(A) The H3K27me3 distribution, repeated from Figure 2F, marks the border between active and repressed domains. (B and C) H3K27ac profiles are shown for mixed and PS7 nuclei; the acetylation mark in PS7 is largely restricted to the active domains. (D and E) Pol-II profiles show peaks at the promoters of Ubx, abd-A, and Abd-B both in whole embryo and in PS7 nuclei. In PS7, polymerase is distributed across the transcription units of Ubx and abd-A, but not Abd-B. The arrow in D marks the PS5/PS6 border; the arrow in E marks the major Abd-B promoter. (F and G) H3K4me3 profiles show prominent peaks over the Ubx and abd-A promoters, both of which drive strong transcription in PS7. (H and I) POLYCOMB profiles show sharp peaks over all known Polycomb Response Elements. In PS7, there is a reduction of the PC peak at the ‘bx PRE’ in the active PS5 domain. There is also a PC peak at the abd-A promoter, which is somewhat reduced in PS7, where Abd-A is transcribed. (J and K) POLYHOMEOTIC protein shows peaks at known PREs and the abd-A promoter in both the active and repressed domains. As with PC, the PH peak at the bx PRE is reduced in PS7. (L and M) SU(Z)12 profiles also mark PREs, but in PS7, the PRE peaks are reduced in all three active domains. The ranges for the vertical axes are indicated above the left edge of each trace.