Three-dimensional proximity mapping of the DRGFP DNA double-strand break site in U2OS cells. Homo sapiens

We mapped the DNA sequences located in physical proximity to an I-SceI endonuclease-dependent DNA double-strand break (DSB) site to be able to study the impact of DSBs on the break-associated chromatin micro-environment. The I-SceI DSB site is part of a DRGFP transgene that serves as a reporter for homology-directed DSB repair and was stably integrated into U2OS human osteosarcoma cells (Pierce et al., Genes Dev, 1999). DRGFP-U2OS cells were modified to carry a stable Doxycycline (Dox)-inducible I-SceI transgene (TRE-I-SceI) as well as the Tet-ON vector from Contech. Circular chromosome conformation capture (4C) was used to identify DSB-proximal DNA. 4C amplified DNA was subjected to Illumina Hi-Seq 200 100 bp paired end sequencing and reads were mapped to the human genome. The resulting genome-wide map of I-SceI/DRGFP-proximal DNA allows for the investigation of changes in DSB-surrounding chromatin features following I-SceI-mediated DSB induction. Overall design: 4C library of I-SceI (DRGFP)-proximal DNA contacts in DRGFP-U2OS cells was generated using Illumina Hi-Seq 2000 sequencing, data sets are from two independent experiments.