FIGURE 6:

Displacement of chromosome-bound Xist. (A) iFRAP analysis of Xist turnover in XMG ES cells. A confocal image series is shown in gray scale (top) and in pseudocolor (bottom). The nuclear pool of MCP-GFP outside the Xist territory was photobleached (white outline). Scale bar, 2 μm. (B) The normalized signal intensity of the iFRAP experiment of the Xist cluster is plotted over time (n = 4). Error bars represent SD. (C) Xist turnover is characterized by its production with rate k₁ from the site of transcription and loss due to dissociation off the chromosome with the dissociation constant k₂. After dissociation Xist is degraded. In steady state the Xist cluster is stable, and production and dissociation balance. (D) The normalized signal intensity of the single experiment shown in A is plotted over time. Red open circles indicate data points of the images in A. The data points were fitted to a kinetic model of Xist transcription and dissociation (black line).