HNF1B/hnf1ba HCNE CRMs bearing the hallmarks of functionality in zebrafish endoderm and human PFG endoderm are sufficient to drive reporter expression in the developing hindbrain but not endoderm. (A) H3K27ac ChIP-seq and ATAC-seq data at human HNF1B and zebrafish hnf1ba loci, respectively. HCNEs overlapping H3K27ac peaks and DARs are indicated in corresponding colors below the tracks. Normalized peak heights in CPM are indicated. HCNE and putative enhancer sequences cloned for reporter assays are outlined. (B) Lateral view of mCherry reporter expression driven by the i4Enh +6–8 kb enhancer at 48 hpf in sox17:GFP embryos injected with the reporter construct at the one-cell stage. Maximum intensity z-projections of 27 z-slices from confocal images. (C) 3D rendering of confocal images showing 10 z-slices at a time going through the embryo along the z-axis from the left to right side. (D) Dorsal; (R) right; (P) posterior; (V) ventral; (L) left; (A) anterior. Scale bars, 100 µm.