Fig. 6. Distribution of PhGFP and PcGFP in the larval salivary gland nuclei and FRAP curves for individual bands. Maximum intensity projections of the fluorescence in whole salivary gland nuclei are shown in A (PhGFP) and C (PcGFP). The amount of the background fluorescence (the unbound protein) differs. Typical FRAP curves from individual PcG loci are shown in B (PhGFP) and D (PcGFP). The amount of background fluorescence substantially changes the aspect of the recovery curves. Images from selected time points in a typical FRAP experiment (PhGFP in this case) are shown in E. Upper panels, overview of part of nucleus with bleach box indicated in the second image. Lower panels, magnified region used for analysis. (F) FRAP curves for sequential bleaching of a single PcGFP locus showing reproducible reassociation kinetics.