Fig. 5. Cp190 prevents regulatory cross-talk between early patterning gene loci.

(A) Extended ftz locus (dm6 coordinates) Hi-C maps presented as in Fig. 1E. (B) NG Capture-C profiles (1-kb resolution) around Scr or ftz TSS viewpoints showing average normalized reads (in reads per million) of biological triplicates excluding bins ±2 kb around the viewpoint (gray). Differential Capture-C profiles in mutant versus WT are shown as log₂ fold change profiles obtained from diffHic. Yellow brackets mark the deleted boundary in SF1^KO. WT Cp190 ChIP peaks are highlighted in blue (two prominent Cp190 ChIP signals in WT overlap a blacklisted region and were not called peaks). Early stripe enhancers with schematized expression patterns are numbered 1 to 5 (references in Materials and Methods). Dotted arrow shows Scr regulation by a hypothetical distal enhancer (question mark). SF1^KO and SF2B^KO deletions are yellow. (C) RNA–fluorescence in situ hybridization (FISH) with cohybridized antisense probes against Scr (red) and ftz (green) mRNAs in 4′,6-diamidino-2-phenylindole (DAPI)–stained early gastrula embryos (anterior left; posterior right; scale bars, 100 μm; merged images on the right). In Cp190⁰, Scr is expressed in its WT stripe and in ectopic ftz stripes (filled arrowheads). In SF1^KO embryos, Scr is lost in its WT stripe (empty arrowhead) and only expressed in ftz stripes (filled arrowheads). In SF2B^KO embryos, Scr and ftz expression seem normal (embryo rotation reveals a normal ventral gap in Scr expression).