Multi-scale chromatin footprinting reveals wide-spread alterations to the structure of DNA regulatory elements [Human BMMC RNA]

Cis-regulatory elements (CREs) are bound by diverse chromatin-associated proteins, cooperate to establish gene expression, and change in structure over time to alter cell fate and function1–3. Here, we develop a footprinting framework that uses deep learning to correct Tn5 sequence bias, improving accuracy and reducing false positives. This framework additionally identifies the interaction of DNA with objects of various sizes. Using these ‘multi-scale footprints’ we find that transcription factor (TF) binding occurs at well-defined distances from nucleosomes. Further, we demonstrate that multi-scale footprints, which include the positions of nucleosomes, enable more accurate inference of TF binding. Using multi-scale footprinting with single-cell multi-omics, we discover wide-spread structural and functional changes of CREs across hematopoiesis, wherein nucleosomes slide, expose DNA for TF binding, and promote gene expression. Finally, we apply this single-cell and footprint approach to characterize age-associated structural changes to CREs within hematopoietic stem cells and identify a spectrum of cells harboring age-associated changes to the epigenome. Interestingly, we find extensive changes to the structure of CREs upon aging, with many age-associated changes altering CRE structure while preserving overall accessibility. Collectively, we reveal the dynamics and functional importance of CRE structure, highlighting changes to gene regulation at single-cell and single-base-pair resolution. SHARE-Seq of bone marrow from 7 human donors