Life Sciences Research for Lifelong Health

Publications peter-fraser

Title / Authors / Details Open Access Download

Genome-wide mapping of long-range contacts unveils clustering of DNA double-strand breaks at damaged active genes.
Aymard F, Aguirrebengoa M, Guillou E, Javierre BM, Bugler B, Arnould C, Rocher V, Iacovoni JS, Biernacka A, Skrzypczak M, Ginalski K, Rowicka M, Fraser P, Legube G

The ability of DNA double-strand breaks (DSBs) to cluster in mammalian cells has been a subject of intense debate in recent years. Here we used a high-throughput chromosome conformation capture assay (capture Hi-C) to investigate clustering of DSBs induced at defined loci in the human genome. The results unambiguously demonstrated that DSBs cluster, but only when they are induced within transcriptionally active genes. Clustering of damaged genes occurs primarily during the G1 cell-cycle phase and coincides with delayed repair. Moreover, DSB clustering depends on the MRN complex as well as the Formin 2 (FMN2) nuclear actin organizer and the linker of nuclear and cytoplasmic skeleton (LINC) complex, thus suggesting that active mechanisms promote clustering. This work reveals that, when damaged, active genes, compared with the rest of the genome, exhibit a distinctive behavior, remaining largely unrepaired and clustered in G1, and being repaired via homologous recombination in postreplicative cells.

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Nature structural & molecular biology, , 1545-9985, , 2017

PMID: 28263325

Lineage-Specific Genome Architecture Links Enhancers and Non-coding Disease Variants to Target Gene Promoters.
Javierre BM, Burren OS, Wilder SP, Kreuzhuber R, Hill SM, Sewitz S, Cairns J, Wingett SW, Várnai C, Thiecke MJ, Burden F, Farrow S, Cutler AJ, Rehnström K, Downes K, Grassi L, Kostadima M, Freire-Pritchett P, Wang F, , Stunnenberg HG, Todd JA, Zerbino DR, Stegle O, Ouwehand WH, Frontini M, Wallace C, Spivakov M, Fraser P

Long-range interactions between regulatory elements and gene promoters play key roles in transcriptional regulation. The vast majority of interactions are uncharted, constituting a major missing link in understanding genome control. Here, we use promoter capture Hi-C to identify interacting regions of 31,253 promoters in 17 human primary hematopoietic cell types. We show that promoter interactions are highly cell type specific and enriched for links between active promoters and epigenetically marked enhancers. Promoter interactomes reflect lineage relationships of the hematopoietic tree, consistent with dynamic remodeling of nuclear architecture during differentiation. Interacting regions are enriched in genetic variants linked with altered expression of genes they contact, highlighting their functional role. We exploit this rich resource to connect non-coding disease variants to putative target promoters, prioritizing thousands of disease-candidate genes and implicating disease pathways. Our results demonstrate the power of primary cell promoter interactomes to reveal insights into genomic regulatory mechanisms underlying common diseases.

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Cell, 167, 1097-4172, 1369-1384.e19, 2016

PMID: 27863249

Open Access

Identifying Causal Genes at the Multiple Sclerosis Associated Region 6q23 Using Capture Hi-C.
Martin P, McGovern A, Massey J, Schoenfelder S, Duffus K, Yarwood A, Barton A, Worthington J, Fraser P, Eyre S, Orozco G

The chromosomal region 6q23 has been found to be associated with multiple sclerosis (MS) predisposition through genome wide association studies (GWAS). There are four independent single nucleotide polymorphisms (SNPs) associated with MS in this region, which spans around 2.5 Mb. Most GWAS variants associated with complex traits, including these four MS associated SNPs, are non-coding and their function is currently unknown. However, GWAS variants have been found to be enriched in enhancers and there is evidence that they may be involved in transcriptional regulation of their distant target genes through long range chromatin looping.

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PloS one, 11, 1932-6203, e0166923, 2016

PMID: 27861577

Defining cell type with chromatin profiling.
Spivakov M, Fraser P

Nature biotechnology, 34, 1546-1696, 1126-1128, 2016

PMID: 27824844

Turning the tide on 3D nuclear organization.
Fraser P

Nature reviews. Molecular cell biology, , 1471-0080, , 2016

PMID: 27808275

Capture Hi-C identifies a novel causal gene, IL20RA, in the pan-autoimmune genetic susceptibility region 6q23.
McGovern A, Schoenfelder S, Martin P, Massey J, Duffus K, Plant D, Yarwood A, Pratt AG, Anderson AE, Isaacs JD, Diboll J, Thalayasingam N, Ospelt C, Barton A, Worthington J, Fraser P, Eyre S, Orozco G

The identification of causal genes from genome-wide association studies (GWAS) is the next important step for the translation of genetic findings into biologically meaningful mechanisms of disease and potential therapeutic targets. Using novel chromatin interaction detection techniques and allele specific assays in T and B cell lines, we provide compelling evidence that redefines causal genes at the 6q23 locus, one of the most important loci that confers autoimmunity risk.

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Genome biology, 17, 1474-760X, 212, 2016

PMID: 27799070

Integrating epigenomic data and 3D genomic structure with a new measure of chromatin assortativity.
Pancaldi V, Carrillo-de-Santa-Pau E, Javierre BM, Juan D, Fraser P, Spivakov M, Valencia A, Rico D

Network analysis is a powerful way of modeling chromatin interactions. Assortativity is a network property used in social sciences to identify factors affecting how people establish social ties. We propose a new approach, using chromatin assortativity, to integrate the epigenomic landscape of a specific cell type with its chromatin interaction network and thus investigate which proteins or chromatin marks mediate genomic contacts.

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Genome biology, 17, 1474-760X, 152, 0

PMID: 27391817

Open Access

CHiCAGO: robust detection of DNA looping interactions in Capture Hi-C data.
Cairns J, Freire-Pritchett P, Wingett SW, Várnai C, Dimond A, Plagnol V, Zerbino D, Schoenfelder S, Javierre BM, Osborne C, Fraser P, Spivakov M

Capture Hi-C (CHi-C) is a method for profiling chromosomal interactions involving targeted regions of interest, such as gene promoters, globally and at high resolution. Signal detection in CHi-C data involves a number of statistical challenges that are not observed when using other Hi-C-like techniques. We present a background model and algorithms for normalisation and multiple testing that are specifically adapted to CHi-C experiments. We implement these procedures in CHiCAGO ( ), an open-source package for robust interaction detection in CHi-C. We validate CHiCAGO by showing that promoter-interacting regions detected with this method are enriched for regulatory features and disease-associated SNPs.

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Genome biology, 17, 1474-760X, 127, 2016

PMID: 27306882

Open Access

HiCUP: pipeline for mapping and processing Hi-C data.
Wingett S, Ewels P, Furlan-Magaril M, Nagano T, Schoenfelder S, Fraser P, Andrews S

HiCUP is a pipeline for processing sequence data generated by Hi-C and Capture Hi-C (CHi-C) experiments, which are techniques used to investigate three-dimensional genomic organisation. The pipeline maps data to a specified reference genome and removes artefacts that would otherwise hinder subsequent analysis. HiCUP also produces an easy-to-interpret yet detailed quality control (QC) report that assists in refining experimental protocols for future studies. The software is freely available and has already been used for processing Hi-C and CHi-C data in several recently published peer-reviewed studies.

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F1000Research, 4, 2046-1402, 1310, 2015

PMID: 26835000

Open Access

Integrated genome-scale analysis of the transcriptional regulatory landscape in a blood stem/progenitor cell model.
Wilson NK, Schoenfelder S, Hannah R, Sánchez Castillo M, Schütte J, Ladopoulos V, Mitchelmore J, Goode DK, Calero-Nieto FJ, Moignard V, Wilkinson AC, Jimenez-Madrid I, Kinston S, Spivakov M, Fraser P, Göttgens B

Comprehensive study of transcriptional control processes will be required to enhance our understanding of both normal and malignant haematopoiesis. Modern sequencing technologies have revolutionized our ability to generate genome-scale expression and histone modification profiles, transcription factor binding maps and also comprehensive chromatin looping information. Many of these technologies however require large numbers of cells, and therefore cannot be applied to rare haematopoietic stem/progenitor cell (HSPC) populations. The stem cell factor (SCF) dependent multipotent progenitor cell line HPC-7 represents a well recognised cell line model for HSPCs. Here we report genome-wide maps for 17 transcription factors (TFs), 3 histone modifications, DNase I hypersensitive sites and high-resolution promoter-enhancer interactomes in HPC-7 cells. Integrated analysis of these complementary datasets revealed transcription factor occupancy patterns of genomic regions involved in promoter-anchored loops. Moreover, preferential associations between pairs of transcription factors bound at either ends of chromatin loops lead to the identification of four previously unrecognised protein-protein interactions between key blood stem cell regulators. All HPC-7 genome-scale datasets are freely available both through standard repositories and a user-friendly web interface. Together with previously generated genome-scale datasets, this study integrates HPC-7 data into a genomic resource on a par with ENCODE tier 1 cell lines, and importantly the only current model with comprehensive genome-scale data that is relevant to HSPC biology.

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Blood, , 1528-0020, , 2016

PMID: 26809507

Capture Hi-C reveals novel candidate genes and complex long-range interactions with related autoimmune risk loci.
Martin P, McGovern A, Orozco G, Duffus K, Yarwood A, Schoenfelder S, Cooper NJ, Barton A, Wallace C, Fraser P, Worthington J, Eyre S

Genome-wide association studies have been tremendously successful in identifying genetic variants associated with complex diseases. The majority of association signals are intergenic and evidence is accumulating that a high proportion of signals lie in enhancer regions. We use Capture Hi-C to investigate, for the first time, the interactions between associated variants for four autoimmune diseases and their functional targets in B- and T-cell lines. Here we report numerous looping interactions and provide evidence that only a minority of interactions are common to both B- and T-cell lines, suggesting interactions may be highly cell-type specific; some disease-associated SNPs do not interact with the nearest gene but with more compelling candidate genes (for example, FOXO1, AZI2) often situated several megabases away; and finally, regions associated with different autoimmune diseases interact with each other and the same promoter suggesting common autoimmune gene targets (for example, PTPRC, DEXI and ZFP36L1).

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Nature communications, 6, 2041-1723, 10069, 2015

PMID: 26616563

Open Access

Single-cell Hi-C for genome-wide detection of chromatin interactions that occur simultaneously in a single cell.
Nagano T, Lubling Y, Yaffe E, Wingett SW, Dean W, Tanay A, Fraser P

Hi-C is a powerful method that provides pairwise information on genomic regions in spatial proximity in the nucleus. Hi-C requires millions of cells as input and, as genome organization varies from cell to cell, a limitation of Hi-C is that it only provides a population average of genome conformations. We developed single-cell Hi-C to create snapshots of thousands of chromatin interactions that occur simultaneously in a single cell. To adapt Hi-C to single-cell analysis, we modified the protocol to include in-nucleus ligation. This enables the isolation of single nuclei carrying Hi-C-ligated DNA into separate tubes, followed by reversal of cross-links, capture of biotinylated ligation junctions on streptavidin-coated magnetic beads and PCR amplification of single-cell Hi-C libraries. The entire laboratory protocol can be carried out in 1 week, and although we have demonstrated its use in mouse T helper (TH1) cells, it should be applicable to any cell type or species for which standard Hi-C has been successful. We also developed an analysis pipeline to filter noise and assess the quality of data sets in a few hours. Although the interactome maps produced by single-cell Hi-C are sparse, the data provide useful information to understand cellular variability in nuclear genome organization and chromosome structure. Standard wet and dry laboratory skills in molecular biology and computational analysis are required.

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Nature protocols, 10, 1750-2799, 1986-2003, 2015

PMID: 26540590

Polycomb repressive complex PRC1 spatially constrains the mouse embryonic stem cell genome.
Schoenfelder S, Sugar R, Dimond A, Javierre BM, Armstrong H, Mifsud B, Dimitrova E, Matheson L, Tavares-Cadete F, Furlan-Magaril M, Segonds-Pichon A, Jurkowski W, Wingett SW, Tabbada K, Andrews S, Herman B, LeProust E, Osborne CS, Koseki H, Fraser P, Luscombe NM, Elderkin S

The Polycomb repressive complexes PRC1 and PRC2 maintain embryonic stem cell (ESC) pluripotency by silencing lineage-specifying developmental regulator genes. Emerging evidence suggests that Polycomb complexes act through controlling spatial genome organization. We show that PRC1 functions as a master regulator of mouse ESC genome architecture by organizing genes in three-dimensional interaction networks. The strongest spatial network is composed of the four Hox gene clusters and early developmental transcription factor genes, the majority of which contact poised enhancers. Removal of Polycomb repression leads to disruption of promoter-promoter contacts in the Hox gene network. In contrast, promoter-enhancer contacts are maintained in the absence of Polycomb repression, with accompanying widespread acquisition of active chromatin signatures at network enhancers and pronounced transcriptional upregulation of network genes. Thus, PRC1 physically constrains developmental transcription factor genes and their enhancers in a silenced but poised spatial network. We propose that the selective release of genes from this spatial network underlies cell fate specification during early embryonic development.

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Nature genetics, , 1546-1718, , 2015

PMID: 26323060

Open Access

Three Dimensional Organization of the Nucleus: adding DNA sequences to the big picture.
Gilbert DM, Fraser P

Genome biology, 16, 1474-760X, 181, 2015

PMID: 26319739

Open Access

Comparison of Hi-C results using in-solution versus in-nucleus ligation.
Nagano T, Várnai C, Schoenfelder S, Javierre BM, Wingett SW, Fraser P

Chromosome conformation capture and various derivative methods such as 4C, 5C and Hi-C have emerged as standard tools to analyze the three-dimensional organization of the genome in the nucleus. These methods employ ligation of diluted cross-linked chromatin complexes, intended to favor proximity-dependent, intra-complex ligation. During development of single-cell Hi-C, we devised an alternative Hi-C protocol with ligation in preserved nuclei rather than in solution. Here we directly compare Hi-C methods employing in-nucleus ligation with the standard in-solution ligation.

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Genome biology, 16, 1474-760X, 175, 2015

PMID: 26306623

Open Access

3D genome architecture from populations to single cells.
Furlan-Magaril M, Várnai C, Nagano T, Fraser P

Dominated by microscopy for decades the nuclear genome organization field has recently undergone a dramatic transition fuelled by new next generation sequencing technologies that are beginning to bridge the gap between microscopic observations and molecular scale studies. It is no longer in doubt that the nucleus is spatially compartmentalized and that the genome organization with respect to these compartments is cell type specific. However, it is still unclear if and how this organization contributes to genome function, or whether it is simply a consequence of it. This uncertainty is partly due to the cell-to-cell variability of genome organization, but also due to limitations of the measurement techniques and the scale of the problem at hand. Here we discuss some of the exciting recent progress made towards understanding three-dimensional genome architecture and function.

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Current opinion in genetics & development, 31, 1879-0380, 36-41, 2015

PMID: 25966907

Mapping long-range promoter contacts in human cells with high-resolution capture Hi-C.
Mifsud B, Tavares-Cadete F, Young AN, Sugar R, Schoenfelder S, Ferreira L, Wingett SW, Andrews S, Grey W, Ewels PA, Herman B, Happe S, Higgs A, LeProust E, Follows GA, Fraser P, Luscombe NM, Osborne CS

Transcriptional control in large genomes often requires looping interactions between distal DNA elements, such as enhancers and target promoters. Current chromosome conformation capture techniques do not offer sufficiently high resolution to interrogate these regulatory interactions on a genomic scale. Here we use Capture Hi-C (CHi-C), an adapted genome conformation assay, to examine the long-range interactions of almost 22,000 promoters in 2 human blood cell types. We identify over 1.6 million shared and cell type-restricted interactions spanning hundreds of kilobases between promoters and distal loci. Transcriptionally active genes contact enhancer-like elements, whereas transcriptionally inactive genes interact with previously uncharacterized elements marked by repressive features that may act as long-range silencers. Finally, we show that interacting loci are enriched for disease-associated SNPs, suggesting how distal mutations may disrupt the regulation of relevant genes. This study provides new insights and accessible tools to dissect the regulatory interactions that underlie normal and aberrant gene regulation.

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Nature genetics, , 1546-1718, , 2015

PMID: 25938943

Open Access

The pluripotent regulatory circuitry connecting promoters to their long-range interacting elements.
Schoenfelder S, Furlan-Magaril M, Mifsud B, Tavares-Cadete F, Sugar R, Javierre BM, Nagano T, Katsman Y, Sakthidevi M, Wingett SW, Dimitrova E, Dimond A, Edelman LB, Elderkin S, Tabbada K, Darbo E, Andrews S, Herman B, Higgs A, LeProust E, Osborne CS, Mitchell JA, Luscombe NM, Fraser P

The mammalian genome harbors up to one million regulatory elements often located at great distances from their target genes. Long-range elements control genes through physical contact with promoters and can be recognized by the presence of specific histone modifications and transcription factor binding. Linking regulatory elements to specific promoters genome-wide is currently impeded by the limited resolution of high-throughput chromatin interaction assays. Here we apply a sequence capture approach to enrich Hi-C libraries for >22,000 annotated mouse promoters to identify statistically significant, long-range interactions at restriction fragment resolution, assigning long-range interacting elements to their target genes genome-wide in embryonic stem cells and fetal liver cells. The distal sites contacting active genes are enriched in active histone modifications and transcription factor occupancy, whereas inactive genes contact distal sites with repressive histone marks, demonstrating the regulatory potential of the distal elements identified. Furthermore, we find that coregulated genes cluster nonrandomly in spatial interaction networks correlated with their biological function and expression level. Interestingly, we find the strongest gene clustering in ES cells between transcription factor genes that control key developmental processes in embryogenesis. The results provide the first genome-wide catalog linking gene promoters to their long-range interacting elements and highlight the complex spatial regulatory circuitry controlling mammalian gene expression.

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Genome research, 25, 1549-5469, 582-97, 2015

PMID: 25752748

Open Access

Capture Hi-C identifies the chromatin interactome of colorectal cancer risk loci.
Jäger R, Migliorini G, Henrion M, Kandaswamy R, Speedy HE, Heindl A, Whiffin N, Carnicer MJ, Broome L, Dryden N, Nagano T, Schoenfelder S, Enge M, Yuan Y, Taipale J, Fraser P, Fletcher O, Houlston RS

Multiple regulatory elements distant from their targets on the linear genome can influence the expression of a single gene through chromatin looping. Chromosome conformation capture implemented in Hi-C allows for genome-wide agnostic characterization of chromatin contacts. However, detection of functional enhancer-promoter interactions is precluded by its effective resolution that is determined by both restriction fragmentation and sensitivity of the experiment. Here we develop a capture Hi-C (cHi-C) approach to allow an agnostic characterization of these physical interactions on a genome-wide scale. Single-nucleotide polymorphisms associated with complex diseases often reside within regulatory elements and exert effects through long-range regulation of gene expression. Applying this cHi-C approach to 14 colorectal cancer risk loci allows us to identify key long-range chromatin interactions in cis and trans involving these loci.

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Nature communications, 6, 2041-1723, 6178, 2015

PMID: 25695508

Open Access

Global Reorganization of the Nuclear Landscape in Senescent Cells.
Chandra T, Ewels PA, Schoenfelder S, Furlan-Magaril M, Wingett SW, Kirschner K, Thuret JY, Andrews S, Fraser P, Reik W

Cellular senescence has been implicated in tumor suppression, development, and aging and is accompanied by large-scale chromatin rearrangements, forming senescence-associated heterochromatic foci (SAHF). However, how the chromatin is reorganized during SAHF formation is poorly understood. Furthermore, heterochromatin formation in senescence appears to contrast with loss of heterochromatin in Hutchinson-Gilford progeria. We mapped architectural changes in genome organization in cellular senescence using Hi-C. Unexpectedly, we find a dramatic sequence- and lamin-dependent loss of local interactions in heterochromatin. This change in local connectivity resolves the paradox of opposing chromatin changes in senescence and progeria. In addition, we observe a senescence-specific spatial clustering of heterochromatic regions, suggesting a unique second step required for SAHF formation. Comparison of embryonic stem cells (ESCs), somatic cells, and senescent cells shows a unidirectional loss in local chromatin connectivity, suggesting that senescence is an endpoint of the continuous nuclear remodelling process during differentiation.

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Cell reports, , 2211-1247, , 2015

PMID: 25640177

Open Access

Unbiased analysis of potential targets of breast cancer susceptibility loci by Capture Hi-C.
Dryden NH, Broome LR, Dudbridge F, Johnson N, Orr N, Schoenfelder S, Nagano T, Andrews S, Wingett S, Kozarewa I, Assiotis I, Fenwick K, Maguire SL, Campbell J, Natrajan R, Lambros M, Perrakis E, Ashworth A, Fraser P, Fletcher O

Genome-wide association studies have identified more than 70 common variants that are associated with breast cancer risk. Most of these variants map to non-protein-coding regions and several map to gene deserts, regions of several hundred kilobases lacking protein-coding genes. We hypothesized that gene deserts harbor long-range regulatory elements that can physically interact with target genes to influence their expression. To test this, we developed Capture Hi-C (CHi-C), which, by incorporating a sequence capture step into a Hi-C protocol, allows high-resolution analysis of targeted regions of the genome. We used CHi-C to investigate long-range interactions at three breast cancer gene deserts mapping to 2q35, 8q24.21, and 9q31.2. We identified interaction peaks between putative regulatory elements ("bait fragments") within the captured regions and "targets" that included both protein-coding genes and long noncoding (lnc) RNAs over distances of 6.6 kb to 2.6 Mb. Target protein-coding genes were IGFBP5, KLF4, NSMCE2, and MYC; and target lncRNAs included DIRC3, PVT1, and CCDC26. For one gene desert, we were able to define two SNPs (rs12613955 and rs4442975) that were highly correlated with the published risk variant and that mapped within the bait end of an interaction peak. In vivo ChIP-qPCR data show that one of these, rs4442975, affects the binding of FOXA1 and implicate this SNP as a putative functional variant.

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Genome research, 24, 1549-5469, 1854-68, 2014

PMID: 25122612

Open Access

The impact of chromosomal rearrangements on regulation of gene expression.
Harewood L, Fraser P

The effects that coding region single-nucleotide polymorphisms or mutations have on gene expression have been well documented, predominantly owing to their association with disease. The effects of structural chromosomal rearrangements are also receiving increasing attention with the development of new techniques that allow accurate, high-resolution data, whether genomic interaction or transcriptome data, to be generated right down to the single-cell level. Over the past 18 months, these advances in experimental techniques have been used to further confirm and delineate the substantial effects that chromosome rearrangements can have on the regulation of gene expression and provide evidence of direct links between the two.

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Human molecular genetics, 23, 1460-2083, R76-82, 2014

PMID: 24907073

Single-cell Hi-C reveals cell-to-cell variability in chromosome structure.
T Nagano, Y Lubling, TJ Stevens, S Schoenfelder, E Yaffe, W Dean, ED Laue, A Tanay, P Fraser

Large-scale chromosome structure and spatial nuclear arrangement have been linked to control of gene expression and DNA replication and repair. Genomic techniques based on chromosome conformation capture (3C) assess contacts for millions of loci simultaneously, but do so by averaging chromosome conformations from millions of nuclei. Here we introduce single-cell Hi-C, combined with genome-wide statistical analysis and structural modelling of single-copy X chromosomes, to show that individual chromosomes maintain domain organization at the megabase scale, but show variable cell-to-cell chromosome structures at larger scales. Despite this structural stochasticity, localization of active gene domains to boundaries of chromosome territories is a hallmark of chromosomal conformation. Single-cell Hi-C data bridge current gaps between genomics and microscopy studies of chromosomes, demonstrating how modular organization underlies dynamic chromosome structure, and how this structure is probabilistically linked with genome activity patterns.

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Nature, 502, 7469, 59-64, 2013

PMID: 24067610
DOI: 10.1038/nature12593

Open Access

Molecular biology. Long noncoding RNAs Xist in three dimensions.
Dimond A, Fraser P

Science (New York, N.Y.), 341, 1095-9203, 720-1, 2013

PMID: 23950517

Sixty years of genome biology.
Doolittle WF, Fraser P, Gerstein MB, Graveley BR, Henikoff S, Huttenhower C, Oshlack A, Ponting CP, Rinn JL, Schatz MC, Ule J, Weigel D, Weinstock GM

Sixty years after Watson and Crick published the double helix model of DNA's structure, thirteen members of Genome Biology's Editorial Board select key advances in the field of genome biology subsequent to that discovery.

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Genome biology, 14, 1474-760X, 113, 2013

PMID: 23651518

Open Access