Chromatin Conformation Research Articles

A biallelically active embryonic enhancer dictates GNAS imprinting through allele-specific conformations

Genomic imprinting controls parental allele-specific gene expression via epigenetic mechanisms. Abnormal imprinting at the GNAS gene causes multiple phenotypes, including pseudohypoparathyroidism type-1B (PHP1B), a disorder of multihormone resistance. Microdeletions affecting the neighboring STX16 gene ablate an imprinting control region (STX16-ICR) of GNAS and lead to PHP1B upon maternal but not paternal inheritance. Mechanisms behind this imprinted inheritance mode remain unknown. Here, we show that the STX16-ICR forms different chromatin conformations with each GNAS parental allele and enhances two GNAS promoters in human embryonic stem cells. When these cells differentiate toward proximal renal tubule cells, STX16-ICR loses its effect, accompanied by a transition to a somatic cell-specific GNAS imprinting status. The activity of STX16-ICR depends on an OCT4 motif, whose disruption impacts transcript levels differentially on each allele. Therefore, a biallelically active embryonic enhancer dictates GNAS imprinting via different chromatin conformations, underlying the allele-specific pathogenicity of STX16-ICR microdeletions.

Genome assembly of a living fossil, the Atlantic horseshoe crab Limulus polyphemus, reveals lineage-specific whole genome duplications, transposable element-based centromeres and a ZW sex chromosome system.

Horseshoe crabs, considered living fossils with a stable morphotype spanning ∼445 million years, are evolutionarily, ecologically and biomedically important species experiencing rapid population decline. Of the four extant species of horseshoe crabs, the Atlantic horseshoe crab, Limulus polyphemus, has become an essential component of the modern medicine toolkit. Here, we present the first chromosome-level genome assembly, and most contiguous and complete assembly to date, for Limulus polyphemus using nanopore long-read sequencing and chromatin conformation analysis. We find support for three horseshoe crab-specific whole genome duplications, but none shared with Arachnopulmonata (spiders and scorpions). Moreover, we discovered tandem duplicates of endotoxin-detection pathway components Factor C and Factor G, identify candidate centromeres consisting of Gypsy retroelements, and classify the ZW sex chromosome system for this species and a sister taxon, Carcinoscorpius rotundicauda. Finally, we revealed this species has been experiencing a steep population decline over the last 5 million years, highlighting the need for international conservation interventions and fisheries-based management for this critical species.

Structural Basis of Differential Gene Expression at eQTLs Loci from High-Resolution Ensemble Models of 3D Single-Cell Chromatin Conformations.

Techniques such as high-throughput chromosome conformation capture (Hi-C) have provided a wealth of information on nucleus organization and genome important for understanding gene expression regulation. Genome-Wide Association Studies (GWASs) have identified numerous loci associated with complex traits. Expression quantitative trait loci (eQTL) studies have further linked the genetic variants to alteration in expression levels of associated target genes across individuals. However, the functional roles of many eQTLs in non-coding regions remain unclear. Current joint analyses of Hi-C and eQTLs data lack advanced computational tools, limiting what can be learned from these data. We developed a computational method for simultaneous analysis of Hi-C and eQTL data, capable of identifying a small set of non-random interactions from all Hi-C interactions. Using these non-random interactions, we reconstructed large ensembles (×105) of high-resolution single-cell 3D chromatin conformations with thorough sampling, accurately replicating Hi-C measurements. Our results revealed many-body interactions in chromatin conformation at the single-cell level within eQTL loci, providing a detailed view of how 3D chromatin structures form the physical foundation for gene regulation, including how genetic variants of eQTLs affect the expression of associated eGenes. Furthermore, our method can deconvolve chromatin heterogeneity and investigate the spatial associations of eQTLs and eGenes at subpopulation level, revealing their regulatory impacts on gene expression. Together, ensemble modeling of thoroughly sampled single-cell chromatin conformations combined with eQTL data, helps decipher how 3D chromatin structures provide the physical basis for gene regulation, expression control, and aid in understanding the overall structure-function relationships of genome organization. It is available at https://github.com/uic-liang-lab/3DChromFolding-eQTL-Loci. Supplementary data are available at Bioinformatics online.

ChromoGen: Diffusion model predicts single-cell chromatin conformations.

Breakthroughs in high-throughput sequencing and microscopic imaging technologies have revealed that chromatin structures vary considerably between cells of the same type. However, a thorough characterization of this heterogeneity remains elusive due to the labor-intensive and time-consuming nature of these experiments. To address these challenges, we introduce ChromoGen, a generative model based on state-of-the-art artificial intelligence techniques that efficiently predicts three-dimensional, single-cell chromatin conformations de novo with both region and cell type specificity. These generated conformations accurately reproduce experimental results at both the single-cell and population levels. Moreover, ChromoGen successfully transfers to cell types excluded from the training data using just DNA sequence and widely available DNase-seq data, thus providing access to chromatin structures in myriad cell types. These achievements come at a remarkably low computational cost. Therefore, ChromoGen enables the systematic investigation of single-cell chromatin organization, its heterogeneity, and its relationship to sequencing data, all while remaining economical.

Single-Cell Hi-C Technologies and Computational Data Analysis.

Single-cell chromatin conformation capture (scHi-C) techniques have evolved to provide significant insights into the structural organization and regulatory mechanisms in individual cells. Although many scHi-C protocols have been developed, they often involve intricate procedures and the resulting data are sparse, leading to computational challenges for systematic data analysis and limited applicability. This review provides a comprehensive overview, quantitative evaluation of thirteen protocols and practical guidance on computational topics. It is first assessed the efficiency of these protocols based on the total number of contacts recovered per cell and the cis/trans ratio. It is then provided systematic considerations for scHi-C quality control and data imputation. Additionally, the capabilities and implementations of various analysis methods, covering cell clustering, A/B compartment calling, topologically associating domain (TAD) calling, loop calling, 3D reconstruction, scHi-C data simulation and differential interaction analysis is summarized. It is further highlighted key computational challenges associated with the specific complexities of scHi-C data and propose potential solutions.

A haplotype-resolved chromosome-level genome assembly of Urochloa decumbens cv. Basilisk resolves its allopolyploid ancestry and composition.

Haplotyped-resolved phased assemblies aim to capture the full allelic diversity in heterozygous and polyploid species to enable accurate genetic analyses. However, building non-collapsed references still presents a challenge. Here, we used long-range interaction Hi-C reads (high-throughput chromatin conformation capture) and HiFi PacBio reads to assemble the genome of the apomictic cultivar Basilisks from Urochloa decumbens (2n = 4x = 36), an outcrossed tetraploid Paniceae grass widely cropped to feed livestock in the tropics. We identified and removed Hi-C reads between homologous unitigs to facilitate their scaffolding and employed methods for the manual curation of rearrangements and misassemblies. Our final phased assembly included the four haplotypes in 36 chromosomes. We found that 18 chromosomes originated from diploid U. brizantha and the other 18 from either U. ruziziensis or diploid U. decumbens. We also identified a chromosomal translocation between chromosomes 5 and 32, as well as evidence of pairing exclusively within subgenomes, except for a homoeologous exchange in chromosome 21. Our results demonstrate that haplotype-aware assemblies accurately capture the allelic diversity in heterozygous species, making them the preferred option over collapsed-haplotype assemblies.

Cutting-edge tools for unveiling the dynamics of plasmid-host interactions.

The plasmid-mediated transfer of antibiotic resistance genes (ARGs) in complex microbiomes presents a significant global health challenge. This review examines recent technological advancements that have enabled us to move beyond the limitations of culture-dependent detection of conjugation and have enhanced our ability to track and understand the movement of ARGs in real-world scenarios. We critically assess the applications of single-cell sequencing, fluorescence-based techniques and advanced high-throughput chromatin conformation capture (Hi-C) approaches in elucidating plasmid-host interactions at unprecedented resolution. We also evaluate emerging techniques such as CRISPR-based phage engineering and discuss their potential for developing targeted strategies to curb ARG dissemination. Emerging data derived from these technologies have challenged our previous paradigms on plasmid-host compatibility and an awareness of an emerging uncharted realm for ARGs.

Chromatin conformation, gene transcription, and nucleosome remodeling as an emergent system.

In single cells, variably sized nanoscale chromatin structures are observed, but it is unknown whether these form a cohesive framework that regulates RNA transcription. Here, we demonstrate that the human genome is an emergent, self-assembling, reinforcement learning system. Conformationally defined heterogeneous, nanoscopic packing domains form by the interplay of transcription, nucleosome remodeling, and loop extrusion. We show that packing domains are not topologically associated domains. Instead, packing domains exist across a structure-function life cycle that couples heterochromatin and transcription in situ, explaining how heterochromatin enzyme inhibition can produce a paradoxical decrease in transcription by destabilizing domain cores. Applied to development and aging, we show the pairing of heterochromatin and transcription at myogenic genes that could be disrupted by nuclear swelling. In sum, packing domains represent a foundation to explore the interactions of chromatin and transcription at the single-cell level in human health.

SEE: A Method for Predicting the Dynamics of Chromatin Conformation Based on Single-Cell Gene Expression.

The dynamics of chromatin conformation involve continuous and reversible changes within the nucleus of a cell, which participate in regulating processes such as gene expression, DNA replication, and damage repair. Here, SEE is introduced, an artificial intelligence (AI) method that utilizes autoencoder and transformer techniques to analyze chromatin dynamics using single-cell RNA sequencing data and a limited number of single-cell Hi-C maps. SEE is employed to investigate chromatin dynamics across different scales, enabling the detection of (i) rearrangements in topologically associating domains (TADs), and (ii) oscillations in chromatin interactions at gene loci. Additionally, SEE facilitates the interpretation of disease-associated single-nucleotide polymorphisms (SNPs) by leveraging the dynamic features of chromatin conformation. Overall, SEE offers a single-cell, high-resolution approach to analyzing chromatin dynamics in both developmental and disease contexts.

Machine and Deep Learning Methods for Predicting 3D Genome Organization.

Three-dimensional (3D) chromatin interactions, such as enhancer-promoter interactions (EPIs), loops, topologically associating domains (TADs), and A/B compartments, play critical roles in a wide range of cellular processes by regulating gene expression. Recent development of chromatin conformation capture technologies has enabled genome-wide profiling of various 3D structures, even with single cells. However, current catalogs of 3D structures remain incomplete and unreliable due to differences in technology, tools, and low data resolution. Machine learning methods have emerged as an alternative to obtain missing 3D interactions and/or improve resolution. Such methods frequently use genome annotation data (ChIP-seq, DNAse-seq, etc.), DNA sequencing information (k-mers and transcription factor binding site (TFBS) motifs), and other genomic properties to learn the associations between genomic features and chromatin interactions. In this review, we discuss computational tools for predicting three types of 3D interactions (EPIs, chromatin interactions, and TAD boundaries) and analyze their pros and cons. We also point out obstacles to the computational prediction of 3D interactions and suggest future research directions.

A generalizable Hi-C foundation model for chromatin architecture, single-cell and multi-omics analysis across species.

Nuclear DNA is organized into a compact three-dimensional (3D) structure that impacts critical cellular processes. High-throughput chromosome conformation capture (Hi-C) is the most widely used method for measuring 3D genome architecture, while linear epigenomic assays, such as ATAC-seq, DNase-seq, and ChIP-seq, are extensively employed to characterize epigenomic regulation. However, the integrative analysis of chromatin interactions and associated epigenomic regulation remains challenging due to the pairwise nature of Hi-C data, mismatched resolution between Hi-C and epigenomic assays, and inconsistencies among analysis tools. Here we propose HiCFoundation, a Hi-C-based foundation model for integrative analysis linking chromatin structure to downstream regulatory function. HiCFoundation is trained from hundreds of Hi-C assays encompassing 118 million contact matrix submatrices. The model achieves state-of-the-art performance on multiple types of 3D genome analysis, including reproducibility analysis, resolution enhancement, and loop detection. We further demonstrate the model's generalizability through genome architecture analysis of 316 species. Notably, by enhancing low-coverage experimental Hi-C data, HiCFoundation reveals genome-wide loop loss during differentiation of hematopoietic stem and progenitor cells (HSPCs) to neutrophils. Additionally, HiCFoundation is able to predict multiple types of epigenomic activity from Hi-C input and further interprets the link between Hi-C input and epigenomic output to reveal the relationship between chromatin conformation and genome function. Finally, HiCFoundation can analyze single-cell Hi-C data, shedding light on genome structure at single-cell resolution. HiCFoundation thus provides a unified, efficient, generalizable, and interpretable foundation for genome architecture, single-cell and multi-omics analysis across species, paving the path for systematically studying genome 3D architecture and its regulatory mechanisms.

Changes in the chromatin structure of honey bee hypopharyngeal gland cells subjected to the absence of pollen

To increase productivity and prevent the loss of swarms during periods of low flowering in beekeeping, energy and protein supplements are widely used. We compared the effects of different protein supplements on the chromatin conformation of the hypopharyngeal glands of Apis mellifera L. bees, to evaluate possible genes alterations. The results of two diets with different amounts of crude protein (one formulated and one commercial) at the critical electrolyte concentration (CEC) were evaluated in bees at 7 and 13 days of life. Metachromasia analysis showed that the treatments altered gene expression, compared to the positive control, and this did not change during the two days evaluated. These results suggest that there is a positive relationship between deprivation of pollen supply consumption and changes in the chromatin conformation of the gland, altering the expression of genes linked to royal jelly production. The CEC results suggest that supplementation would not be enough to compensate for the damage caused by nutritional stress, in hives that do not have access to pollen as a source of nutrients.

High quality genome assembly and annotation (v1) of the eukaryotic freshwater microalga Coccomyxa elongata SAG 216-3b.

Unicellular green algae of the genus Coccomyxa are recognized for their worldwide distribution and ecological versatility. Coccomyxa elongata is a freshwater species of the Coccomyxa simplex clade, which also includes lichen symbionts. To facilitate future molecular and phylogenomic studies of this versatile clade of algae, we generated a high-quality genome assembly for Coccomyxa elongata Chodat & Jaag SAG 216-3b within the framework of the Biodiversity Genomics Center Cologne (BioC2) initiative. A combination of long-read PacBio HiFi and Oxford Nanopore Technologies with chromatin conformation capture (Hi-C) sequencing led to the assembly of the genome into 21 scaffolds with a total length of 51.4 Mb and an N50 of 2.8 Mb. Nineteen of the scaffolds represent highly complete nuclear chromosomes delimited by telomeric repeats, while the two additional scaffolds represent the mitochondrial and plastid genomes. Transcriptome-guided gene annotation resulted in the identification of 14,811 protein-coding genes, of which 61% have annotated PFAM domains and 841 are predicted to be secreted. BUSCO analysis against the Chlorophyta database identified a total of 1,494 (98.4 %) complete gene models, suggesting a highly complete genome annotation.

The Lyn/RUVBL1 Complex Promotes Colorectal Cancer Liver Metastasis by Regulating Arachidonic Acid Metabolism Through Chromatin Remodeling.

Liver metastasis is a common cause of death in colorectal cancer (CRC) patients, but epigenetic remodeling and metabolic reprogramming for CRC liver metastasis remain unclear. The study revealed that the Lyn/RUVBL1 complex is highly expressed in CRC and is closely correlated with liver metastasis. On the one hand, ATAC-seq and HiCut suggested that Lyn/RUVBL1 regulates the expression of TRIB3 through the POL II-mediated chromatin conformation of TRIB3 and thus the expression of β-catenin. This promotes the proliferation and migration of CRC through β-catenin-mediated upregulation of MMP9 and VEGF. On the other hand, metabolomics revealed that Lyn/RUVBL1 regulates the expression of PGE2 through the enzyme COX2, thereby promoting arachidonic acid (AA) metabolism. CUT-Tag showed that Lyn/RUVBL1 silencing reduces the H3K27ac level in the COX2 promoter. Then, it is found that COX2 is regulated by the transcription factor FOXA1. Lyn/RUVBL1 modulates AA metabolism by regulating the chromatin accessibility of FOXA1. AA metabolism promotes the metastasis of CRC by affecting β-catenin nuclear translocation and upregulating MMP9 and VEGF. These findings suggest that the Lyn/RUVBL1 complex mediates epigenetic remodeling to regulate the metabolic reprogramming of AA, highlighting its role in promoting the metastasis of CRC.

Integration of multi-omics layers empowers precision diagnosis through unveiling pathogenic mechanisms on maple syrup urine disease.

Maple syrup urine disease (MSUD) is a rare inherited metabolic disorder characterized by deficient activity of the branched-chain alpha-ketoacid dehydrogenase (BCKDH) complex, required to metabolize the amino acids leucine, isoleucine, and valine. Despite its profound metabolic implications, the molecular alterations underlying this metabolic impairment had not yet been completely elucidated. We performed a comprehensive multi-omics integration analysis, including genomic, epigenomic, and transcriptomic data from fibroblasts derived from a cohort of MSUD patients and unaffected controls to genetically characterize an MSUD case and to unravel the MSUD pathophysiology. MSUD patients exhibit a defined episignature that reshapes the global DNA methylation landscape, resulting in the stimulation of HOX cluster genes and the restriction of cell cycle gene-related signatures. Subsequent data integration revealed the impact of AP1-related and CEBPB transcription factors on the observed molecular reorganization, with MEIS1 emerging as a potential downstream candidate affected by robust epigenetic repression in MSUD patients. Furthermore, the integration of multi-omics layers facilitated the identification of a strong epigenetic repression in the DBT promoter in a patient wherein no BCKDH pathogenic variants had been detected. A Circular Chromatin Conformation Capture assay indicated a disturbance of the interactions of DBT promoter, thereby unveiling alternative modes of disease inheritance. Integration of multi-omics data unveiled underlying molecular networks rewired in MSUD patients and represents a powerful approach with diagnostic potential for rare genetic disorders with unknown genetic bases.

PfMORC protein regulates chromatin accessibility and transcriptional repression in the human malaria parasite, Plasmodium falciparum.

The environmental challenges the human malaria parasite, Plasmodium falciparum, faces during its progression into its various lifecycle stages warrant the use of effective and highly regulated access to chromatin for transcriptional regulation. Microrchidia (MORC) proteins have been implicated in DNA compaction and gene silencing across plant and animal kingdoms. Accumulating evidence has shed light on the role MORC protein plays as a transcriptional switch in apicomplexan parasites. In this study, using the CRISPR/Cas9 genome editing tool along with complementary molecular and genomics approaches, we demonstrate that PfMORC not only modulates chromatin structure and heterochromatin formation throughout the parasite erythrocytic cycle, but is also essential to the parasite survival. Chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) experiments suggests that PfMORC binds to not only sub-telomeric regions and genes involved in antigenic variation but may also play a role in modulating stage transition. Protein knockdown experiments followed by chromatin conformation capture (Hi-C) studies indicate that downregulation of PfMORC impairs key histone marks and induces the collapse of the parasite heterochromatin structure leading to its death. All together these findings confirm that PfMORC plays a crucial role in chromatin structure and gene regulation, validating this factor as a strong candidate for novel antimalarial strategies.

The landscape of fusion transcripts in plants: a new insight into genome complexity

BackgroundFusion transcripts (FTs), generated by the fusion of genes at the DNA level or RNA-level splicing events significantly contribute to transcriptome diversity. FTs are usually considered unique features of neoplasia and serve as biomarkers and therapeutic targets for multiple cancers. The latest findings show the presence of FTs in normal human physiology. Several discrete reports mentioned the presence of fusion transcripts in planta, has important roles in stress responses, morphological alterations, or traits (e.g. seed size, etc.).ResultsIn this study, we identified 169,197 fusion transcripts in 2795 transcriptome datasets of Arabidopsis thaliana, Cicer arietinum, and Oryza sativa by using a combination of tools, and confirmed the translational activity of 150 fusion transcripts through proteomic datasets. Analysis of the FT junction sequences and their association with epigenetic factors, as revealed by ChIP-Seq datasets, demonstrated an organised process of fusion formation at the DNA level. We investigated the possible impact of three-dimensional chromatin conformation on intra-chromosomal fusion events by leveraging the Hi-C datasets with the incidence of fusion transcripts. We further utilised the long-read RNA-Seq datasets to validate the most reoccurring fusion transcripts in each plant species followed by further authentication through RT-PCR and Sanger sequencing.ConclusionsOur findings suggest that a significant portion of fusion events may be attributed to alternative splicing during transcription, accounting for numerous fusion events without a proportional increase in the number of RNA pairs. Even non-nuclear DNA transcripts from mitochondria and chloroplasts can participate in intra- and inter-chromosomal fusion formation. Genes in close spatial proximity are more prone to undergoing fusion formation, especially in intra-chromosomal FTs. Most of the fusion transcripts may not undergo translation and serve as long non-coding RNAs. The low validation rate of FTs in plants indicated that the fusion transcripts are expressed at very low levels, like in the case of humans. FTs often originate from parental genes involved in essential biological processes, suggesting their relevance across diverse tissues and stress conditions. This study presents a comprehensive repository of fusion transcripts, offering valuable insights into their roles in vital physiological processes and stress responses.

Identification of responsible sequences which mutations cause maternal H19-ICR hypermethylation with Beckwith–Wiedemann syndrome-like overgrowth

Beckwith-Wiedemann syndrome (BWS) is caused by a gain of methylation (GOM) at the imprinting control region within the Igf2-H19 domain on the maternal allele (H19-ICR GOM). Mutations in the binding sites of several transcription factors are involved in H19-ICR GOM and BWS. However, the responsible sequence(s) for H19-ICR GOM with BWS-like overgrowth has not been identified in mice. Here, we report that a mutation in the SOX-OCT binding site (SOBS) causes partial H19-ICR GOM, which does not extend beyond CTCF binding site 3 (CTS3). Moreover, simultaneously mutating both SOBS and CTS3 causes complete GOM of the entire H19-ICR, leading to the misexpression of the imprinted genes, and frequent BWS-like overgrowth. In addition, CTS3 is critical for CTCF/cohesin-mediated chromatin conformation. These results indicate that SOBS and CTS3 are the sequences in which mutations cause H19-ICR GOM leading to BWS-like overgrowth and are essential for maintaining the unmethylated state of maternal H19-ICR.

Chromosome-level genome assembly of Iodes seguinii and its metabonomic implications for rheumatoid arthritis treatment.

Iodes seguinii is a woody vine known for its potential therapeutic applications in treating rheumatoid arthritis (RA) due to its rich bioactive components. Here, we achieved the first chromosome-level assembly of the nuclear genome of I. seguinii using PacBio HiFi and chromatin conformation capture (Hi-C) sequencing data. The initial assembly with PacBio data produced contigs with an N50 length of 9.71 Mb, and Hi-C data anchored these contigs into 13 chromosomes, achieving a total length of 273.58 Mb, closely matching the estimated genome size. Quality assessments, including BUSCO, long terminal repeat assembly index, transcriptome mapping rates, and sequencing coverage, confirmed the high quality, completeness, and continuity of the assembly, identifying 115.28 Mb of repetitive sequences, 1062 RNA genes, and 25,270 protein-coding genes. Additionally, we assembled and annotated the 150,599bp chloroplast genome using Illumina sequencing data, containing 121 genes including key DNA barcodes, with maturase K (matK) proving effective for species identification. Phylogenetic analysis positioned I. seguinii at the base of the Lamiales clade, identifying significant gene family expansions and contractions, particularly related to secondary metabolite synthesis and DNA damage repair. Metabolite analysis identified 84 active components in I. seguinii, including the discovery of luteolin, with 119 targets predicted for RA treatment, including core targets like AKT1, toll-like receptor 4 (TLR4), epidermal growth factor receptor (EGFR), tumor necrosis factor (TNF), TP53, NFKB1, janus kinase 2 (JAK2), BCL2, mitogen-activated protein kinase 1 (MAPK1), and spleen-associated tyrosine kinase (SYK). Key active components such as flavonoids and polyphenols with anti-inflammatory activities were highlighted. The discovery of luteolin, in particular, underscores its potential therapeutic role. These findings provide a valuable genomic resource and a scientific basis for the development and application of I. seguinii, addressing the genomic gap in the genus Iodes and the order Icacinales and underscoring the need for further research in genomics, transcriptomics, and metabolomics to fully explore its potential.

CHARMER: detecting and harmonizing high-confidence chromatin interactions across tissues and Hi-C protocols.

Chromatin conformation capture experiments (CCC), such as Hi-C and Capture Hi-C (CHiC) work to elucidate the three-dimensional organization of the genome and the underlying epigenetic regulatory structures within. CCC experiments produce large amounts of FASTQ sequencing data with a substantial amount of technical noise and require sophisticated computational pipelines in order to extract meaningful results. Large-scale CCC data repositories like 4D Nucleome and ENCODE mostly provide raw contact information but lack annotated, statistically significant interaction data suitable for downstream genetic and genomic analyses. Here, we present CHARMER, an end-to-end pipeline integrated across multiple CCC assay types (HiC, CHiC) which generates statistically significant, harmonized, queryable, chromatin interactions in a consistent BED-like format across cell/tissue types and CCC assays. CHARMER is freely available at https://bitbucket.org/wanglab-upenn/CHARMER and harmonized chromatin interaction data will be available in the upcoming version of the FILER database (https://lisanwanglab.org/FILER).