Transcriptional Bursting: The Two-State Gene Expression Model

Genes don't transcribe at a steady, continuous rate — most flicker between transcriptionally silent and active chromatin states, firing bursts of mRNA when the promoter is briefly ON. This simulator renders that mechanism directly in 3D: a gene locus switches stochastically between OFF and ON, RNA polymerase fires mRNA transcripts during ON periods, ribosomes translate each transcript into protein, and both species decay over time. Tune the promoter switching rates and the transcription/translation rates to move between smooth, low-noise expression and sparse, high-variance bursting, and watch the live mRNA and protein counts — plus the Fano factor, the standard measure of expression noise — respond in real time.