ASH1 and FSH extensively co-localize on chromatin. Genome-wide maps of ASH1 and FSH chromatin occupancy were generated using ChIP-seq. (A) Modified UCSC genome browser view of the bithorax gene cluster (BX-C) in S2-DRSC cells shows ASH1, FSH co-localization at TRX-C, PRC1-bound sites. The position of regulatory iab regions (capped bars) and cloned PREs (solid boxes) are indicated above track area. ASH1 and FSH tracks show coverage profiles calculated from aligned ChIP-seq reads; solid boxes of PRC1 track (black) depict regions significantly co-enriched for the PRC1 core subunits PC, PH, and PSC; the TRX-C track (yellow) displays intervals enriched for the C-terminal fragment of TRX. FlyBase gene models and non-coding RNAs are shown below track area. (B) FSH-specific immunostainings of Drosophila salivary gland chromosomes. (C) ASH1 and FSH peaks are closer to TSS then expected by chance. Graph shows empirical cumulative density functions (ECDFs) for the distance between identified ASH1, FSH peaks and the closest TSS. For comparison, the ECDFs calculated form shuffled peak intervals are plotted as dashed lines. (D) Accumulation of ASH1, FSH ChIP-seq signal around TSS. Graph displays normalized read coverage for ASH1, FSH averaged over 1-kb windows centered at known TSS.
Kockmann et al. Genome Biology 2013 14:R18 doi:10.1186/gb-2013-14-2-r18