1
|
Puerto M, Shukla M, Bujosa P, Pérez-Roldán J, Torràs-Llort M, Tamirisa S, Carbonell A, Solé C, Puspo J, Cummings C, de Nadal E, Posas F, Azorín F, Rowley M. The zinc-finger protein Z4 cooperates with condensin II to regulate somatic chromosome pairing and 3D chromatin organization. Nucleic Acids Res 2024; 52:5596-5609. [PMID: 38520405 PMCID: PMC11162801 DOI: 10.1093/nar/gkae198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 02/16/2024] [Accepted: 03/07/2024] [Indexed: 03/25/2024] Open
Abstract
Chromosome pairing constitutes an important level of genome organization, yet the mechanisms that regulate pairing in somatic cells and the impact on 3D chromatin organization are still poorly understood. Here, we address these questions in Drosophila, an organism with robust somatic pairing. In Drosophila, pairing preferentially occurs at loci consisting of numerous architectural protein binding sites (APBSs), suggesting a role of architectural proteins (APs) in pairing regulation. Amongst these, the anti-pairing function of the condensin II subunit CAP-H2 is well established. However, the factors that regulate CAP-H2 localization and action at APBSs remain largely unknown. Here, we identify two factors that control CAP-H2 occupancy at APBSs and, therefore, regulate pairing. We show that Z4, interacts with CAP-H2 and is required for its localization at APBSs. We also show that hyperosmotic cellular stress induces fast and reversible unpairing in a Z4/CAP-H2 dependent manner. Moreover, by combining the opposite effects of Z4 depletion and osmostress, we show that pairing correlates with the strength of intrachromosomal 3D interactions, such as active (A) compartment interactions, intragenic gene-loops, and polycomb (Pc)-mediated chromatin loops. Altogether, our results reveal new players in CAP-H2-mediated pairing regulation and the intimate interplay between inter-chromosomal and intra-chromosomal 3D interactions.
Collapse
Affiliation(s)
- Marta Puerto
- Institute of Molecular Biology of Barcelona, IBMB, CSIC, Baldiri Reixac 4, 08028 Barcelona, Spain
- Institute for Research in Biomedicine of Barcelona, IRB Barcelona. The Barcelona Institute of Science and Technology. Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Mamta Shukla
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA
| | - Paula Bujosa
- Institute of Molecular Biology of Barcelona, IBMB, CSIC, Baldiri Reixac 4, 08028 Barcelona, Spain
- Institute for Research in Biomedicine of Barcelona, IRB Barcelona. The Barcelona Institute of Science and Technology. Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Juan Pérez-Roldán
- Institute of Molecular Biology of Barcelona, IBMB, CSIC, Baldiri Reixac 4, 08028 Barcelona, Spain
- Institute for Research in Biomedicine of Barcelona, IRB Barcelona. The Barcelona Institute of Science and Technology. Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Mònica Torràs-Llort
- Institute of Molecular Biology of Barcelona, IBMB, CSIC, Baldiri Reixac 4, 08028 Barcelona, Spain
- Institute for Research in Biomedicine of Barcelona, IRB Barcelona. The Barcelona Institute of Science and Technology. Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Srividya Tamirisa
- Institute of Molecular Biology of Barcelona, IBMB, CSIC, Baldiri Reixac 4, 08028 Barcelona, Spain
- Institute for Research in Biomedicine of Barcelona, IRB Barcelona. The Barcelona Institute of Science and Technology. Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Albert Carbonell
- Institute of Molecular Biology of Barcelona, IBMB, CSIC, Baldiri Reixac 4, 08028 Barcelona, Spain
- Institute for Research in Biomedicine of Barcelona, IRB Barcelona. The Barcelona Institute of Science and Technology. Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Carme Solé
- Institute for Research in Biomedicine of Barcelona, IRB Barcelona. The Barcelona Institute of Science and Technology. Baldiri Reixac 10, 08028 Barcelona, Spain
- Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Joynob Akter Puspo
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA
| | | | - Eulàlia de Nadal
- Institute for Research in Biomedicine of Barcelona, IRB Barcelona. The Barcelona Institute of Science and Technology. Baldiri Reixac 10, 08028 Barcelona, Spain
- Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Francesc Posas
- Institute for Research in Biomedicine of Barcelona, IRB Barcelona. The Barcelona Institute of Science and Technology. Baldiri Reixac 10, 08028 Barcelona, Spain
- Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Fernando Azorín
- Institute of Molecular Biology of Barcelona, IBMB, CSIC, Baldiri Reixac 4, 08028 Barcelona, Spain
- Institute for Research in Biomedicine of Barcelona, IRB Barcelona. The Barcelona Institute of Science and Technology. Baldiri Reixac 10, 08028 Barcelona, Spain
| | - M Jordan Rowley
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA
| |
Collapse
|
2
|
Li J, Lin Y, Li D, He M, Kui H, Bai J, Chen Z, Gou Y, Zhang J, Wang T, Tang Q, Kong F, Jin L, Li M. Building Haplotype-Resolved 3D Genome Maps of Chicken Skeletal Muscle. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2305706. [PMID: 38582509 PMCID: PMC11200017 DOI: 10.1002/advs.202305706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 03/07/2024] [Indexed: 04/08/2024]
Abstract
Haplotype-resolved 3D chromatin architecture related to allelic differences in avian skeletal muscle development has not been addressed so far, although chicken husbandry for meat consumption has been prevalent feature of cultures on every continent for more than thousands of years. Here, high-resolution Hi-C diploid maps (1.2-kb maximum resolution) are generated for skeletal muscle tissues in chicken across three developmental stages (embryonic day 15 to day 30 post-hatching). The sequence features governing spatial arrangement of chromosomes and characterize homolog pairing in the nucleus, are identified. Multi-scale characterization of chromatin reorganization between stages from myogenesis in the fetus to myofiber hypertrophy after hatching show concordant changes in transcriptional regulation by relevant signaling pathways. Further interrogation of parent-of-origin-specific chromatin conformation supported that genomic imprinting is absent in birds. This study also reveals promoter-enhancer interaction (PEI) differences between broiler and layer haplotypes in skeletal muscle development-related genes are related to genetic variation between breeds, however, only a minority of breed-specific variations likely contribute to phenotypic divergence in skeletal muscle potentially via allelic PEI rewiring. Beyond defining the haplotype-specific 3D chromatin architecture in chicken, this study provides a rich resource for investigating allelic regulatory divergence among chicken breeds.
Collapse
Affiliation(s)
- Jing Li
- State Key Laboratory of Swine and Poultry Breeding IndustryCollege of Animal Science and TechnologySichuan Agricultural UniversityChengdu611130China
| | - Yu Lin
- State Key Laboratory of Swine and Poultry Breeding IndustryCollege of Animal Science and TechnologySichuan Agricultural UniversityChengdu611130China
| | - Diyan Li
- School of PharmacyChengdu UniversityChengdu610106China
| | - Mengnan He
- Wildlife Conservation Research DepartmentChengdu Research Base of Giant Panda BreedingChengdu610057China
| | - Hua Kui
- State Key Laboratory of Swine and Poultry Breeding IndustryCollege of Animal Science and TechnologySichuan Agricultural UniversityChengdu611130China
| | - Jingyi Bai
- State Key Laboratory of Swine and Poultry Breeding IndustryCollege of Animal Science and TechnologySichuan Agricultural UniversityChengdu611130China
| | - Ziyu Chen
- State Key Laboratory of Swine and Poultry Breeding IndustryCollege of Animal Science and TechnologySichuan Agricultural UniversityChengdu611130China
| | - Yuwei Gou
- State Key Laboratory of Swine and Poultry Breeding IndustryCollege of Animal Science and TechnologySichuan Agricultural UniversityChengdu611130China
| | - Jiaman Zhang
- State Key Laboratory of Swine and Poultry Breeding IndustryCollege of Animal Science and TechnologySichuan Agricultural UniversityChengdu611130China
| | - Tao Wang
- School of PharmacyChengdu UniversityChengdu610106China
| | - Qianzi Tang
- State Key Laboratory of Swine and Poultry Breeding IndustryCollege of Animal Science and TechnologySichuan Agricultural UniversityChengdu611130China
| | - Fanli Kong
- College of Life ScienceSichuan Agricultural UniversityYa'an625014China
| | - Long Jin
- State Key Laboratory of Swine and Poultry Breeding IndustryCollege of Animal Science and TechnologySichuan Agricultural UniversityChengdu611130China
| | - Mingzhou Li
- State Key Laboratory of Swine and Poultry Breeding IndustryCollege of Animal Science and TechnologySichuan Agricultural UniversityChengdu611130China
| |
Collapse
|
3
|
Marshall WF, Fung JC. Modeling homologous chromosome recognition via nonspecific interactions. Proc Natl Acad Sci U S A 2024; 121:e2317373121. [PMID: 38722810 PMCID: PMC11098084 DOI: 10.1073/pnas.2317373121] [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: 10/06/2023] [Accepted: 03/18/2024] [Indexed: 05/18/2024] Open
Abstract
In many organisms, most notably Drosophila, homologous chromosomes associate in somatic cells, a phenomenon known as somatic pairing, which takes place without double strand breaks or strand invasion, thus requiring some other mechanism for homologs to recognize each other. Several studies have suggested a "specific button" model, in which a series of distinct regions in the genome, known as buttons, can associate with each other, mediated by different proteins that bind to these different regions. Here, we use computational modeling to evaluate an alternative "button barcode" model, in which there is only one type of recognition site or adhesion button, present in many copies in the genome, each of which can associate with any of the others with equal affinity. In this model, buttons are nonuniformly distributed, such that alignment of a chromosome with its correct homolog, compared with a nonhomolog, is energetically favored; since to achieve nonhomologous alignment, chromosomes would be required to mechanically deform in order to bring their buttons into mutual register. By simulating randomly generated nonuniform button distributions, many highly effective button barcodes can be easily found, some of which achieve virtually perfect pairing fidelity. This model is consistent with existing literature on the effect of translocations of different sizes on homolog pairing. We conclude that a button barcode model can attain highly specific homolog recognition, comparable to that seen in actual cells undergoing somatic homolog pairing, without the need for specific interactions. This model may have implications for how meiotic pairing is achieved.
Collapse
Affiliation(s)
- Wallace F. Marshall
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA94158
| | - Jennifer C. Fung
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, CA94158
- Center for Reproductive Sciences, University of California, San Francisco, CA94158
| |
Collapse
|
4
|
Gilliland WD, May DP, Bowen AO, Conger KO, Elrad D, Marciniak M, Mashburn SA, Presbitero G, Welk LF. A cytological F1 RNAi screen for defects in Drosophila melanogaster female meiosis. Genetics 2024; 227:iyae046. [PMID: 38531678 PMCID: PMC11075555 DOI: 10.1093/genetics/iyae046] [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: 01/11/2024] [Revised: 01/11/2024] [Accepted: 03/16/2024] [Indexed: 03/28/2024] Open
Abstract
Genetic screens for recessive alleles induce mutations, make the mutated chromosomes homozygous, and then assay those homozygotes for the phenotype of interest. When screening for genes required for female meiosis, the phenotype of interest has typically been nondisjunction from chromosome segregation errors. As this requires that mutant females be viable and fertile, any mutants that are lethal or sterile when homozygous cannot be recovered by this approach. To overcome these limitations, we have screened the VALIUM22 collection of RNAi constructs that target germline-expressing genes in a vector optimized for germline expression by driving RNAi with GAL4 under control of a germline-specific promoter (nanos or mat-alpha4). This allowed us to test genes that would be lethal if knocked down in all cells, and by examining unfertilized metaphase-arrested mature oocytes, we could identify defects in sterile females. After screening >1,450 lines of the collection for two different defects (chromosome congression and the hypoxic sequestration of Mps1-GFP to ooplasmic filaments), we obtained multiple hits for both phenotypes, identified novel meiotic phenotypes for genes that had been previously characterized in other processes, and identified the first phenotypes to be associated with several previously uncharacterized genes.
Collapse
Affiliation(s)
- William D Gilliland
- Department of Biological Sciences, DePaul University, Chicago, IL 60614, USA
| | - Dennis P May
- Department of Biological Sciences, DePaul University, Chicago, IL 60614, USA
| | - Amelia O Bowen
- Department of Biological Sciences, DePaul University, Chicago, IL 60614, USA
| | - Kelly O Conger
- Department of Biological Sciences, DePaul University, Chicago, IL 60614, USA
| | - Doreen Elrad
- Department of Biological Sciences, DePaul University, Chicago, IL 60614, USA
| | - Marcin Marciniak
- Department of Biological Sciences, DePaul University, Chicago, IL 60614, USA
| | - Sarah A Mashburn
- Department of Biological Sciences, DePaul University, Chicago, IL 60614, USA
| | | | - Lucas F Welk
- Department of Biological Sciences, DePaul University, Chicago, IL 60614, USA
| |
Collapse
|
5
|
Abdennur N, Abraham S, Fudenberg G, Flyamer IM, Galitsyna AA, Goloborodko A, Imakaev M, Oksuz BA, Venev SV, Xiao Y. Cooltools: Enabling high-resolution Hi-C analysis in Python. PLoS Comput Biol 2024; 20:e1012067. [PMID: 38709825 PMCID: PMC11098495 DOI: 10.1371/journal.pcbi.1012067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 05/16/2024] [Accepted: 04/10/2024] [Indexed: 05/08/2024] Open
Abstract
Chromosome conformation capture (3C) technologies reveal the incredible complexity of genome organization. Maps of increasing size, depth, and resolution are now used to probe genome architecture across cell states, types, and organisms. Larger datasets add challenges at each step of computational analysis, from storage and memory constraints to researchers' time; however, analysis tools that meet these increased resource demands have not kept pace. Furthermore, existing tools offer limited support for customizing analysis for specific use cases or new biology. Here we introduce cooltools (https://github.com/open2c/cooltools), a suite of computational tools that enables flexible, scalable, and reproducible analysis of high-resolution contact frequency data. Cooltools leverages the widely-adopted cooler format which handles storage and access for high-resolution datasets. Cooltools provides a paired command line interface (CLI) and Python application programming interface (API), which respectively facilitate workflows on high-performance computing clusters and in interactive analysis environments. In short, cooltools enables the effective use of the latest and largest genome folding datasets.
Collapse
Affiliation(s)
- Open2C
- https://open2c.github.io/
| | - Nezar Abdennur
- Department of Genomics and Computational Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Sameer Abraham
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, United States of America
| | - Geoffrey Fudenberg
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California, United States of America
| | - Ilya M. Flyamer
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Aleksandra A. Galitsyna
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, United States of America
| | - Anton Goloborodko
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Maxim Imakaev
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, United States of America
| | - Betul A. Oksuz
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Sergey V. Venev
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Yao Xiao
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California, United States of America
| |
Collapse
|
6
|
Abdennur N, Fudenberg G, Flyamer IM, Galitsyna AA, Goloborodko A, Imakaev M, Venev SV. Pairtools: From sequencing data to chromosome contacts. PLoS Comput Biol 2024; 20:e1012164. [PMID: 38809952 PMCID: PMC11164360 DOI: 10.1371/journal.pcbi.1012164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 06/10/2024] [Accepted: 05/13/2024] [Indexed: 05/31/2024] Open
Abstract
The field of 3D genome organization produces large amounts of sequencing data from Hi-C and a rapidly-expanding set of other chromosome conformation protocols (3C+). Massive and heterogeneous 3C+ data require high-performance and flexible processing of sequenced reads into contact pairs. To meet these challenges, we present pairtools-a flexible suite of tools for contact extraction from sequencing data. Pairtools provides modular command-line interface (CLI) tools that can be flexibly chained into data processing pipelines. The core operations provided by pairtools are parsing of.sam alignments into Hi-C pairs, sorting and removal of PCR duplicates. In addition, pairtools provides auxiliary tools for building feature-rich 3C+ pipelines, including contact pair manipulation, filtration, and quality control. Benchmarking pairtools against popular 3C+ data pipelines shows advantages of pairtools for high-performance and flexible 3C+ analysis. Finally, pairtools provides protocol-specific tools for restriction-based protocols, haplotype-resolved contacts, and single-cell Hi-C. The combination of CLI tools and tight integration with Python data analysis libraries makes pairtools a versatile foundation for a broad range of 3C+ pipelines.
Collapse
Affiliation(s)
- Open2C
- https://open2c.github.io/
| | - Nezar Abdennur
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Geoffrey Fudenberg
- Department of Computational and Quantitative Biology, University of Southern California, Los Angeles, California, United States of America
| | - Ilya M. Flyamer
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Aleksandra A. Galitsyna
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, United States of America
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Anton Goloborodko
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Maxim Imakaev
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, United States of America
| | - Sergey V. Venev
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| |
Collapse
|
7
|
Lin Y, Li J, Gu Y, Jin L, Bai J, Zhang J, Wang Y, Liu P, Long K, He M, Li D, Liu C, Han Z, Zhang Y, Li X, Zeng B, Lu L, Kong F, Sun Y, Fan Y, Wang X, Wang T, Jiang A, Ma J, Shen L, Zhu L, Jiang Y, Tang G, Fan X, Liu Q, Li H, Wang J, Chen L, Ge L, Li X, Tang Q, Li M. Haplotype-resolved 3D chromatin architecture of the hybrid pig. Genome Res 2024; 34:310-325. [PMID: 38479837 PMCID: PMC10984390 DOI: 10.1101/gr.278101.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 02/15/2024] [Indexed: 03/22/2024]
Abstract
In diploid mammals, allele-specific three-dimensional (3D) genome architecture may lead to imbalanced gene expression. Through ultradeep in situ Hi-C sequencing of three representative somatic tissues (liver, skeletal muscle, and brain) from hybrid pigs generated by reciprocal crosses of phenotypically and physiologically divergent Berkshire and Tibetan pigs, we uncover extensive chromatin reorganization between homologous chromosomes across multiple scales. Haplotype-based interrogation of multi-omic data revealed the tissue dependence of 3D chromatin conformation, suggesting that parent-of-origin-specific conformation may drive gene imprinting. We quantify the effects of genetic variations and histone modifications on allelic differences of long-range promoter-enhancer contacts, which likely contribute to the phenotypic differences between the parental pig breeds. We also observe the fine structure of somatically paired homologous chromosomes in the pig genome, which has a functional implication genome-wide. This work illustrates how allele-specific chromatin architecture facilitates concomitant shifts in allele-biased gene expression, as well as the possible consequential phenotypic changes in mammals.
Collapse
Affiliation(s)
- Yu Lin
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Jing Li
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China;
| | - Yiren Gu
- College of Animal and Veterinary Sciences, Southwest Minzu University, Chengdu 610041, China
- Animal Breeding and Genetics Key Laboratory of Sichuan Province, Sichuan Animal Science Academy, Chengdu 610066, China
| | - Long Jin
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Jingyi Bai
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Jiaman Zhang
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Yujie Wang
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Pengliang Liu
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Keren Long
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Mengnan He
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Diyan Li
- School of Pharmacy, Chengdu University, Chengdu 610106, China
| | - Can Liu
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Ziyin Han
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Yu Zhang
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Xiaokai Li
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Bo Zeng
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Lu Lu
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Fanli Kong
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Ying Sun
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
- Institute of Geriatric Health, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
| | - Yongliang Fan
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Xun Wang
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Tao Wang
- School of Pharmacy, Chengdu University, Chengdu 610106, China
| | - An'an Jiang
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Jideng Ma
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Linyuan Shen
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Li Zhu
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Yanzhi Jiang
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Guoqing Tang
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Xiaolan Fan
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Qingyou Liu
- Animal Molecular Design and Precise Breeding Key Laboratory of Guangdong Province, School of Life Science and Engineering, Foshan University, Foshan 528225, China
| | - Hua Li
- Animal Molecular Design and Precise Breeding Key Laboratory of Guangdong Province, School of Life Science and Engineering, Foshan University, Foshan 528225, China
| | - Jinyong Wang
- Pig Industry Sciences Key Laboratory of Ministry of Agriculture and Rural Affairs, Chongqing Academy of Animal Sciences, Chongqing 402460, China
- National Center of Technology Innovation for Pigs, Chongqing 402460, China
| | - Li Chen
- Pig Industry Sciences Key Laboratory of Ministry of Agriculture and Rural Affairs, Chongqing Academy of Animal Sciences, Chongqing 402460, China
- National Center of Technology Innovation for Pigs, Chongqing 402460, China
| | - Liangpeng Ge
- Pig Industry Sciences Key Laboratory of Ministry of Agriculture and Rural Affairs, Chongqing Academy of Animal Sciences, Chongqing 402460, China
- National Center of Technology Innovation for Pigs, Chongqing 402460, China
| | - Xuewei Li
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Qianzi Tang
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China;
| | - Mingzhou Li
- State Key Laboratory of Swine and Poultry Breeding Industry, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China;
| |
Collapse
|
8
|
Lee L, Rosin LF. Uncharted territories: Solving the mysteries of male meiosis in flies. PLoS Genet 2024; 20:e1011185. [PMID: 38489251 PMCID: PMC10942038 DOI: 10.1371/journal.pgen.1011185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2024] Open
Abstract
The segregation of homologous chromosomes during meiosis typically requires tight end-to-end chromosome pairing. However, in Drosophila spermatogenesis, male flies segregate their chromosomes without classic synaptonemal complex formation and without recombination, instead compartmentalizing homologs into subnuclear domains known as chromosome territories (CTs). How homologs find each other in the nucleus and are separated into CTs has been one of the biggest riddles in chromosome biology. Here, we discuss our current understanding of pairing and CT formation in flies and review recent data on how homologs are linked and partitioned during meiosis in male flies.
Collapse
Affiliation(s)
- LingSze Lee
- Unit on Chromosome Dynamics, Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Leah F. Rosin
- Unit on Chromosome Dynamics, Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| |
Collapse
|
9
|
Blum JA, Wells M, Huxley-Reicher Z, Johnson JE, Bateman JR. Transvection between nonallelic genomic positions in Drosophila. G3 (BETHESDA, MD.) 2024; 14:jkad255. [PMID: 37949840 PMCID: PMC10849331 DOI: 10.1093/g3journal/jkad255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/24/2023] [Accepted: 11/03/2023] [Indexed: 11/12/2023]
Abstract
In Drosophila, pairing of maternal and paternal homologous chromosomes can permit trans-interactions between enhancers on one homolog and promoters on another, an example of transvection. Although trans-interactions have been observed at many loci in the Drosophila genome and in other organisms, the parameters that govern enhancer action in trans remain poorly understood. Using a transgenic reporter system, we asked whether enhancers and promoters at nonallelic, but nearby, genomic positions can communication in trans. Using one transgenic insertion carrying the synthetic enhancer GMR and another nearby insertion carrying the hsp70 promoter driving a fluorescent reporter, we show that transgenes separated by 2.6 kb of linear distance can support enhancer action in trans at the 53F8 locus. Furthermore, transvection between the nonallelic insertions can be augmented by a small deletion flanking one insert, likely via changes to the paired configuration of the homologs. Subsequent analyses of other insertions in 53F8 that carry different transgenic sequences demonstrate that the capacity to support transvection between nonallelic sites varies greatly, suggesting that factors beyond the linear distance between insertion sites play an important role. Finally, analysis of transvection between nearby nonallelic sites at other genomic locations shows evidence of position effects, where one locus supported GMR action in trans over a linear distance of over 10 kb, whereas another locus showed no evidence of transvection over a span <200 bp. Overall, our data demonstrate that transvection between nonallelic sites represents a complex interplay between genomic context, interallelic distance, and promoter identity.
Collapse
Affiliation(s)
- Jacob A Blum
- Biology Department, 2 Polar Loop, Bowdoin College, Brunswick, ME 04011, USA
| | - Michelle Wells
- Biology Department, 2 Polar Loop, Bowdoin College, Brunswick, ME 04011, USA
| | | | - Justine E Johnson
- Biology Department, 2 Polar Loop, Bowdoin College, Brunswick, ME 04011, USA
| | - Jack R Bateman
- Biology Department, 2 Polar Loop, Bowdoin College, Brunswick, ME 04011, USA
| |
Collapse
|
10
|
Gao Z, Su Y, Chang L, Jiao G, Ou Y, Yang M, Xu C, Liu P, Wang Z, Qi Z, Liu W, Sun L, He G, Deng XW, He H. Increased long-distance and homo-trans interactions related to H3K27me3 in Arabidopsis hybrids. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2024; 66:208-227. [PMID: 38326968 DOI: 10.1111/jipb.13620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 01/04/2024] [Indexed: 02/09/2024]
Abstract
In plants, the genome structure of hybrids changes compared with their parents, but the effects of these changes in hybrids remain elusive. Comparing reciprocal crosses between Col × C24 and C24 × Col in Arabidopsis using high-throughput chromosome conformation capture assay (Hi-C) analysis, we found that hybrid three-dimensional (3D) chromatin organization had more long-distance interactions relative to parents, and this was mainly located in promoter regions and enriched in genes with heterosis-related pathways. The interactions between euchromatin and heterochromatin were increased, and the compartment strength decreased in hybrids. In compartment domain (CD) boundaries, the distal interactions were more in hybrids than their parents. In the hybrids of CURLY LEAF (clf) mutants clfCol × clfC24 and clfC24 × clfCol , the heterosis phenotype was damaged, and the long-distance interactions in hybrids were fewer than in their parents with lower H3K27me3. ChIP-seq data revealed higher levels of H3K27me3 in the region adjacent to the CD boundary and the same interactional homo-trans sites in the wild-type (WT) hybrids, which may have led to more long-distance interactions. In addition, the differentially expressed genes (DEGs) located in the boundaries of CDs and loop regions changed obviously in WT, and the functional enrichment for DEGs was different between WT and clf in the long-distance interactions and loop regions. Our findings may therefore propose a new epigenetic explanation of heterosis in the Arabidopsis hybrids and provide new insights into crop breeding and yield increase.
Collapse
Affiliation(s)
- Zhaoxu Gao
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
| | - Yanning Su
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
| | - Le Chang
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
| | - Guanzhong Jiao
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
| | - Yang Ou
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
| | - Mei Yang
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
| | - Chao Xu
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
| | - Pengtao Liu
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
| | - Zejia Wang
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
| | - Zewen Qi
- College of Grassland Science, Beijing Forestry University, Beijing, 100083, China
| | - Wenwen Liu
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
| | - Linhua Sun
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
| | - Guangming He
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
| | - Xing Wang Deng
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
- Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences in Weifang, Weifang 261325, China
| | - Hang He
- School of Advanced Agriculture Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, 100871, China
- Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences in Weifang, Weifang 261325, China
| |
Collapse
|
11
|
Gilliland WD, May DP, Bowen AO, Conger KO, Elrad D, Marciniak M, Mashburn SA, Presbitero G, Welk LF. A Cytological F1 RNAi Screen for Defects in Drosophila melanogaster Female Meiosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.12.575435. [PMID: 38293152 PMCID: PMC10827134 DOI: 10.1101/2024.01.12.575435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Genetic screens for recessive alleles induce mutations, make the mutated chromosomes homozygous, and then assay those homozygotes for the phenotype of interest. When screening for genes required for female meiosis, the phenotype of interest has typically been nondisjunction from chromosome segregation errors. As this requires that mutant females be viable and fertile, any mutants that are lethal or sterile when homozygous cannot be recovered by this approach. To overcome these limitations, our lab has screened the VALIUM22 collection produced by the Harvard TRiP Project, which contains RNAi constructs targeting genes known to be expressed in the germline in a vector optimized for germline expression. By driving RNAi with GAL4 under control of a germline-specific promoter (nanos or mat-alpha4), we can test genes that would be lethal if knocked down in all cells, and by examining unfertilized metaphase-arrested mature oocytes, we can identify defects associated with genes whose knockdown results in sterility or causes other errors besides nondisjunction. We screened this collection to identify genes that disrupt either of two phenotypes when knocked down: the ability of meiotic chromosomes to congress to a single mass at the end of prometaphase, and the sequestration of Mps1-GFP to ooplasmic filaments in response to hypoxia. After screening >1450 lines of the collection, we obtained multiple hits for both phenotypes, identified novel meiotic phenotypes for genes that had been previously characterized in other processes, and identified the first phenotypes to be associated with several previously uncharacterized genes.
Collapse
Affiliation(s)
| | | | | | | | - Doreen Elrad
- DePaul University Department of Biological Sciences
| | | | | | | | | |
Collapse
|
12
|
Jia BB, Jussila A, Kern C, Zhu Q, Ren B. A spatial genome aligner for resolving chromatin architectures from multiplexed DNA FISH. Nat Biotechnol 2023; 41:1004-1017. [PMID: 36593410 PMCID: PMC10344783 DOI: 10.1038/s41587-022-01568-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 10/13/2022] [Indexed: 01/03/2023]
Abstract
Multiplexed fluorescence in situ hybridization (FISH) is a widely used approach for analyzing three-dimensional genome organization, but it is challenging to derive chromosomal conformations from noisy fluorescence signals, and tracing chromatin is not straightforward. Here we report a spatial genome aligner that parses true chromatin signal from noise by aligning signals to a DNA polymer model. Using genomic distances separating imaged loci, our aligner estimates spatial distances expected to separate loci on a polymer in three-dimensional space. Our aligner then evaluates the physical probability observed signals belonging to these loci are connected, thereby tracing chromatin structures. We demonstrate that this spatial genome aligner can efficiently model chromosome architectures from DNA FISH data across multiple scales and be used to predict chromosome ploidies de novo in interphase cells. Reprocessing of previous whole-genome chromosome tracing data with this method indicates the spatial aggregation of sister chromatids in S/G2 phase cells in asynchronous mouse embryonic stem cells and provides evidence for extranumerary chromosomes that remain tightly paired in postmitotic neurons of the adult mouse cortex.
Collapse
Affiliation(s)
- Bojing Blair Jia
- Bioinformatics and Systems Biology Graduate Program, University of California San Diego, La Jolla, CA, USA
- Medical Scientist Training Program, University of California San Diego, La Jolla, CA, USA
| | - Adam Jussila
- Bioinformatics and Systems Biology Graduate Program, University of California San Diego, La Jolla, CA, USA
| | - Colin Kern
- Department of Cellular and Molecular Medicine, Center for Epigenomics, University of California San Diego, La Jolla, CA, USA
| | - Quan Zhu
- Department of Cellular and Molecular Medicine, Center for Epigenomics, University of California San Diego, La Jolla, CA, USA
| | - Bing Ren
- Department of Cellular and Molecular Medicine, Center for Epigenomics, University of California San Diego, La Jolla, CA, USA.
- Ludwig Institute for Cancer Research, La Jolla, CA, USA.
- Institute of Genomic Medicine, Moores Cancer Center, School of Medicine, University of California San Diego, La Jolla, CA, USA.
| |
Collapse
|
13
|
Marshall WF, Fung JC. Homologous chromosome recognition via nonspecific interactions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.09.544427. [PMID: 37333079 PMCID: PMC10274854 DOI: 10.1101/2023.06.09.544427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
In many organisms, most notably Drosophila, homologous chromosomes in somatic cells associate with each other, a phenomenon known as somatic homolog pairing. Unlike in meiosis, where homology is read out at the level of DNA sequence complementarity, somatic homolog pairing takes place without double strand breaks or strand invasion, thus requiring some other mechanism for homologs to recognize each other. Several studies have suggested a "specific button" model, in which a series of distinct regions in the genome, known as buttons, can associate with each other, presumably mediated by different proteins that bind to these different regions. Here we consider an alternative model, which we term the "button barcode" model, in which there is only one type of recognition site or adhesion button, present in many copies in the genome, each of which can associate with any of the others with equal affinity. An important component of this model is that the buttons are non-uniformly distributed, such that alignment of a chromosome with its correct homolog, compared with a non-homolog, is energetically favored; since to achieve nonhomologous alignment, chromosomes would be required to mechanically deform in order to bring their buttons into mutual register. We investigated several types of barcodes and examined their effect on pairing fidelity. We found that high fidelity homolog recognition can be achieved by arranging chromosome pairing buttons according to an actual industrial barcode used for warehouse sorting. By simulating randomly generated non-uniform button distributions, many highly effective button barcodes can be easily found, some of which achieve virtually perfect pairing fidelity. This model is consistent with existing literature on the effect of translocations of different sizes on homolog pairing. We conclude that a button barcode model can attain highly specific homolog recognition, comparable to that seen in actual cells undergoing somatic homolog pairing, without the need for specific interactions. This model may have implications for how meiotic pairing is achieved.
Collapse
|
14
|
Puerto M, Shukla M, Bujosa P, Perez-Roldan J, Tamirisa S, Solé C, de Nadal E, Posas F, Azorin F, Rowley MJ. Somatic chromosome pairing has a determinant impact on 3D chromatin organization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.29.534693. [PMID: 37034722 PMCID: PMC10081234 DOI: 10.1101/2023.03.29.534693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
In the nucleus, chromatin is intricately structured into multiple layers of 3D organization important for genome activity. How distinct layers influence each other is not well understood. In particular, the contribution of chromosome pairing to 3D chromatin organization has been largely neglected. Here, we address this question in Drosophila, an organism that shows robust chromosome pairing in interphasic somatic cells. The extent of chromosome pairing depends on the balance between pairing and anti-pairing factors, with the anti-pairing activity of the CAP-H2 condensin II subunit being the best documented. Here, we identify the zinc-finger protein Z4 as a strong anti-pairer that interacts with and mediates the chromatin binding of CAP-H2. We also report that hyperosmotic cellular stress induces fast and reversible chromosome unpairing that depends on Z4/CAP-H2. And, most important, by combining Z4 depletion and osmostress, we show that chromosome pairing reinforces intrachromosomal 3D interactions. On the one hand, pairing facilitates RNAPII occupancy that correlates with enhanced intragenic gene-loop interactions. In addition, acting at a distance, pairing reinforces chromatin-loop interactions mediated by Polycomb (Pc). In contrast, chromosome pairing does not affect which genomic intervals segregate to active (A) and inactive (B) compartments, with only minimal effects on the strength of A-A compartmental interactions. Altogether, our results unveil the intimate interplay between inter-chromosomal and intra-chromosomal 3D interactions, unraveling the interwoven relationship between different layers of chromatin organization and the essential contribution of chromosome pairing.
Collapse
|
15
|
Mazur AK, Gladyshev E. C-DNA may facilitate homologous DNA pairing. Trends Genet 2023:S0168-9525(23)00023-9. [PMID: 36804168 DOI: 10.1016/j.tig.2023.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/23/2023] [Accepted: 01/30/2023] [Indexed: 02/17/2023]
Abstract
Recombination-independent homologous pairing represents a prominent yet largely enigmatic feature of chromosome biology. As suggested by studies in the fungus Neurospora crassa, this process may be based on the direct pairing of homologous DNA molecules. Theoretical search for the DNA structures consistent with those genetic results has led to an all-atom model in which the B-DNA conformation of the paired double helices is strongly shifted toward C-DNA. Coincidentally, C-DNA also features a very shallow major groove that could permit initial homologous contacts without atom-atom clashes. The hereby conjectured role of C-DNA in homologous pairing should encourage the efforts to discover its biological functions and may also clarify the mechanism of recombination-independent recognition of DNA homology.
Collapse
Affiliation(s)
- Alexey K Mazur
- CNRS, Université Paris Cité, UPR 9080, Laboratoire de Biochimie Théorique, 13 rue Pierre et Marie Curie, Paris, France; Institut Pasteur, Université Paris Cité, Group Fungal Epigenomics, Paris, France.
| | - Eugene Gladyshev
- Institut Pasteur, Université Paris Cité, Group Fungal Epigenomics, Paris, France.
| |
Collapse
|
16
|
Abdennur N, Fudenberg G, Flyamer IM, Galitsyna AA, Goloborodko A, Imakaev M, Venev SV. Pairtools: from sequencing data to chromosome contacts. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.13.528389. [PMID: 36824968 PMCID: PMC9949071 DOI: 10.1101/2023.02.13.528389] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The field of 3D genome organization produces large amounts of sequencing data from Hi-C and a rapidly-expanding set of other chromosome conformation protocols (3C+). Massive and heterogeneous 3C+ data require high-performance and flexible processing of sequenced reads into contact pairs. To meet these challenges, we present pairtools - a flexible suite of tools for contact extraction from sequencing data. Pairtools provides modular command-line interface (CLI) tools that can be flexibly chained into data processing pipelines. Pairtools provides both crucial core tools as well as auxiliary tools for building feature-rich 3C+ pipelines, including contact pair manipulation, filtration, and quality control. Benchmarking pairtools against popular 3C+ data pipelines shows advantages of pairtools for high-performance and flexible 3C+ analysis. Finally, pairtools provides protocol-specific tools for multi-way contacts, haplotype-resolved contacts, and single-cell Hi-C. The combination of CLI tools and tight integration with Python data analysis libraries makes pairtools a versatile foundation for a broad range of 3C+ pipelines.
Collapse
Affiliation(s)
- Open2C
- https://open2c.github.io/
| | - Nezar Abdennur
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Chan Medical School, Worcester, MA, 01605, MA
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
| | - Geoffrey Fudenberg
- Department of Computational and Quantitative Biology, University of Southern California, Los Angeles, CA, USA
| | - Ilya M. Flyamer
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
| | - Aleksandra A. Galitsyna
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, 02139, USA
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Anton Goloborodko
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Maxim Imakaev
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, 02139, USA
| | - Sergey V. Venev
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA
| |
Collapse
|
17
|
A global high-density chromatin interaction network reveals functional long-range and trans-chromosomal relationships. Genome Biol 2022; 23:238. [PMID: 36352464 PMCID: PMC9647974 DOI: 10.1186/s13059-022-02790-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 10/10/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chromatin contacts are essential for gene-expression regulation; however, obtaining a high-resolution genome-wide chromatin contact map is still prohibitively expensive owing to large genome sizes and the quadratic scale of pairwise data. Chromosome conformation capture (3C)-based methods such as Hi-C have been extensively used to obtain chromatin contacts. However, since the sparsity of these maps increases with an increase in genomic distance between contacts, long-range or trans-chromatin contacts are especially challenging to sample. RESULTS Here, we create a high-density reference genome-wide chromatin contact map using a meta-analytic approach. We integrate 3600 human, 6700 mouse, and 500 fly Hi-C experiments to create species-specific meta-Hi-C chromatin contact maps with 304 billion, 193 billion, and 19 billion contacts in respective species. We validate that meta-Hi-C contact maps are uniquely powered to capture functional chromatin contacts in both cis and trans. We find that while individual dataset Hi-C networks are largely unable to predict any long-range coexpression (median 0.54 AUC), meta-Hi-C networks perform comparably in both cis and trans (0.65 AUC vs 0.64 AUC). Similarly, for long-range expression quantitative trait loci (eQTL), meta-Hi-C contacts outperform all individual Hi-C experiments, providing an improvement over the conventionally used linear genomic distance-based association. Assessing between species, we find patterns of chromatin contact conservation in both cis and trans and strong associations with coexpression even in species for which Hi-C data is lacking. CONCLUSIONS We have generated an integrated chromatin interaction network which complements a large number of methodological and analytic approaches focused on improved specificity or interpretation. This high-depth "super-experiment" is surprisingly powerful in capturing long-range functional relationships of chromatin interactions, which are now able to predict coexpression, eQTLs, and cross-species relationships. The meta-Hi-C networks are available at https://labshare.cshl.edu/shares/gillislab/resource/HiC/ .
Collapse
|
18
|
Fleck K, Raj R, Erceg J. The 3D genome landscape: Diverse chromosomal interactions and their functional implications. Front Cell Dev Biol 2022; 10:968145. [PMID: 36036013 PMCID: PMC9402908 DOI: 10.3389/fcell.2022.968145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
Genome organization includes contacts both within a single chromosome and between distinct chromosomes. Thus, regulatory organization in the nucleus may include interplay of these two types of chromosomal interactions with genome activity. Emerging advances in omics and single-cell imaging technologies have allowed new insights into chromosomal contacts, including those of homologs and sister chromatids, and their significance to genome function. In this review, we highlight recent studies in this field and discuss their impact on understanding the principles of chromosome organization and associated functional implications in diverse cellular processes. Specifically, we describe the contributions of intra-chromosomal, inter-homolog, and inter-sister chromatid contacts to genome organization and gene expression.
Collapse
Affiliation(s)
- Katherine Fleck
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Romir Raj
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Jelena Erceg
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
- Institute for Systems Genomics, University of Connecticut, Storrs, CT, United States
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT, United States
- *Correspondence: Jelena Erceg,
| |
Collapse
|
19
|
Bylino OV, Ibragimov AN, Digilio FA, Giordano E, Shidlovskii YV. Application of the 3C Method to Study the Developmental Genes in Drosophila Larvae. Front Genet 2022; 13:734208. [PMID: 35910225 PMCID: PMC9335292 DOI: 10.3389/fgene.2022.734208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 06/08/2022] [Indexed: 11/13/2022] Open
Abstract
A transition from one developmental stage to another is accompanied by activation of developmental programs and corresponding gene ensembles. Changes in the spatial conformation of the corresponding loci are associated with this activation and can be investigated with the help of the Chromosome Conformation Capture (3C) methodology. Application of 3C to specific developmental stages is a sophisticated task. Here, we describe the use of the 3C method to study the spatial organization of developmental loci in Drosophila larvae. We critically analyzed the existing protocols and offered our own solutions and the optimized protocol to overcome limitations. To demonstrate the efficiency of our procedure, we studied the spatial organization of the developmental locus Dad in 3rd instar Drosophila larvae. Differences in locus conformation were found between embryonic cells and living wild-type larvae. We also observed the establishment of novel regulatory interactions in the presence of an adjacent transgene upon activation of its expression in larvae. Our work fills the gap in the application of the 3C method to Drosophila larvae and provides a useful guide for establishing 3C on an animal model.
Collapse
Affiliation(s)
- Oleg V. Bylino
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Airat N. Ibragimov
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | | | - Ennio Giordano
- Department of Biology, Università di Napoli Federico II, Naples, Italy
| | - Yulii V. Shidlovskii
- Department of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- Department of Biology and General Genetics, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
- *Correspondence: Yulii V. Shidlovskii,
| |
Collapse
|
20
|
Roy S, Juste SS, Sneider M, Auradkar A, Klanseck C, Li Z, Julio AHF, Lopez del Amo V, Bier E, Guichard A. Cas9/Nickase-induced allelic conversion by homologous chromosome-templated repair in Drosophila somatic cells. SCIENCE ADVANCES 2022; 8:eabo0721. [PMID: 35776792 PMCID: PMC10883370 DOI: 10.1126/sciadv.abo0721] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Repair of double-strand breaks (DSBs) in somatic cells is primarily accomplished by error-prone nonhomologous end joining and less frequently by precise homology-directed repair preferentially using the sister chromatid as a template. Here, a Drosophila system performs efficient somatic repair of both DSBs and single-strand breaks (SSBs) using intact sequences from the homologous chromosome in a process we refer to as homologous chromosome-templated repair (HTR). Unexpectedly, HTR-mediated allelic conversion at the white locus was more efficient (40 to 65%) in response to SSBs induced by Cas9-derived nickases D10A or H840A than to DSBs induced by fully active Cas9 (20 to 30%). Repair phenotypes elicited by Nickase versus Cas9 differ in both developmental timing (late versus early stages, respectively) and the production of undesired mutagenic events (rare versus frequent). Nickase-mediated HTR represents an efficient and unanticipated mechanism for allelic correction, with far-reaching potential applications in the field of gene editing.
Collapse
Affiliation(s)
- Sitara Roy
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Sara Sanz Juste
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Marketta Sneider
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Ankush Auradkar
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Carissa Klanseck
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Zhiqian Li
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Alison Henrique Ferreira Julio
- Instituto de Ciências Biomédicas (ICB), Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, Rio de Janeiro, 21941-902 RJ, Brazil
| | - Victor Lopez del Amo
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| | - Ethan Bier
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
- Tata Institute for Genetics and Society-UCSD, La Jolla, CA 92093-0335, USA
| | - Annabel Guichard
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0335, USA
| |
Collapse
|
21
|
Sister chromatid-sensitive Hi-C to map the conformation of replicated genomes. Nat Protoc 2022; 17:1486-1517. [PMID: 35478248 DOI: 10.1038/s41596-022-00687-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 01/19/2022] [Indexed: 12/23/2022]
Abstract
Chromosome conformation capture (Hi-C) techniques map the 3D organization of entire genomes. How sister chromatids fold in replicated chromosomes, however, cannot be determined with conventional Hi-C because of the identical DNA sequences of sister chromatids. Here, we present a protocol for sister chromatid-sensitive Hi-C (scsHi-C) that enables the distinction of DNA contacts within individual sister chromatids (cis sister contacts) from those between sister chromatids (trans sister contacts), thereby allowing investigation of the organization of replicated genomes. scsHi-C is based on live-cell labeling of nascent DNA by the synthetic nucleoside 4-thio-thymidine (4sT), which incorporates into a distinct DNA strand on each sister chromatid because of semi-conservative DNA replication. After purification of genomic DNA and in situ Hi-C library preparation, 4sT is chemically converted into 5-methyl-cytosine in the presence of OsO4/NH4Cl to introduce T-to-C signature point mutations on 4sT-labeled DNA. The Hi-C library is then sequenced, and ligated fragments are assigned to sister chromatids on the basis of strand orientation and the presence of signature mutations. The ensemble of scsHi-C contacts thereby represents genome-wide contact probabilities within and across sister chromatids. scsHi-C can be completed in 2 weeks, has been successfully applied in HeLa cells and can potentially be established for any cell type that allows proper cell cycle synchronization and incorporation of sufficient amounts of 4sT. The genome-wide maps of replicated chromosomes detected by scsHi-C enable investigation of the molecular mechanisms shaping sister chromatid topologies and the relevance of sister chromatid conformation in crucial processes like DNA repair, mitotic chromosome formation and potentially other biological processes.
Collapse
|
22
|
Galouzis CC, Prud’homme B. Relevance and mechanisms of transvection. C R Biol 2021; 344:373-387. [DOI: 10.5802/crbiol.69] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 11/15/2021] [Indexed: 11/24/2022]
|
23
|
Moretti C, Stévant I, Ghavi-Helm Y. 3D genome organisation in Drosophila. Brief Funct Genomics 2021; 19:92-100. [PMID: 31796947 DOI: 10.1093/bfgp/elz029] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/02/2019] [Accepted: 09/20/2019] [Indexed: 12/17/2022] Open
Abstract
Ever since Thomas Hunt Morgan's discovery of the chromosomal basis of inheritance by using Drosophila melanogaster as a model organism, the fruit fly has remained an essential model system in studies of genome biology, including chromatin organisation. Very much as in vertebrates, in Drosophila, the genome is organised in territories, compartments and topologically associating domains (TADs). However, these domains might be formed through a slightly different mechanism than in vertebrates due to the presence of a large and potentially redundant set of insulator proteins and the minor role of dCTCF in TAD boundary formation. Here, we review the different levels of chromatin organisation in Drosophila and discuss mechanisms and factors that might be involved in TAD formation. The dynamics of TADs and enhancer-promoter interactions in the context of transcription are covered in the light of currently conflicting results. Finally, we illustrate the value of polymer modelling approaches to infer the principles governing the three-dimensional organisation of the Drosophila genome.
Collapse
Affiliation(s)
- Charlotte Moretti
- Institut de Génomique Fonctionnelle de Lyon, Univ Lyon, CNRS UMR 5242, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, 46 allée d'Italie F-69364 Lyon, France
| | - Isabelle Stévant
- Institut de Génomique Fonctionnelle de Lyon, Univ Lyon, CNRS UMR 5242, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, 46 allée d'Italie F-69364 Lyon, France
| | - Yad Ghavi-Helm
- Institut de Génomique Fonctionnelle de Lyon, Univ Lyon, CNRS UMR 5242, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, 46 allée d'Italie F-69364 Lyon, France
| |
Collapse
|
24
|
Li J, Lin Y, Tang Q, Li M. Understanding three-dimensional chromatin organization in diploid genomes. Comput Struct Biotechnol J 2021; 19:3589-3598. [PMID: 34257838 PMCID: PMC8246089 DOI: 10.1016/j.csbj.2021.06.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 06/11/2021] [Accepted: 06/12/2021] [Indexed: 11/17/2022] Open
Abstract
The three-dimensional (3D) organization of chromatin in the nucleus of diploid eukaryotic organisms has fascinated biologists for many years. Despite major progress in chromatin conformation studies, current knowledge regarding the spatial organization of diploid (maternal and paternal) genomes is still limited. Recent advances in Hi-C technology and data processing approaches have enabled construction of diploid Hi-C contact maps. These maps greatly accelerated the pace of novel discoveries in haplotype-resolved 3D genome studies, revealing the role of allele biased chromatin conformation in transcriptional regulation. Here, we review emerging concepts and haplotype phasing strategies of Hi-C data in 3D diploid genome studies. We discuss new insights on homologous chromosomal organization and the interplay between allelic biased chromatin architecture and several nuclear functions, explaining how haplotype-resolved Hi-C technologies have been used to resolve important biological questions.
Collapse
Affiliation(s)
- Jing Li
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Yu Lin
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Qianzi Tang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Mingzhou Li
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| |
Collapse
|
25
|
Child MB, Bateman JR, Jahangiri A, Reimer A, Lammers NC, Sabouni N, Villamarin D, McKenzie-Smith GC, Johnson JE, Jost D, Garcia HG. Live imaging and biophysical modeling support a button-based mechanism of somatic homolog pairing in Drosophila. eLife 2021; 10:64412. [PMID: 34100718 PMCID: PMC8294847 DOI: 10.7554/elife.64412] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 06/07/2021] [Indexed: 12/22/2022] Open
Abstract
Three-dimensional eukaryotic genome organization provides the structural basis for gene regulation. In Drosophila melanogaster, genome folding is characterized by somatic homolog pairing, where homologous chromosomes are intimately paired from end to end; however, how homologs identify one another and pair has remained mysterious. Recently, this process has been proposed to be driven by specifically interacting 'buttons' encoded along chromosomes. Here, we turned this hypothesis into a quantitative biophysical model to demonstrate that a button-based mechanism can lead to chromosome-wide pairing. We tested our model using live-imaging measurements of chromosomal loci tagged with the MS2 and PP7 nascent RNA labeling systems. We show solid agreement between model predictions and experiments in the pairing dynamics of individual homologous loci. Our results strongly support a button-based mechanism of somatic homolog pairing in Drosophila and provide a theoretical framework for revealing the molecular identity and regulation of buttons.
Collapse
Affiliation(s)
- Myron Barber Child
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.,Department of Physics, University of California, Berkeley, Berkeley, United States
| | - Jack R Bateman
- Biology Department, Bowdoin College, Brunswick, United States
| | - Amir Jahangiri
- Univ Grenoble Alpes CNRS, Grenoble INP, TIMC-IMAG, Grenoble, France
| | - Armando Reimer
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, United States
| | - Nicholas C Lammers
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, United States
| | - Nica Sabouni
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | | | | | | | - Daniel Jost
- Univ Grenoble Alpes CNRS, Grenoble INP, TIMC-IMAG, Grenoble, France.,Université de Lyon, ENS de Lyon, Univ Claude Bernard, CNRS, Laboratory of Biology and Modeling of the Cell, Lyon, France
| | - Hernan G Garcia
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.,Department of Physics, University of California, Berkeley, Berkeley, United States.,Biophysics Graduate Group, University of California, Berkeley, Berkeley, United States.,Institute for Quantitative Biosciences-QB3, University of California, Berkeley, Berkeley, United States
| |
Collapse
|
26
|
Peterson SC, Samuelson KB, Hanlon SL. Multi-Scale Organization of the Drosophila melanogaster Genome. Genes (Basel) 2021; 12:817. [PMID: 34071789 PMCID: PMC8228293 DOI: 10.3390/genes12060817] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/21/2021] [Accepted: 05/26/2021] [Indexed: 12/16/2022] Open
Abstract
Interphase chromatin, despite its appearance, is a highly organized framework of loops and bends. Chromosomes are folded into topologically associating domains, or TADs, and each chromosome and its homolog occupy a distinct territory within the nucleus. In Drosophila, genome organization is exceptional because homologous chromosome pairing is in both germline and somatic tissues, which promote interhomolog interactions such as transvection that can affect gene expression in trans. In this review, we focus on what is known about genome organization in Drosophila and discuss it from TADs to territory. We start by examining intrachromosomal organization at the sub-chromosome level into TADs, followed by a comprehensive analysis of the known proteins that play a key role in TAD formation and boundary establishment. We then zoom out to examine interhomolog interactions such as pairing and transvection that are abundant in Drosophila but rare in other model systems. Finally, we discuss chromosome territories that form within the nucleus, resulting in a complete picture of the multi-scale organization of the Drosophila genome.
Collapse
Affiliation(s)
| | | | - Stacey L. Hanlon
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA; (S.C.P.); (K.B.S.)
| |
Collapse
|
27
|
Mitter M, Gasser C, Takacs Z, Langer CCH, Tang W, Jessberger G, Beales CT, Neuner E, Ameres SL, Peters JM, Goloborodko A, Micura R, Gerlich DW. Conformation of sister chromatids in the replicated human genome. Nature 2020; 586:139-144. [PMID: 32968280 PMCID: PMC7116725 DOI: 10.1038/s41586-020-2744-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 06/30/2020] [Indexed: 02/07/2023]
Abstract
The three-dimensional organization of the genome supports regulated gene expression, recombination, DNA repair, and chromosome segregation during mitosis. Chromosome conformation capture (Hi-C)1,2 analysis has revealed a complex genomic landscape of internal chromosomal structures in vertebrate cells3-7, but the identical sequence of sister chromatids has made it difficult to determine how they topologically interact in replicated chromosomes. Here we describe sister-chromatid-sensitive Hi-C (scsHi-C), which is based on labelling of nascent DNA with 4-thio-thymidine and nucleoside conversion chemistry. Genome-wide conformation maps of human chromosomes reveal that sister-chromatid pairs interact most frequently at the boundaries of topologically associating domains (TADs). Continuous loading of a dynamic cohesin pool separates sister-chromatid pairs inside TADs and is required to focus sister-chromatid contacts at TAD boundaries. We identified a subset of TADs that are overall highly paired and are characterized by facultative heterochromatin and insulated topological domains that form separately within individual sister chromatids. The rich pattern of sister-chromatid topologies and our scsHi-C technology will make it possible to investigate how physical interactions between identical DNA molecules contribute to DNA repair, gene expression, chromosome segregation, and potentially other biological processes.
Collapse
Affiliation(s)
- Michael Mitter
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria.
| | - Catherina Gasser
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI), Leopold-Franzens University, Innsbruck, Austria
| | - Zsuzsanna Takacs
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Christoph C H Langer
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Wen Tang
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Gregor Jessberger
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Charlie T Beales
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Eva Neuner
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI), Leopold-Franzens University, Innsbruck, Austria
| | - Stefan L Ameres
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Anton Goloborodko
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI), Leopold-Franzens University, Innsbruck, Austria
| | - Daniel W Gerlich
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria.
| |
Collapse
|
28
|
Hiraoka Y. Phase separation drives pairing of homologous chromosomes. Curr Genet 2020; 66:881-887. [PMID: 32285141 DOI: 10.1007/s00294-020-01077-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/04/2020] [Accepted: 04/06/2020] [Indexed: 01/06/2023]
Abstract
Pairing of homologous chromosomes is crucial for ensuring accurate segregation of chromosomes during meiosis. Molecular mechanisms of homologous chromosome pairing in meiosis have been extensively studied in the fission yeast Schizosaccharomyces pombe. In this organism, meiosis-specific noncoding RNA transcribed from specific genes accumulates at the respective gene loci, and chromosome-associated RNA-protein complexes mediate meiotic pairing of homologous loci through phase separation. Pairing of homologous chromosomes also occurs in somatic diploid cells in certain situations. For example, somatic pairing of homologous chromosomes occurs during the early embryogenesis in diptera, and relies on the transcription-associated chromatin architecture. Earlier models also suggest that transcription factories along the chromosome mediate pairing of homologous chromosomes in plants. These studies suggest that RNA bodies formed on chromosomes mediate the pairing of homologous chromosomes. This review summarizes lessons from S. pombe to provide general insights into mechanisms of homologous chromosome pairing mediated by phase separation of chromosome-associated RNA-protein complexes.
Collapse
Affiliation(s)
- Yasushi Hiraoka
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, 565-0871, Japan.
| |
Collapse
|
29
|
Pericentromeric heterochromatin is hierarchically organized and spatially contacts H3K9me2 islands in euchromatin. PLoS Genet 2020; 16:e1008673. [PMID: 32203508 PMCID: PMC7147806 DOI: 10.1371/journal.pgen.1008673] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 04/10/2020] [Accepted: 02/14/2020] [Indexed: 01/02/2023] Open
Abstract
Membraneless pericentromeric heterochromatin (PCH) domains play vital roles in chromosome dynamics and genome stability. However, our current understanding of 3D genome organization does not include PCH domains because of technical challenges associated with repetitive sequences enriched in PCH genomic regions. We investigated the 3D architecture of Drosophila melanogaster PCH domains and their spatial associations with the euchromatic genome by developing a novel analysis method that incorporates genome-wide Hi-C reads originating from PCH DNA. Combined with cytogenetic analysis, we reveal a hierarchical organization of the PCH domains into distinct “territories.” Strikingly, H3K9me2-enriched regions embedded in the euchromatic genome show prevalent 3D interactions with the PCH domain. These spatial contacts require H3K9me2 enrichment, are likely mediated by liquid-liquid phase separation, and may influence organismal fitness. Our findings have important implications for how PCH architecture influences the function and evolution of both repetitive heterochromatin and the gene-rich euchromatin. The three dimensional (3D) organization of genomes in cell nuclei can influence a wide variety of genome functions. However, most of our understanding of this critical architecture has been limited to the gene-rich euchromatin, and largely ignores the gene-poor and repeat-rich pericentromeric heterochromatin, or PCH. PCH comprises a large part of most eukaryotic genomes, forms 3D membraneless PCH domains in nuclei, and plays a vital role in chromosome dynamics and genome stability. In this study, we developed a new method that overcomes the technical challenges imposed by the highly repetitive PCH DNA, and generated a comprehensive picture of its 3D organization. Combined with image analyses, we reveal a hierarchical organization of the PCH domains. Surprisingly, we showed that distant euchromatic regions enriched for repressive epigenetic marks also dynamically interact with the main PCH domains. These 3D interactions are likely mediated by liquid-liquid phase separation (similar to how oil and vinegar separate in salad dressing) and the resulting liquid-like fusion events, and can influence the fitness of individuals. Our discoveries have strong implications for how seemingly “junk” DNA could impact functions in the gene-rich euchromatin.
Collapse
|
30
|
George P, Kinney NA, Liang J, Onufriev AV, Sharakhov IV. Three-dimensional Organization of Polytene Chromosomes in Somatic and Germline Tissues of Malaria Mosquitoes. Cells 2020; 9:cells9020339. [PMID: 32024176 PMCID: PMC7072178 DOI: 10.3390/cells9020339] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/22/2020] [Accepted: 01/28/2020] [Indexed: 12/17/2022] Open
Abstract
Spatial organization of chromosome territories and interactions between interphase chromosomes themselves, as well as with the nuclear periphery, play important roles in epigenetic regulation of the genome function. However, the interplay between inter-chromosomal contacts and chromosome-nuclear envelope attachments in an organism’s development is not well-understood. To address this question, we conducted microscopic analyses of the three-dimensional chromosome organization in malaria mosquitoes. We employed multi-colored oligonucleotide painting probes, spaced 1 Mb apart along the euchromatin, to quantitatively study chromosome territories in larval salivary gland cells and adult ovarian nurse cells of Anopheles gambiae, An. coluzzii, and An. merus. We found that the X chromosome territory has a significantly smaller volume and is more compact than the autosomal arm territories. The number of inter-chromosomal, and the percentage of the chromosome–nuclear envelope, contacts were conserved among the species within the same cell type. However, the percentage of chromosome regions located at the nuclear periphery was typically higher, while the number of inter-chromosomal contacts was lower, in salivary gland cells than in ovarian nurse cells. The inverse correlation was considerably stronger for the autosomes. Consistent with previous theoretical arguments, our data indicate that, at the genome-wide level, there is an inverse relationship between chromosome-nuclear envelope attachments and chromosome–chromosome interactions, which is a key feature of the cell type-specific nuclear architecture.
Collapse
Affiliation(s)
- Phillip George
- Department of Entomology, Virginia Tech, Blacksburg, VA 24061, USA; (P.G.); (J.L.)
| | - Nicholas A. Kinney
- Genomics, Bioinformatics and Computational Biology, Virginia Tech, Blacksburg, VA 24061, USA; (N.A.K.); (A.V.O.)
| | - Jiangtao Liang
- Department of Entomology, Virginia Tech, Blacksburg, VA 24061, USA; (P.G.); (J.L.)
| | - Alexey V. Onufriev
- Genomics, Bioinformatics and Computational Biology, Virginia Tech, Blacksburg, VA 24061, USA; (N.A.K.); (A.V.O.)
- Department of Computer Science, Virginia Tech, Blacksburg, VA 24061, USA
| | - Igor V. Sharakhov
- Department of Entomology, Virginia Tech, Blacksburg, VA 24061, USA; (P.G.); (J.L.)
- Genomics, Bioinformatics and Computational Biology, Virginia Tech, Blacksburg, VA 24061, USA; (N.A.K.); (A.V.O.)
- Department of Cytology and Genetics, Tomsk State University, 634050 Tomsk, Russian Federation
- Correspondence: ; Tel.: +1-540-231-7316
| |
Collapse
|
31
|
Corbett-Detig RB, Said I, Calzetta M, Genetti M, McBroome J, Maurer NW, Petrarca V, Della Torre A, Besansky NJ. Fine-Mapping Complex Inversion Breakpoints and Investigating Somatic Pairing in the Anopheles gambiae Species Complex Using Proximity-Ligation Sequencing. Genetics 2019; 213:1495-1511. [PMID: 31666292 PMCID: PMC6893396 DOI: 10.1534/genetics.119.302385] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 10/21/2019] [Indexed: 11/18/2022] Open
Abstract
Chromosomal inversions are fundamental drivers of genome evolution. In the main Afrotropical malaria vector species, belonging to the Anopheles gambiae species complex, inversions play an important role in local adaptation and have a rich history of cytological study. Despite the importance and ubiquity of some chromosomal inversions across the species complex, inversion breakpoints are often challenging to map molecularly due to the presence of large repetitive regions. Here, we develop an approach that uses Hi-C sequencing data to molecularly fine-map the breakpoints of inversions. We demonstrate that this approach is robust and likely to be widely applicable for both identification and fine-mapping inversion breakpoints in species whose inversions have heretofore been challenging to characterize. We apply our method to interrogate the previously unknown inversion breakpoints of 2Rbc and 2Rd in An. coluzzii We found that inversion breakpoints occur in large repetitive regions, and, strikingly, among three inversions analyzed, two breakpoints appear to be reused in two separate inversions. These breakpoint-adjacent regions are strongly enriched for the presence of a 30 bp satellite repeat sequence. Because low frequency inversion breakpoints are not correlated with genomic regions containing this satellite, we suggest that interrupting this particular repeat may result in arrangements with higher relative fitness. Additionally, we use heterozygous individuals to quantitatively investigate the impacts of somatic pairing in the regions immediately surrounding inversion breakpoints. Finally, we discuss important considerations for possible applications of this approach for inversion breakpoint identification in a range of organisms.
Collapse
Affiliation(s)
- Russell B Corbett-Detig
- Department of Biomolecular Engineering, University of California Santa Cruz, California 95064
- Genomics Institute, University of California Santa Cruz, California 95064
| | - Iskander Said
- Department of Biomolecular Engineering, University of California Santa Cruz, California 95064
| | - Maria Calzetta
- Dipartimento di Sanità Pubblica e Malattie Infettive and Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "La Sapienza", 00185 Rome, Italy
| | - Max Genetti
- Department of Biomolecular Engineering, University of California Santa Cruz, California 95064
| | - Jakob McBroome
- Department of Biomolecular Engineering, University of California Santa Cruz, California 95064
| | - Nicholas W Maurer
- Department of Biomolecular Engineering, University of California Santa Cruz, California 95064
| | - Vincenzo Petrarca
- Dipartimento di Sanità Pubblica e Malattie Infettive and Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "La Sapienza", 00185 Rome, Italy
| | - Alessandra Della Torre
- Dipartimento di Sanità Pubblica e Malattie Infettive and Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "La Sapienza", 00185 Rome, Italy
| | - Nora J Besansky
- Eck Institute for Global Health and Department of Biological Sciences, University of Notre Dame, Indiana 46556
| |
Collapse
|
32
|
Global chromatin conformation differences in the Drosophila dosage compensated chromosome X. Nat Commun 2019; 10:5355. [PMID: 31767860 PMCID: PMC6877619 DOI: 10.1038/s41467-019-13350-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 11/01/2019] [Indexed: 01/08/2023] Open
Abstract
In Drosophila melanogaster the single male chromosome X undergoes an average twofold transcriptional upregulation for balancing the transcriptional output between sexes. Previous literature hypothesised that a global change in chromosome structure may accompany this process. However, recent studies based on Hi-C failed to detect these differences. Here we show that global conformational differences are specifically present in the male chromosome X and detectable using Hi-C data on sex-sorted embryos, as well as male and female cell lines, by leveraging custom data analysis solutions. We find the male chromosome X has more mid-/long-range interactions. We also identify differences at structural domain boundaries containing BEAF-32 in conjunction with CP190 or Chromator. Weakening of these domain boundaries in male chromosome X co-localizes with the binding of the dosage compensation complex and its co-factor CLAMP, reported to enhance chromatin accessibility. Together, our data strongly indicate that chromosome X dosage compensation affects global chromosome structure. In Drosophila, dosage compensation involves a twofold transcriptional upregulation of the single male chromosome X. Here the authors show that global conformational differences are specifically present in the male X chromosome and detectable using Hi-C data, indicating that dosage compensation affects global chromosome structure.
Collapse
|
33
|
Mazur AK, Nguyen TS, Gladyshev E. Direct Homologous dsDNA-dsDNA Pairing: How, Where, and Why? J Mol Biol 2019; 432:737-744. [PMID: 31726060 DOI: 10.1016/j.jmb.2019.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/22/2019] [Accepted: 11/05/2019] [Indexed: 10/25/2022]
Abstract
The ability of homologous chromosomes (or selected chromosomal loci) to pair specifically in the apparent absence of DNA breakage and recombination represents a prominent feature of eukaryotic biology. The mechanism of homology recognition at the basis of such recombination-independent pairing has remained elusive. A number of studies have supported the idea that sequence homology can be sensed between intact DNA double helices in vivo. In particular, recent analyses of the two silencing phenomena in fungi, known as "repeat-induced point mutation" (RIP) and "meiotic silencing by unpaired DNA" (MSUD), have provided genetic evidence for the existence of the direct homologous dsDNA-dsDNA pairing. Both RIP and MSUD likely rely on the same search strategy, by which dsDNA segments are matched as arrays of interspersed base-pair triplets. This process is general and very efficient, yet it proceeds normally without the RecA/Rad51/Dmc1 proteins. Further studies of RIP and MSUD may yield surprising insights into the function of DNA in the cell.
Collapse
Affiliation(s)
- Alexey K Mazur
- CNRS, Université de Paris, UPR 9080, Laboratoire de Biochimie Théorique, 13 Rue Pierre et Marie Curie, F-75005 Paris, France; Group Fungal Epigenomics, Department of Mycology, Institut Pasteur, Paris 75015, France; Institut de Biologie Physico-Chimique-Fondation Edmond de Rothschild, PSL Research University, Paris, France
| | - Tinh-Suong Nguyen
- Group Fungal Epigenomics, Department of Mycology, Institut Pasteur, Paris 75015, France
| | - Eugene Gladyshev
- Group Fungal Epigenomics, Department of Mycology, Institut Pasteur, Paris 75015, France.
| |
Collapse
|
34
|
Viets K, Sauria MEG, Chernoff C, Rodriguez Viales R, Echterling M, Anderson C, Tran S, Dove A, Goyal R, Voortman L, Gordus A, Furlong EEM, Taylor J, Johnston RJ. Characterization of Button Loci that Promote Homologous Chromosome Pairing and Cell-Type-Specific Interchromosomal Gene Regulation. Dev Cell 2019; 51:341-356.e7. [PMID: 31607649 DOI: 10.1016/j.devcel.2019.09.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 06/07/2019] [Accepted: 09/09/2019] [Indexed: 01/05/2023]
Abstract
Homologous chromosomes colocalize to regulate gene expression in processes including genomic imprinting, X-inactivation, and transvection. In Drosophila, homologous chromosomes pair throughout development, promoting transvection. The "button" model of pairing proposes that specific regions along chromosomes pair with high affinity. Here, we identify buttons interspersed across the fly genome that pair with their homologous sequences, even when relocated to multiple positions in the genome. A majority of transgenes that span a full topologically associating domain (TAD) function as buttons, but not all buttons contain TADs. Additionally, buttons are enriched for insulator protein clusters. Fragments of buttons do not pair, suggesting that combinations of elements within a button are required for pairing. Pairing is necessary but not sufficient for transvection. Additionally, pairing and transvection are stronger in some cell types than in others, suggesting that pairing strength regulates transvection efficiency between cell types. Thus, buttons pair homologous chromosomes to facilitate cell-type-specific interchromosomal gene regulation.
Collapse
Affiliation(s)
- Kayla Viets
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Michael E G Sauria
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Chaim Chernoff
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | | | - Max Echterling
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Caitlin Anderson
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Sang Tran
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Abigail Dove
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Raghav Goyal
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Lukas Voortman
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Andrew Gordus
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Eileen E M Furlong
- European Molecular Biology Laboratory, Department of Genome Biology, Heidelberg 69117, Germany
| | - James Taylor
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Robert J Johnston
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA.
| |
Collapse
|
35
|
Mirny LA, Imakaev M, Abdennur N. Two major mechanisms of chromosome organization. Curr Opin Cell Biol 2019; 58:142-152. [PMID: 31228682 DOI: 10.1016/j.ceb.2019.05.001] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/14/2019] [Accepted: 05/03/2019] [Indexed: 12/13/2022]
Abstract
The spatial organization of chromosomes has long been connected to their polymeric nature and is believed to be important for their biological functions, including the control of interactions between genomic elements, the maintenance of genetic information, and the compaction and safe transfer of chromosomes to cellular progeny. chromosome conformation capture techniques, particularly Hi-C, have provided a comprehensive picture of spatial chromosome organization and revealed new features and elements of chromosome folding. Furthermore, recent advances in microscopy have made it possible to obtain distance maps for extensive regions of chromosomes (Bintu et al., 2018; Nir et al., 2018 [2••,3]), providing information complementary to, and in excellent agreement with, Hi-C maps. Not only has the resolution of both techniques advanced significantly, but new perturbation data generated in the last two years have led to the identification of molecular mechanisms behind large-scale genome organization. Two major mechanisms that have been proposed to govern chromosome organization are (i) the active (ATP-dependent) process of loop extrusion by Structural Maintenance of Chromosomes (SMC) complexes, and (ii) the spatial compartmentalization of the genome, which is likely mediated by affinity interactions between heterochromatic regions (Falk et al., 2019 [76••]) rather than by ATP-dependent processes. Here, we review existing evidence that these two processes operate together to fold chromosomes in interphase and that loop extrusion alone drives mitotic compaction. We discuss possible implications of these mechanisms for chromosome function.
Collapse
Affiliation(s)
- Leonid A Mirny
- Institute for Medical Engineering and Science, and Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139, USA.
| | - Maxim Imakaev
- Institute for Medical Engineering and Science, and Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139, USA
| | - Nezar Abdennur
- Institute for Medical Engineering and Science, and Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139, USA.
| |
Collapse
|
36
|
Piwko P, Vitsaki I, Livadaras I, Delidakis C. The Role of Insulators in Transgene Transvection in Drosophila. Genetics 2019; 212:489-508. [PMID: 30948430 PMCID: PMC6553826 DOI: 10.1534/genetics.119.302165] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/02/2019] [Indexed: 12/19/2022] Open
Abstract
Transvection is the phenomenon where a transcriptional enhancer activates a promoter located on the homologous chromosome. It has been amply documented in Drosophila where homologs are closely paired in most, if not all, somatic nuclei, but it has been known to rarely occur in mammals as well. We have taken advantage of site-directed transgenesis to insert reporter constructs into the same genetic locus in Drosophila and have evaluated their ability to engage in transvection by testing many heterozygous combinations. We find that transvection requires the presence of an insulator element on both homologs. Homotypic trans-interactions between four different insulators can support transvection: the gypsy insulator (GI), Wari, Fab-8 and 1A2; GI and Fab-8 are more effective than Wari or 1A2 We show that, in the presence of insulators, transvection displays the characteristics that have been previously described: it requires homolog pairing, but can happen at any of several loci in the genome; a solitary enhancer confronted with an enhancerless reporter is sufficient to drive transcription; it is weaker than the action of the same enhancer-promoter pair in cis, and it is further suppressed by cis-promoter competition. Though necessary, the presence of homotypic insulators is not sufficient for transvection; their position, number and orientation matters. A single GI adjacent to both enhancer and promoter is the optimal configuration. The identity of enhancers and promoters in the vicinity of a trans-interacting insulator pair is also important, indicative of complex insulator-enhancer-promoter interactions.
Collapse
Affiliation(s)
- Pawel Piwko
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion 70013, Crete, Greece
- Department of Biology, University of Crete, Heraklion 70013, Crete, Greece
| | - Ilektra Vitsaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion 70013, Crete, Greece
- Department of Biology, University of Crete, Heraklion 70013, Crete, Greece
| | - Ioannis Livadaras
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion 70013, Crete, Greece
| | - Christos Delidakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Heraklion 70013, Crete, Greece
- Department of Biology, University of Crete, Heraklion 70013, Crete, Greece
| |
Collapse
|