields of view 61 to 80) glucose. Corresponds to figures 1H (2%) and 1I (0%) Images were taken every 10 minutes.
121123_Y1.nd2
single-HXT2 with sensors in 0.1% glucose, 125ng/ml DOX
single-HXT2 with sensors were grown in 0.1% glucose, with 125ng/ml DOX. Fields of view 41 to 60.
121115_D2_Dox125ng002.nd2
single-HXT2 with sensors in 0.1% glucose, 250ng/ml DOX
single-HXT2 with sensors were grown in 0.1% glucose, with 250ng/ml DOX. Fields of view 41 to 60.
121111_D2_Dox250ng.nd2
single-HXT2 with sensors in 0.1% glucose, 1250ng/ml DOX
single-HXT2 with sensors were grown in 0.1% glucose, with 1250ng/ml DOX. Field of view 41 to 60.
121114_D2_Dox1p25ug001.nd2
single-HXT2 with sensors in 0.1% glucose, 2500ng/ml DOX
single-HXT2 with sensors were grown in 0.1% glucose, with 2500ng/ml DOX. Field of view 41 to 60.
121113_D2_Dox2p5ug.nd2
single-HXT2 without sensors in 0.1% glucose, no DOX
single-HXT2 without sensors were grown in 0.1% glucose, with DOX. Fields of view 1 to 20
130116_Y4noDox.nd2
single-HXT2 without sensors in 0.1% glucose, 2500 ng/ml DOX AND single-HXT4 without sensors in 0.1% or 2% glucose 2500ng/ml DOX
Single-HXT2 without sensors were grown in 0.1% glucose, with 2500ng/ml DOX. Field of view 41 to 60. Single-HXT4 without sensors were grown in 0.1% (Fields of view 41 to 60) or 2% (Fields of view 61 to 80) glucose, with 2500ng/ml DOX.
130121_Y4_2p5Dox001.nd2