1
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Kanata E, Duffié R, Schulz EG. Establishment and maintenance of random monoallelic expression. Development 2024; 151:dev201741. [PMID: 38813842 PMCID: PMC11166465 DOI: 10.1242/dev.201741] [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] [Indexed: 05/31/2024]
Abstract
This Review elucidates the regulatory principles of random monoallelic expression by focusing on two well-studied examples: the X-chromosome inactivation regulator Xist and the olfactory receptor gene family. Although the choice of a single X chromosome or olfactory receptor occurs in different developmental contexts, common gene regulatory principles guide monoallelic expression in both systems. In both cases, an event breaks the symmetry between genetically and epigenetically identical copies of the gene, leading to the expression of one single random allele, stabilized through negative feedback control. Although many regulatory steps that govern the establishment and maintenance of monoallelic expression have been identified, key pieces of the puzzle are still missing. We provide an overview of the current knowledge and models for the monoallelic expression of Xist and olfactory receptors. We discuss their similarities and differences, and highlight open questions and approaches that could guide the study of other monoallelically expressed genes.
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Affiliation(s)
- Eleni Kanata
- Systems Epigenetics, Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Rachel Duffié
- Department of Biochemistry and Molecular Biophysics, Mortimer B. Zuckerman Mind, Brain, and Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Edda G. Schulz
- Systems Epigenetics, Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
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2
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Chriss A, Börner GV, Ryan SD. Agent-based modeling of nuclear chromosome ensembles identifies determinants of homolog pairing during meiosis. PLoS Comput Biol 2024; 20:e1011416. [PMID: 38739641 PMCID: PMC11115365 DOI: 10.1371/journal.pcbi.1011416] [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: 08/08/2023] [Revised: 05/23/2024] [Accepted: 04/10/2024] [Indexed: 05/16/2024] Open
Abstract
During meiosis, pairing of homologous chromosomes (homologs) ensures the formation of haploid gametes from diploid precursor cells, a prerequisite for sexual reproduction. Pairing during meiotic prophase I facilitates crossover recombination and homolog segregation during the ensuing reductional cell division. Mechanisms that ensure stable homolog alignment in the presence of an excess of non-homologous chromosomes have remained elusive, but rapid chromosome movements appear to play a role in the process. Apart from homolog attraction, provided by early intermediates of homologous recombination, dissociation of non-homologous associations also appears to contribute to homolog pairing, as suggested by the detection of stable non-homologous chromosome associations in pairing-defective mutants. Here, we have developed an agent-based model for homolog pairing derived from the dynamics of a naturally occurring chromosome ensemble. The model simulates unidirectional chromosome movements, as well as collision dynamics determined by attractive and repulsive forces arising from close-range physical interactions. Chromosome number and size as well as movement velocity and repulsive forces are identified as key factors in the kinetics and efficiency of homologous pairing in addition to homolog attraction. Dissociation of interactions between non-homologous chromosomes may contribute to pairing by crowding homologs into a limited nuclear area thus creating preconditions for close-range homolog attraction. Incorporating natural chromosome lengths, the model accurately recapitulates efficiency and kinetics of homolog pairing observed for wild-type and mutant meiosis in budding yeast, and can be adapted to nuclear dimensions and chromosome sets of other organisms.
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Affiliation(s)
- Ariana Chriss
- Department of Mathematics and Statistics, Cleveland State University, Cleveland, Ohio, United States of America
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University, Cleveland, Ohio, United States of America
| | - G. Valentin Börner
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University, Cleveland, Ohio, United States of America
- Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, Ohio, United States of America
| | - Shawn D. Ryan
- Department of Mathematics and Statistics, Cleveland State University, Cleveland, Ohio, United States of America
- Center for Applied Data Analysis and Modeling, Cleveland State University, Cleveland, Ohio, United States of America
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3
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Malcore RM, Kalantry S. A Comparative Analysis of Mouse Imprinted and Random X-Chromosome Inactivation. EPIGENOMES 2024; 8:8. [PMID: 38390899 PMCID: PMC10885068 DOI: 10.3390/epigenomes8010008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 02/01/2024] [Accepted: 02/06/2024] [Indexed: 02/24/2024] Open
Abstract
The mammalian sexes are distinguished by the X and Y chromosomes. Whereas males harbor one X and one Y chromosome, females harbor two X chromosomes. To equalize X-linked gene expression between the sexes, therian mammals have evolved X-chromosome inactivation as a dosage compensation mechanism. During X-inactivation, most genes on one of the two X chromosomes in females are transcriptionally silenced, thus equalizing X-linked gene expression between the sexes. Two forms of X-inactivation characterize eutherian mammals, imprinted and random. Imprinted X-inactivation is defined by the exclusive inactivation of the paternal X chromosome in all cells, whereas random X-inactivation results in the silencing of genes on either the paternal or maternal X chromosome in individual cells. Both forms of X-inactivation have been studied intensively in the mouse model system, which undergoes both imprinted and random X-inactivation early in embryonic development. Stable imprinted and random X-inactivation requires the induction of the Xist long non-coding RNA. Following its induction, Xist RNA recruits proteins and complexes that silence genes on the inactive-X. In this review, we present a current understanding of the mechanisms of Xist RNA induction, and, separately, the establishment and maintenance of gene silencing on the inactive-X by Xist RNA during imprinted and random X-inactivation.
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Affiliation(s)
| | - Sundeep Kalantry
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48105, USA
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4
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Chriss A, Börner GV, Ryan SD. Agent-based modeling of nuclear chromosome ensemble identifies determinants of homolog pairing during meiosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.09.552574. [PMID: 38260664 PMCID: PMC10802385 DOI: 10.1101/2023.08.09.552574] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
During meiosis, pairing of homologous chromosomes (homologs) ensures the formation of haploid gametes from diploid precursor cells, a prerequisite for sexual reproduction. Pairing during meiotic prophase I facilitates crossover recombination and homolog segregation during the ensuing reductional cell division. Mechanisms that ensure stable homolog alignment in the presence of an excess of non-homologous chromosomes have remained elusive, but rapid chromosome movements during prophase I appear to play a role in the process. Apart from homolog attraction, provided by early intermediates of homologous recombination, dissociation of non-homologous associations also appears to contribute to homolog pairing, as suggested by the detection of stable non-homologous chromosome associations in pairing-defective mutants. Here, we have developed an agent-based model for homolog pairing derived from the dynamics of a naturally occurring chromosome ensemble. The model simulates unidirectional chromosome movements, as well as collision dynamics determined by attractive and repulsive forces arising from close-range physical interactions. In addition to homolog attraction, chromosome number and size as well as movement velocity and repulsive forces are identified as key factors in the kinetics and efficiency of homologous pairing. Dissociation of interactions between non-homologous chromosomes may contribute to pairing by crowding homologs into a limited nuclear area thus creating preconditions for close-range homolog attraction. Predictions from the model are readily compared to experimental data from budding yeast, parameters can be adjusted to other cellular systems and predictions from the model can be tested via experimental manipulation of the relevant chromosomal features.
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Affiliation(s)
- Ariana Chriss
- Department of Mathematics and Statistics, Cleveland State University, Cleveland, OH 44115
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University, Cleveland, OH 44115
| | - G. Valentin Börner
- Department of Biological, Geological, and Environmental Sciences, Cleveland State University, Cleveland, OH 44115
- Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH 44115
| | - Shawn D. Ryan
- Department of Mathematics and Statistics, Cleveland State University, Cleveland, OH 44115
- Center for Applied Data Analysis and Modeling, Cleveland State University, Cleveland, OH 44115
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5
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Lei X, Tian X, Wang H, Xu X, Li G, Liu W, Wang D, Xiao Z, Zhang M, Li MJ, Zhang Z, Ma Z, Liu Z. Noncoding SNP at rs1663689 represses ADGRG6 via interchromosomal interaction and reduces lung cancer progression. EMBO Rep 2023; 24:e56212. [PMID: 37154297 PMCID: PMC10328068 DOI: 10.15252/embr.202256212] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 04/05/2023] [Accepted: 04/18/2023] [Indexed: 05/10/2023] Open
Abstract
A previous genome-wide association study (GWAS) revealed an association of the noncoding SNP rs1663689 with susceptibility to lung cancer in the Chinese population. However, the underlying mechanism is unknown. In this study, using allele-specific 4C-seq in heterozygous lung cancer cells combined with epigenetic information from CRISPR/Cas9-edited cell lines, we show that the rs1663689 C/C variant represses the expression of ADGRG6, a gene located on a separate chromosome, through an interchromosomal interaction of the rs1663689 bearing region with the ADGRG6 promoter. This reduces downstream cAMP-PKA signaling and subsequently tumor growth both in vitro and in xenograft models. Using patient-derived organoids, we show that rs1663689 T/T-but not C/C-bearing lung tumors are sensitive to the PKA inhibitor H89, potentially informing therapeutic strategies. Our study identifies a genetic variant-mediated interchromosomal interaction underlying ADGRG6 regulation and suggests that targeting the cAMP-PKA signaling pathway may be beneficial in lung cancer patients bearing the homozygous risk genotype at rs1663689.
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Affiliation(s)
- Xinyue Lei
- Department of Lung Cancer CenterTianjin Medical University Cancer Institute and HospitalHaihe Laboratory of Cell EcosystemState Key Laboratory of Experimental HematologyDepartment of UrologyThe Second Hospital of Tianjin Medical UniversityKey Laboratory of Immune Microenvironment and Disease of the Ministry of EducationDepartment of ImmunologySchool of Basic Medical SciencesTianjin Medical UniversityTianjinChina
| | - Xiaoling Tian
- Department of Lung Cancer CenterTianjin Medical University Cancer Institute and HospitalHaihe Laboratory of Cell EcosystemState Key Laboratory of Experimental HematologyDepartment of UrologyThe Second Hospital of Tianjin Medical UniversityKey Laboratory of Immune Microenvironment and Disease of the Ministry of EducationDepartment of ImmunologySchool of Basic Medical SciencesTianjin Medical UniversityTianjinChina
| | - Hao Wang
- Department of Lung Cancer CenterTianjin Medical University Cancer Institute and HospitalHaihe Laboratory of Cell EcosystemState Key Laboratory of Experimental HematologyDepartment of UrologyThe Second Hospital of Tianjin Medical UniversityKey Laboratory of Immune Microenvironment and Disease of the Ministry of EducationDepartment of ImmunologySchool of Basic Medical SciencesTianjin Medical UniversityTianjinChina
| | - Xinran Xu
- Department of Pharmacology, School of Basic Medical SciencesTianjin Medical UniversityTianjinChina
| | - Guoli Li
- Department of Lung Cancer CenterTianjin Medical University Cancer Institute and HospitalHaihe Laboratory of Cell EcosystemState Key Laboratory of Experimental HematologyDepartment of UrologyThe Second Hospital of Tianjin Medical UniversityKey Laboratory of Immune Microenvironment and Disease of the Ministry of EducationDepartment of ImmunologySchool of Basic Medical SciencesTianjin Medical UniversityTianjinChina
| | - Wenxu Liu
- Department of Lung Cancer CenterTianjin Medical University Cancer Institute and HospitalHaihe Laboratory of Cell EcosystemState Key Laboratory of Experimental HematologyDepartment of UrologyThe Second Hospital of Tianjin Medical UniversityKey Laboratory of Immune Microenvironment and Disease of the Ministry of EducationDepartment of ImmunologySchool of Basic Medical SciencesTianjin Medical UniversityTianjinChina
| | - Dan Wang
- Department of Lung Cancer CenterTianjin Medical University Cancer Institute and HospitalHaihe Laboratory of Cell EcosystemState Key Laboratory of Experimental HematologyDepartment of UrologyThe Second Hospital of Tianjin Medical UniversityKey Laboratory of Immune Microenvironment and Disease of the Ministry of EducationDepartment of ImmunologySchool of Basic Medical SciencesTianjin Medical UniversityTianjinChina
| | - Zengtuan Xiao
- Department of Lung Cancer CenterTianjin Medical University Cancer Institute and HospitalHaihe Laboratory of Cell EcosystemState Key Laboratory of Experimental HematologyDepartment of UrologyThe Second Hospital of Tianjin Medical UniversityKey Laboratory of Immune Microenvironment and Disease of the Ministry of EducationDepartment of ImmunologySchool of Basic Medical SciencesTianjin Medical UniversityTianjinChina
| | - Mengzhe Zhang
- Department of Lung Cancer CenterTianjin Medical University Cancer Institute and HospitalHaihe Laboratory of Cell EcosystemState Key Laboratory of Experimental HematologyDepartment of UrologyThe Second Hospital of Tianjin Medical UniversityKey Laboratory of Immune Microenvironment and Disease of the Ministry of EducationDepartment of ImmunologySchool of Basic Medical SciencesTianjin Medical UniversityTianjinChina
| | - Mulin Jun Li
- Department of Pharmacology, School of Basic Medical SciencesTianjin Medical UniversityTianjinChina
| | - Zhenfa Zhang
- Department of Lung Cancer CenterTianjin Medical University Cancer Institute and HospitalHaihe Laboratory of Cell EcosystemState Key Laboratory of Experimental HematologyDepartment of UrologyThe Second Hospital of Tianjin Medical UniversityKey Laboratory of Immune Microenvironment and Disease of the Ministry of EducationDepartment of ImmunologySchool of Basic Medical SciencesTianjin Medical UniversityTianjinChina
| | - Zhenyi Ma
- Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Department of Cell Biology, School of Basic Medical SciencesHangzhou Normal UniversityHangzhouChina
| | - Zhe Liu
- Department of Lung Cancer CenterTianjin Medical University Cancer Institute and HospitalHaihe Laboratory of Cell EcosystemState Key Laboratory of Experimental HematologyDepartment of UrologyThe Second Hospital of Tianjin Medical UniversityKey Laboratory of Immune Microenvironment and Disease of the Ministry of EducationDepartment of ImmunologySchool of Basic Medical SciencesTianjin Medical UniversityTianjinChina
- Department of Pharmacology, School of Basic Medical SciencesTianjin Medical UniversityTianjinChina
- Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Department of Cell Biology, School of Basic Medical SciencesHangzhou Normal UniversityHangzhouChina
- Collaborative Innovation Center for Cancer Personalized MedicineNanjing Medical UniversityNanjingChina
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6
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Ocañas SR, Ansere VA, Kellogg CM, Isola JVV, Chucair-Elliott AJ, Freeman WM. Chromosomal and gonadal factors regulate microglial sex effects in the aging brain. Brain Res Bull 2023; 195:157-171. [PMID: 36804773 PMCID: PMC10810555 DOI: 10.1016/j.brainresbull.2023.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 02/10/2023] [Accepted: 02/14/2023] [Indexed: 02/17/2023]
Abstract
Biological sex contributes to phenotypic sex effects through genetic (sex chromosomal) and hormonal (gonadal) mechanisms. There are profound sex differences in the prevalence and progression of age-related brain diseases, including neurodegenerative diseases. Inflammation of neural tissue is one of the most consistent age-related phenotypes seen with healthy aging and disease. The pro-inflammatory environment of the aging brain has primarily been attributed to microglial reactivity and adoption of heterogeneous reactive states dependent upon intrinsic (i.e., sex) and extrinsic (i.e., age, disease state) factors. Here, we review sex effects in microglia across the lifespan, explore potential genetic and hormonal molecular mechanisms of microglial sex effects, and discuss currently available models and methods to study sex effects in the aging brain. Despite recent attention to this area, significant further research is needed to mechanistically understand the regulation of microglial sex effects across the lifespan, which may open new avenues for sex informed prevention and treatment strategies.
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Affiliation(s)
- Sarah R Ocañas
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA; Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
| | - Victor A Ansere
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA; Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Collyn M Kellogg
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA; Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Jose V V Isola
- Aging & Metabolism Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Ana J Chucair-Elliott
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Willard M Freeman
- Genes & Human Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA; Oklahoma City Veterans Affairs Medical Center, Oklahoma City, OK, USA; Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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7
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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: 4] [Impact Index Per Article: 4.0] [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.
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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.
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8
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Vargas LN, Silveira MM, Franco MM. Epigenetic Reprogramming and Somatic Cell Nuclear Transfer. Methods Mol Biol 2023; 2647:37-58. [PMID: 37041328 DOI: 10.1007/978-1-0716-3064-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Epigenetics is an area of genetics that studies the heritable modifications in gene expression and phenotype that are not controlled by the primary sequence of DNA. The main epigenetic mechanisms are DNA methylation, post-translational covalent modifications in histone tails, and non-coding RNAs. During mammalian development, there are two global waves of epigenetic reprogramming. The first one occurs during gametogenesis and the second one begins immediately after fertilization. Environmental factors such as exposure to pollutants, unbalanced nutrition, behavioral factors, stress, in vitro culture conditions can negatively affect epigenetic reprogramming events. In this review, we describe the main epigenetic mechanisms found during mammalian preimplantation development (e.g., genomic imprinting, X chromosome inactivation). Moreover, we discuss the detrimental effects of cloning by somatic cell nuclear transfer on the reprogramming of epigenetic patterns and some molecular alternatives to minimize these negative impacts.
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Affiliation(s)
- Luna N Vargas
- Laboratory of Animal Reproduction, Embrapa Genetic Resources and Biotechnology, Brasília, Distrito Federal, Brazil
- Institute of Biotechnology, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Márcia M Silveira
- Laboratory of Animal Reproduction, Embrapa Genetic Resources and Biotechnology, Brasília, Distrito Federal, Brazil
- Institute of Biotechnology, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil
| | - Maurício M Franco
- Laboratory of Animal Reproduction, Embrapa Genetic Resources and Biotechnology, Brasília, Distrito Federal, Brazil.
- Institute of Biotechnology, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil.
- School of Veterinary Medicine, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil.
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9
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Grimm NB, Lee JT. Selective Xi reactivation and alternative methods to restore MECP2 function in Rett syndrome. Trends Genet 2022; 38:920-943. [PMID: 35248405 PMCID: PMC9915138 DOI: 10.1016/j.tig.2022.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 01/15/2022] [Accepted: 01/19/2022] [Indexed: 10/19/2022]
Abstract
The human X-chromosome harbors only 4% of our genome but carries over 20% of genes associated with intellectual disability. Given that they inherit only one X-chromosome, males are more frequently affected by X-linked neurodevelopmental genetic disorders than females. However, despite inheriting two X-chromosomes, females can also be affected because X-chromosome inactivation enables only one of two X-chromosomes to be expressed per cell. For Rett syndrome and similar X-linked disorders affecting females, disease-specific treatments have remained elusive. However, a cure may be found within their own cells because every sick cell carries a healthy copy of the affected gene on the inactive X (Xi). Therefore, selective Xi reactivation may be a viable approach that would address the root cause of various X-linked disorders. Here, we discuss Rett syndrome and compare current approaches in the pharmaceutical pipeline to restore MECP2 function. We then focus on Xi reactivation and review available methods, lessons learned, and future directions.
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Affiliation(s)
- Niklas-Benedikt Grimm
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA; Department of Genetics, The Blavatnik Institute, Harvard Medical School, Boston, MA, USA; Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Jeannie T Lee
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA; Department of Genetics, The Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
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10
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Samanta MK, Gayen S, Harris C, Maclary E, Murata-Nakamura Y, Malcore RM, Porter RS, Garay PM, Vallianatos CN, Samollow PB, Iwase S, Kalantry S. Activation of Xist by an evolutionarily conserved function of KDM5C demethylase. Nat Commun 2022; 13:2602. [PMID: 35545632 PMCID: PMC9095838 DOI: 10.1038/s41467-022-30352-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 04/26/2022] [Indexed: 12/03/2022] Open
Abstract
XX female and XY male therian mammals equalize X-linked gene expression through the mitotically-stable transcriptional inactivation of one of the two X chromosomes in female somatic cells. Here, we describe an essential function of the X-linked homolog of an ancestral X-Y gene pair, Kdm5c-Kdm5d, in the expression of Xist lncRNA, which is required for stable X-inactivation. Ablation of Kdm5c function in females results in a significant reduction in Xist RNA expression. Kdm5c encodes a demethylase that enhances Xist expression by converting histone H3K4me2/3 modifications into H3K4me1. Ectopic expression of mouse and human KDM5C, but not the Y-linked homolog KDM5D, induces Xist in male mouse embryonic stem cells (mESCs). Similarly, marsupial (opossum) Kdm5c but not Kdm5d also upregulates Xist in male mESCs, despite marsupials lacking Xist, suggesting that the KDM5C function that activates Xist in eutherians is strongly conserved and predates the divergence of eutherian and metatherian mammals. In support, prototherian (platypus) Kdm5c also induces Xist in male mESCs. Together, our data suggest that eutherian mammals co-opted the ancestral demethylase KDM5C during sex chromosome evolution to upregulate Xist for the female-specific induction of X-inactivation.
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Affiliation(s)
- Milan Kumar Samanta
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109-5618, USA
| | - Srimonta Gayen
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109-5618, USA
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, Karnataka, 560012, India
| | - Clair Harris
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109-5618, USA
| | - Emily Maclary
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109-5618, USA
- Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA
| | - Yumie Murata-Nakamura
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109-5618, USA
| | - Rebecca M Malcore
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109-5618, USA
| | - Robert S Porter
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109-5618, USA
| | - Patricia M Garay
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109-5618, USA
- Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI, 48109-5618, USA
| | - Christina N Vallianatos
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109-5618, USA
| | - Paul B Samollow
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4458, USA
| | - Shigeki Iwase
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109-5618, USA
- Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI, 48109-5618, USA
| | - Sundeep Kalantry
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109-5618, USA.
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11
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Komoto T, Fujii M, Awazu A. Epigenetic-structural changes in X chromosomes promote Xic pairing during early differentiation of mouse embryonic stem cells. Biophys Physicobiol 2022; 19:1-14. [PMID: 35797402 PMCID: PMC9174021 DOI: 10.2142/biophysico.bppb-v19.0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/02/2022] [Indexed: 12/01/2022] Open
Abstract
X chromosome inactivation center (Xic) pairing occurs during the differentiation of embryonic stem (ES) cells from female mouse embryos, and is related to X chromosome inactivation, the circadian clock, intra-nucleus architecture, and metabolism. However, the mechanisms underlying the identification and approach of X chromosome pairs in the crowded nucleus are unclear. To elucidate the driving force of Xic pairing, we developed a coarse-grained molecular dynamics model of intranuclear chromosomes in ES cells and in cells 2 days after the onset of differentiation (2-day cells) by considering intrachromosomal epigenetic-structural feature-dependent mechanics. The analysis of the experimental data showed that X-chromosomes exhibit the rearrangement of their distributions of open/closed chromatin regions on their surfaces during cell differentiation. By simulating models where the excluded volume effects of closed chromatin regions are stronger than those of open chromatin regions, such rearrangement of open/closed chromatin regions on X-chromosome surfaces promoted the mutual approach of the Xic pair. These findings suggested that local intrachromosomal epigenetic features may contribute to the regulation of cell species-dependent differences in intranuclear architecture.
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Affiliation(s)
- Tetsushi Komoto
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Masashi Fujii
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Akinori Awazu
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
- Research Center for the Mathematics on Chromatin Live Dynamics, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
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12
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Li J, Ming Z, Yang L, Wang T, Liu G, Ma Q. Long noncoding RNA XIST: Mechanisms for X chromosome inactivation, roles in sex-biased diseases, and therapeutic opportunities. Genes Dis 2022; 9:1478-1492. [PMID: 36157489 PMCID: PMC9485286 DOI: 10.1016/j.gendis.2022.04.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/16/2022] [Accepted: 04/18/2022] [Indexed: 11/30/2022] Open
Abstract
Sexual dimorphism has been reported in various human diseases including autoimmune diseases, neurological diseases, pulmonary arterial hypertension, and some types of cancers, although the underlying mechanisms remain poorly understood. The long noncoding RNA (lncRNA) X-inactive specific transcript (XIST) is involved in X chromosome inactivation (XCI) in female placental mammals, a process that ensures the balanced expression dosage of X-linked genes between sexes. XIST is abnormally expressed in many sex-biased diseases. In addition, escape from XIST-mediated XCI and skewed XCI also contribute to sex-biased diseases. Therefore, its expression or modification can be regarded as a biomarker for the diagnosis and prognosis of many sex-biased diseases. Genetic manipulation of XIST expression can inhibit the progression of some of these diseases in animal models, and therefore XIST has been proposed as a potential therapeutic target. In this manuscript, we summarize the current knowledge about the mechanisms for XIST-mediated XCI and the roles of XIST in sex-biased diseases, and discuss potential therapeutic strategies targeting XIST.
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13
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Gene regulation in time and space during X-chromosome inactivation. Nat Rev Mol Cell Biol 2022; 23:231-249. [PMID: 35013589 DOI: 10.1038/s41580-021-00438-7] [Citation(s) in RCA: 85] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2021] [Indexed: 12/21/2022]
Abstract
X-chromosome inactivation (XCI) is the epigenetic mechanism that ensures X-linked dosage compensation between cells of females (XX karyotype) and males (XY). XCI is essential for female embryos to survive through development and requires the accurate spatiotemporal regulation of many different factors to achieve remarkable chromosome-wide gene silencing. As a result of XCI, the active and inactive X chromosomes are functionally and structurally different, with the inactive X chromosome undergoing a major conformational reorganization within the nucleus. In this Review, we discuss the multiple layers of genetic and epigenetic regulation that underlie initiation of XCI during development and then maintain it throughout life, in light of the most recent findings in this rapidly advancing field. We discuss exciting new insights into the regulation of X inactive-specific transcript (XIST), the trigger and master regulator of XCI, and into the mechanisms and dynamics that underlie the silencing of nearly all X-linked genes. Finally, given the increasing interest in understanding the impact of chromosome organization on gene regulation, we provide an overview of the factors that are thought to reshape the 3D structure of the inactive X chromosome and of the relevance of such structural changes for XCI establishment and maintenance.
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14
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Robert-Finestra T, Tan BF, Mira-Bontenbal H, Timmers E, Gontan C, Merzouk S, Giaimo BD, Dossin F, van IJcken WFJ, Martens JWM, Borggrefe T, Heard E, Gribnau J. SPEN is required for Xist upregulation during initiation of X chromosome inactivation. Nat Commun 2021; 12:7000. [PMID: 34853312 PMCID: PMC8636516 DOI: 10.1038/s41467-021-27294-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 11/08/2021] [Indexed: 01/11/2023] Open
Abstract
At initiation of X chromosome inactivation (XCI), Xist is monoallelically upregulated from the future inactive X (Xi) chromosome, overcoming repression by its antisense transcript Tsix. Xist recruits various chromatin remodelers, amongst them SPEN, which are involved in silencing of X-linked genes in cis and establishment of the Xi. Here, we show that SPEN plays an important role in initiation of XCI. Spen null female mouse embryonic stem cells (ESCs) are defective in Xist upregulation upon differentiation. We find that Xist-mediated SPEN recruitment to the Xi chromosome happens very early in XCI, and that SPEN-mediated silencing of the Tsix promoter is required for Xist upregulation. Accordingly, failed Xist upregulation in Spen-/- ESCs can be rescued by concomitant removal of Tsix. These findings indicate that SPEN is not only required for the establishment of the Xi, but is also crucial in initiation of the XCI process.
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Affiliation(s)
- Teresa Robert-Finestra
- Department of Developmental Biology, Erasmus University Medical Center, Oncode Institute, 3015GD, Rotterdam, The Netherlands
| | - Beatrice F Tan
- Department of Developmental Biology, Erasmus University Medical Center, Oncode Institute, 3015GD, Rotterdam, The Netherlands
| | - Hegias Mira-Bontenbal
- Department of Developmental Biology, Erasmus University Medical Center, Oncode Institute, 3015GD, Rotterdam, The Netherlands
| | - Erika Timmers
- Department of Developmental Biology, Erasmus University Medical Center, Oncode Institute, 3015GD, Rotterdam, The Netherlands
| | - Cristina Gontan
- Department of Developmental Biology, Erasmus University Medical Center, Oncode Institute, 3015GD, Rotterdam, The Netherlands
| | - Sarra Merzouk
- Department of Developmental Biology, Erasmus University Medical Center, Oncode Institute, 3015GD, Rotterdam, The Netherlands
| | | | - François Dossin
- European Molecular Biology Laboratory, Director's Research, 69117, Heidelberg, Germany
| | - Wilfred F J van IJcken
- Center for Biomics, Erasmus University Medical Center, 3015CN, Rotterdam, The Netherlands
| | - John W M Martens
- Department of Medical Oncology, Erasmus MC Cancer Institute and Cancer Genomics Netherlands, Erasmus University Medical Center, 3015CN, Rotterdam, The Netherlands
| | - Tilman Borggrefe
- Institute of Biochemistry, University of Giessen, 35392, Giessen, Germany
| | - Edith Heard
- European Molecular Biology Laboratory, Director's Research, 69117, Heidelberg, Germany
| | - Joost Gribnau
- Department of Developmental Biology, Erasmus University Medical Center, Oncode Institute, 3015GD, Rotterdam, The Netherlands.
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15
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Aizawa E, Kaufmann C, Sting S, Boigner S, Freimann R, Di Minin G, Wutz A. Haploid mouse germ cell precursors from embryonic stem cells reveal Xist activation from a single X chromosome. Stem Cell Reports 2021; 17:43-52. [PMID: 34919812 PMCID: PMC8758942 DOI: 10.1016/j.stemcr.2021.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 11/15/2021] [Accepted: 11/15/2021] [Indexed: 12/03/2022] Open
Abstract
Mammalian haploid cells have applications for genetic screening and substituting gametic genomes. Here, we characterize a culture system for obtaining haploid primordial germ cell-like cells (PGCLCs) from haploid mouse embryonic stem cells (ESCs). We find that haploid cells show predisposition for PGCLCs, whereas a large fraction of somatic cells becomes diploid. Characterization of the differentiating haploid ESCs (haESCs) reveals that Xist is activated from and colocalizes with the single X chromosome. This observation suggests that X chromosome inactivation (XCI) is initiated in haploid cells consistent with a model where autosomal blocking factors set a threshold for X-linked activators. We further find that Xist expression is lost at later timepoints in differentiation, which likely reflects the loss of X-linked activators. In vitro differentiation of haploid PGCLCs can be a useful approach for future studies of potential X-linked activators of Xist. A culture system for obtaining haploid PGCLCs Predisposition of haploid cells in the germline over somatic lineages A single X chromosome in haploid cells leads to activation of Xist Mutation of Xist is insufficient to prevent diploidization of haESCs
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Affiliation(s)
- Eishi Aizawa
- Institute of Molecular Health Sciences, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
| | - Corinne Kaufmann
- Institute of Molecular Health Sciences, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
| | - Sarah Sting
- Institute of Molecular Health Sciences, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
| | - Sarah Boigner
- Institute of Molecular Health Sciences, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
| | - Remo Freimann
- Institute of Molecular Health Sciences, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
| | - Giulio Di Minin
- Institute of Molecular Health Sciences, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
| | - Anton Wutz
- Institute of Molecular Health Sciences, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland.
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16
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Carlier F, Nguyen TS, Mazur AK, Gladyshev E. Modulation of C-to-T mutation by recombination-independent pairing of closely positioned DNA repeats. Biophys J 2021; 120:4325-4336. [PMID: 34509507 DOI: 10.1016/j.bpj.2021.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 08/14/2021] [Accepted: 09/07/2021] [Indexed: 11/29/2022] Open
Abstract
Repeat-induced point mutation is a genetic process that creates cytosine-to-thymine (C-to-T) transitions in duplicated genomic sequences in fungi. Repeat-induced point mutation detects duplications (irrespective of their origin, specific sequence, coding capacity, and genomic positions) by a recombination-independent mechanism that likely matches intact DNA double helices directly, without relying on the annealing of complementary single strands. In the fungus Neurospora crassa, closely positioned repeats can induce mutation of the adjoining nonrepetitive regions. This process is related to heterochromatin assembly and requires the cytosine methyltransferase DIM-2. Using DIM-2-dependent mutation as a readout of homologous pairing, we find that GC-rich repeats produce a much stronger response than AT-rich repeats, independently of their intrinsic propensity to become mutated. We also report that direct repeats trigger much stronger DIM-2-dependent mutation than inverted repeats. These results can be rationalized in the light of a recently proposed model of homologous DNA pairing, in which DNA double helices associate by forming sequence-specific quadruplex-based contacts with a concomitant release of supercoiling. A similar process featuring pairing-induced supercoiling may initiate epigenetic silencing of repetitive DNA in other organisms, including humans.
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Affiliation(s)
- Florian Carlier
- Group "Fungal Epigenomics", Department of Mycology, Institut Pasteur, Paris, France
| | - Tinh-Suong Nguyen
- Group "Fungal Epigenomics", Department of Mycology, Institut Pasteur, Paris, France
| | - Alexey K Mazur
- Group "Fungal Epigenomics", Department of Mycology, Institut Pasteur, Paris, France; CNRS, Université de Paris, UPR 9080, Laboratoire de Biochimie Théorique, Paris, France.
| | - Eugene Gladyshev
- Group "Fungal Epigenomics", Department of Mycology, Institut Pasteur, Paris, France.
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17
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18
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Yin H, Wei C, Lee JT. Revisiting the consequences of deleting the X inactivation center. Proc Natl Acad Sci U S A 2021; 118:e2102683118. [PMID: 34161282 PMCID: PMC8237661 DOI: 10.1073/pnas.2102683118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mammalian cells equalize X-linked dosages between the male (XY) and female (XX) sexes by silencing one X chromosome in the female sex. This process, known as "X chromosome inactivation" (XCI), requires a master switch within the X inactivation center (Xic). The Xic spans several hundred kilobases in the mouse and includes a number of regulatory noncoding genes that produce functional transcripts. Over three decades, transgenic and deletional analyses have demonstrated both the necessity and sufficiency of the Xic to induce XCI, including the steps of X chromosome counting, choice, and initiation of whole-chromosome silencing. One recent study, however, reported that deleting the noncoding sequences of the Xic surprisingly had no effect for XCI and attributed a sufficiency to drive counting to the coding gene, Rnf12/Rlim Here, we revisit the question by creating independent Xic deletion cell lines. Multiple independent clones carrying heterozygous deletions of the Xic display an inability to up-regulate Xist expression, consistent with a counting defect. This defect is rescued by a second site mutation in Tsix occurring in trans, bypassing the defect in counting. These findings reaffirm the essential nature of noncoding Xic elements for the initiation of XCI.
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Affiliation(s)
- Hao Yin
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114
- Department of Genetics, Harvard Medical School, Boston, MA 02114
| | - Chunyao Wei
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114
- Department of Genetics, Harvard Medical School, Boston, MA 02114
| | - Jeannie T Lee
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114;
- Department of Genetics, Harvard Medical School, Boston, MA 02114
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19
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Wang W, Min L, Qiu X, Wu X, Liu C, Ma J, Zhang D, Zhu L. Biological Function of Long Non-coding RNA (LncRNA) Xist. Front Cell Dev Biol 2021; 9:645647. [PMID: 34178980 PMCID: PMC8222981 DOI: 10.3389/fcell.2021.645647] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 05/12/2021] [Indexed: 12/24/2022] Open
Abstract
Long non-coding RNAs (lncRNAs) regulate gene expression in a variety of ways at epigenetic, chromatin remodeling, transcriptional, and translational levels. Accumulating evidence suggests that lncRNA X-inactive specific transcript (lncRNA Xist) serves as an important regulator of cell growth and development. Despites its original roles in X-chromosome dosage compensation, lncRNA Xist also participates in the development of tumor and other human diseases by functioning as a competing endogenous RNA (ceRNA). In this review, we comprehensively summarized recent progress in understanding the cellular functions of lncRNA Xist in mammalian cells and discussed current knowledge regarding the ceRNA network of lncRNA Xist in various diseases. Long non-coding RNAs (lncRNAs) are transcripts that are more than 200 nt in length and without an apparent protein-coding capacity (Furlan and Rougeulle, 2016; Maduro et al., 2016). These RNAs are believed to be transcribed by the approximately 98-99% non-coding regions of the human genome (Derrien et al., 2012; Fu, 2014; Montalbano et al., 2017; Slack and Chinnaiyan, 2019), as well as a large variety of genomic regions, such as exonic, tronic, and intergenic regions. Hence, lncRNAs are also divided into eight categories: Intergenic lncRNAs, Intronic lncRNAs, Enhancer lncRNAs, Promoter lncRNAs, Natural antisense/sense lncRNAs, Small nucleolar RNA-ended lncRNAs (sno-lncRNAs), Bidirectional lncRNAs, and non-poly(A) lncRNAs (Ma et al., 2013; Devaux et al., 2015; St Laurent et al., 2015; Chen, 2016; Quinn and Chang, 2016; Richard and Eichhorn, 2018; Connerty et al., 2020). A range of evidence has suggested that lncRNAs function as key regulators in crucial cellular functions, including proliferation, differentiation, apoptosis, migration, and invasion, by regulating the expression level of target genes via epigenomic, transcriptional, or post-transcriptional approaches (Cao et al., 2018). Moreover, lncRNAs detected in body fluids were also believed to serve as potential biomarkers for the diagnosis, prognosis, and monitoring of disease progression, and act as novel and potential drug targets for therapeutic exploitation in human disease (Jiang W. et al., 2018; Zhou et al., 2019a). Long non-coding RNA X-inactive specific transcript (lncRNA Xist) are a set of 15,000-20,000 nt sequences localized in the X chromosome inactivation center (XIC) of chromosome Xq13.2 (Brown et al., 1992; Debrand et al., 1998; Kay, 1998; Lee et al., 2013; da Rocha and Heard, 2017; Yang Z. et al., 2018; Brockdorff, 2019). Previous studies have indicated that lncRNA Xist regulate X chromosome inactivation (XCI), resulting in the inheritable silencing of one of the X-chromosomes during female cell development. Also, it serves a vital regulatory function in the whole spectrum of human disease (notably cancer) and can be used as a novel diagnostic and prognostic biomarker and as a potential therapeutic target for human disease in the clinic (Liu et al., 2018b; Deng et al., 2019; Dinescu et al., 2019; Mutzel and Schulz, 2020; Patrat et al., 2020; Wang et al., 2020a). In particular, lncRNA Xist have been demonstrated to be involved in the development of multiple types of tumors including brain tumor, Leukemia, lung cancer, breast cancer, and liver cancer, with the prominent examples outlined in Table 1. It was also believed that lncRNA Xist (Chaligne and Heard, 2014; Yang Z. et al., 2018) contributed to other diseases, such as pulmonary fibrosis, inflammation, neuropathic pain, cardiomyocyte hypertrophy, and osteoarthritis chondrocytes, and more specific details can be found in Table 2. This review summarizes the current knowledge on the regulatory mechanisms of lncRNA Xist on both chromosome dosage compensation and pathogenesis (especially cancer) processes, with a focus on the regulatory network of lncRNA Xist in human disease.
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Affiliation(s)
| | | | | | | | | | | | - Dongyi Zhang
- Department of Biology and Chemistry, College of Liberal Arts and Sciences, National University of Defense Technology, Changsha, China
| | - Lingyun Zhu
- Department of Biology and Chemistry, College of Liberal Arts and Sciences, National University of Defense Technology, Changsha, China
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20
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Mutzel V, Schulz EG. Dosage Sensing, Threshold Responses, and Epigenetic Memory: A Systems Biology Perspective on Random X-Chromosome Inactivation. Bioessays 2021; 42:e1900163. [PMID: 32189388 DOI: 10.1002/bies.201900163] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 01/27/2020] [Indexed: 02/06/2023]
Abstract
X-chromosome inactivation ensures dosage compensation between the sexes in mammals by randomly choosing one out of the two X chromosomes in females for inactivation. This process imposes a plethora of questions: How do cells count their X chromosome number and ensure that exactly one stays active? How do they randomly choose one of two identical X chromosomes for inactivation? And how do they stably maintain this state of monoallelic expression? Here, different regulatory concepts and their plausibility are evaluated in the context of theoretical studies that have investigated threshold behavior, ultrasensitivity, and bistability through mathematical modeling. It is discussed how a twofold difference between a single and a double dose of X-linked genes might be converted to an all-or-nothing response and how mutually exclusive expression can be initiated and maintained. Finally, candidate factors that might mediate the proposed regulatory principles are reviewed.
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Affiliation(s)
- Verena Mutzel
- Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, Berlin, 14195, Germany
| | - Edda G Schulz
- Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, Berlin, 14195, Germany
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21
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Tang D, Zhao H, Wu Y, Peng B, Gao Z, Sun Y, Duan J, Qi Y, Li Y, Zhou Z, Guo G, Zhang Y, Li C, Sui J, Li W. Transcriptionally inactive hepatitis B virus episome DNA preferentially resides in the vicinity of chromosome 19 in 3D host genome upon infection. Cell Rep 2021; 35:109288. [PMID: 34192543 DOI: 10.1016/j.celrep.2021.109288] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 03/07/2021] [Accepted: 06/02/2021] [Indexed: 12/12/2022] Open
Abstract
The hepatitis B virus (HBV) infects 257 million people worldwide. HBV infection requires establishment and persistence of covalently closed circular (ccc) DNA, a viral episome, in nucleus. Here, we study cccDNA spatial localization in the 3D host genome by using chromosome conformation capture-based sequencing analysis and fluorescence in situ hybridization (FISH). We show that transcriptionally inactive cccDNA is not randomly distributed in host nucleus. Rather, it is preferentially accumulated at specialized areas, including regions close to chromosome 19 (chr.19). Activation of the cccDNA is apparently associated with its re-localization, from a pre-established heterochromatin hub formed by 5 regions of chr.19 to transcriptionally active regions formed by chr.19 and nearby chromosomes including chr.16, 17, 20, and 22. This active versus inactive positioning at discrete regions of the host genome is primarily controlled by the viral HBx protein and by host factors including the structural maintenance of chromosomes protein 5/6 (SMC5/6) complex.
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Affiliation(s)
- Dingbin Tang
- Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, School of Life Sciences, Peking University, Beijing, China; National Institute of Biological Sciences, Beijing, China
| | - Hanqing Zhao
- National Institute of Biological Sciences, Beijing, China
| | - Yumeng Wu
- Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, School of Life Sciences, Peking University, Beijing, China; National Institute of Biological Sciences, Beijing, China
| | - Bo Peng
- Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, School of Life Sciences, Peking University, Beijing, China; National Institute of Biological Sciences, Beijing, China
| | - Zhenchao Gao
- National Institute of Biological Sciences, Beijing, China
| | - Yinyan Sun
- National Institute of Biological Sciences, Beijing, China
| | - Jinzhi Duan
- National Institute of Biological Sciences, Beijing, China
| | - Yonghe Qi
- National Institute of Biological Sciences, Beijing, China
| | - Yunfei Li
- National Institute of Biological Sciences, Beijing, China
| | - Zhongmin Zhou
- College of Life Sciences, Beijing Normal University, Beijing, China; National Institute of Biological Sciences, Beijing, China
| | - Guilan Guo
- College of Life Sciences, Beijing Normal University, Beijing, China; National Institute of Biological Sciences, Beijing, China
| | - Yu Zhang
- National Institute of Biological Sciences, Beijing, China
| | - Cheng Li
- School of Life Sciences, Center for Statistical Science, Center for Bioinformatics, Peking University, Beijing, China
| | - Jianhua Sui
- National Institute of Biological Sciences, Beijing, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| | - Wenhui Li
- National Institute of Biological Sciences, Beijing, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China.
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22
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trans-Acting Factors and cis Elements Involved in the Human Inactive X Chromosome Organization and Compaction. Genet Res (Camb) 2021; 2021:6683460. [PMID: 34035662 PMCID: PMC8121581 DOI: 10.1155/2021/6683460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 04/06/2021] [Accepted: 04/30/2021] [Indexed: 11/23/2022] Open
Abstract
During X chromosome inactivation, many chromatin changes occur on the future inactive X chromosome, including acquisition of a variety of repressive covalent histone modifications, heterochromatin protein associations, and DNA methylation of promoters. Here, we summarize trans-acting factors and cis elements that have been shown to be involved in the human inactive X chromosome organization and compaction.
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23
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Lobato R. A quantum mechanical approach to random X chromosome inactivation. AIMS BIOPHYSICS 2021. [DOI: 10.3934/biophy.2021026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
<abstract>
<p>The X chromosome inactivation is an essential mechanism in mammals' development, that despite having been investigated for 60 years, many questions about its choice process have yet to be fully answered. Therefore, a theoretical model was proposed here for the first time in an attempt to explain this puzzling phenomenon through a quantum mechanical approach. Based on previous data, this work theoretically demonstrates how a shared delocalized proton at a key base pair position could explain the random, instantaneous, and mutually exclusive nature of the choice process in X chromosome inactivation. The main purpose of this work is to contribute to a comprehensive understanding of the X inactivation mechanism with a model proposal that can complement the existent ones, along with introducing a quantum mechanical approach that could be applied to other cell differentiation mechanisms.</p>
</abstract>
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24
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Aeby E, Lee HG, Lee YW, Kriz A, del Rosario BC, Oh HJ, Boukhali M, Haas W, Lee JT. Decapping enzyme 1A breaks X-chromosome symmetry by controlling Tsix elongation and RNA turnover. Nat Cell Biol 2020; 22:1116-1129. [PMID: 32807903 DOI: 10.1038/s41556-020-0558-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/09/2020] [Indexed: 12/27/2022]
Abstract
How allelic asymmetry is generated remains a major unsolved problem in epigenetics. Here we model the problem using X-chromosome inactivation by developing "BioRBP", an enzymatic RNA-proteomic method that enables probing of low-abundance interactions and an allelic RNA-depletion and -tagging system. We identify messenger RNA-decapping enzyme 1A (DCP1A) as a key regulator of Tsix, a noncoding RNA implicated in allelic choice through X-chromosome pairing. DCP1A controls Tsix half-life and transcription elongation. Depleting DCP1A causes accumulation of X-X pairs and perturbs the transition to monoallelic Tsix expression required for Xist upregulation. While ablating DCP1A causes hyperpairing, forcing Tsix degradation resolves pairing and enables Xist upregulation. We link pairing to allelic partitioning of CCCTC-binding factor (CTCF) and show that tethering DCP1A to one Tsix allele is sufficient to drive monoallelic Xist expression. Thus, DCP1A flips a bistable switch for the mutually exclusive determination of active and inactive Xs.
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25
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Guh CY, Hsieh YH, Chu HP. Functions and properties of nuclear lncRNAs-from systematically mapping the interactomes of lncRNAs. J Biomed Sci 2020; 27:44. [PMID: 32183863 PMCID: PMC7079490 DOI: 10.1186/s12929-020-00640-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 03/06/2020] [Indexed: 02/07/2023] Open
Abstract
Protein and DNA have been considered as the major components of chromatin. But beyond that, an increasing number of studies show that RNA occupies a large amount of chromatin and acts as a regulator of nuclear architecture. A significant fraction of long non-coding RNAs (lncRNAs) prefers to stay in the nucleus and cooperate with protein complexes to modulate epigenetic regulation, phase separation, compartment formation, and nuclear organization. An RNA strand also can invade into double-stranded DNA to form RNA:DNA hybrids (R-loops) in living cells, contributing to the regulation of gene expression and genomic instability. In this review, we discuss how nuclear lncRNAs orchestrate cellular processes through their interactions with proteins and DNA and summarize the recent genome-wide techniques to study the functions of lncRNAs by revealing their interactomes in vivo.
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Affiliation(s)
- Chia-Yu Guh
- Institute of Molecular and Cellular Biology, National Taiwan University, No. 1 Sec. 4 Roosevelt Road, Taipei, Taiwan, Republic of China
| | - Yu-Hung Hsieh
- Institute of Molecular and Cellular Biology, National Taiwan University, No. 1 Sec. 4 Roosevelt Road, Taipei, Taiwan, Republic of China
| | - Hsueh-Ping Chu
- Institute of Molecular and Cellular Biology, National Taiwan University, No. 1 Sec. 4 Roosevelt Road, Taipei, Taiwan, Republic of China.
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26
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King TD, Leonard CJ, Cooper JC, Nguyen S, Joyce EF, Phadnis N. Recurrent Losses and Rapid Evolution of the Condensin II Complex in Insects. Mol Biol Evol 2020; 36:2195-2204. [PMID: 31270536 PMCID: PMC6759200 DOI: 10.1093/molbev/msz140] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Condensins play a crucial role in the organization of genetic material by compacting and disentangling chromosomes. Based on studies in a few model organisms, the condensins I and II complexes are considered to have distinct functions, with the condensin II complex playing a role in meiosis and somatic pairing of homologous chromosomes in Drosophila. Intriguingly, the Cap-G2 subunit of condensin II is absent in Drosophila melanogaster, and this loss may be related to the high levels of chromosome pairing seen in flies. Here, we find that all three non-SMC subunits of condensin II (Cap-G2, Cap-D3, and Cap-H2) have been repeatedly and independently lost in taxa representing multiple insect orders, with some taxa lacking all three. We also find that all non-Dipteran insects display near-uniform low-pairing levels regardless of their condensin II complex composition, suggesting that some key aspects of genome organization are robust to condensin II subunit losses. Finally, we observe consistent signatures of positive selection in condensin subunits across flies and mammals. These findings suggest that these ancient complexes are far more evolutionarily labile than previously suspected, and are at the crossroads of several forms of genomic conflicts. Our results raise fundamental questions about the specific functions of the two condensin complexes in taxa that have experienced subunit losses, and open the door to further investigations to elucidate the diversity of molecular mechanisms that underlie genome organization across various life forms.
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Affiliation(s)
- Thomas D King
- School of Biological Sciences, University of Utah, Salt Lake City, UT
| | | | - Jacob C Cooper
- School of Biological Sciences, University of Utah, Salt Lake City, UT
| | - Son Nguyen
- Department of Genetics, Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Eric F Joyce
- Department of Genetics, Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Nitin Phadnis
- School of Biological Sciences, University of Utah, Salt Lake City, UT
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27
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Sigurdardottir HL, Lanzenberger R, Kranz GS. Genetics of sex differences in neuroanatomy and function. HANDBOOK OF CLINICAL NEUROLOGY 2020; 175:179-193. [PMID: 33008524 DOI: 10.1016/b978-0-444-64123-6.00013-8] [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] [Indexed: 03/25/2023]
Abstract
Sex differences are observed at many distinct biologic levels, such as in the anatomy and functioning of the brain, behavior, and susceptibility to neuropsychiatric disorders. Previously, these differences were believed to entirely result from the secretion of gonadal hormones; however, recent research has demonstrated that differences are also the consequence of direct or nonhormonal effects of genes located on the sex chromosomes. This chapter reviews the four core genotype model that separates the effects of hormones and sex chromosomes and highlights a few genes that are believed to be partly responsible for sex dimorphism of the brain, in particular, the Sry gene. Genetics of the brain's neurochemistry is discussed and the susceptibility to certain neurologic and psychiatric disorders is reviewed. Lastly, we discuss the sex-specific genetic contribution in disorders of sexual development. The precise molecular mechanisms underlying these differences are currently not entirely known. An increased knowledge and understanding of the role of candidate genes will undeniably be of great aid in elucidating the molecular basis of sex-biased disorders and potentially allow for more sex-specific therapies.
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Affiliation(s)
- Helen L Sigurdardottir
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria.
| | - Rupert Lanzenberger
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - Georg S Kranz
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria; Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, People's Republic of China; The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, People's Republic of China
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28
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Wang F, Bach I. Rlim/Rnf12, Rex1, and X Chromosome Inactivation. Front Cell Dev Biol 2019; 7:258. [PMID: 31737626 PMCID: PMC6834644 DOI: 10.3389/fcell.2019.00258] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 10/16/2019] [Indexed: 12/28/2022] Open
Abstract
RLIM/Rnf12 is an E3 ubiquitin ligase that has originally been identified as a transcriptional cofactor associated with LIM domain transcription factors. Indeed, this protein modulates transcriptional activities and multiprotein complexes recruited by several classes of transcription factors thereby enhancing or repressing transcription. Around 10 years ago, RLIM/Rnf12 has been identified as a major regulator for the process of X chromosome inactivation (XCI), the transcriptional silencing of one of the two X chromosomes in female mice and ESCs. However, the precise roles of RLIM during XCI have been controversial. Here, we discuss the cellular and developmental functions of RLIM as an E3 ubiquitin ligase and its roles during XCI in conjunction with its target protein Rex1.
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Affiliation(s)
- Feng Wang
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, United States
| | - Ingolf Bach
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, United States
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29
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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.
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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.
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30
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Nguyen HQ, Lee SD, Wu CT. Paircounting. Trends Genet 2019; 35:787-790. [PMID: 31521404 DOI: 10.1016/j.tig.2019.07.010] [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: 05/02/2019] [Accepted: 07/24/2019] [Indexed: 10/26/2022]
Abstract
X inactivation presents two longstanding puzzles: the counting and choice of X chromosomes. Here, we consider counting and choice in the context of pairing, both of the X and of the autosomes.
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Affiliation(s)
- Huy Q Nguyen
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - S Dean Lee
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - C-Ting Wu
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA.
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31
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Mechanisms of Interplay between Transcription Factors and the 3D Genome. Mol Cell 2019; 76:306-319. [PMID: 31521504 DOI: 10.1016/j.molcel.2019.08.010] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/20/2019] [Accepted: 08/09/2019] [Indexed: 12/31/2022]
Abstract
Transcription factors (TFs) bind DNA in a sequence-specific manner and thereby serve as the protein anchors and determinants of 3D genome organization. Conversely, chromatin conformation shapes TF activity, for example, by looping TF-bound enhancers to distally located target genes. Despite considerable effort, our understanding of the mechanistic relation between TFs and 3D genome organization remains limited, in large part due to this interdependency. In this review, we summarize the evidence for the diverse mechanisms by which TFs and their activity shape the 3D genome and vice versa. We further highlight outstanding questions and potential approaches for untangling the complex relation between TF activity and the 3D genome.
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32
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Migeon BR. The Non-random Location of Autosomal Genes That Participate in X Inactivation. Front Cell Dev Biol 2019; 7:144. [PMID: 31555643 PMCID: PMC6691350 DOI: 10.3389/fcell.2019.00144] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 07/11/2019] [Indexed: 12/15/2022] Open
Abstract
Mammals compensate for sex differences in the number of X chromosomes by inactivating all but one X chromosome. Although they differ in the details of X inactivation, all mammals use long non-coding RNAs in the silencing process. By transcribing XIST RNA, the human inactive X chromosome has a prime role in X-dosage compensation. Yet, the autosomes also play an important role in the process. Multiple genes on human chromosome 1 interact with XIST RNA to silence the future inactive Xs. Also, it is likely that multiple genes on human chromosome 19 prevent the silencing of the single active X - a highly dosage sensitive process. Previous studies of the organization of chromosomes in the nucleus and their genomic interactions indicate that most contacts are intra-chromosomal. Co-ordinate transcription and dosage regulation can be achieved by clustering of genes and mingling of interacting chromosomes in 3D space. Unlike the genes on chromosome 1, those within the critical eight MB region of chromosome 19, have remained together in all mammals assayed, except rodents, indicating that their proximity in non-rodent mammals is evolutionarily conserved. I propose that the autosomal genes that play key roles in the process of X inactivation are non-randomly distributed in the genome and that this arrangement facilitates their coordinate regulation.
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Affiliation(s)
- Barbara R. Migeon
- Departments of Genetic Medicine and Pediatrics, The Johns Hopkins University, Baltimore, MD, United States
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33
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Male-Specific Long Noncoding RNA TTTY15 Inhibits Non-Small Cell Lung Cancer Proliferation and Metastasis via TBX4. Int J Mol Sci 2019; 20:ijms20143473. [PMID: 31311130 PMCID: PMC6678590 DOI: 10.3390/ijms20143473] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/11/2019] [Accepted: 07/13/2019] [Indexed: 12/20/2022] Open
Abstract
Gender affects cancer susceptibility. Currently, there are only a few studies on Y chromosome-linked long noncoding RNAs (lncRNAs), and the potential association between lncRNAs and cancers in males has not been fully elucidated. Here, we examined the expression of testis-specific transcript Y-linked 15 (TTTY15) in 37 males with non-small cell lung cancer (NSCLC), and performed circular chromosome conformation capture with next-generation sequencing to determine the genomic interaction regions of the TTTY15 gene. Our results showed that the expression levels of TTTY15 were lower in NSCLC tissues. Lower TTTY15 expression levels were associated with Tumor-Node-Metastasis (TNM) stage. A TTTY15 knockdown promoted malignant transformation of NSCLC cells. Based on the bioinformatics analysis of circular chromosome conformation capture data, we found that T-box transcription factor 4 (TBX4) may be a potential target gene of TTTY15. The RNA immunoprecipitation and chromatin immunoprecipitation results showed that TTTY15 may interact with DNA (cytosine-5)-methyltransferase 3A (DNMT3A), and the TTTY15 knockdown increased the binding of DNMT3A to the TBX4 promoter. We concluded that low TTTY15 expression correlates with worse prognosis among patients with NSCLC. TTTY15 promotes TBX4 expression via DNMT3A-mediated regulation. The identification of lncRNAs encoded by male-specific genes may help to identify potential targets for NSCLC therapy.
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34
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Laskowski AI, Neems DS, Laster K, Strojny-Okyere C, Rice EL, Konieczna IM, Voss JH, Mathew JM, Leventhal JR, Ramsey-Goldman R, Smith ED, Kosak ST. Varying levels of X chromosome coalescence in female somatic cells alters the balance of X-linked dosage compensation and is implicated in female-dominant systemic lupus erythematosus. Sci Rep 2019; 9:8011. [PMID: 31142749 PMCID: PMC6541617 DOI: 10.1038/s41598-019-44229-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 05/08/2019] [Indexed: 11/25/2022] Open
Abstract
The three-dimensional organization of the genome in mammalian interphase nuclei is intrinsically linked to the regulation of gene expression. Whole chromosome territories and their encoded gene loci occupy preferential positions within the nucleus that changes according to the expression profile of a given cell lineage or stage. To further illuminate the relationship between chromosome organization, epigenetic environment, and gene expression, here we examine the functional organization of chromosome X and corresponding X-linked genes in a variety of healthy human and disease state X diploid (XX) cells. We observe high frequencies of homologous chromosome X colocalization (or coalescence), typically associated with initiation of X-chromosome inactivation, occurring in XX cells outside of early embryogenesis. Moreover, during chromosome X coalescence significant changes in Xist, H3K27me3, and X-linked gene expression occur, suggesting the potential exchange of gene regulatory information between the active and inactive X chromosomes. We also observe significant differences in chromosome X coalescence in disease-implicated lymphocytes isolated from systemic lupus erythematosus (SLE) patients compared to healthy controls. These results demonstrate that X chromosomes can functionally interact outside of embryogenesis when X inactivation is initiated and suggest a potential gene regulatory mechanism aberration underlying the increased frequency of autoimmunity in XX individuals.
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Affiliation(s)
- Agnieszka I Laskowski
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Daniel S Neems
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Kyle Laster
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Chelsee Strojny-Okyere
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Ellen L Rice
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Iwona M Konieczna
- Comprehensive Transplant Center, Department of Medicine, Surgery Division, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Jessica H Voss
- Comprehensive Transplant Center, Department of Medicine, Surgery Division, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - James M Mathew
- Comprehensive Transplant Center, Department of Medicine, Surgery Division, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Joseph R Leventhal
- Comprehensive Transplant Center, Department of Medicine, Surgery Division, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Rosalind Ramsey-Goldman
- Deparment of Medicine, Rheumatology Division, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Erica D Smith
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Steven T Kosak
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA.
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35
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Kim S, Dunham MJ, Shendure J. A combination of transcription factors mediates inducible interchromosomal contacts. eLife 2019; 8:e42499. [PMID: 31081754 PMCID: PMC6548505 DOI: 10.7554/elife.42499] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 05/11/2019] [Indexed: 12/30/2022] Open
Abstract
The genome forms specific three-dimensional contacts in response to cellular or environmental conditions. However, it remains largely unknown which proteins specify and mediate such contacts. Here we describe an assay, MAP-C (Mutation Analysis in Pools by Chromosome conformation capture), that simultaneously characterizes the effects of hundreds of cis or trans-acting mutations on a chromosomal contact. Using MAP-C, we show that inducible interchromosomal pairing between HAS1pr-TDA1pr alleles in saturated cultures of Saccharomyces yeast is mediated by three transcription factors, Leu3, Sdd4 (Ypr022c), and Rgt1. The coincident, combined binding of all three factors is strongest at the HAS1pr-TDA1pr locus and is also specific to saturated conditions. We applied MAP-C to further explore the biochemical mechanism of these contacts, and find they require the structured regulatory domain of Rgt1, but no known interaction partners of Rgt1. Altogether, our results demonstrate MAP-C as a powerful method for dissecting the mechanistic basis of chromosome conformation.
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Affiliation(s)
- Seungsoo Kim
- Department of Genome SciencesUniversity of WashingtonSeattleUnited States
| | - Maitreya J Dunham
- Department of Genome SciencesUniversity of WashingtonSeattleUnited States
| | - Jay Shendure
- Department of Genome SciencesUniversity of WashingtonSeattleUnited States
- Howard Hughes Medical InstituteSeattleUnited States
- Brotman Baty Institute for Precision MedicineSeattleUnited States
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36
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Pollex T, Heard E. Nuclear positioning and pairing of X-chromosome inactivation centers are not primary determinants during initiation of random X-inactivation. Nat Genet 2019; 51:285-295. [PMID: 30643252 DOI: 10.1038/s41588-018-0305-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 11/02/2018] [Indexed: 01/29/2023]
Abstract
During X-chromosome inactivation (XCI), one of the two X-inactivation centers (Xics) upregulates the noncoding RNA Xist to initiate chromosomal silencing in cis. How one Xic is chosen to upregulate Xist remains unclear. Models proposed include localization of one Xic at the nuclear envelope or transient homologous Xic pairing followed by asymmetric transcription factor distribution at Xist's antisense Xite/Tsix locus. Here, we use a TetO/TetR system that can inducibly relocate one or both Xics to the nuclear lamina in differentiating mouse embryonic stem cells. We find that neither nuclear lamina localization nor reduction of Xic homologous pairing influences monoallelic Xist upregulation or choice-making. We also show that transient pairing is associated with biallelic expression, not only at Xist/Tsix but also at other X-linked loci that can escape XCI. Finally, we show that Xic pairing occurs in wavelike patterns, coinciding with genome dynamics and the onset of global regulatory programs during early differentiation.
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Affiliation(s)
- Tim Pollex
- Mammalian Developmental Epigenetics Group, Genetics and Developmental Biology Unit, Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France.,European Molecular Biology Laboratory, Heidelberg, Germany
| | - Edith Heard
- Mammalian Developmental Epigenetics Group, Genetics and Developmental Biology Unit, Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France.
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37
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Trans-allelic mutational effects at the Peg3 imprinted locus. PLoS One 2018; 13:e0206112. [PMID: 30335829 PMCID: PMC6193732 DOI: 10.1371/journal.pone.0206112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 09/05/2018] [Indexed: 11/19/2022] Open
Abstract
How one allele interacts with the other for the function of a gene is not well understood. In this study, we tested potential allelic interaction at the Peg3 imprinted locus with several mutant alleles targeting an Imprinting Control Region, the Peg3-DMR. According to the results, maternal deletion of the Peg3-DMR resulted in 2-fold up-regulation of two paternally expressed genes, Peg3 and Usp29. These trans-allelic mutational effects were observed consistently throughout various tissues with different developmental stages. These effects were also associated mainly with the genetic manipulation of the Peg3-DMR, but not with the other genomic changes within the Peg3 locus. The observed trans-allelic effects were unidirectional with the maternal influencing the paternal allele, but not with the opposite direction. Overall, the observed mutational effects suggest the presence of previously unrecognized trans-allelic regulation associated with the Peg3-DMR.
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38
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Galupa R, Heard E. X-Chromosome Inactivation: A Crossroads Between Chromosome Architecture and Gene Regulation. Annu Rev Genet 2018; 52:535-566. [PMID: 30256677 DOI: 10.1146/annurev-genet-120116-024611] [Citation(s) in RCA: 144] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In somatic nuclei of female therian mammals, the two X chromosomes display very different chromatin states: One X is typically euchromatic and transcriptionally active, and the other is mostly silent and forms a cytologically detectable heterochromatic structure termed the Barr body. These differences, which arise during female development as a result of X-chromosome inactivation (XCI), have been the focus of research for many decades. Initial approaches to define the structure of the inactive X chromosome (Xi) and its relationship to gene expression mainly involved microscopy-based approaches. More recently, with the advent of genomic techniques such as chromosome conformation capture, molecular details of the structure and expression of the Xi have been revealed. Here, we review our current knowledge of the 3D organization of the mammalian X-chromosome chromatin and discuss its relationship with gene activity in light of the initiation, spreading, and maintenance of XCI, as well as escape from gene silencing.
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Affiliation(s)
- Rafael Galupa
- Genetics and Developmental Biology Unit and Mammalian Developmental Epigenetics Group, Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, 75248 Paris, France; .,Current affiliation: Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Edith Heard
- Genetics and Developmental Biology Unit and Mammalian Developmental Epigenetics Group, Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, 75248 Paris, France; .,Collège de France, 75231 Paris, France
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39
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Laskowski AI, Fanslow DA, Smith ED, Kosak ST. Clinical Epigenetic Therapies Disrupt Sex Chromosome Dosage Compensation in Human Female Cells. GENDER AND THE GENOME 2018; 2:2-7. [PMID: 30899898 DOI: 10.1177/2470289718787106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Sex chromosome gene dosage compensation is required to ensure equivalent levels of X-linked gene expression between males (46, XY) and females (46, XX). To achieve similar expression, X-chromosome inactivation (XCI) is initiated in female cells during early stages of embryogenesis. Within each cell, either the maternal or paternal X chromosome is selected for whole chromosome transcriptional silencing, which is initiated and maintained by epigenetic and chromatin conformation mechanisms. With the emergence of small-molecule epigenetic inhibitors for the treatment of disease, such as cancer, the epigenetic mechanism underlying XCI may be inadvertently targeted. Here, we test 2 small-molecule epigenetic inhibitors being used clinically, GSK126 (a histone H3 lysine 27 methyltransferase inhibitor) and suberoylanilide hydroxamic acid (a histone deacetylase inhibitor), on their effects of the inactive X (Xi) in healthy human female fibroblasts. The combination of these modifiers, at subcancer therapeutic levels, leads to the inability to detect the repressive H3K27me3 modification characteristic of XCI in the majority of the cells. Importantly, genes positioned near the X-inactivation center (Xic), where inactivation is initiated, exhibit robust expression with treatment of the inhibitors, while genes located near the distal ends of the X chromosome intriguingly exhibit significant downregulation. These results demonstrate that small-molecule epigenetic inhibitors can have profound consequences on XCI in human cells, and they underscore the importance of considering gender when developing and clinically testing small-molecule epigenetic inhibitors, in particular those that target the well-characterized mechanisms of X inactivation.
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Affiliation(s)
- Agnieszka I Laskowski
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Danielle A Fanslow
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Erica D Smith
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Steven T Kosak
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
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40
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Johanson TM, Coughlan HD, Lun ATL, Bediaga NG, Naselli G, Garnham AL, Harrison LC, Smyth GK, Allan RS. Genome-wide analysis reveals no evidence of trans chromosomal regulation of mammalian immune development. PLoS Genet 2018; 14:e1007431. [PMID: 29883495 PMCID: PMC6010296 DOI: 10.1371/journal.pgen.1007431] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 06/20/2018] [Accepted: 05/18/2018] [Indexed: 12/31/2022] Open
Abstract
It has been proposed that interactions between mammalian chromosomes, or transchromosomal interactions (also known as kissing chromosomes), regulate gene expression and cell fate determination. Here we aimed to identify novel transchromosomal interactions in immune cells by high-resolution genome-wide chromosome conformation capture. Although we readily identified stable interactions in cis, and also between centromeres and telomeres on different chromosomes, surprisingly we identified no gene regulatory transchromosomal interactions in either mouse or human cells, including previously described interactions. We suggest that advances in the chromosome conformation capture technique and the unbiased nature of this approach allow more reliable capture of interactions between chromosomes than previous methods. Overall our findings suggest that stable transchromosomal interactions that regulate gene expression are not present in mammalian immune cells and that lineage identity is governed by cis, not trans chromosomal interactions. It is a widely held belief that, in the darkness of the nucleus, strands of DNA that make up different chromosomes frequently meet to ‘kiss’. These kisses, or transchromosomal interactions, are thought to be important for the expression of genes and thus cell development. Here, we aimed to identify novel transchromosomal interactions in mouse and human immune cells by high-resolution genome-wide chromosome conformation capture methods. Although we readily identified stable interactions within chromosomes and also between centromeres and telomeres on different chromosomes, surprisingly we identified no gene regulatory transchromosomal interactions in either mouse or human cells, including those previously described. Overall our findings suggest that stable transchromosomal interactions that regulate gene expression are not present in mammalian immune cells and that chromosomes are doing far less kissing than was previously believed.
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Affiliation(s)
- Timothy M. Johanson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - Hannah D. Coughlan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - Aaron T. L. Lun
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - Naiara G. Bediaga
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - Gaetano Naselli
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Alexandra L. Garnham
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - Leonard C. Harrison
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
| | - Gordon K. Smyth
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
| | - Rhys S. Allan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Australia
- * E-mail:
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41
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Sousa EJ, Stuart HT, Bates LE, Ghorbani M, Nichols J, Dietmann S, Silva JCR. Exit from Naive Pluripotency Induces a Transient X Chromosome Inactivation-like State in Males. Cell Stem Cell 2018; 22:919-928.e6. [PMID: 29804891 PMCID: PMC5989057 DOI: 10.1016/j.stem.2018.05.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 12/21/2017] [Accepted: 05/01/2018] [Indexed: 02/06/2023]
Abstract
A hallmark of naive pluripotency is the presence of two active X chromosomes in females. It is not clear whether prevention of X chromosome inactivation (XCI) is mediated by gene networks that preserve the naive state. Here, we show that robust naive pluripotent stem cell (nPSC) self-renewal represses expression of Xist, the master regulator of XCI. We found that nPSCs accumulate Xist on the male X chromosome and on both female X chromosomes as they become NANOG negative at the onset of differentiation. This is accompanied by the appearance of a repressive chromatin signature and partial X-linked gene silencing, suggesting a transient and rapid XCI-like state in male nPSCs. In the embryo, Xist is transiently expressed in males and in females from both X chromosomes at the onset of naive epiblast differentiation. In conclusion, we propose that XCI initiation is gender independent and triggered by destabilization of naive identity, suggesting that gender-specific mechanisms follow, rather than precede, XCI initiation.
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Affiliation(s)
- Elsa J Sousa
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK; Graduate Program in Areas of Basic and Applied Biology, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - Hannah T Stuart
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK; Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | - Lawrence E Bates
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK; Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | | | - Jennifer Nichols
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK; Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - Sabine Dietmann
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK
| | - José C R Silva
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK; Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK.
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42
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de Hoon B, Splinter E, Eussen B, Douben JCW, Rentmeester E, van de Heijning M, Laven JSE, de Klein JEMM, Liebelt J, Gribnau J. X chromosome inactivation in a female carrier of a 1.28 Mb deletion encompassing the human X inactivation centre. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0359. [PMID: 28947658 PMCID: PMC5627161 DOI: 10.1098/rstb.2016.0359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2017] [Indexed: 11/12/2022] Open
Abstract
X chromosome inactivation (XCI) is a mechanism specifically initiated in female cells to silence one X chromosome, thereby equalizing the dose of X-linked gene products between male and female cells. XCI is regulated by a locus on the X chromosome termed the X-inactivation centre (XIC). Located within the XIC is XIST, which acts as a master regulator of XCI. During XCI, XIST is upregulated on the inactive X chromosome and chromosome-wide cis spreading of XIST leads to inactivation. In mouse, the Xic comprises Xist and all cis-regulatory elements and genes involved in Xist regulation. The activity of the XIC is regulated by trans-acting factors located elsewhere in the genome: X-encoded XCI activators positively regulating XCI, and autosomally encoded XCI inhibitors providing the threshold for XCI initiation. Whether human XCI is regulated through a similar mechanism, involving trans-regulatory factors acting on the XIC has remained elusive so far. Here, we describe a female individual with ovarian dysgenesis and a small X chromosomal deletion of the XIC. SNP-array and targeted locus amplification (TLA) analysis defined the deletion to a 1.28 megabase region, including XIST and all elements and genes that perform cis-regulatory functions in mouse XCI. Cells carrying this deletion still initiate XCI on the unaffected X chromosome, indicating that XCI can be initiated in the presence of only one XIC. Our results indicate that the trans-acting factors required for XCI initiation are located outside the deletion, providing evidence that the regulatory mechanisms of XCI are conserved between mouse and human. This article is part of the themed issue ‘X-chromosome inactivation: a tribute to Mary Lyon’.
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Affiliation(s)
- B de Hoon
- Department of Developmental Biology, Rotterdam, The Netherlands
| | | | - B Eussen
- Department of Clinical Genetics, Rotterdam, The Netherlands
| | - J C W Douben
- Department of Clinical Genetics, Rotterdam, The Netherlands
| | - E Rentmeester
- Department of Developmental Biology, Rotterdam, The Netherlands
| | | | - J S E Laven
- Department of Obstetrics and Gynaecology, Erasmus MC, Rotterdam, The Netherlands
| | | | - J Liebelt
- Division of Genetics and Molecular Pathology, Women's and Children's Hospital, North Adelaide, South Australia, Australia
| | - J Gribnau
- Department of Developmental Biology, Rotterdam, The Netherlands
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43
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Lyu G, Tan T, Guan Y, Sun L, Liang Q, Tao W. Changes in the position and volume of inactive X chromosomes during the G0/G1 transition. Chromosome Res 2018; 26:179-189. [PMID: 29679205 DOI: 10.1007/s10577-018-9577-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 02/24/2018] [Accepted: 03/29/2018] [Indexed: 10/17/2022]
Abstract
In female mammals, each cell silences one X chromosome by converting it into transcriptionally inert heterochromatin. The inactivation is concomitant with epigenetic changes including methylation of specific histone residues and incorporation of macroH2A. Such epigenetic changes may exert influence on the positioning of the inactive X chromosome (Xi) within the nucleus beyond the level of chromatin structure. However, the dynamic positioning of the inactive X chromosome during cell cycle remains unclear. Here, we show that H3K27me3 is a cell-cycle-independent marker for the inactivated X chromosomes in WI38 cells. By utilizing this marker, three types of Xi locations in the nuclei are classified, which are envelope position (associated with envelope), mid-position (between the envelope and nucleolus), and nucleolus position (associated with the nucleolus). Moreover, serial-section analysis revealed that the inactive X chromosomes in the mid-position appear to be sparser and less condensed than those associated with the nuclear envelope or nucleolus. During the transition from G0 to G1 phase, the inactive X chromosomes tend to move from the envelope position to the nucleolus position in WI38 cells. Our results imply a role of chromosome positioning in maintaining the organization of the inactive X chromosomes in different cell phases.
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Affiliation(s)
- Guoliang Lyu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Peking University, Beijing, 100871, People's Republic of China
| | - Tan Tan
- Beijing Key Laboratory of Gene Resource and Molecular Development/ Key Laboratory for Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, 100875, People's Republic of China.,Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study / Department of Biological Science & Technology, University of South China, Hengyang, 421001, Hunan Province, People's Republic of China
| | - Yiting Guan
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Peking University, Beijing, 100871, People's Republic of China
| | - Lei Sun
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Peking University, Beijing, 100871, People's Republic of China
| | - Qianjin Liang
- Beijing Key Laboratory of Gene Resource and Molecular Development/ Key Laboratory for Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, 100875, People's Republic of China.
| | - Wei Tao
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Peking University, Beijing, 100871, People's Republic of China.
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44
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Saha P, Verma S, Pathak RU, Mishra RK. Long Noncoding RNAs in Mammalian Development and Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1008:155-198. [PMID: 28815540 DOI: 10.1007/978-981-10-5203-3_6] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Following analysis of sequenced genomes and transcriptome of many eukaryotes, it is evident that virtually all protein-coding genes have already been discovered. These advances have highlighted an intriguing paradox whereby the relative amount of protein-coding sequences remain constant but nonprotein-coding sequences increase consistently in parallel to increasing evolutionary complexity. It is established that differences between species map to nonprotein-coding regions of the genome that surprisingly is transcribed extensively. These transcripts regulate epigenetic processes and constitute an important layer of regulatory information essential for organismal development and play a causative role in diseases. The noncoding RNA-directed regulatory circuit controls complex characteristics. Sequence variations in noncoding RNAs influence evolution, quantitative traits, and disease susceptibility. This chapter presents an account on a class of such noncoding transcripts that are longer than 200 nucleotides (long noncoding RNA-lncRNA) in mammalian development and diseases.
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Affiliation(s)
- Parna Saha
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500007, India
| | - Shreekant Verma
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500007, India
| | - Rashmi U Pathak
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500007, India.
| | - Rakesh K Mishra
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500007, India.
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45
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Programming asynchronous replication in stem cells. Nat Struct Mol Biol 2017; 24:1132-1138. [PMID: 29131141 DOI: 10.1038/nsmb.3503] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 10/12/2017] [Indexed: 01/12/2023]
Abstract
Many regions of the genome replicate asynchronously and are expressed monoallelically. It is thought that asynchronous replication may be involved in choosing one allele over the other, but little is known about how these patterns are established during development. We show that, unlike somatic cells, which replicate in a clonal manner, embryonic and adult stem cells are programmed to undergo switching, such that daughter cells with an early-replicating paternal allele are derived from mother cells that have a late-replicating paternal allele. Furthermore, using ground-state embryonic stem (ES) cells, we demonstrate that in the initial transition to asynchronous replication, it is always the paternal allele that is chosen to replicate early, suggesting that primary allelic choice is directed by preset gametic DNA markers. Taken together, these studies help define a basic general strategy for establishing allelic discrimination and generating allelic diversity throughout the organism.
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46
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Matsushita M, Ochiai H, Suzuki KIT, Hayashi S, Yamamoto T, Awazu A, Sakamoto N. Dynamic changes in the interchromosomal interaction of early histone gene loci during development of sea urchin. J Cell Sci 2017; 130:4097-4107. [PMID: 29084822 DOI: 10.1242/jcs.206862] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 10/22/2017] [Indexed: 12/21/2022] Open
Abstract
The nuclear positioning and chromatin dynamics of eukaryotic genes are closely related to the regulation of gene expression, but they have not been well examined during early development, which is accompanied by rapid cell cycle progression and dynamic changes in nuclear organization, such as nuclear size and chromatin constitution. In this study, we focused on the early development of the sea urchin Hemicentrotus pulcherrimus and performed three-dimensional fluorescence in situ hybridization of gene loci encoding early histones (one of the types of histone in sea urchin). There are two non-allelic early histone gene loci per sea urchin genome. We found that during the morula stage, when the early histone gene expression levels are at their maximum, interchromosomal interactions were often formed between the early histone gene loci on separate chromosomes and that the gene loci were directed to locate to more interior positions. Furthermore, these interactions were associated with the active transcription of the early histone genes. Thus, such dynamic interchromosomal interactions may contribute to the efficient synthesis of early histone mRNA during the morula stage of sea urchin development.
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Affiliation(s)
- Masaya Matsushita
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Hiroshi Ochiai
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.,JST, PRESTO, Higashi-Hiroshima 739-8530, Japan
| | - Ken-Ichi T Suzuki
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Sayaka Hayashi
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Takashi Yamamoto
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.,Research Center for the Mathematics on Chromatin Live Dynamics, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Akinori Awazu
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.,Research Center for the Mathematics on Chromatin Live Dynamics, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Naoaki Sakamoto
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan .,Research Center for the Mathematics on Chromatin Live Dynamics, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
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47
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Asaka MN, Uranishi K, Suzuki A, Hirasaki M, Nishimoto M, Okuda A. Link between embryonic stem cell pluripotency and homologous allelic pairing of Oct4 loci. Dev Growth Differ 2017; 59:639-647. [PMID: 28967672 DOI: 10.1111/dgd.12403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 08/22/2017] [Accepted: 08/22/2017] [Indexed: 01/11/2023]
Abstract
The Oct4 gene is a master regulator of the pluripotent properties of embryonic stem cells (ESCs). Recently, Oct4 loci were shown to frequently localize in close proximity to one another during the early stage of cellular differentiation, implicating this event as an important prerequisite step for ESCs to exert their full differentiation potential. Although the differentiation capacity of embryonal carcinoma cells (ECCs), such as F9 and P19 ECC lines, is severely restricted compared with ESCs, ECCs bear a highly similar expression profile to that of ESCs including expression of Oct4 and other pluripotency marker genes. Therefore, we examined whether allelic pairing of Oct4 loci also occurs during differentiation of F9 and P19 ECCs. Our data clearly demonstrate that this event is only observed within ESCs, but not ECCs, subjected to induction of differentiation, indicating transient allelic pairing of Oct4 loci as a specific feature of pluripotent ESCs. Moreover, our data revealed that this pairing did not occur broadly across chromosome 17, which carries the Oct4 gene, but occurred locally between Oct4 loci, suggesting that Oct4 loci somehow exert a driving force for their allelic pairing.
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Affiliation(s)
- Masamitsu N Asaka
- Division of Developmental Biology, Research Center for Genomic Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama, 350-1241, Japan
| | - Kousuke Uranishi
- Division of Developmental Biology, Research Center for Genomic Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama, 350-1241, Japan
| | - Ayumu Suzuki
- Division of Developmental Biology, Research Center for Genomic Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama, 350-1241, Japan
| | - Masataka Hirasaki
- Division of Developmental Biology, Research Center for Genomic Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama, 350-1241, Japan
| | - Masazumi Nishimoto
- Division of Developmental Biology, Research Center for Genomic Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama, 350-1241, Japan
| | - Akihiko Okuda
- Division of Developmental Biology, Research Center for Genomic Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama, 350-1241, Japan
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48
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Monahan K, Schieren I, Cheung J, Mumbey-Wafula A, Monuki ES, Lomvardas S. Cooperative interactions enable singular olfactory receptor expression in mouse olfactory neurons. eLife 2017; 6. [PMID: 28933695 PMCID: PMC5608512 DOI: 10.7554/elife.28620] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 08/28/2017] [Indexed: 12/16/2022] Open
Abstract
The monogenic and monoallelic expression of only one out of >1000 mouse olfactory receptor (ORs) genes requires the formation of large heterochromatic chromatin domains that sequester the OR gene clusters. Within these domains, intergenic transcriptional enhancers evade heterochromatic silencing and converge into interchromosomal hubs that assemble over the transcriptionally active OR. The significance of this nuclear organization in OR choice remains elusive. Here, we show that transcription factors Lhx2 and Ebf specify OR enhancers by binding in a functionally cooperative fashion to stereotypically spaced motifs that defy heterochromatin. Specific displacement of Lhx2 and Ebf from OR enhancers resulted in pervasive, long-range, and trans downregulation of OR transcription, whereas pre-assembly of a multi-enhancer hub increased the frequency of OR choice in cis. Our data provide genetic support for the requirement and sufficiency of interchromosomal interactions in singular OR choice and generate general regulatory principles for stochastic, mutually exclusive gene expression programs.
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Affiliation(s)
- Kevin Monahan
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States
| | - Ira Schieren
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States
| | - Jonah Cheung
- New York Structural Biology Center, New York, United States
| | - Alice Mumbey-Wafula
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States
| | - Edwin S Monuki
- Department of Pathology and Laboratory Medicine, School of Medicine, University of California Irvine, Irvine, United States
| | - Stavros Lomvardas
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States.,Department of Neuroscience, Columbia University, New York, United States.,Zuckerman Mind Brain and Behavior Institute, Columbia University, New York, United States
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49
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Stathopoulou C, Kapsetaki M, Stratigi K, Spilianakis C. Long non-coding RNA SeT and miR-155 regulate the Tnfα gene allelic expression profile. PLoS One 2017; 12:e0184788. [PMID: 28910376 PMCID: PMC5599032 DOI: 10.1371/journal.pone.0184788] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 08/30/2017] [Indexed: 01/01/2023] Open
Abstract
It is becoming increasingly appreciated that the non-coding genome may have a great impact on the regulation of chromatin structure and gene expression. The innate immune response can be mediated upon lipopolysaccharide stimulation of macrophages which leads to immediate transcriptional activation of early responsive genes including tumor necrosis factor alpha (Tnfα). The functional role of non-coding RNAs, such as lncRNAs and microRNAs, on the transcriptional activation of proinflammatory genes and the subsequent regulation of the innate immune response is still lacking mechanistic insights. In this study we wanted to unravel the functional role of the lncRNA SeT, which is encoded from the murine Tnfα gene locus, and miR-155 on the transcriptional regulation of the Tnfα gene. We utilized genetically modified mice harboring either a deletion of the SeT promoter elements or the mature miR-155 and studied the response of macrophages to lipopolysaccharide (LPS) stimulation. We found that decreased expression of the lncRNA SeT in murine primary macrophages resulted in increased mortality of mice challenged with LPS, which was corroborated by increased Tnfα steady state mRNA levels and a higher frequency of biallelically expressing macrophages. On the contrary, miR-155 deletion resulted in reduced Tnfα mRNA levels supported by a lower frequency of biallelically expressing macrophages upon stimulation with LPS. In both cases, in the absence of either lncRNA SeT or miR-155 we observed a deregulation of the Tnfα allele homologous pairing, previously shown to regulate the switch from mono- to bi-allelic gene expression. Although lncRNA SeT was not found to be a direct target of miR-155 its stability was increased upon miR-155 deletion. This study suggests a role of the non-coding genome in mediating Tnfα mRNA dosage control based on the regulation of homologous pairing of gene alleles and their subsequent biallelic expression.
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Affiliation(s)
- Chrysoula Stathopoulou
- Department of Molecular Biology and Genetics, building 10 University Campus, Dragana Alexandroupolis, Greece
- Institute of Molecular Biology and Biotechnology-Foundation for Research and Technology Hellas, Nikolaou Plastira 100, Heraklion, Greece
| | - Manouela Kapsetaki
- Institute of Molecular Biology and Biotechnology-Foundation for Research and Technology Hellas, Nikolaou Plastira 100, Heraklion, Greece
| | - Kalliopi Stratigi
- Institute of Molecular Biology and Biotechnology-Foundation for Research and Technology Hellas, Nikolaou Plastira 100, Heraklion, Greece
- Department of Biology, University of Crete, Heraklion, Greece
| | - Charalampos Spilianakis
- Institute of Molecular Biology and Biotechnology-Foundation for Research and Technology Hellas, Nikolaou Plastira 100, Heraklion, Greece
- Department of Biology, University of Crete, Heraklion, Greece
- * E-mail:
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50
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Krivega I, Dean A. A tetrad of chromatin interactions for chromosome pairing in X inactivation. Nat Struct Mol Biol 2017; 24:607-608. [PMID: 28771462 PMCID: PMC6247907 DOI: 10.1038/nsmb.3447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
An unusual pairing of homologous X chromosomes occurs during X inactivation. A new study in mouse embryonic stem cells shows that telomeres and the telomeric RNA PAR-TERRA are responsible for additional pairwise interactions that guide Xic–Xic pairing.
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Affiliation(s)
- Ivan Krivega
- Laboratory of Cellular and Developmental Biology at the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
| | - Ann Dean
- Laboratory of Cellular and Developmental Biology at the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
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