Fig. 4.

Transcriptional bursting in eve stripe 2. (A) Single-nucleus measurements reveal that nuclei transcribe in bursts. (B) Two-state model of bursting of a single promoter. (C) The same hidden rate of RNAP loading (Bottom) can correspond to different observable numbers of RNAP molecules on the gene (Top), such that standard hidden Markov model approaches cannot be used to infer the hidden promoter state. (D) Fluorescent puncta are composed of 2 distinct transcriptional loci within a diffraction-limited spot, each corresponding to a sister chromatid. (E) Three-state model of promoter switching within a fluorescent punctum that accounts for the combined action of both sister chromatids. (F) Effective 2-state model of transcriptional bursting. (In A, error bars are obtained from estimation of background fluorescent fluctuations; Materials and Methods and ref. 27.)