University of Massachusetts Medical School Faculty Publications

UMMS Affiliation

Program in Systems Biology; Department of Biochemistry and Molecular Pharmacology; Program in Molecular Medicine; Diabetes Center of Excellence; Graduate School of Biomedical Sciences

Publication Date

2020-12-27

Document Type

Article Preprint

Disciplines

Biochemistry | Computational Biology | Genomics | Molecular Biology | Structural Biology

Abstract

Chromosome conformation capture (3C)-based assays are used to map chromatin interactions genome-wide. Quantitative analyses of chromatin interaction maps can lead to insights into the spatial organization of chromosomes and the mechanisms by which they fold. A number of protocols such as in situ Hi-C and Micro-C are now widely used and these differ in key experimental parameters including cross-linking chemistry and chromatin fragmentation strategy. To understand how the choice of experimental protocol determines the ability to detect and quantify aspects of chromosome folding we have performed a systematic evaluation of experimental parameters of 3C-based protocols. We find that different protocols capture different 3D genome features with different efficiencies. First, the use of cross-linkers such as DSG in addition to formaldehyde improves signal-to-noise allowing detection of thousands of additional loops and strengthens the compartment signal. Second, fragmenting chromatin to the level of nucleosomes using MNase allows detection of more loops. On the other hand, protocols that generate larger multi-kb fragments produce stronger compartmentalization signals. We confirmed our results for multiple cell types and cell cycle stages. We find that cell type-specific quantitative differences in chromosome folding are not detected or underestimated by some protocols. Based on these insights we developed Hi-C 3.0, a single protocol that can be used to both efficiently detect chromatin loops and to quantify compartmentalization. Finally, this study produced ultra-deeply sequenced reference interaction maps using conventional Hi-C, Micro-C and Hi-C 3.0 for commonly used cell lines in the 4D Nucleome Project.

Keywords

Genomics, chromatin, chromatin interaction, chromosome folding

Rights and Permissions

The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license.

DOI of Published Version

10.1101/2020.12.26.424448

Source

bioRxiv 2020.12.26.424448; doi: https://doi.org/10.1101/2020.12.26.424448. Link to preprint on bioRxiv.

Comments

This article is a preprint. Preprints are preliminary reports of work that have not been certified by peer review.

The PDF available for download is Version 2 of this preprint. The complete version history of this preprint is available at bioRxiv.

Full author list omitted for brevity. For the full list of authors, see article.

Journal/Book/Conference Title

bioRxiv

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

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