Fig. 1

5C analysis of the human PKD2 locus in primary human cells. a Hi-C data from the A549 human cell line reveal that PKD2 lies in a large TAD that contains several other genes [48]. PKD2 is further contained within a sub-TAD. The Hi-C data are shown in heatmap form where the increasing colour intensity reflects higher interaction frequencies between genomic regions in 40 kb-resolution bins. The grey lines outline the TADs while the dotted lines represent the sub-TADs. The genes contained within the marked area are shown under the heatmap. b Linear schematic representation of the ~ 540 kb genomic region characterized in this study. Arrows indicate transcription orientation. The PKD2 gene is shown in black and the neighbouring genes in grey. c Anchored 5C primer design scheme used to map the genomic environment of the PKD2 promoter. The two reverse “bait” 5C primers covering the PKD2 promoter are shown in red. The 24 Forward 5C primers shown in blue represent the rest of the locus. The green areas indicate regions not probed by 5C. The region coverage is summarized at the top, and individual fragments are shown at the bottom. 5C primer sequences are found in Additional file 1: Table S1