Fig. 4.

GAF is required for the functioning of chromatin boundaries and PREs in BX-C. a The diagram shows the BX-C TARDs, containing Ubx, abd-A, and Abd-B genes and their respective cis-regulatory domains. The positions of the boundaries and PREs are indicated above and below the sequence coordinate line correspondingly. The red arrow marks Fab-7 boundary. The red, yellow and green ovals are regions bound by GAF, CTCF or E(z) and Ph, respectively. b The Fab-7 boundary has four nuclease hypersensitive regions: one minor—HS* and three prominent—HS1, HS2, and HS3. The locations of the recognition motifs for GAF, Pho, Elba and Insv proteins known to be associated with Fab-7 are indicated. The LBC complex binds to distal half of HS1 (dHS1) and HS3