Single-cell multi-omic profiling of chromatin conformation and DNA methylome

Recent advances in the development of single cell epigenomic assays have facilitated the analysis of the gene regulatory landscapes in complex biological systems. Single-cell variations of methods such as DNA methylation-sequencing and ATAC-seq hold tremendous promise for delineating distinct cell types and identifying their critical cis-regulatory sequences. Emerging evidence in recent years has shown that in addition to cis-regulatory sequences, dynamic regulation of 3D chromatin conformation is a critical mechanism for the modulation of gene expressions during development and disease. While assays for the investigation of single-cell 3D chromatin structure have been developed, cell-type specific chromatin conformation in primary human tissues has not been extensively explored. It remains unclear whether single-cell Chromatin Conformation Capture (3C) or Hi-C profiles are suitable for cell type identification and allow the reconstruction of cell-type specific chromatin conformation maps. To address these challenges, we have developed a multi-omic method single-nucleus methyl-3C sequencing (sn-m3C) to profile chromatin conformation and DNA methylation from the same cell. We have shown that bulk m3C and sn-m3C accurately capture chromatin organization information and robustly separate mouse cell types. We have developed a fluorescent-activated nuclei sorting strategy based on DNA content that eliminates nuclei multiplets caused by crosslinking. The sn-m3C-seq method allows high-resolution cell-type classification using two orthogonal types of epigenomic information and the reconstruction of cell-type specific chromatin conformation maps. Overall design: chromatin conformation and DNA methylome