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Monteagudo-Sánchez A, Richard Albert J, Scarpa M, Noordermeer D, Greenberg MVC. The impact of the embryonic DNA methylation program on CTCF-mediated genome regulation. Nucleic Acids Res 2024:gkae724. [PMID: 39180406 DOI: 10.1093/nar/gkae724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 07/23/2024] [Accepted: 08/21/2024] [Indexed: 08/26/2024] Open
Abstract
During mammalian embryogenesis, both the 5-cytosine DNA methylation (5meC) landscape and three dimensional (3D) chromatin architecture are profoundly remodeled during a process known as 'epigenetic reprogramming.' An understudied aspect of epigenetic reprogramming is how the 5meC flux, per se, affects the 3D genome. This is pertinent given the 5meC-sensitivity of DNA binding for a key regulator of chromosome folding: CTCF. We profiled the CTCF binding landscape using a mouse embryonic stem cell (ESC) differentiation protocol that models embryonic 5meC dynamics. Mouse ESCs lacking DNA methylation machinery are able to exit naive pluripotency, thus allowing for dissection of subtle effects of CTCF on gene expression. We performed CTCF HiChIP in both wild-type and mutant conditions to assess gained CTCF-CTCF contacts in the absence of 5meC. We performed H3K27ac HiChIP to determine the impact that ectopic CTCF binding has on cis-regulatory contacts. Using 5meC epigenome editing, we demonstrated that the methyl-mark is able to impair CTCF binding at select loci. Finally, a detailed dissection of the imprinted Zdbf2 locus showed how 5meC-antagonism of CTCF allows for proper gene regulation during differentiation. This work provides a comprehensive overview of how 5meC impacts the 3D genome in a relevant model for early embryonic events.
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Affiliation(s)
| | | | - Margherita Scarpa
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Daan Noordermeer
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), F-91998 Gif-sur-Yvette, France
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2
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Chang LH, Noordermeer D. Permeable TAD boundaries and their impact on genome-associated functions. Bioessays 2024:e2400137. [PMID: 39093600 DOI: 10.1002/bies.202400137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/12/2024] [Accepted: 07/17/2024] [Indexed: 08/04/2024]
Abstract
TAD boundaries are genomic elements that separate biological processes in neighboring domains by blocking DNA loops that are formed through Cohesin-mediated loop extrusion. Most TAD boundaries consist of arrays of binding sites for the CTCF protein, whose interaction with the Cohesin complex blocks loop extrusion. TAD boundaries are not fully impermeable though and allow a limited amount of inter-TAD loop formation. Based on the reanalysis of Nano-C data, a multicontact Chromosome Conformation Capture assay, we propose a model whereby clustered CTCF binding sites promote the successive stalling of Cohesin and subsequent dissociation from the chromatin. A fraction of Cohesin nonetheless achieves boundary read-through. Due to a constant rate of Cohesin dissociation elsewhere in the genome, the maximum length of inter-TAD loops is restricted though. We speculate that the DNA-encoded organization of stalling sites regulates TAD boundary permeability and discuss implications for enhancer-promoter loop formation and other genomic processes.
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Affiliation(s)
- Li-Hsin Chang
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- Blood and Transplant Research Unit in Precision Cellular Therapeutics, National Institute of Health Research, Oxford, UK
| | - Daan Noordermeer
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, Gif-sur-Yvette, France
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3
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Cornman RS. A genomic hotspot of diversifying selection and structural change in the hoary bat ( Lasiurus cinereus). PeerJ 2024; 12:e17482. [PMID: 38832043 PMCID: PMC11146322 DOI: 10.7717/peerj.17482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 05/07/2024] [Indexed: 06/05/2024] Open
Abstract
Background Previous work found that numerous genes positively selected within the hoary bat (Lasiurus cinereus) lineage are physically clustered in regions of conserved synteny. Here I further validate and expand on those finding utilizing an updated L. cinereus genome assembly and additional bat species as well as other tetrapod outgroups. Methods A chromosome-level assembly was generated by chromatin-contact mapping and made available by DNAZoo (www.dnazoo.org). The genomic organization of orthologous genes was extracted from annotation data for multiple additional bat species as well as other tetrapod clades for which chromosome-level assemblies were available from the National Center for Biotechnology Information (NCBI). Tests of branch-specific positive selection were performed for L. cinereus using PAML as well as with the HyPhy package for comparison. Results Twelve genes exhibiting significant diversifying selection in the L. cinereus lineage were clustered within a 12-Mb genomic window; one of these (Trpc4) also exhibited diversifying selection in bats generally. Ten of the 12 genes are landmarks of two distinct blocks of ancient synteny that are not linked in other tetrapod clades. Bats are further distinguished by frequent structural rearrangements within these synteny blocks, which are rarely observed in other Tetrapoda. Patterns of gene order and orientation among bat taxa are incompatible with phylogeny as presently understood, implying parallel evolution or subsequent reversals. Inferences of positive selection were found to be robust to alternative phylogenetic topologies as well as a strong shift in background nucleotide composition in some taxa. Discussion This study confirms and further localizes a genomic hotspot of protein-coding divergence in the hoary bat, one that also exhibits an increased tempo of structural change in bats compared with other mammals. Most genes in the two synteny blocks have elevated expression in brain tissue in humans and model organisms, and genetic studies implicate the selected genes in cranial and neurological development, among other functions.
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Affiliation(s)
- Robert S. Cornman
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, United States
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4
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Jehangir M, Ahmad SF, Singchat W, Panthum T, Thong T, Aramsirirujiwet P, Lisachov A, Muangmai N, Han K, Koga A, Duengkae P, Srikulnath K. Hi-C sequencing unravels dynamic three-dimensional chromatin interactions in muntjac lineage: insights from chromosome fusions in Fea's muntjac genome. Chromosome Res 2023; 31:34. [PMID: 38017297 DOI: 10.1007/s10577-023-09744-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 10/08/2023] [Accepted: 11/08/2023] [Indexed: 11/30/2023]
Abstract
Eukaryotes have varying numbers and structures of characteristic chromosomes across lineages or species. The evolutionary trajectory of species may have been affected by spontaneous genome rearrangements. Chromosome fusion drastically alters karyotypes. However, the mechanisms and consequences of chromosome fusions, particularly in muntjac species, are poorly understood. Recent research-based advancements in three-dimensional (3D) genomics, particularly high-throughput chromatin conformation capture (Hi-C) sequencing, have allowed for the identification of chromosome fusions and provided mechanistic insights into three muntjac species: Muntiacus muntjak, M. reevesi, and M. crinifrons. This study aimed to uncover potential genome rearrangement patterns in the threatened species Fea's muntjac (Muntiacus feae), which have not been previously examined for such characteristics. Deep Hi-C sequencing (31.42 × coverage) was performed to reveal the 3D chromatin architecture of the Fea's muntjac genome. Patterns of repeated chromosome fusions that were potentially mediated by high-abundance transposable elements were identified. Comparative Hi-C maps demonstrated linkage homology between the sex chromosomes in Fea's muntjac and autosomes in M. reevesi, indicating that fusions may have played a crucial role in the evolution of the sex chromosomes of the lineage. The species-level dynamics of topologically associated domains (TADs) suggest that TAD organization could be altered by differential chromosome interactions owing to repeated chromosome fusions. However, research on the effect of TADs on muntjac genome evolution is insufficient. This study generated Hi-C data for the Fea's muntjac, providing a genomic resource for future investigations of the evolutionary patterns of chromatin conformation at the chromosomal level.
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Affiliation(s)
- Maryam Jehangir
- Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand
| | - Syed Farhan Ahmad
- Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand.
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand.
- The International Undergraduate Program in Bioscience and Technology, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand.
| | - Worapong Singchat
- Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand
| | - Thitipong Panthum
- Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand
| | - Thanyapat Thong
- Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand
| | - Pakpoom Aramsirirujiwet
- Deparment of National Park, Wildlife and Plant Conservation, Ministry of Natural Resources and Environment, Bangkok, 10900, Thailand
| | - Artem Lisachov
- Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand
| | - Narongrit Muangmai
- Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand
- Department of Fishery Biology, Faculty of Fisheries, Kasetsart University, Bangkok, 10900, Thailand
| | - Kyudong Han
- Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand
- Department of Microbiology, Dankook University, Cheonan, 31116, Korea
- Bio-Medical Engineering Core Facility Research Center, Dankook University, Cheonan, 31116, Korea
| | - Akihiko Koga
- Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand
| | - Prateep Duengkae
- Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand
| | - Kornsorn Srikulnath
- Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand.
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand.
- The International Undergraduate Program in Bioscience and Technology, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok, 10900, Thailand.
- Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Kasetsart University, Bangkok, 10900, Thailand.
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5
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Abstract
The raison d'être of meiosis is shuffling of genetic information via Mendelian segregation and, within individual chromosomes, by DNA crossing-over. These outcomes are enabled by a complex cellular program in which interactions between homologous chromosomes play a central role. We first provide a background regarding the basic principles of this program. We then summarize the current understanding of the DNA events of recombination and of three processes that involve whole chromosomes: homolog pairing, crossover interference, and chiasma maturation. All of these processes are implemented by direct physical interaction of recombination complexes with underlying chromosome structures. Finally, we present convergent lines of evidence that the meiotic program may have evolved by coupling of this interaction to late-stage mitotic chromosome morphogenesis.
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Affiliation(s)
- Denise Zickler
- Institute for Integrative Biology of the Cell (I2BC), Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Nancy Kleckner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA;
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6
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da Costa-Nunes JA, Noordermeer D. TADs: Dynamic structures to create stable regulatory functions. Curr Opin Struct Biol 2023; 81:102622. [PMID: 37302180 DOI: 10.1016/j.sbi.2023.102622] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/12/2023] [Accepted: 05/15/2023] [Indexed: 06/13/2023]
Abstract
Mammalian chromosomes are organized at different length scales within the cell nucleus. Topologically Associating Domains (TADs) are structural units of 3D genome organization with functions in gene regulation, DNA replication, recombination and repair. Whereas TADs were initially interpreted as insulated domains, recent studies are revealing that these domains should be interpreted as dynamic collections of actively extruding loops. This process of loop extrusion is subsequently blocked at dedicated TAD boundaries, thereby promoting intra-domain interactions over their surroundings. In this review, we discuss how mammalian TAD structure can emerge from this dynamic process and we discuss recent evidence that TAD boundaries can have regulatory functions.
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Affiliation(s)
- José A da Costa-Nunes
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Daan Noordermeer
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
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7
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Natarajan P, Shrinivas K, Chakraborty AK. A model for cis-regulation of transcriptional condensates and gene expression by proximal lncRNAs. Biophys J 2023; 122:2757-2772. [PMID: 37277993 PMCID: PMC10397817 DOI: 10.1016/j.bpj.2023.05.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 05/01/2023] [Accepted: 05/31/2023] [Indexed: 06/07/2023] Open
Abstract
Long noncoding RNAs (lncRNAs) perform several important functions in cells including cis-regulation of transcription. Barring a few specific cases, the mechanisms underlying transcriptional regulation by lncRNAs remain poorly understood. Transcriptional proteins can form condensates via phase separation at protein-binding loci (BL) on the genome (e.g., enhancers and promoters). lncRNA-coding genes are present at loci in close genomic proximity of these BL and these RNAs can interact with transcriptional proteins via attractive heterotypic interactions mediated by their net charge. Motivated by these observations, we propose that lncRNAs can dynamically regulate transcription in cis via charge-based heterotypic interactions with transcriptional proteins in condensates. To study the consequences of this mechanism, we developed and studied a dynamical phase-field model. We find that proximal lncRNAs can promote condensate formation at the BL. Vicinally localized lncRNA can migrate to the BL to attract more protein because of favorable interaction free energies. However, increasing the distance beyond a threshold leads to a sharp decrease in protein recruitment to the BL. This finding could potentially explain why genomic distances between lncRNA-coding genes and protein-coding genes are conserved across metazoans. Finally, our model predicts that lncRNA transcription can fine-tune transcription from neighboring condensate-controlled genes, repressing transcription from highly expressed genes and enhancing transcription of genes expressed at a low level. This nonequilibrium effect can reconcile conflicting reports that lncRNAs can enhance or repress transcription from proximal genes.
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Affiliation(s)
- Pradeep Natarajan
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Krishna Shrinivas
- NSF-Simons Center for Mathematical & Statistical Analysis of Biology, Harvard University, Cambridge, Massachusetts
| | - Arup K Chakraborty
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts; Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts; Institute of Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts; Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts.
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8
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Teng Z, Zhu Y, Lin D, Hao Q, Yue Q, Yu X, Sun S, Jiang L, Lu S. Deciphering the chromatin spatial organization landscapes during BMMSC differentiation. J Genet Genomics 2023; 50:264-275. [PMID: 36720443 DOI: 10.1016/j.jgg.2023.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/18/2023] [Accepted: 01/18/2023] [Indexed: 01/31/2023]
Abstract
The differentiation imbalance in bone marrow mesenchymal stem cells (BMMSCs) is critical for the development of bone density diseases as the population ages. BMMSCs are precursor cells for osteoblasts and adipocytes; however, the chromatin organization landscapes during BMMSC differentiation remain elusive. In this study, we systematically delineate the four-dimensional (4D) genome and dynamic epigenetic atlas of BMMSCs by RNA sequencing (RNA-seq), assay for transposase-accessible chromatin sequencing (ATAC-seq), and high-throughput chromosome conformation capture (Hi-C). The structure analyses reveal 17.5% common and 28.5%-30% specific loops among BMMSCs, osteoblasts, and adipocytes. The subsequent correlation of genome-wide association studies (GWAS) and expression quantitative trait locus (eQTL) data with multi-omics analysis reveal 274 genes and 3634 single nucleotide polymorphisms (SNPs) associated with bone degeneration and osteoporosis (OP). We hypothesize that SNP mutations affect transcription factor (TF) binding sites, thereby affecting changes in gene expression. Furthermore, 26 motifs, 260 TFs, and 291 SNPs are identified to affect the eQTL. Among these genes, DAAM2, TIMP2, and TMEM241 were found to be essential for diseases such as bone degeneration and OP and may serve as potential drug targets.
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Affiliation(s)
- Zhaowei Teng
- Department of Orthopedics, The First People's Hospital of Yunnan Province, Affiliated Hospital of Kunming University of Science and Technology, Kunming, Yunnan 650032, China; Key Laboratory of Yunnan Provincial Innovative Application of Traditional Chinese Medicine, The First People's Hospital of Yunnan Province, Kunming, Yunnan 650032, China; Clinical Medical Research Center, The First People's Hospital of Yunnan Province, Kunming, Yunnan 650032, China.
| | - Yun Zhu
- The Sixth Affiliated Hospital of Kunming Medical University, Yuxi, Yunnan 653100, China
| | - Da Lin
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Qinggang Hao
- Center for Life Sciences, School of Life Sciences, Yunnan University, Kunming, Yunnan 650504, China
| | - Qiaoning Yue
- The Sixth Affiliated Hospital of Kunming Medical University, Yuxi, Yunnan 653100, China
| | - Xiaochao Yu
- The Sixth Affiliated Hospital of Kunming Medical University, Yuxi, Yunnan 653100, China
| | - Shuo Sun
- The Sixth Affiliated Hospital of Kunming Medical University, Yuxi, Yunnan 653100, China
| | - Lihong Jiang
- Key Laboratory of Yunnan Provincial Innovative Application of Traditional Chinese Medicine, The First People's Hospital of Yunnan Province, Kunming, Yunnan 650032, China.
| | - Sheng Lu
- Department of Orthopedics, The First People's Hospital of Yunnan Province, Affiliated Hospital of Kunming University of Science and Technology, Kunming, Yunnan 650032, China.
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9
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Zhang P, Wu Y, Zhou H, Zhou B, Zhang H, Wu H. CLNN-loop: a deep learning model to predict CTCF-mediated chromatin loops in the different cell lines and CTCF-binding sites (CBS) pair types. Bioinformatics 2022; 38:4497-4504. [PMID: 35997565 DOI: 10.1093/bioinformatics/btac575] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 06/28/2022] [Accepted: 08/22/2022] [Indexed: 12/24/2022] Open
Abstract
MOTIVATION Three-dimensional (3D) genome organization is of vital importance in gene regulation and disease mechanisms. Previous studies have shown that CTCF-mediated chromatin loops are crucial to studying the 3D structure of cells. Although various experimental techniques have been developed to detect chromatin loops, they have been found to be time-consuming and costly. Nowadays, various sequence-based computational methods can capture significant features of 3D genome organization and help predict chromatin loops. However, these methods have low performance and poor generalization ability in predicting chromatin loops. RESULTS Here, we propose a novel deep learning model, called CLNN-loop, to predict chromatin loops in different cell lines and CTCF-binding sites (CBS) pair types by fusing multiple sequence-based features. The analysis of a series of examinations based on the datasets in the previous study shows that CLNN-loop has satisfactory performance and is superior to the existing methods in terms of predicting chromatin loops. In addition, we apply the SHAP framework to interpret the predictions of different models, and find that CTCF motif and sequence conservation are important signs of chromatin loops in different cell lines and CBS pair types. AVAILABILITY AND IMPLEMENTATION The source code of CLNN-loop is freely available at https://github.com/HaoWuLab-Bioinformatics/CLNN-loop and the webserver of CLNN-loop is freely available at http://hwclnn.sdu.edu.cn. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Pengyu Zhang
- School of Software, Shandong University, Jinan, Shandong 250101, China.,College of Information Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yingfu Wu
- College of Information Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Haoru Zhou
- College of Information Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Bing Zhou
- College of Information Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Hongming Zhang
- College of Information Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Hao Wu
- School of Software, Shandong University, Jinan, Shandong 250101, China
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10
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Sharma SP, Peterson T. Complex chromosomal rearrangements induced by transposons in maize. Genetics 2022; 223:6702042. [PMID: 36111993 PMCID: PMC9910405 DOI: 10.1093/genetics/iyac124] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
Eukaryotic genomes are large and complex, and gene expression can be affected by multiple regulatory elements and their positions within the dynamic chromatin architecture. Transposable elements are known to play important roles in genome evolution, yet questions remain as to how transposable elements alter genome structure and affect gene expression. Previous studies have shown that genome rearrangements can be induced by Reversed Ends Transposition involving termini of Activator and related transposable elements in maize and other plants. Here, we show that complex alleles can be formed by the rapid and progressive accumulation of Activator-induced duplications and rearrangements. The p1 gene enhancer in maize can induce ectopic expression of the nearby p2 gene in pericarp tissue when placed near it via different structural rearrangements. By screening for p2 expression, we identified and studied 5 cases in which multiple sequential transposition events occurred and increased the p1 enhancer copy number. We see active p2 expression due to multiple copies of the p1 enhancer present near p2 in all 5 cases. The p1 enhancer effects are confirmed by the observation that loss of p2 expression is correlated with transposition-induced excision of the p1 enhancers. We also performed a targeted Chromosome Conformation Capture experiment to test the physical interaction between the p1 enhancer and p2 promoter region. Together, our results show that transposon-induced rearrangements can accumulate rapidly and progressively increase genetic variation important for genomic evolution.
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Affiliation(s)
- Sharu Paul Sharma
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
| | - Thomas Peterson
- Corresponding author: Department of Genetics, Development and Cell Biology, Iowa State University, 2258 Molecular Biology, Iowa State University, Ames, IA 50011, USA.
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11
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Korolev N, Zinchenko A, Soman A, Chen Q, Wong SY, Berezhnoy NV, Basak R, van der Maarel JRC, van Noort J, Nordenskiöld L. Reconstituted TAD-size chromatin fibers feature heterogeneous nucleosome clusters. Sci Rep 2022; 12:15558. [PMID: 36114220 PMCID: PMC9481575 DOI: 10.1038/s41598-022-19471-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 08/30/2022] [Indexed: 11/14/2022] Open
Abstract
Large topologically associated domains (TADs) contain irregularly spaced nucleosome clutches, and interactions between such clutches are thought to aid the compaction of these domains. Here, we reconstituted TAD-sized chromatin fibers containing hundreds of nucleosomes on native source human and lambda-phage DNA and compared their mechanical properties at the single-molecule level with shorter ‘601’ arrays with various nucleosome repeat lengths. Fluorescent imaging showed increased compaction upon saturation of the DNA with histones and increasing magnesium concentration. Nucleosome clusters and their structural fluctuations were visualized in confined nanochannels. Force spectroscopy revealed not only similar mechanical properties of the TAD-sized fibers as shorter fibers but also large rupture events, consistent with breaking the interactions between distant clutches of nucleosomes. Though the arrays of native human DNA, lambda-phage and ‘601’ DNA featured minor differences in reconstitution yield and nucleosome stability, the fibers’ global structural and mechanical properties were similar, including the interactions between nucleosome clutches. These single-molecule experiments quantify the mechanical forces that stabilize large TAD-sized chromatin domains consisting of disordered, dynamically interacting nucleosome clutches and their effect on the condensation of large chromatin domains.
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12
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Dossin F, Heard E. The Molecular and Nuclear Dynamics of X-Chromosome Inactivation. Cold Spring Harb Perspect Biol 2022; 14:a040196. [PMID: 34312245 PMCID: PMC9121902 DOI: 10.1101/cshperspect.a040196] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In female eutherian mammals, dosage compensation of X-linked gene expression is achieved during development through transcriptional silencing of one of the two X chromosomes. Following X chromosome inactivation (XCI), the inactive X chromosome remains faithfully silenced throughout somatic cell divisions. XCI is dependent on Xist, a long noncoding RNA that coats and silences the X chromosome from which it is transcribed. Xist coating triggers a cascade of chromosome-wide changes occurring at the levels of transcription, chromatin composition, chromosome structure, and spatial organization within the nucleus. XCI has emerged as a paradigm for the study of such crucial nuclear processes and the dissection of their functional interplay. In the past decade, the advent of tools to characterize and perturb these processes have provided an unprecedented understanding into their roles during XCI. The mechanisms orchestrating the initiation of XCI as well as its maintenance are thus being unraveled, although many questions still remain. Here, we introduce key aspects of the XCI process and review the recent discoveries about its molecular basis.
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Affiliation(s)
- François Dossin
- European Molecular Biology Laboratory, Director's Unit, 69117 Heidelberg, Germany
| | - Edith Heard
- European Molecular Biology Laboratory, Director's Unit, 69117 Heidelberg, Germany
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13
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Segueni J, Noordermeer D. CTCF: a misguided jack-of-all-trades in cancer cells. Comput Struct Biotechnol J 2022; 20:2685-2698. [PMID: 35685367 PMCID: PMC9166472 DOI: 10.1016/j.csbj.2022.05.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/20/2022] [Accepted: 05/21/2022] [Indexed: 12/13/2022] Open
Abstract
The emergence and progression of cancers is accompanied by a dysregulation of transcriptional programs. The three-dimensional (3D) organization of the human genome has emerged as an important multi-level mediator of gene transcription and regulation. In cancer cells, this organization can be restructured, providing a framework for the deregulation of gene activity. The CTCF protein, initially identified as the product from a tumor suppressor gene, is a jack-of-all-trades for the formation of 3D genome organization in normal cells. Here, we summarize how CTCF is involved in the multi-level organization of the human genome and we discuss emerging insights into how perturbed CTCF function and DNA binding causes the activation of oncogenes in cancer cells, mostly through a process of enhancer hijacking. Moreover, we highlight non-canonical functions of CTCF that can be relevant for the emergence of cancers as well. Finally, we provide guidelines for the computational identification of perturbed CTCF binding and reorganized 3D genome structure in cancer cells.
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14
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Sefer E. ProbC: joint modeling of epigenome and transcriptome effects in 3D genome. BMC Genomics 2022; 23:287. [PMID: 35397520 PMCID: PMC8994916 DOI: 10.1186/s12864-022-08498-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 03/23/2022] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Hi-C and its high nucleosome resolution variant Micro-C provide a window into the spatial packing of a genome in 3D within the cell. Even though both techniques do not directly depend on the binding of specific antibodies, previous work has revealed enriched interactions and domain structures around multiple chromatin marks; epigenetic modifications and transcription factor binding sites. However, the joint impact of chromatin marks in Hi-C and Micro-C interactions have not been globally characterized, which limits our understanding of 3D genome characteristics. An emerging question is whether it is possible to deduce 3D genome characteristics and interactions by integrative analysis of multiple chromatin marks and associate interactions to functionality of the interacting loci. RESULT We come up with a probabilistic method PROBC to decompose Hi-C and Micro-C interactions by known chromatin marks. PROBC is based on convex likelihood optimization, which can directly take into account both interaction existence and nonexistence. Through PROBC, we discover histone modifications (H3K27ac, H3K9me3, H3K4me3, H3K4me1) and CTCF as particularly predictive of Hi-C and Micro-C contacts across cell types and species. Moreover, histone modifications are more effective than transcription factor binding sites in explaining the genome's 3D shape through these interactions. PROBC can successfully predict Hi-C and Micro-C interactions in given species, while it is trained on different cell types or species. For instance, it can predict missing nucleosome resolution Micro-C interactions in human ES cells trained on mouse ES cells only from these 5 chromatin marks with above 0.75 AUC. Additionally, PROBC outperforms the existing methods in predicting interactions across almost all chromosomes. CONCLUSION Via our proposed method, we optimally decompose Hi-C interactions in terms of these chromatin marks at genome and chromosome levels. We find a subset of histone modifications and transcription factor binding sites to be predictive of both Hi-C and Micro-C interactions and TADs across human, mouse, and different cell types. Through learned models, we can predict interactions on species just from chromatin marks for which Hi-C data may be limited.
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Affiliation(s)
- Emre Sefer
- Department of Computer Science, Ozyegin University, Istanbul, Turkey.
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15
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Wu H, Zhang P, Ai Z, Wei L, Zhang H, Yang F, Cui L. StackTADB: a stacking-based ensemble learning model for predicting the boundaries of topologically associating domains (TADs) accurately in fruit flies. Brief Bioinform 2022; 23:6531900. [PMID: 35181793 DOI: 10.1093/bib/bbac023] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/29/2021] [Accepted: 01/17/2022] [Indexed: 11/13/2022] Open
Abstract
Chromosome is composed of many distinct chromatin domains, referred to variably as topological domains or topologically associating domains (TADs). The domains are stable across different cell types and highly conserved across species, thus these chromatin domains have been considered as the basic units of chromosome folding and regarded as an important secondary structure in chromosome organization. However, the identification of TAD boundaries is still a great challenge due to the high cost and low resolution of Hi-C data or experiments. In this study, we propose a novel ensemble learning framework, termed as StackTADB, for predicting the boundaries of TADs. StackTADB integrates four base classifiers including Random Forest, Logistic Regression, K-NearestNeighbor and Support Vector Machine. From the analysis of a series of examinations on the data set in the previous study, it is concluded that StackTADB has optimal performance in six metrics, AUC, Accuracy, MCC, Precision, Recall and F1 score, and it is superior to the existing methods. In addition, the comparison of the performance of multiple features shows that Kmers-based features play an essential role in predicting TADs boundaries of fruit flies, and we also apply the SHapley Additive exPlanations (SHAP) framework to interpret the predictions of StackTADB to identify the reason why Kmers-based features are vital. The experimental results show that the subsequences matching the BEAF-32 motif play a crucial role in predicting the boundaries of TADs. The source code is freely available at https://github.com/HaoWuLab-Bioinformatics/StackTADB and the webserver of StackTADB is freely available at http://hwtad.sdu.edu.cn:8002/StackTADB.
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Affiliation(s)
- Hao Wu
- College of Information Engineering, Northwest A&F University, Yangling, 712100, Shaanxi, China.,School of Software, Shandong University, Jinan, 250101, Shandong, China
| | - Pengyu Zhang
- College of Information Engineering, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Zhaoheng Ai
- College of Information Engineering, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Leyi Wei
- School of Software, Shandong University, Jinan, 250101, Shandong, China
| | - Hongming Zhang
- College of Information Engineering, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Fan Yang
- Department of Biostatistics, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250100, Shandong, China.,Institute for Medical Dataology, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, 250100, Shandong, China
| | - Lizhen Cui
- School of Software, Shandong University, Jinan, 250101, Shandong, China
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16
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Meyer BJ. Mechanisms of sex determination and X-chromosome dosage compensation. Genetics 2022; 220:6498458. [PMID: 35100381 PMCID: PMC8825453 DOI: 10.1093/genetics/iyab197] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 10/25/2021] [Indexed: 12/03/2022] Open
Abstract
Abnormalities in chromosome number have the potential to disrupt the balance of gene expression and thereby decrease organismal fitness and viability. Such abnormalities occur in most solid tumors and also cause severe developmental defects and spontaneous abortions. In contrast to the imbalances in chromosome dose that cause pathologies, the difference in X-chromosome dose used to determine sexual fate across diverse species is well tolerated. Dosage compensation mechanisms have evolved in such species to balance X-chromosome gene expression between the sexes, allowing them to tolerate the difference in X-chromosome dose. This review analyzes the chromosome counting mechanism that tallies X-chromosome number to determine sex (XO male and XX hermaphrodite) in the nematode Caenorhabditis elegans and the associated dosage compensation mechanism that balances X-chromosome gene expression between the sexes. Dissecting the molecular mechanisms underlying X-chromosome counting has revealed how small quantitative differences in intracellular signals can be translated into dramatically different fates. Dissecting the process of X-chromosome dosage compensation has revealed the interplay between chromatin modification and chromosome structure in regulating gene expression over vast chromosomal territories.
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Affiliation(s)
- Barbara J Meyer
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720-3204, USA
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17
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Socha M, Sowińska-Seidler A, Melo US, Kragesteen BK, Franke M, Heinrich V, Schöpflin R, Nagel I, Gruchy N, Mundlos S, Sreenivasan VK, López C, Vingron M, Bukowska-Olech E, Spielmann M, Jamsheer A. Position effects at the FGF8 locus are associated with femoral hypoplasia. Am J Hum Genet 2021; 108:1725-1734. [PMID: 34433009 DOI: 10.1016/j.ajhg.2021.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 08/04/2021] [Indexed: 10/20/2022] Open
Abstract
Copy-number variations (CNVs) are a common cause of congenital limb malformations and are interpreted primarily on the basis of their effect on gene dosage. However, recent studies show that CNVs also influence the 3D genome chromatin organization. The functional interpretation of whether a phenotype is the result of gene dosage or a regulatory position effect remains challenging. Here, we report on two unrelated families with individuals affected by bilateral hypoplasia of the femoral bones, both harboring de novo duplications on chromosome 10q24.32. The ∼0.5 Mb duplications include FGF8, a key regulator of limb development and several limb enhancer elements. To functionally characterize these variants, we analyzed the local chromatin architecture in the affected individuals' cells and re-engineered the duplications in mice by using CRISPR-Cas9 genome editing. We found that the duplications were associated with ectopic chromatin contacts and increased FGF8 expression. Transgenic mice carrying the heterozygous tandem duplication including Fgf8 exhibited proximal shortening of the limbs, resembling the human phenotype. To evaluate whether the phenotype was a result of gene dosage, we generated another transgenic mice line, carrying the duplication on one allele and a concurrent Fgf8 deletion on the other allele, as a control. Surprisingly, the same malformations were observed. Capture Hi-C experiments revealed ectopic interaction with the duplicated region and Fgf8, indicating a position effect. In summary, we show that duplications at the FGF8 locus are associated with femoral hypoplasia and that the phenotype is most likely the result of position effects altering FGF8 expression rather than gene dosage effects.
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18
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Liu N, Low WY, Alinejad-Rokny H, Pederson S, Sadlon T, Barry S, Breen J. Seeing the forest through the trees: prioritising potentially functional interactions from Hi-C. Epigenetics Chromatin 2021; 14:41. [PMID: 34454581 PMCID: PMC8399707 DOI: 10.1186/s13072-021-00417-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 08/19/2021] [Indexed: 11/30/2022] Open
Abstract
Eukaryotic genomes are highly organised within the nucleus of a cell, allowing widely dispersed regulatory elements such as enhancers to interact with gene promoters through physical contacts in three-dimensional space. Recent chromosome conformation capture methodologies such as Hi-C have enabled the analysis of interacting regions of the genome providing a valuable insight into the three-dimensional organisation of the chromatin in the nucleus, including chromosome compartmentalisation and gene expression. Complicating the analysis of Hi-C data, however, is the massive amount of identified interactions, many of which do not directly drive gene function, thus hindering the identification of potentially biologically functional 3D interactions. In this review, we collate and examine the downstream analysis of Hi-C data with particular focus on methods that prioritise potentially functional interactions. We classify three groups of approaches: structural-based discovery methods, e.g. A/B compartments and topologically associated domains, detection of statistically significant chromatin interactions, and the use of epigenomic data integration to narrow down useful interaction information. Careful use of these three approaches is crucial to successfully identifying potentially functional interactions within the genome.
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Affiliation(s)
- Ning Liu
- Computational & Systems Biology, Precision Medicine Theme, South Australian Health & Medical Research Institute, SA, 5000, Adelaide, Australia
- Robinson Research Institute, University of Adelaide, SA, 5005, Adelaide, Australia
- Adelaide Medical School, University of Adelaide, SA, 5005, Adelaide, Australia
| | - Wai Yee Low
- The Davies Research Centre, School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, SA, 5371, Australia
| | - Hamid Alinejad-Rokny
- BioMedical Machine Learning Lab, The Graduate School of Biomedical Engineering, The University of New South Wales, NSW, 2052, Sydney, Australia
- Core Member of UNSW Data Science Hub, The University of New South Wales, 2052, Sydney, Australia
| | - Stephen Pederson
- Adelaide Medical School, University of Adelaide, SA, 5005, Adelaide, Australia
- Dame Roma Mitchell Cancer Research Laboratories (DRMCRL), Adelaide Medical School, University of Adelaide, SA, 5005, Adelaide, Australia
| | - Timothy Sadlon
- Robinson Research Institute, University of Adelaide, SA, 5005, Adelaide, Australia
- Women's & Children's Health Network, SA, 5006, North Adelaide, Australia
| | - Simon Barry
- Robinson Research Institute, University of Adelaide, SA, 5005, Adelaide, Australia
- Core Member of UNSW Data Science Hub, The University of New South Wales, 2052, Sydney, Australia
- Women's & Children's Health Network, SA, 5006, North Adelaide, Australia
| | - James Breen
- Computational & Systems Biology, Precision Medicine Theme, South Australian Health & Medical Research Institute, SA, 5000, Adelaide, Australia.
- Robinson Research Institute, University of Adelaide, SA, 5005, Adelaide, Australia.
- Adelaide Medical School, University of Adelaide, SA, 5005, Adelaide, Australia.
- South Australian Genomics Centre (SAGC), South Australian Health & Medical Research Institute (SAHMRI), SA, 5000, Adelaide, Australia.
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19
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Wong X, Cutler JA, Hoskins VE, Gordon M, Madugundu AK, Pandey A, Reddy KL. Mapping the micro-proteome of the nuclear lamina and lamina-associated domains. Life Sci Alliance 2021; 4:e202000774. [PMID: 33758005 PMCID: PMC8008952 DOI: 10.26508/lsa.202000774] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 01/13/2023] Open
Abstract
The nuclear lamina is a proteinaceous network of filaments that provide both structural and gene regulatory functions by tethering proteins and large domains of DNA, the so-called lamina-associated domains (LADs), to the periphery of the nucleus. LADs are a large fraction of the mammalian genome that are repressed, in part, by their association to the nuclear periphery. The genesis and maintenance of LADs is poorly understood as are the proteins that participate in these functions. In an effort to identify proteins that reside at the nuclear periphery and potentially interact with LADs, we have taken a two-pronged approach. First, we have undertaken an interactome analysis of the inner nuclear membrane bound LAP2β to further characterize the nuclear lamina proteome. To accomplish this, we have leveraged the BioID system, which previously has been successfully used to characterize the nuclear lamina proteome. Second, we have established a system to identify proteins that bind to LADs by developing a chromatin-directed BioID system. We combined the BioID system with the m6A-tracer system which binds to LADs in live cells to identify both LAD proximal and nuclear lamina proteins. In combining these datasets, we have further characterized the protein network at the nuclear lamina, identified putative LAD proximal proteins and found several proteins that appear to interface with both micro-proteomes. Importantly, several proteins essential for LAD function, including heterochromatin regulating proteins related to H3K9 methylation, were identified in this study.
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Affiliation(s)
- Xianrong Wong
- Department of Biological Chemistry, Johns Hopkins University of Medicine, Baltimore, MD, USA
- Center for Epigenetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Laboratory of Developmental and Regenerative Biology, Institute of Medical Biology, Agency for Science, Technology and Research (A∗STAR), Immunos, Singapore
| | - Jevon A Cutler
- Department of Biological Chemistry, Johns Hopkins University of Medicine, Baltimore, MD, USA
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Center for Epigenetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Victoria E Hoskins
- Department of Biological Chemistry, Johns Hopkins University of Medicine, Baltimore, MD, USA
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Center for Epigenetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Molly Gordon
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Anil K Madugundu
- Department of Biological Chemistry, Johns Hopkins University of Medicine, Baltimore, MD, USA
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Center for Molecular Medicine, National Institute of Mental Health and Neurosciences (NIMHNS), Bangalore, India
- Institute of Bioinformatics, International Technology Park, Bangalore, India
| | - Akhilesh Pandey
- Department of Biological Chemistry, Johns Hopkins University of Medicine, Baltimore, MD, USA
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Center for Molecular Medicine, National Institute of Mental Health and Neurosciences (NIMHNS), Bangalore, India
- Institute of Bioinformatics, International Technology Park, Bangalore, India
- Manipal Academy of Higher Education (MAHE), Manipal, India
- Departments of Pathology and Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Karen L Reddy
- Department of Biological Chemistry, Johns Hopkins University of Medicine, Baltimore, MD, USA
- Center for Epigenetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Sidney Kimmel Cancer Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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20
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Paik S, Maule F, Gallo M. Dysregulation of chromatin organization in pediatric and adult brain tumors: oncoepigenomic contributions to tumorigenesis and cancer stem cell properties. Genome 2020; 64:326-336. [PMID: 33075237 DOI: 10.1139/gen-2020-0097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The three-dimensional (3D) organization of the genome is a crucial enabler of cell fate, identity, and function. In this review, we will focus on the emerging role of altered 3D genome organization in the etiology of disease, with a special emphasis on brain cancers. We discuss how different genetic alterations can converge to disrupt the epigenome in childhood and adult brain tumors, by causing aberrant DNA methylation and by affecting the amounts and genomic distribution of histone post-translational modifications. We also highlight examples that illustrate how epigenomic alterations have the potential to affect 3D genome architecture in brain tumors. Finally, we will propose the concept of "epigenomic erosion" to explain the transition from stem-like cells to differentiated cells in hierarchically organized brain cancers.
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Affiliation(s)
- Seungil Paik
- Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Francesca Maule
- Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Marco Gallo
- Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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21
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Sánchez-Gaya V, Mariner-Faulí M, Rada-Iglesias A. Rare or Overlooked? Structural Disruption of Regulatory Domains in Human Neurocristopathies. Front Genet 2020; 11:688. [PMID: 32765580 PMCID: PMC7379850 DOI: 10.3389/fgene.2020.00688] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 06/04/2020] [Indexed: 12/15/2022] Open
Abstract
In the last few years, the role of non-coding regulatory elements and their involvement in human disease have received great attention. Among the non-coding regulatory sequences, enhancers are particularly important for the proper establishment of cell type-specific gene-expression programs. Furthermore, the disruption of enhancers can lead to human disease through two main mechanisms: (i) Mutations or copy number variants can directly alter the enhancer sequences and thereby affect expression of their target genes; (ii) structural variants can provoke changes in 3-D chromatin organization that alter neither the enhancers nor their target genes, but rather the physical communication between them. In this review, these pathomechanisms are mostly discussed in the context of neurocristopathies, congenital disorders caused by defects that occur during neural crest development. We highlight why, due to its contribution to multiple tissues and organs, the neural crest represents an important, yet understudied, cell type involved in multiple congenital disorders. Moreover, we discuss currently available resources and experimental models for the study of human neurocristopathies. Last, we provide some practical guidelines that can be followed when investigating human neurocristopathies caused by structural variants. Importantly, these guidelines can be useful not only to uncover the etiology of human neurocristopathies, but also of other human congenital disorders in which enhancer disruption is involved.
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Affiliation(s)
- Víctor Sánchez-Gaya
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas-University of Cantabria-Sociedad para el Desarrollo de Cantabria, Santander, Spain
| | - Maria Mariner-Faulí
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas-University of Cantabria-Sociedad para el Desarrollo de Cantabria, Santander, Spain
| | - Alvaro Rada-Iglesias
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas-University of Cantabria-Sociedad para el Desarrollo de Cantabria, Santander, Spain
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- Cluster of Excellence Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
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22
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Kumari K, Duenweg B, Padinhateeri R, Prakash JR. Computing 3D Chromatin Configurations from Contact Probability Maps by Inverse Brownian Dynamics. Biophys J 2020; 118:2193-2208. [PMID: 32389215 PMCID: PMC7203009 DOI: 10.1016/j.bpj.2020.02.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 02/04/2020] [Accepted: 02/11/2020] [Indexed: 01/20/2023] Open
Abstract
The three-dimensional (3D) organization of chromatin, on the length scale of a few genes, is crucial in determining the functional state-accessibility and amount of gene expression-of the chromatin. Recent advances in chromosome conformation capture experiments provide partial information on the chromatin organization in a cell population, namely the contact count between any segment pairs, but not on the interaction strength that leads to these contact counts. However, given the contact matrix, determining the complete 3D organization of the whole chromatin polymer is an inverse problem. In this work, a novel inverse Brownian dynamics method based on a coarse-grained bead-spring chain model has been proposed to compute the optimal interaction strengths between different segments of chromatin such that the experimentally measured contact count probability constraints are satisfied. Applying this method to the α-globin gene locus in two different cell types, we predict the 3D organizations corresponding to active and repressed states of chromatin at the locus. We show that the average distance between any two segments of the region has a broad distribution and cannot be computed as a simple inverse relation based on the contact probability alone. The results presented for multiple normalization methods suggest that all measurable quantities may crucially depend on the nature of normalization. We argue that by experimentally measuring predicted quantities, one may infer the appropriate form of normalization.
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Affiliation(s)
- Kiran Kumari
- Department of Chemical Engineering, Monash University, Melbourne, Victoria, Australia; Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India; IITB-Monash Research Academy, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
| | - Burkhard Duenweg
- Department of Chemical Engineering, Monash University, Melbourne, Victoria, Australia; Max Planck Institute for Polymer Research, Mainz, Germany
| | - Ranjith Padinhateeri
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India.
| | - J Ravi Prakash
- Department of Chemical Engineering, Monash University, Melbourne, Victoria, Australia.
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23
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Wang F, Hao Y, Li Q, Li J, Zhang H, Zhang X, Wang L, Bustamante C, Fan C. Programming PAM antennae for efficient CRISPR-Cas9 DNA editing. SCIENCE ADVANCES 2020; 6:eaay9948. [PMID: 32494703 PMCID: PMC7209990 DOI: 10.1126/sciadv.aay9948] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Accepted: 02/19/2020] [Indexed: 05/30/2023]
Abstract
Bacterial CRISPR-Cas9 nucleases have been repurposed as powerful genome editing tools. Whereas engineering guide RNAs or Cas nucleases have proven to improve the efficiency of CRISPR editing, modulation of protospacer-adjacent motif (PAM), indispensable for CRISPR, has been less explored. Here, we develop a DNA origami-based platform to program a PAM antenna microenvironment and address its performance at the single-molecule level with submolecular resolution. To mimic spatially controlled in vivo PAM distribution as may occur in chromatin, we investigate the effect of PAM antennae surrounding target DNA. We find that PAM antennae effectively sensitize the DNA cleavage by recruiting Cas9 molecules. Super-resolution tracking of single single-guide RNA/Cas9s reveals localized translocation of Cas9 among spatially proximal PAMs. We find that the introduction of the PAM antennae effectively modulates the microenvironment for enhanced target cleavage (up to ~50%). These results provide insight into factors that promote more efficient genome editing.
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Affiliation(s)
- Fei Wang
- Joint Research Center for Precision Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital South Campus, Southern Medical University Affiliated Fengxian Hospital, Shanghai 201499, China
- School of Chemistry and Chemical Engineering, Frontiers Science Center of Transformative Molecules, and Institute of Molecular Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yaya Hao
- School of Chemistry and Chemical Engineering, Frontiers Science Center of Transformative Molecules, and Institute of Molecular Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qian Li
- School of Chemistry and Chemical Engineering, Frontiers Science Center of Transformative Molecules, and Institute of Molecular Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jiang Li
- CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- Shanghai Synchrotron Radiation Facility, Zhangjiang Laboratory, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Honglu Zhang
- Department of Chemistry, Institute for Quantitative Biosciences (QB3), Department of Physics, Department of Molecular and Cell Biology, Kavli Energy Nanosciences Institute at Berkeley, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Xueli Zhang
- Joint Research Center for Precision Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital South Campus, Southern Medical University Affiliated Fengxian Hospital, Shanghai 201499, China
| | - Lihua Wang
- CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China
| | - Carlos Bustamante
- Department of Chemistry, Institute for Quantitative Biosciences (QB3), Department of Physics, Department of Molecular and Cell Biology, Kavli Energy Nanosciences Institute at Berkeley, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Chunhai Fan
- School of Chemistry and Chemical Engineering, Frontiers Science Center of Transformative Molecules, and Institute of Molecular Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
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24
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Tan X, Ravasio A, Ong HT, Wu J, Hew CL. White spot syndrome viral protein VP9 alters the cellular higher-order chromatin structure. FASEB Bioadv 2020; 2:264-279. [PMID: 32259052 PMCID: PMC7133739 DOI: 10.1096/fba.2019-00086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 10/26/2019] [Accepted: 02/05/2020] [Indexed: 12/21/2022] Open
Abstract
Viral protein 9 (VP9) is a non-structural protein of white spot syndrome virus (WSSV) highly expressed during the early stage of infection. The crystal structure of VP9 suggests that the polymers of VP9 dimers resemble a DNA mimic, but its function remains elusive. In this study, we demonstrated that VP9 impedes histones binding to DNA via single-molecule manipulation. We established VP9 expression in HeLa cells due to the lack of a WSSV-susceptible cell line, and observed abundant VP9 in the nucleus, which mirrors its distribution in the hemocytes of WSSV-infected shrimp. VP9 expression increased the dynamics and rotational mobility of histones in stable H3-GFP HeLa cells as revealed by fluorescent recovery after photobleaching and fluorescence anisotropy imaging, which suggested a loosened compaction of chromatin structure. Successive salt fractionation showed that a prominent population of histones was solubilized in high salt concentrations, which implies alterations of bulk chromatin structure. Southern blotting identified that VP9 alters juxtacentromeric chromatin structures to be more accessible to micrococcal nuclease digestion. RNA microarray revealed that VP9 expression also leads to significant changes of cellular gene expression. Our findings provide evidence that VP9 alters the cellular higher-order chromatin structure, uncovering a potential strategy adopted by WSSV to facilitate its replication.
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Affiliation(s)
- Xi Tan
- Mechanobiology InstituteNational University of SingaporeSingaporeSingapore
- Present address:
School of Basic Medical SciencesGuizhou University of Traditional Chinese MedicineGuiyangGuizhou ProvinceChina
| | - Andrea Ravasio
- Institute for Biological and Medical EngineeringSchools of Engineering, Medicine and Biological SciencesPontificia Universidad Católica de ChileSantiago de ChileChile
| | - Hui T. Ong
- Mechanobiology InstituteNational University of SingaporeSingaporeSingapore
| | - Jinlu Wu
- Department of Biological SciencesNational University of SingaporeSingaporeSingapore
| | - Choy L. Hew
- Mechanobiology InstituteNational University of SingaporeSingaporeSingapore
- Department of Biological SciencesNational University of SingaporeSingaporeSingapore
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Bansal P, Kondaveeti Y, Pinter SF. Forged by DXZ4, FIRRE, and ICCE: How Tandem Repeats Shape the Active and Inactive X Chromosome. Front Cell Dev Biol 2020; 7:328. [PMID: 32076600 PMCID: PMC6985041 DOI: 10.3389/fcell.2019.00328] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 11/26/2019] [Indexed: 12/11/2022] Open
Abstract
Recent efforts in mapping spatial genome organization have revealed three evocative and conserved structural features of the inactive X in female mammals. First, the chromosomal conformation of the inactive X reveals a loss of topologically associated domains (TADs) present on the active X. Second, the macrosatellite DXZ4 emerges as a singular boundary that suppresses physical interactions between two large TAD-depleted "megadomains." Third, DXZ4 reaches across several megabases to form "superloops" with two other X-linked tandem repeats, FIRRE and ICCE, which also loop to each other. Although all three structural features are conserved across rodents and primates, deletion of mouse and human orthologs of DXZ4 and FIRRE from the inactive X have revealed limited impact on X chromosome inactivation (XCI) and escape in vitro. In contrast, loss of Xist or SMCHD1 have been shown to impair TAD erasure and gene silencing on the inactive X. In this perspective, we summarize these results in the context of new research describing disruption of X-linked tandem repeats in vivo, and discuss their possible molecular roles through the lens of evolutionary conservation and clinical genetics. As a null hypothesis, we consider whether the conservation of some structural features on the inactive X may reflect selection for X-linked tandem repeats on account of necessary cis- and trans-regulatory roles they may play on the active X, rather than the inactive X. Additional hypotheses invoking a role for X-linked tandem repeats on X reactivation, for example in the germline or totipotency, remain to be assessed in multiple developmental models spanning mammalian evolution.
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Affiliation(s)
- Prakhar Bansal
- Department of Genetics and Genome Sciences, School of Medicine, UCONN Health, University of Connecticut, Farmington, CT, United States
- Institute for Systems Genomics, University of Connecticut, Farmington, CT, United States
| | - Yuvabharath Kondaveeti
- Department of Genetics and Genome Sciences, School of Medicine, UCONN Health, University of Connecticut, Farmington, CT, United States
- Institute for Systems Genomics, University of Connecticut, Farmington, CT, United States
| | - Stefan F. Pinter
- Department of Genetics and Genome Sciences, School of Medicine, UCONN Health, University of Connecticut, Farmington, CT, United States
- Institute for Systems Genomics, University of Connecticut, Farmington, CT, United States
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26
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Kim D, Park Y. Molecular mechanism for the multiple sclerosis risk variant rs17594362. Hum Mol Genet 2019; 28:3600-3609. [PMID: 31509193 PMCID: PMC6927461 DOI: 10.1093/hmg/ddz216] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/31/2019] [Accepted: 09/02/2019] [Indexed: 12/12/2022] Open
Abstract
Multiple sclerosis (MS) is known as an autoimmune demyelinating disease of the central nervous system. However, its cause remains elusive. Given previous studies suggesting that dysfunctional oligodendrocytes (OLs) may trigger MS, we tested whether single nucleotide polymorphisms (SNPs) associated with MS affect OL enhancers, potentially increasing MS risk by dysregulating gene expression of OL lineage cells. We found that two closely spaced OL enhancers, which are 3 Kb apart on chromosome 13, overlap two MS SNPs in linkage disequilibrium-rs17594362 and rs12429256. Our data revealed that the two MS SNPs significantly up-regulate the associated OL enhancers, which we have named as Rgcc-E1 and Rgcc-E2. Analysis of Hi-C data and epigenome editing experiments shows that Rgcc is the primary target of Rgcc-E1 and Rgcc-E2. Collectively, these data indicate that the molecular mechanism of rs17594362 and rs12429256 is to induce Rgcc overexpression by potentiating the enhancer activity of Rgcc-E1 and Rgcc-E2. Importantly, the dosage of the rs17594362/rs12429256 risk allele is positively correlated with the expression level of Rgcc in the human population, confirming our molecular mechanism. Our study also suggests that Rgcc overexpression in OL lineage cells may be a key cellular mechanism of rs17594362 and rs12429256 for MS.
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Affiliation(s)
- Dongkyeong Kim
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, Hunter James Kelly Research Institute, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Yungki Park
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, Hunter James Kelly Research Institute, State University of New York at Buffalo, Buffalo, NY 14203, USA
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27
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Razin SV, Ulianov SV, Gavrilov AA. 3D Genomics. Mol Biol 2019; 53:802-812. [DOI: 10.1134/s0026893319060153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/01/2019] [Accepted: 06/03/2019] [Indexed: 08/30/2023]
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28
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Kim D, An H, Shearer RS, Sharif M, Fan C, Choi JO, Ryu S, Park Y. A principled strategy for mapping enhancers to genes. Sci Rep 2019; 9:11043. [PMID: 31363138 PMCID: PMC6667464 DOI: 10.1038/s41598-019-47521-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/18/2019] [Indexed: 12/18/2022] Open
Abstract
Mapping enhancers to genes is a fundamental goal of modern biology. We have developed an innovative strategy that maps enhancers to genes in a principled manner. We illustrate its power by applying it to Myrf. Despite being a master regulator of oligodendrocytes, oligodendrocyte enhancers governing Myrf expression remain elusive. Since chromatin conformation capture studies have shown that a gene and its enhancer tend to be found in the same topologically associating domain (TAD), we started with the delineation of the Myrf TAD. A genome-wide map of putative oligodendrocyte enhancers uncovered 6 putative oligodendrocyte enhancers in the Myrf TAD, narrowing down the search space for Myrf enhancers from the entire genome to 6 loci in a principled manner. Epigenome editing experiments revealed that two of them govern Myrf expression for oligodendrocyte development. Our new method is simple, principled, and powerful, providing a systematic way to find enhancers that regulate the expression of a gene of interest. Since it can be applied to most cell types, it would greatly facilitate our effort to unravel transcriptional regulatory networks of diverse cell types.
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Affiliation(s)
- Dongkyeong Kim
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Hongjoo An
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Randall S Shearer
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Mohamed Sharif
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Chuandong Fan
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Jin-Ok Choi
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Sun Ryu
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Yungki Park
- Hunter James Kelly Research Institute, Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA.
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Abstract
Structural and quantitative chromosomal rearrangements, collectively referred to as structural variation (SV), contribute to a large extent to the genetic diversity of the human genome and thus are of high relevance for cancer genetics, rare diseases and evolutionary genetics. Recent studies have shown that SVs can not only affect gene dosage but also modulate basic mechanisms of gene regulation. SVs can alter the copy number of regulatory elements or modify the 3D genome by disrupting higher-order chromatin organization such as topologically associating domains. As a result of these position effects, SVs can influence the expression of genes distant from the SV breakpoints, thereby causing disease. The impact of SVs on the 3D genome and on gene expression regulation has to be considered when interpreting the pathogenic potential of these variant types.
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Affiliation(s)
- Malte Spielmann
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Darío G Lupiáñez
- Epigenetics and Sex Development Group, Berlin Institute for Medical Systems Biology, Max-Delbrück Center for Molecular Medicine, Berlin-Buch, Germany
| | - Stefan Mundlos
- Max Planck Institute for Molecular Genetics, RG Development & Disease, Berlin, Germany. .,Institute for Medical and Human Genetics, Charité Universitätsmedizin Berlin, Berlin, Germany.
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30
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van Heyningen V. Genome sequencing-the dawn of a game-changing era. Heredity (Edinb) 2019; 123:58-66. [PMID: 31189904 PMCID: PMC6781137 DOI: 10.1038/s41437-019-0226-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 04/16/2019] [Indexed: 01/14/2023] Open
Abstract
The development of genome sequencing technologies has revolutionized the biological sciences in ways which could not have been imagined at the time. This article sets out to document the dawning of the age of genomics and to consider the impact of this revolution on biological investigation, our understanding of life, and the relationship between science and society.
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Affiliation(s)
- Veronica van Heyningen
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Crewe Road, Edinburgh, EH4 2XU, UK.
- Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK.
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31
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Maeshima K, Ide S, Babokhov M. Dynamic chromatin organization without the 30-nm fiber. Curr Opin Cell Biol 2019; 58:95-104. [DOI: 10.1016/j.ceb.2019.02.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 02/08/2019] [Accepted: 02/14/2019] [Indexed: 12/24/2022]
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Highly interacting regions of the human genome are enriched with enhancers and bound by DNA repair proteins. Sci Rep 2019; 9:4577. [PMID: 30872630 PMCID: PMC6418152 DOI: 10.1038/s41598-019-40770-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 02/12/2019] [Indexed: 11/08/2022] Open
Abstract
In specific cases, chromatin clearly forms long-range loops that place distant regulatory elements in close proximity to transcription start sites, but we have limited understanding of many loops identified by Chromosome Conformation Capture (such as Hi-C) analyses. In efforts to elucidate their characteristics and functions, we have identified highly interacting regions (HIRs) using intra-chromosomal Hi-C datasets with a new computational method based on looking at the eigenvector that corresponds to the smallest eigenvalue (here unity). Analysis of these regions using ENCODE data shows that they are in general enriched in bound factors involved in DNA damage repair and have actively transcribed genes. However, both highly transcribed regions as well as transcriptionally inactive regions can form HIRs. The results also indicate that enhancers and super-enhancers in particular form long-range interactions within the same chromosome. The accumulation of DNA repair factors in most identified HIRs suggests that protection from DNA damage in these regions is essential for avoidance of detrimental rearrangements.
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33
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Sefer E, Kingsford C. Semi-nonparametric modeling of topological domain formation from epigenetic data. Algorithms Mol Biol 2019; 14:4. [PMID: 30867673 PMCID: PMC6399866 DOI: 10.1186/s13015-019-0142-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 02/26/2019] [Indexed: 01/01/2023] Open
Abstract
Background Hi-C experiments capturing the 3D genome architecture have led to the discovery of topologically-associated domains (TADs) that form an important part of the 3D genome organization and appear to play a role in gene regulation and other functions. Several histone modifications have been independently associated with TAD formation, but their combinatorial effects on domain formation remain poorly understood at a global scale. Results We propose a convex semi-nonparametric approach called nTDP based on Bernstein polynomials to explore the joint effects of histone markers on TAD formation as well as predict TADs solely from the histone data. We find a small subset of modifications to be predictive of TADs across species. By inferring TADs using our trained model, we are able to predict TADs across different species and cell types, without the use of Hi-C data, suggesting their effect is conserved. This work provides the first comprehensive joint model of the effect of histone markers on domain formation. Conclusions Our approach, nTDP, can form the basis of a unified, explanatory model of the relationship between epigenetic marks and topological domain structures. It can be used to predict domain boundaries for cell types, species, and conditions for which no Hi-C data is available. The model may also be of use for improving Hi-C-based domain finders.
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34
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Raviram R, Rocha PP, Luo VM, Swanzey E, Miraldi ER, Chuong EB, Feschotte C, Bonneau R, Skok JA. Analysis of 3D genomic interactions identifies candidate host genes that transposable elements potentially regulate. Genome Biol 2018; 19:216. [PMID: 30541598 PMCID: PMC6292174 DOI: 10.1186/s13059-018-1598-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 11/28/2018] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The organization of chromatin in the nucleus plays an essential role in gene regulation. About half of the mammalian genome comprises transposable elements. Given their repetitive nature, reads associated with these elements are generally discarded or randomly distributed among elements of the same type in genome-wide analyses. Thus, it is challenging to identify the activities and properties of individual transposons. As a result, we only have a partial understanding of how transposons contribute to chromatin folding and how they impact gene regulation. RESULTS Using PCR and Capture-based chromosome conformation capture (3C) approaches, collectively called 4Tran, we take advantage of the repetitive nature of transposons to capture interactions from multiple copies of endogenous retrovirus (ERVs) in the human and mouse genomes. With 4Tran-PCR, reads are selectively mapped to unique regions in the genome. This enables the identification of transposable element interaction profiles for individual ERV families and integration events specific to particular genomes. With this approach, we demonstrate that transposons engage in long-range intra-chromosomal interactions guided by the separation of chromosomes into A and B compartments as well as topologically associated domains (TADs). In contrast to 4Tran-PCR, Capture-4Tran can uniquely identify both ends of an interaction that involve retroviral repeat sequences, providing a powerful tool for uncovering the individual transposable element insertions that interact with and potentially regulate target genes. CONCLUSIONS 4Tran provides new insight into the manner in which transposons contribute to chromosome architecture and identifies target genes that transposable elements can potentially control.
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Affiliation(s)
- Ramya Raviram
- Department of Pathology, New York University School of Medicine, New York, NY 10016 USA
- Department of Biology, New York University, New York, NY 10003 USA
- Ludwig Institute for Cancer Research, La Jolla, CA USA
| | - Pedro P. Rocha
- Department of Pathology, New York University School of Medicine, New York, NY 10016 USA
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892 USA
| | - Vincent M. Luo
- Department of Pathology, New York University School of Medicine, New York, NY 10016 USA
- Department of Biology, New York University, New York, NY 10003 USA
| | - Emily Swanzey
- Department of Developmental Genetics, New York University School of Medicine, New York, NY 10016 USA
| | - Emily R. Miraldi
- Department of Biology, New York University, New York, NY 10003 USA
- Department of Computer Science, Courant Institute of Mathematical Sciences, New York, NY 10003 USA
- Simons Center for Data Analysis, New York, NY 10010 USA
- Divisions of Immunobiology and Biomedical Informatics, Cincinnati Children’s Hospital, Cincinnati, OH 45229 USA
| | - Edward B. Chuong
- BioFrontiers Institute, Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO 80309 USA
| | - Cédric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850 USA
| | - Richard Bonneau
- Department of Biology, New York University, New York, NY 10003 USA
- Department of Computer Science, Courant Institute of Mathematical Sciences, New York, NY 10003 USA
- Simons Center for Data Analysis, New York, NY 10010 USA
| | - Jane A. Skok
- Department of Pathology, New York University School of Medicine, New York, NY 10016 USA
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35
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Astakhov AM, Nechaev SK, Polovnikov KE. Statistical Properties of a Polymer Globule Formed during Collapse with the Irreversible Coalescence of Units. POLYMER SCIENCE SERIES C 2018. [DOI: 10.1134/s1811238218020017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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36
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Krefting J, Andrade-Navarro MA, Ibn-Salem J. Evolutionary stability of topologically associating domains is associated with conserved gene regulation. BMC Biol 2018; 16:87. [PMID: 30086749 PMCID: PMC6091198 DOI: 10.1186/s12915-018-0556-x] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 07/26/2018] [Indexed: 12/18/2022] Open
Abstract
Background The human genome is highly organized in the three-dimensional nucleus. Chromosomes fold locally into topologically associating domains (TADs) defined by increased intra-domain chromatin contacts. TADs contribute to gene regulation by restricting chromatin interactions of regulatory sequences, such as enhancers, with their target genes. Disruption of TADs can result in altered gene expression and is associated to genetic diseases and cancers. However, it is not clear to which extent TAD regions are conserved in evolution and whether disruption of TADs by evolutionary rearrangements can alter gene expression. Results Here, we hypothesize that TADs represent essential functional units of genomes, which are stable against rearrangements during evolution. We investigate this using whole-genome alignments to identify evolutionary rearrangement breakpoints of different vertebrate species. Rearrangement breakpoints are strongly enriched at TAD boundaries and depleted within TADs across species. Furthermore, using gene expression data across many tissues in mouse and human, we show that genes within TADs have more conserved expression patterns. Disruption of TADs by evolutionary rearrangements is associated with changes in gene expression profiles, consistent with a functional role of TADs in gene expression regulation. Conclusions Together, these results indicate that TADs are conserved building blocks of genomes with regulatory functions that are often reshuffled as a whole instead of being disrupted by rearrangements. Electronic supplementary material The online version of this article (10.1186/s12915-018-0556-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jan Krefting
- Faculty of Biology, Johannes Gutenberg University of Mainz, 55128, Mainz, Germany.,Institute of Molecular Biology, 55128, Mainz, Germany
| | - Miguel A Andrade-Navarro
- Faculty of Biology, Johannes Gutenberg University of Mainz, 55128, Mainz, Germany.,Institute of Molecular Biology, 55128, Mainz, Germany
| | - Jonas Ibn-Salem
- Faculty of Biology, Johannes Gutenberg University of Mainz, 55128, Mainz, Germany. .,Institute of Molecular Biology, 55128, Mainz, Germany.
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37
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Comparing and Contrasting the Effects of Drosophila Condensin II Subunit dCAP-D3 Overexpression and Depletion in Vivo. Genetics 2018; 210:531-546. [PMID: 30068527 PMCID: PMC6216582 DOI: 10.1534/genetics.118.301344] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 07/31/2018] [Indexed: 11/18/2022] Open
Abstract
The Condensin II complex plays important, conserved roles in genome organization throughout the cell cycle and in the regulation of gene expression. Previous studies have linked decreased Condensin II subunit expression with a variety of diseases. Here, we show that elevated levels of Condensin II subunits are detected in somatic cancers. To evaluate potential biological effects of elevated Condensin II levels, we overexpressed the Condensin II subunit, dCAP-D3 in Drosophila melanogaster larval tissues and examined the effects on the mitotic- and interphase-specific functions of Condensin II. Interestingly, while ubiquitous overexpression resulted in pupal lethality, tissue specific overexpression of dCAP-D3 caused formation of nucleoplasmic protein aggregates which slowed mitotic prophase progression, mimicking results observed when dCAP-D3 levels are depleted. Surprisingly, dCAP-D3 aggregate formation resulted in faster transitions from metaphase to anaphase. Overexpressed dCAP-D3 protein failed to precipitate other Condensin II subunits in nondividing tissues, but did cause changes to gene expression which occurred in a manner opposite of what was observed when dCAP-D3 levels were depleted in both dividing and nondividing tissues. Our findings show that altering dCAP-D3 levels in either direction has detrimental effects on mitotic timing, the regulation of gene expression, and organism development. Taken together, these data suggest that the different roles for Condensin II throughout the cell cycle may be independent of each other and/or that dCAP-D3 may possess functions that are separate from those involving its association with the Condensin II complex. If conserved, these findings could have implications for tumors harboring elevated CAP-D3 levels.
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38
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Zhu DL, Chen XF, Hu WX, Dong SS, Lu BJ, Rong Y, Chen YX, Chen H, Thynn HN, Wang NN, Guo Y, Yang TL. Multiple Functional Variants at 13q14 Risk Locus for Osteoporosis Regulate RANKL Expression Through Long-Range Super-Enhancer. J Bone Miner Res 2018. [PMID: 29528523 DOI: 10.1002/jbmr.3419] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
RANKL is a key regulator involved in bone metabolism, and a drug target for osteoporosis. The clinical diagnosis and assessment of osteoporosis are mainly based on bone mineral density (BMD). Previous powerful genomewide association studies (GWASs) have identified multiple intergenic single-nucleotide polymorphisms (SNPs) located over 100 kb upstream of RANKL and 65 kb downstream of AKAP11 at 13q14.11 for osteoporosis. Whether these SNPs exert their roles on osteoporosis through RANKL is unknown. In this study, we conducted integrative analyses combining expression quantitative trait locus (eQTL), genomic chromatin interaction (high-throughput chromosome conformation capture [Hi-C]), epigenetic annotation, and a series of functional assays. The eQTL analysis identified six potential functional SNPs (rs9533090, rs9594738, r8001611, rs9533094, rs9533095, and rs9594759) exclusively correlated with RANKL gene expression (p < 0.001) at 13q14.11. Co-localization analyses suggested that eQTL signal for RANKL and BMD-GWAS signal shared the same causal variants. Hi-C analysis and functional annotation further validated that the first five osteoporosis SNPs are located in a super-enhancer region to regulate the expression of RANKL via long-range chromosomal interaction. Particularly, dual-luciferase assay showed that the region harboring rs9533090 in the super-enhancer has the strongest enhancer activity, and rs9533090 is an allele-specific regulatory SNP. Furthermore, deletion of the region harboring rs9533090 using CRISPR/Cas9 genome editing significantly reduced RANKL expression in both mRNA level and protein level. Finally, we found that the rs9533090-C robustly recruits transcription factor NFIC, which efficiently elevates the enhancer activity and increases the RANKL expression. In summary, we provided a feasible method to identify regulatory noncoding SNPs to distally regulate their target gene underlying the pathogenesis of osteoporosis by using bioinformatics data analyses and experimental validation. Our findings would be a potential and promising therapeutic target for precision medicine in osteoporosis. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Dong-Li Zhu
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, Shaanxi, Xi'an, People's Republic of China
| | - Xiao-Feng Chen
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, Shaanxi, Xi'an, People's Republic of China
| | - Wei-Xin Hu
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, Shaanxi, Xi'an, People's Republic of China
| | - Shan-Shan Dong
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, Shaanxi, Xi'an, People's Republic of China
| | - Bing-Jie Lu
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, Shaanxi, Xi'an, People's Republic of China
| | - Yu Rong
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, Shaanxi, Xi'an, People's Republic of China
| | - Yi-Xiao Chen
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, Shaanxi, Xi'an, People's Republic of China
| | - Hao Chen
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, Shaanxi, Xi'an, People's Republic of China
| | - Hlaing Nwe Thynn
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, Shaanxi, Xi'an, People's Republic of China
| | - Nai-Ning Wang
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, Shaanxi, Xi'an, People's Republic of China
| | - Yan Guo
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, Shaanxi, Xi'an, People's Republic of China
| | - Tie-Lin Yang
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, Shaanxi, Xi'an, People's Republic of China
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39
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Matthews BJ, Waxman DJ. Computational prediction of CTCF/cohesin-based intra-TAD loops that insulate chromatin contacts and gene expression in mouse liver. eLife 2018; 7:e34077. [PMID: 29757144 PMCID: PMC5986275 DOI: 10.7554/elife.34077] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 04/30/2018] [Indexed: 12/18/2022] Open
Abstract
CTCF and cohesin are key drivers of 3D-nuclear organization, anchoring the megabase-scale Topologically Associating Domains (TADs) that segment the genome. Here, we present and validate a computational method to predict cohesin-and-CTCF binding sites that form intra-TAD DNA loops. The intra-TAD loop anchors identified are structurally indistinguishable from TAD anchors regarding binding partners, sequence conservation, and resistance to cohesin knockdown; further, the intra-TAD loops retain key functional features of TADs, including chromatin contact insulation, blockage of repressive histone mark spread, and ubiquity across tissues. We propose that intra-TAD loops form by the same loop extrusion mechanism as the larger TAD loops, and that their shorter length enables finer regulatory control in restricting enhancer-promoter interactions, which enables selective, high-level expression of gene targets of super-enhancers and genes located within repressive nuclear compartments. These findings elucidate the role of intra-TAD cohesin-and-CTCF binding in nuclear organization associated with widespread insulation of distal enhancer activity.
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Affiliation(s)
- Bryan J Matthews
- Department of Biology and Bioinformatics ProgramBoston UniversityBostonUnited States
| | - David J Waxman
- Department of Biology and Bioinformatics ProgramBoston UniversityBostonUnited States
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40
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Razin SV, Gavrilov AA. Structural–Functional Domains of the Eukaryotic Genome. BIOCHEMISTRY (MOSCOW) 2018; 83:302-312. [DOI: 10.1134/s0006297918040028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/27/2017] [Indexed: 08/30/2023]
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41
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Man J, Barnett P, Christoffels VM. Structure and function of the Nppa-Nppb cluster locus during heart development and disease. Cell Mol Life Sci 2018; 75:1435-1444. [PMID: 29302701 PMCID: PMC5852170 DOI: 10.1007/s00018-017-2737-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 12/07/2017] [Accepted: 12/20/2017] [Indexed: 01/20/2023]
Abstract
Atrial natriuretic factor and brain natriuretic peptide are two important biomarkers in clinical cardiology. These two natriuretic peptide hormones are encoded by the paralogous genes Nppa and Nppb, which are evolutionary conserved. Both genes are predominantly expressed by the heart muscle during the embryonic and fetal stages, and in particular Nppa expression is strongly reduced in the ventricles after birth. Upon cardiac stress, Nppa and Nppb are strongly upregulated in the ventricular myocardium. Much is known about the molecular and physiological ques inducing Nppa and Nppb expression; however, the transcriptional regulatory mechanisms of the Nppa-Nppb cluster in vivo has proven to be quite complex and is not well understood. In this review, we will provide recent insights into the dynamic and complex regulation of Nppa and Nppb during heart development and hypertrophy, and the association of this gene cluster with the cardiomyocyte-intrinsic program of heart regeneration.
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Affiliation(s)
- Joyce Man
- Department of Medical Biology, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ, Amsterdam, The Netherlands.
| | - Phil Barnett
- Department of Medical Biology, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ, Amsterdam, The Netherlands
| | - Vincent M Christoffels
- Department of Medical Biology, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ, Amsterdam, The Netherlands
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42
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Drabik G, Kaszuba-Zwoińska J, Wiśniowski Z, Konieczny L, Roterman I. Chromatin 3D – will it make understanding of cancer transformation finally possible? BIO-ALGORITHMS AND MED-SYSTEMS 2018. [DOI: 10.1515/bams-2018-0002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Despite enormous progress in molecular analysis of cancer cell genomes, the mechanism of tumorigenesis remains unclear. The information present in the genome is not limited to the DNA sequence itself. Indeed, a significant portion of this information is concealed in the spatial structure of chromatin. Ongoing scientific studies that focus on the three-dimensional structure of chromatin raise hopes of arriving at a general explanation of the cancer transformation phenomenon.
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43
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Abstract
The use of 3C-based methods has revealed the importance of the 3D organization of the chromatin for key aspects of genome biology. However, the different caveats of the variants of 3C techniques have limited their scope and the range of scientific fields that could benefit from these approaches. To address these limitations, we present 4Cin, a method to generate 3D models and derive virtual Hi-C (vHi-C) heat maps of genomic loci based on 4C-seq or any kind of 4C-seq-like data, such as those derived from NG Capture-C. 3D genome organization is determined by integrative consideration of the spatial distances derived from as few as four 4C-seq experiments. The 3D models obtained from 4C-seq data, together with their associated vHi-C maps, allow the inference of all chromosomal contacts within a given genomic region, facilitating the identification of Topological Associating Domains (TAD) boundaries. Thus, 4Cin offers a much cheaper, accessible and versatile alternative to other available techniques while providing a comprehensive 3D topological profiling. By studying TAD modifications in genomic structural variants associated to disease phenotypes and performing cross-species evolutionary comparisons of 3D chromatin structures in a quantitative manner, we demonstrate the broad potential and novel range of applications of our method. Chromatin conformation capture (3C) methods have revealed the importance of the 3D organization of the chromatin, which is key to understand many aspects of genome biology. But each of these methods have their own limitations. Here we present 4Cin, a software that generates 3D models of the chromatin from a small number of 4C-seq experiments, a 3C-based method that provides the frequency of contacts between one fragments and the genome (one vs all). These 3D models are used to infer all chromosomal contacts within a given genomic region (many vs many). The contact maps facilitate the identification of Topological Associating Domains boundaries. Our software offers a much cheaper, accessible and versatile alternative to other available techniques while providing a comprehensive 3D topological profiling. We applied our software to two different loci to study modifications in genomic structural variants associated to disease phenotypes and to compare the chromatin organization in two different species in a quantitative manner.
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44
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Bian Q, Anderson EC, Brejc K, Meyer BJ. Dynamic Control of Chromosome Topology and Gene Expression by a Chromatin Modification. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2018; 82:279-291. [PMID: 29472317 PMCID: PMC6041165 DOI: 10.1101/sqb.2017.82.034439] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The function of chromatin modification in establishing higher-order chromosome structure during gene regulation has been elusive. We dissected the machinery and mechanism underlying the enrichment of histone modification H4K20me1 on hermaphrodite X chromosomes during Caenorhabditis elegans dosage compensation and discovered a key role for H4K20me1 in regulating X-chromosome topology and chromosome-wide gene expression. Structural and functional analysis of the dosage compensation complex (DCC) subunit DPY-21 revealed a novel Jumonji C demethylase subfamily that converts H4K20me2 to H4K20me1 in worms and mammals. Inactivation of demethylase activity in vivo by genome editing eliminated H4K20me1 enrichment on X chromosomes of somatic cells, increased X-linked gene expression, reduced X-chromosome compaction, and disrupted X-chromosome conformation by diminishing the formation of topologically associated domains. H4K20me1 is also enriched on the inactive X of female mice, making our studies directly relevant to mammalian development. Unexpectedly, DPY-21 also associates specifically with autosomes of nematode germ cells in a DCC-independent manner to enrich H4K20me1 and trigger chromosome compaction. Thus, DPY-21 is an adaptable chromatin regulator. Its H4K20me2 demethylase activity can be harnessed during development for distinct biological functions by targeting it to diverse genomic locations through different mechanisms. In both somatic cells and germ cells, H4K20me1 enrichment modulates three-dimensional chromosome architecture, demonstrating the direct link between chromatin modification and higher-order chromosome structure.
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Affiliation(s)
- Qian Bian
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3204
| | - Erika C Anderson
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3204
| | - Katjuša Brejc
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3204
| | - Barbara J Meyer
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3204
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45
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Li Y, He Y, Liang Z, Wang Y, Chen F, Djekidel MN, Li G, Zhang X, Xiang S, Wang Z, Gao J, Zhang MQ, Chen Y. Alterations of specific chromatin conformation affect ATRA-induced leukemia cell differentiation. Cell Death Dis 2018; 9:200. [PMID: 29422670 PMCID: PMC5833835 DOI: 10.1038/s41419-017-0173-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Revised: 10/10/2017] [Accepted: 11/20/2017] [Indexed: 12/31/2022]
Abstract
Chromatin conformation plays a key role in regulating gene expression and controlling cell differentiation. However, the whole-genome chromatin conformation changes that occur during leukemia cell differentiation are poorly understood. Here, we characterized the changes in chromatin conformation, histone states, chromatin accessibility, and gene expression using an all-trans retinoic acid (ATRA)-induced HL-60 cell differentiation model. The results showed that the boundaries of topological associated domains (TADs) were stable during differentiation; however, the chromatin conformations within several specific TADs were obviously changed. By combining H3K4me3, H3K27ac, and Hi-C signals, we annotated the differential gene-regulatory chromatin interactions upon ATRA induction. The gains and losses of the gene-regulatory chromatin interactions are significantly correlated with gene expression and chromatin accessibility. Finally, we found that the loss of GATA2 expression and DNA binding are crucial for the differentiation process, and changes in the chromatin structure around the GATA2 regulate its expression upon ATRA induction. This study provided both statistical insights and experimental details regarding the relationship between chromatin conformation changes and transcription regulation during leukemia cell differentiation, and the results suggested that the chromatin conformation is a new type of potential drug target for cancer therapy.
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Affiliation(s)
- Yanjian Li
- MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, School of Medicine, Tsinghua University, Beijing, 100084, China
| | - Yi He
- School of Pharmaceutical Sciences, Tsinghua University, Beijing, 100084, China
| | - Zhengyu Liang
- MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, School of Medicine, Tsinghua University, Beijing, 100084, China
| | - Yang Wang
- MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, Department of Automation, Tsinghua University, Beijing, 100084, China
| | - Fengling Chen
- MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, Department of Automation, Tsinghua University, Beijing, 100084, China
| | - Mohamed Nadhir Djekidel
- MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, Department of Automation, Tsinghua University, Beijing, 100084, China
| | - Guipeng Li
- MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, Department of Automation, Tsinghua University, Beijing, 100084, China
| | - Xu Zhang
- MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, Department of Automation, Tsinghua University, Beijing, 100084, China
| | - Shuqin Xiang
- MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, School of Medicine, Tsinghua University, Beijing, 100084, China
| | - Zejun Wang
- MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, Department of Automation, Tsinghua University, Beijing, 100084, China
| | - Juntao Gao
- MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, Department of Automation, Tsinghua University, Beijing, 100084, China
| | - Michael Q Zhang
- MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, School of Medicine, Tsinghua University, Beijing, 100084, China. .,MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, Department of Automation, Tsinghua University, Beijing, 100084, China. .,Department of Biological Sciences, Center for Systems Biology, The University of Texas, Dallas 800 West Campbell Road, RL11, Richardson, TX, 75080-3021, USA.
| | - Yang Chen
- MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, School of Medicine, Tsinghua University, Beijing, 100084, China. .,MOE Key Laboratory of Bioinformatics, Bioinformatics Division and Center for Synthetic & Systems Biology, TNLIST, Department of Automation, Tsinghua University, Beijing, 100084, China.
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46
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3D Genome Organization Influences the Chromosome Translocation Pattern. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1044:113-133. [PMID: 29956294 DOI: 10.1007/978-981-13-0593-1_8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recent imaging, molecular, and computational modeling studies have greatly enhanced our knowledge of how eukaryotic chromosomes are folded in the nuclear space. This work has begun to reveal how 3D genome structure contributes to various DNA-mediated metabolic activities such as replication, transcription, recombination, and repair. Failure of proper DNA repair can lead to the chromosomal translocations observed in human cancers and other diseases. Questions about the role of 3D genome structure in translocation mechanisms have interested scientists for decades. Recent applications of imaging and Chromosome Conformation Capture approaches have clarified the influence of proximal positioning of chromosomal domains and gene loci on the formation of chromosomal translocations. These approaches have revealed the importance of 3D genome structure not only in translocation partner selection, but also in repair efficiency, likelihood of DNA damage, and the biological implications of translocations. This chapter focuses on our current understanding of the role of 3D genome structure in chromosome translocation formation and its potential implications in disease outcome.
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47
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Shah FR, Bhat YA, Wani AH. Subnuclear distribution of proteins: Links with genome architecture. Nucleus 2018; 9:42-55. [PMID: 28910577 PMCID: PMC5973252 DOI: 10.1080/19491034.2017.1361578] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 07/25/2017] [Accepted: 07/26/2017] [Indexed: 02/08/2023] Open
Abstract
Metazoan genomes have a hierarchal 3-dimensional (3D) organization scaling from nucleosomes, loops, topologically associating domains (TADs), compartments, to chromosome territories. The 3D organization of genome has been linked with development, differentiation and disease. However, the principles governing the 3D chromatin architecture are just beginning to get unraveled. The nucleus has very high concentration of proteins and these proteins are either diffusely distributed throughout the nucleus, or aggregated in the form of foci/bodies/clusters/speckles or in combination of both. Several evidences suggest that the distribution of proteins within the nuclear space is linked to the organization and function of genome. Here, we describe advances made in understanding the relationship between subnuclear distribution of proteins and genome architecture.
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Affiliation(s)
- Fouziya R. Shah
- Biotechnology, School of Biological Sciences, University of Kashmir, Srinagar, India
| | - Younus A. Bhat
- Biotechnology, School of Biological Sciences, University of Kashmir, Srinagar, India
| | - Ajazul H. Wani
- Biotechnology, School of Biological Sciences, University of Kashmir, Srinagar, India
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48
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Tan JY, Smith AAT, Ferreira da Silva M, Matthey-Doret C, Rueedi R, Sönmez R, Ding D, Kutalik Z, Bergmann S, Marques AC. cis-Acting Complex-Trait-Associated lincRNA Expression Correlates with Modulation of Chromosomal Architecture. Cell Rep 2017; 18:2280-2288. [PMID: 28249171 DOI: 10.1016/j.celrep.2017.02.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 12/16/2016] [Accepted: 01/30/2017] [Indexed: 11/26/2022] Open
Abstract
Intergenic long noncoding RNAs (lincRNAs) are the largest class of transcripts in the human genome. Although many have recently been linked to complex human traits, the underlying mechanisms for most of these transcripts remain undetermined. We investigated the regulatory roles of a high-confidence and reproducible set of 69 trait-relevant lincRNAs (TR-lincRNAs) in human lymphoblastoid cells whose biological relevance is supported by their evolutionary conservation during recent human history and genetic interactions with other trait-associated loci. Their enrichment in enhancer-like chromatin signatures, interactions with nearby trait-relevant protein-coding loci, and preferential location at topologically associated domain (TAD) boundaries provide evidence that TR-lincRNAs likely regulate proximal trait-relevant gene expression in cis by modulating local chromosomal architecture. This is consistent with the positive and significant correlation found between TR-lincRNA abundance and intra-TAD DNA-DNA contacts. Our results provide insights into the molecular mode of action by which TR-lincRNAs contribute to complex human traits.
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Affiliation(s)
- Jennifer Yihong Tan
- Department of Physiology, University of Lausanne, 1015 Lausanne, Switzerland; Department of Computational Biology, University of Lausanne, 1015 Lausanne, Switzerland.
| | - Adam Alexander Thil Smith
- Department of Physiology, University of Lausanne, 1015 Lausanne, Switzerland; Department of Computational Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Maria Ferreira da Silva
- Department of Physiology, University of Lausanne, 1015 Lausanne, Switzerland; Department of Computational Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Cyril Matthey-Doret
- Department of Physiology, University of Lausanne, 1015 Lausanne, Switzerland; Department of Computational Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Rico Rueedi
- Department of Computational Biology, University of Lausanne, 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Reyhan Sönmez
- Department of Computational Biology, University of Lausanne, 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - David Ding
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Zoltán Kutalik
- Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland; Institute of Social and Preventive Medicine, University Hospital Lausanne (CHUV), 1011 Lausanne, Switzerland
| | - Sven Bergmann
- Department of Computational Biology, University of Lausanne, 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Ana Claudia Marques
- Department of Physiology, University of Lausanne, 1015 Lausanne, Switzerland; Department of Computational Biology, University of Lausanne, 1015 Lausanne, Switzerland.
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49
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Schwarzer W, Abdennur N, Goloborodko A, Pekowska A, Fudenberg G, Loe-Mie Y, Fonseca NA, Huber W, Haering CH, Mirny L, Spitz F. Two independent modes of chromatin organization revealed by cohesin removal. Nature 2017; 551:51-56. [PMID: 29094699 PMCID: PMC5687303 DOI: 10.1038/nature24281] [Citation(s) in RCA: 717] [Impact Index Per Article: 102.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 09/19/2017] [Indexed: 01/01/2023]
Abstract
Imaging and chromosome conformation capture studies have revealed several layers of chromosome organization, including segregation into megabase-sized active and inactive compartments, and partitioning into sub-megabase domains (TADs). It remains unclear, however, how these layers of organization form, interact with one another and influence genome function. Here we show that deletion of the cohesin-loading factor Nipbl in mouse liver leads to a marked reorganization of chromosomal folding. TADs and associated Hi-C peaks vanish globally, even in the absence of transcriptional changes. By contrast, compartmental segregation is preserved and even reinforced. Strikingly, the disappearance of TADs unmasks a finer compartment structure that accurately reflects the underlying epigenetic landscape. These observations demonstrate that the three-dimensional organization of the genome results from the interplay of two independent mechanisms: cohesin-independent segregation of the genome into fine-scale compartments, defined by chromatin state; and cohesin-dependent formation of TADs, possibly by loop extrusion, which helps to guide distant enhancers to their target genes.
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Affiliation(s)
- Wibke Schwarzer
- Developmental Biology Unit. European Molecular Biology Laboratory. 69117 Heidelberg, Germany
| | - Nezar Abdennur
- Computational and Systems Biology Program, Massachusetts Institute of Technology, Cambridge, Massachusetts USA
| | - Anton Goloborodko
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts USA
| | - Aleksandra Pekowska
- Genome Biology Unit. European Molecular Biology Laboratory. 69117 Heidelberg, Germany
| | - Geoffrey Fudenberg
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts USA
| | - Yann Loe-Mie
- Institut Pasteur, (Epi)genomics of Animal Development Unit, Developmental and Stem Cell Biology Department. Institut Pasteur. 75015 Paris, France
- CNRS, UMR3738, 25 rue du Dr Roux, 75015 Paris, France
| | - Nuno A Fonseca
- European Bioinformatics Institute. European Molecular Biology Laboratory. Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, UK
| | - Wolfgang Huber
- Genome Biology Unit. European Molecular Biology Laboratory. 69117 Heidelberg, Germany
| | - Christian H Haering
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Leonid Mirny
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts USA
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts USA
| | - Francois Spitz
- Developmental Biology Unit. European Molecular Biology Laboratory. 69117 Heidelberg, Germany
- Genome Biology Unit. European Molecular Biology Laboratory. 69117 Heidelberg, Germany
- Institut Pasteur, (Epi)genomics of Animal Development Unit, Developmental and Stem Cell Biology Department. Institut Pasteur. 75015 Paris, France
- CNRS, UMR3738, 25 rue du Dr Roux, 75015 Paris, France
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50
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Carelli FN, Sharma G, Ahringer J. Broad Chromatin Domains: An Important Facet of Genome Regulation. Bioessays 2017; 39. [PMID: 29058338 DOI: 10.1002/bies.201700124] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 09/09/2017] [Indexed: 12/19/2022]
Abstract
Chromatin composition differs across the genome, with distinct compositions characterizing regions associated with different properties and functions. Whereas many histone modifications show local enrichment over genes or regulatory elements, marking can also span large genomic intervals defining broad chromatin domains. Here we highlight structural and functional features of chromatin domains marked by histone modifications, with a particular emphasis on the potential roles of H3K27 methylation domains in the organization and regulation of genome activity in metazoans.
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Affiliation(s)
- Francesco N Carelli
- The Gurdon Institute and Department of Genetics, University of Cambridge, Cambridge CB2 1QN, United Kingdom
| | - Garima Sharma
- The Gurdon Institute and Department of Genetics, University of Cambridge, Cambridge CB2 1QN, United Kingdom
| | - Julie Ahringer
- The Gurdon Institute and Department of Genetics, University of Cambridge, Cambridge CB2 1QN, United Kingdom
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