Standard SA circuit
MEMORY ONAverage TF100%
Local TF100%
Output0
Interactive research figure
Can a cell remember while it grows?
Test how phase-separated condensates protect a synthetic gene circuit from growth-mediated dilution.
Publication simulation · 45 seconds
After rapid growth, which circuit will remember its ON state?
Drop-SA circuit
MEMORY ONAverage TF100%
Local TF100%
Output0
0.0 h
Transcription factor concentration through time
Standard: average/local TFDrop-SA: average TFDrop-SA: local TF
The condensate protects circuit memory.
Growth lowers the average TF concentration in both cells. In the standard circuit, local TF falls below the activation threshold and positive feedback collapses. In Drop-SA, the condensate temporarily shrinks but maintains a high local TF concentration at the promoter, allowing expression to recover.
The idea behind the game
A self-activating circuit must keep enough transcription factor near its promoter to sustain its own production. Fast cell growth creates dilution. Fusing the TF to an intrinsically disordered region promotes condensate formation, enriching TF where it is needed.
change in TF = production − degradation − growth dilution
The trajectories are generated from the publication’s Gillespie cell-growth and phase-separation model using its reported parameters. Fixed random seeds make this demonstration reproducible; an individual stochastic run is not an experimental measurement.
What to watch
1Dilution beginsBoth cells elongate and divide.
2The droplet shrinksAverage TF decreases, but enrichment persists.
3Memory divergesStandard SA switches OFF; Drop-SA recovers.