4C-seq to show the effects of insertion of STITCH into NEUROG2-65kb positions on the chromatin conformation in neural progenitor cells differentiated from human iPSCs.

We reconstituted arrays of CTCF binding sites (L1, L2, L3, L4, R1, R2, and R3) and devised a synthetic topological insulator with tetO for chromatin-engineering (STITCH). By coupling STITCH with tetR linked to the KRAB domain to induce heterochromatin and disable the insulation, we developed a drug-inducible system to control gene activation by enhancers. We inserted STITCH into the 65-kb downstream of NEUROG2 in human iPSCs and integrated a transgene consisting of tetR-KRAB followed by DNA encoding the 2A peptide and the puromycin resistant gene with piggyBac transposition into the genome in the STITCH/NEUROG2 clone (NEUROG2/KRAB). We performed 4C-seq (Circular chromatin conformation capture assay followed by deep-sequencing) from the viewpoint designed at R3 of the inserted STITCH in the differentiated neural progenitor cells with and without DOX.