Concurrent Mapping of Multiple Epigenetic Marks and Co-enrichment Using ACT2-seq

Genome-wide profiling of epigenetic marks is a core technology in molecular genetics. Co-occupancy of different epigenetic marks or protein factors on chromatin is often inferred from their existence at the same genomic locations. However, this strategy does not provide direct evidence whether the epigenetic marks or protein factors occupy the same chromatin loci in the same cell due to the existence of cellular heterogeneity. To address this issue, we report a technique termed ACT2-seq that is capable of concurrently profiling multiple epigenetic marks in a single biological sample. While profiling simultaneously different epigenetic marks or protein factors genome-wide, ACT2 is capable of directly detecting co-occupancy of two different marks or factors on chromatin. This strategy provides direct evidence of co-localization without requiring complex single-molecule, single-cell, or magnetic bead-based approaches. We conclude that ACT2 presents an attractive option for epigenomic profiling due to its ease of use, potential for reducing sample and sequencing costs, and ability to profile co-occupancy of different epigenetic marks and protein factors on chromatin A method for profiling co-occupancy of different epigenetic marks or protein factors on chromatin