Combinatorial profiling of multiple histone modifications and transcriptome in single cells using scMTR-seq.

Profiling combinations of histone modifications identifies gene regulatory elements in different states and discovers features controlling transcriptional and epigenetic programs. However, efforts to map chromatin states in complex, heterogeneous samples are hindered by the lack of methods that can profile multiple histone modifications together with transcriptomes in individual cells. Here, we describe single-cell multitargets and mRNA sequencing (scMTR-seq), a high-throughput method that enables simultaneous profiling of six histone modifications and transcriptome in single cells. We apply scMTR-seq to uncover dynamic and coordinated changes in chromatin states and transcriptomes during human endoderm differentiation. We also use scMTR-seq to produce lineage-resolved chromatin maps and gene regulatory networks in mouse blastocysts, revealing epigenetic asymmetries at gene regulatory regions between the three embryo lineages and identifying Trps1 as a potential repressor in epiblast cells of trophectoderm-associated enhancer networks and their target genes. Together, scMTR-seq enables investigation of combinatorial chromatin landscapes in a broad range of heterogeneous samples, providing insights into epigenetic regulatory systems.