PT  - JOURNAL ARTICLE
AU  - Steven Henikoff
AU  - Jorja G. Henikoff
AU  - Hatice S. Kaya-Okur
AU  - Kami Ahmad
TI  - Efficient transcription-coupled chromatin accessibility mapping <em>in situ</em>
AID  - 10.1101/2020.04.15.043083
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.04.15.043083
4099  - http://biorxiv.org/content/early/2020/09/18/2020.04.15.043083.short
4100  - http://biorxiv.org/content/early/2020/09/18/2020.04.15.043083.full
AB  - Chromatin accessibility mapping is a powerful approach to identify potential regulatory elements. In the popular ATAC-seq method, Tn5 transposase inserts sequencing adapters into accessible DNA (‘tagmentation’). CUT&Tag is a tagmentation-based epigenomic profiling method in which antibody tethering of Tn5 to a chromatin epitope of interest profiles specific chromatin features in small samples and single cells. Here we show that by simply modifying the tagmentation conditions for histone H3K4me2/3 CUT&Tag, antibody-tethered tagmentation of accessible DNA sites is redirected to produce accessible DNA maps that are indistinguishable from the best ATAC-seq maps. Thus, DNA accessibility maps can be produced in parallel with CUT&Tag maps of other epitopes with all steps from nuclei to amplified sequencing-ready libraries performed in single PCR tubes in the laboratory or on a home workbench. As H3K4 methylation is produced by transcription at promoters and enhancers, our method identifies transcription-coupled accessible regulatory sites.Competing Interest StatementThe authors have declared no competing interest.