Fig. 1

Fig. 1

a Comparison of the basic structure of the human and zebrafish adult pancreas. Above: Dissected adult male Tg(insulin:GFP, elastase:mCherry) zebrafish; insulin and elastase promoters drive GFP expression in beta-cells (green) and mCherry in acinar cells (red), respectively. IN, intestine; LRL, Liver right lobe; LT, left testis; PI, principal islet; SI, secondary islets; SB, swim bladder. Below: Histology of the pancreas; transverse sections with hematoxylin/eosin staining showing islets of Langerhans (black dashed lines) surrounded by exocrine tissue in zebrafish and human pancreas. Magnification: ×40 and scale bar: 1 mm. b Genomic landscape of gata6 in the zebrafish adult pancreas showing the H3K27ac ChIP-seq profile (black) and ATAC-seq peaks (blue) from whole pancreas, RNA-seq from exocrine pancreas (green) and a heat map for chromatin interactions with gata6 promoter detected by HiChIP for H3K4me3 from whole pancreas (below). A putative enhancer sequence that interacts with the gata6 promoter is highlighted by the light blue box. c Bar plot (left panel) showing the number of genes with active promoters (defined by H3K4me3 signal, gray bar) and putative active enhancers in adult zebrafish pancreas (defined by H3K27ac mark, green bar), and their distribution throughout the regions of the genome (right panel). d Above: Venn diagram showing the overlap of putative active enhancers in adult zebrafish pancreas and stages of zebrafish embryonic development. Putative active enhancers exclusive to the adult pancreas form the pancreas-specific enhancers (PsE) group, while the shared enhancers belong to the developmental shared enhancers (DevE) group (Supplementary Dataset 1e, f). Below: Heat maps showing clusters of H3K27ac mark for PsE and DevE enhancers during embryonic development [dome, 80% epiboly (80%epi), 24 hpf, 48 hpf] and in adult pancreas. A window of 10 kb around the reference coordinates for each sequence was used and the density files were subjected to k-means clustering, obtaining four different clusters in DevE: C1, Cluster 1; C2, Cluster 2; C3, Cluster 3; and C4, Cluster 4. For c, d, source data are provided as a Source Data file.