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Irastorza-Azcarate I, Kukalev A, Kempfer R, Thieme CJ, Mastrobuoni G, Markowski J, Loof G, Sparks TM, Brookes E, Natarajan KN, Sauer S, Fisher AG, Nicodemi M, Ren B, Schwarz RF, Kempa S, Pombo A. Extensive folding variability between homologous chromosomes in mammalian cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.08.591087. [PMID: 38766012 PMCID: PMC11100664 DOI: 10.1101/2024.05.08.591087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Genetic variation and 3D chromatin structure have major roles in gene regulation. Due to challenges in mapping chromatin conformation with haplotype-specific resolution, the effects of genetic sequence variation on 3D genome structure and gene expression imbalance remain understudied. Here, we applied Genome Architecture Mapping (GAM) to a hybrid mouse embryonic stem cell (mESC) line with high density of single nucleotide polymorphisms (SNPs). GAM resolved haplotype-specific 3D genome structures with high sensitivity, revealing extensive allelic differences in chromatin compartments, topologically associating domains (TADs), long-range enhancer-promoter contacts, and CTCF loops. Architectural differences often coincide with allele-specific differences in gene expression, mediated by Polycomb repression. We show that histone genes are expressed with allelic imbalance in mESCs, are involved in haplotype-specific chromatin contact marked by H3K27me3, and are targets of Polycomb repression through conditional knockouts of Ezh2 or Ring1b. Our work reveals highly distinct 3D folding structures between homologous chromosomes, and highlights their intricate connections with allelic gene expression.
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Hauth A, Panten J, Kneuss E, Picard C, Servant N, Rall I, Pérez-Rico YA, Clerquin L, Servaas N, Villacorta L, Jung F, Luong C, Chang HY, Zaugg JB, Stegle O, Odom DT, Loda A, Heard E. Escape from X inactivation is directly modulated by levels of Xist non-coding RNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.22.581559. [PMID: 38559194 PMCID: PMC10979913 DOI: 10.1101/2024.02.22.581559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
In placental females, one copy of the two X chromosomes is largely silenced during a narrow developmental time window, in a process mediated by the non-coding RNA Xist1. Here, we demonstrate that Xist can initiate X-chromosome inactivation (XCI) well beyond early embryogenesis. By modifying its endogenous level, we show that Xist has the capacity to actively silence genes that escape XCI both in neuronal progenitor cells (NPCs) and in vivo, in mouse embryos. We also show that Xist plays a direct role in eliminating TAD-like structures associated with clusters of escapee genes on the inactive X chromosome, and that this is dependent on Xist's XCI initiation partner, SPEN2. We further demonstrate that Xist's function in suppressing gene expression of escapees and topological domain formation is reversible for up to seven days post-induction, but that sustained Xist up-regulation leads to progressively irreversible silencing and CpG island DNA methylation of facultative escapees. Thus, the distinctive transcriptional and regulatory topologies of the silenced X chromosome is actively, directly - and reversibly - controlled by Xist RNA throughout life.
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Affiliation(s)
- Antonia Hauth
- European Molecular Biology Laboratory, Directors' Research, 69117 Heidelberg, Germany
- Collaboration for joint PhD degree between EMBL and Heidelberg University, Germany
| | - Jasper Panten
- Division of Regulatory Genomics and Cancer Evolution, German Cancer Research Centre (DKFZ), 69120, Heidelberg, Germany
- Division of Computational Genomics and Systems Genetics, German Cancer Research Centre (DKFZ), 69120, Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, 69117, Heidelberg, Germany
| | - Emma Kneuss
- European Molecular Biology Laboratory, Directors' Research, 69117 Heidelberg, Germany
| | - Christel Picard
- European Molecular Biology Laboratory, Directors' Research, 69117 Heidelberg, Germany
- Present address: Institute of Molecular Genetics of Montpellier University of Montpellier, CNRS, 34090 Montpellier, France
| | - Nicolas Servant
- Bioinformatics and Computational Systems Biology of Cancer, INSERM U900, Paris 75005, France
| | - Isabell Rall
- European Molecular Biology Laboratory, Directors' Research, 69117 Heidelberg, Germany
- Present address: Institute of Human Biology (IHB), Roche Innovation Center Basel, 4070 Basel, Switzerland
| | - Yuvia A Pérez-Rico
- European Molecular Biology Laboratory, Directors' Research, 69117 Heidelberg, Germany
| | - Lena Clerquin
- European Molecular Biology Laboratory, Directors' Research, 69117 Heidelberg, Germany
| | - Nila Servaas
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
| | - Laura Villacorta
- European Molecular Biology Laboratory, Genomics Core Facility, 69117 Heidelberg, Germany
| | - Ferris Jung
- European Molecular Biology Laboratory, Genomics Core Facility, 69117 Heidelberg, Germany
| | - Christy Luong
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA 94305, USA
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA 94305, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Judith B Zaugg
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, 69117 Heidelberg, Germany
- Molecular Medicine Partnership Unit, EMBL-University of Heidelberg, Heidelberg, Germany
| | - Oliver Stegle
- European Molecular Biology Laboratory, Genome Biology Unit, 69117 Heidelberg, Germany
- Division of Computational Genomics and Systems Genetics, German Cancer Research Centre (DKFZ), 69120, Heidelberg, Germany
| | - Duncan T Odom
- Division of Regulatory Genomics and Cancer Evolution, German Cancer Research Centre (DKFZ), 69120, Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, 69117, Heidelberg, Germany
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK
| | - Agnese Loda
- European Molecular Biology Laboratory, Directors' Research, 69117 Heidelberg, Germany
| | - Edith Heard
- European Molecular Biology Laboratory, Directors' Research, 69117 Heidelberg, Germany
- Collège de France, Paris 75005, France
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Chang G, Ying L, Zhang Q, Feng B, Yao R, Ding Y, Li J, Huang X, Shen Y, Yu T, Wang J, Wang X. Genetic variants of ABCC8 and clinical manifestations in eight Chinese children with hyperinsulinemic hypoglycemia. BMC Endocr Disord 2024; 24:8. [PMID: 38212772 PMCID: PMC10785495 DOI: 10.1186/s12902-023-01527-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 12/06/2023] [Indexed: 01/13/2024] Open
Abstract
BACKGROUND ABCC8 variants can cause hyperinsulinemia by activating or deactivating gene expression. This study used targeted exon sequencing to investigate genetic variants of ABCC8 and the associated phenotypic features in Chinese patients with hyperinsulinemic hypoglycemia (HH). METHODS We enrolled eight Chinese children with HH and analyzed their clinical characteristics, laboratory results, and genetic variations. RESULTS The age at presentation among the patients ranged from neonates to 0.6 years old, and the age at diagnosis ranged from 1 month to 5 years, with an average of 1.3 ± 0.7 years. Among these patients, three presented with seizures, and five with hypoglycemia. One patient (Patient 7) also had microcephaly. All eight patients exhibited ABCC8 abnormalities, including six missense mutations (c. 2521 C > G, c. 3784G > A, c. 4478G > A, c. 4532T > C, c. 2669T > C, and c. 331G > A), two deletion-insertion mutations (c. 3126_3129delinsTC and c. 3124_3126delins13), and one splicing mutation (c. 1332 + 2T > C). Two of these mutations (c. 3126_3129delinsTC and c. 4532T > C) are novel. Six variations were paternal, two were maternal, and one was de novo. Three patients responded to diazoxide and one patient responded to octreotide treatment. All there patients had diazoxide withdrawal with age. Two patients (patients 3 and 7) were unresponsive to both diazoxide and octreotide and had mental retardation. CONCLUSIONS Gene analysis can aid in the classification, treatment, and prognosis of children with HH. In this study, the identification of seven known and two novel variants in the ABCC8 gene further enriched the variation spectrum of the gene.
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Affiliation(s)
- Guoying Chang
- Department of Endocrinology and Metabolism, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 1678 Dongfang Road, 200127, Shanghai, China
| | - Lingwen Ying
- Department of Endocrinology and Metabolism, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 1678 Dongfang Road, 200127, Shanghai, China
| | - Qianwen Zhang
- Department of Endocrinology and Metabolism, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 1678 Dongfang Road, 200127, Shanghai, China
| | - Biyun Feng
- Department of Endocrinology and Metabolism, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 1678 Dongfang Road, 200127, Shanghai, China
| | - Ruen Yao
- Department of Medical Genetics and Molecular Diagnostics laboratory, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 200127, Shanghai, China
| | - Yu Ding
- Department of Endocrinology and Metabolism, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 1678 Dongfang Road, 200127, Shanghai, China
| | - Juan Li
- Department of Endocrinology and Metabolism, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 1678 Dongfang Road, 200127, Shanghai, China
| | - Xiaodong Huang
- Department of Endocrinology and Metabolism, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 1678 Dongfang Road, 200127, Shanghai, China
| | - Yongnian Shen
- Department of Endocrinology and Metabolism, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 1678 Dongfang Road, 200127, Shanghai, China
| | - Tingting Yu
- Department of Medical Genetics and Molecular Diagnostics laboratory, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 200127, Shanghai, China
| | - Jian Wang
- International Peace Maternity and Child Health Hospital, Shanghai Jiao Tong University School of Medicine, 200030, Shanghai, China.
| | - Xiumin Wang
- Department of Endocrinology and Metabolism, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 1678 Dongfang Road, 200127, Shanghai, China.
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Xu X, Lu H, Li J, Duan J, Wang Z, Yang J, Gu S, Luo R, Liang S, Tang W, Zhang F, Hang J, Ge J, Lin X, Qu J, Jia X, Xu J. Heterozygous CARD9 mutation favors the development of allergic bronchopulmonary aspergillosis. Chin Med J (Engl) 2023; 136:1949-1958. [PMID: 37461235 PMCID: PMC10431571 DOI: 10.1097/cm9.0000000000002786] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Indexed: 08/18/2023] Open
Abstract
BACKGROUND Previous research demonstrated that a homozygous mutation of g.136372044G>A (S12N) in caspase recruitment domain family member 9 ( CARD9 ) is critical for producing Aspergillus fumigatus -induced ( Af -induced) T helper 2 (T H 2)-mediated responses in allergic bronchopulmonary aspergillosis (ABPA). However, it remains unclear whether the CARD9S12N mutation, especially the heterozygous occurrence, predisposes the host to ABPA. METHODS A total of 61 ABPA patients and 264 controls (including 156 healthy controls and 108 asthma patients) were recruited for sequencing the CARD9 locus to clarify whether patients with this heterozygous single-nucleotide polymorphisms are predisposed to the development of ABPA. A series of in vivo and in vitro experiments, such as quantitative real-time polymerase chain reaction, flow cytometry, and RNA isolation and quantification, were used to illuminate the involved mechanism of the disease. RESULTS The presence of the p.S12N mutation was associated with a significant risk of ABPA in ABPA patients when compared with healthy controls and asthma patients, regardless of Aspergillus sensitivity. Relative to healthy controls without relevant allergies, the mutation of p.S12N was associated with a significant risk of ABPA (OR: 2.69 and 4.17 for GA and AA genotypes, P = 0.003 and 0.029, respectively). Compared with patients with asthma, ABPA patients had a significantly higher heterozygous mutation (GA genotype), indicating that p.S12N might be a significant ABPA-susceptibility locus ( aspergillus sensitized asthma: OR: 3.02, P = 0.009; aspergillus unsensitized asthma: OR: 2.94, P = 0.005). The mutant allele was preferentially expressed in ABPA patients with heterozygous CARD9S12N , which contributes to its functional alterations to facilitate Af -induced T H 2-mediated ABPA development. In terms of mechanism, Card9 wild-type ( Card9WT ) expression levels decreased significantly due to Af -induced decay of its messenger RNA compared to the heterozygous Card9S12N . In addition, ABPA patients with heterozygous CARD9S12N had increased Af -induced interleukin-5 production. CONCLUSION Our study provides the genetic evidence showing that the heterozygous mutation of CARD9S12N , followed by allele expression imbalance of CARD9S12N , facilitates the development of ABPA.
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Affiliation(s)
- Xia Xu
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, Institute of Respiratory Medicine, School of Medicine, Tongji University, Shanghai 200433, China
- Department of Immunology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Haiwen Lu
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, Institute of Respiratory Medicine, School of Medicine, Tongji University, Shanghai 200433, China
| | - Jianxiong Li
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, Institute of Respiratory Medicine, School of Medicine, Tongji University, Shanghai 200433, China
| | - Jielin Duan
- Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Zhongwei Wang
- Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Jiawei Yang
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, Institute of Respiratory Medicine, School of Medicine, Tongji University, Shanghai 200433, China
| | - Shuyi Gu
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, Institute of Respiratory Medicine, School of Medicine, Tongji University, Shanghai 200433, China
| | - Rongguang Luo
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, Institute of Respiratory Medicine, School of Medicine, Tongji University, Shanghai 200433, China
| | - Shuo Liang
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, Institute of Respiratory Medicine, School of Medicine, Tongji University, Shanghai 200433, China
| | - Wei Tang
- Department of Respiratory and Critical Care Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
| | - Fengying Zhang
- Department of Respiratory and Critical Care Medicine, Shanghai Putuo District People's Hospital, Shanghai 200060, China
| | - Jingqing Hang
- Department of Respiratory and Critical Care Medicine, Shanghai Putuo District People's Hospital, Shanghai 200060, China
| | - Juan Ge
- Department of Respiratory and Critical Care Medicine, Nantong Hospital, Shanghai University, Nantong, Jiangsu 226007, China
| | - Xin Lin
- Institute for Immunology, Tsinghua University School of Medicine, Tsinghua-Peking Center for Life Sciences, Beijing 100083, China
| | - Jieming Qu
- Department of Respiratory and Critical Care Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
| | - Xinming Jia
- Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Jinfu Xu
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, Institute of Respiratory Medicine, School of Medicine, Tongji University, Shanghai 200433, China
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Kravitz SN, Ferris E, Love MI, Thomas A, Quinlan AR, Gregg C. Random allelic expression in the adult human body. Cell Rep 2023; 42:111945. [PMID: 36640362 PMCID: PMC10484211 DOI: 10.1016/j.celrep.2022.111945] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 10/17/2022] [Accepted: 12/15/2022] [Indexed: 01/07/2023] Open
Abstract
Genes are typically assumed to express both parental alleles similarly, yet cell lines show random allelic expression (RAE) for many autosomal genes that could shape genetic effects. Thus, understanding RAE in human tissues could improve our understanding of phenotypic variation. Here, we develop a methodology to perform genome-wide profiling of RAE and biallelic expression in GTEx datasets for 832 people and 54 tissues. We report 2,762 autosomal genes with some RAE properties similar to randomly inactivated X-linked genes. We found that RAE is associated with rapidly evolving regions in the human genome, adaptive signaling processes, and genes linked to age-related diseases such as neurodegeneration and cancer. We define putative mechanistic subtypes of RAE distinguished by gene overlaps on sense and antisense DNA strands, aggregation in clusters near telomeres, and increased regulatory complexity and inputs compared with biallelic genes. We provide foundations to study RAE in human phenotypes, evolution, and disease.
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Affiliation(s)
- Stephanie N Kravitz
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA; Neurobiology, University of Utah, Salt Lake City, UT, USA
| | - Elliott Ferris
- Neurobiology, University of Utah, Salt Lake City, UT, USA
| | - Michael I Love
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Alun Thomas
- Department of Internal Medicine, Epidemiology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Aaron R Quinlan
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA
| | - Christopher Gregg
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA; Neurobiology, University of Utah, Salt Lake City, UT, USA.
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Kubasova N, Alves-Pereira CF, Gupta S, Vinogradova S, Gimelbrant A, Barreto VM. In Vivo Clonal Analysis Reveals Random Monoallelic Expression in Lymphocytes That Traces Back to Hematopoietic Stem Cells. Front Cell Dev Biol 2022; 10:827774. [PMID: 36003148 PMCID: PMC9393635 DOI: 10.3389/fcell.2022.827774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 05/16/2022] [Indexed: 11/24/2022] Open
Abstract
Evaluating the epigenetic landscape in the stem cell compartment at the single-cell level is essential to assess the cells’ heterogeneity and predict their fate. Here, using a genome-wide transcriptomics approach in vivo, we evaluated the allelic expression imbalance in the progeny of single hematopoietic cells (HSCs) as a read-out of epigenetic marking. After 4 months of extensive proliferation and differentiation, we found that X-chromosome inactivation (XCI) is tightly maintained in all single-HSC derived hematopoietic cells. In contrast, the vast majority of the autosomal genes did not show clonal patterns of random monoallelic expression (RME). However, a persistent allele-specific autosomal transcription in HSCs and their progeny was found in a rare number of cases, none of which has been previously reported. These data show that: 1) XCI and RME in the autosomal chromosomes are driven by different mechanisms; 2) the previously reported high frequency of genes under RME in clones expanded in vitro (up to 15%) is not found in clones undergoing multiple differentiation steps in vivo; 3) prior to differentiation, HSCs have stable patterns of autosomal RME. We propose that most RME patterns in autosomal chromosomes are erased and established de novo during cell lineage differentiation.
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Affiliation(s)
- Nadiya Kubasova
- Chronic Diseases Research Centre, Nova Medical School, CEDOC, Lisbon, Portugal
- Genetagus, Egas Moniz – Cooperativa de Ensino Superior, CRL, Monte de Caparica, Portugal
| | - Clara F. Alves-Pereira
- Center of Cancer Systems Biology, Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, United States
- Department of Genetics, Harvard Medical School, Boston, MA, United States
- Broad Institute of MIT and Harvard, Cambridge, MA, United States
- Department of Genetics, Smurfit Institute of Genetics, Trinity College Dublin, University of Dublin, Dublin, Ireland
| | - Saumya Gupta
- Center of Cancer Systems Biology, Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, United States
- Department of Genetics, Harvard Medical School, Boston, MA, United States
- Broad Institute of MIT and Harvard, Cambridge, MA, United States
| | - Svetlana Vinogradova
- Center of Cancer Systems Biology, Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, United States
- Department of Genetics, Harvard Medical School, Boston, MA, United States
- Broad Institute of MIT and Harvard, Cambridge, MA, United States
| | - Alexander Gimelbrant
- Center of Cancer Systems Biology, Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, United States
- Department of Genetics, Harvard Medical School, Boston, MA, United States
- Broad Institute of MIT and Harvard, Cambridge, MA, United States
- *Correspondence: Vasco M. Barreto, ; Alexander Gimelbrant,
| | - Vasco M. Barreto
- Chronic Diseases Research Centre, Nova Medical School, CEDOC, Lisbon, Portugal
- UCIBIO, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Costa da Caparica, Portugal
- *Correspondence: Vasco M. Barreto, ; Alexander Gimelbrant,
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Kissiov DU, Ethell A, Chen S, Wolf NK, Zhang C, Dang SM, Jo Y, Madsen KN, Paranjpe I, Lee AY, Chim B, Muljo SA, Raulet DH. Binary outcomes of enhancer activity underlie stable random monoallelic expression. eLife 2022; 11:e74204. [PMID: 35617021 PMCID: PMC9135403 DOI: 10.7554/elife.74204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 03/21/2022] [Indexed: 11/21/2022] Open
Abstract
Mitotically stable random monoallelic gene expression (RME) is documented for a small percentage of autosomal genes. We developed an in vivo genetic model to study the role of enhancers in RME using high-resolution single-cell analysis of natural killer (NK) cell receptor gene expression and enhancer deletions in the mouse germline. Enhancers of the RME NK receptor genes were accessible and enriched in H3K27ac on silent and active alleles alike in cells sorted according to allelic expression status, suggesting enhancer activation and gene expression status can be decoupled. In genes with multiple enhancers, enhancer deletion reduced gene expression frequency, in one instance converting the universally expressed gene encoding NKG2D into an RME gene, recapitulating all aspects of natural RME including mitotic stability of both the active and silent states. The results support the binary model of enhancer action, and suggest that RME is a consequence of general properties of gene regulation by enhancers rather than an RME-specific epigenetic program. Therefore, many and perhaps all genes may be subject to some degree of RME. Surprisingly, this was borne out by analysis of several genes that define different major hematopoietic lineages, that were previously thought to be universally expressed within those lineages: the genes encoding NKG2D, CD45, CD8α, and Thy-1. We propose that intrinsically probabilistic gene allele regulation is a general property of enhancer-controlled gene expression, with previously documented RME representing an extreme on a broad continuum.
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Affiliation(s)
- Djem U Kissiov
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Alexander Ethell
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Sean Chen
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Natalie K Wolf
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Chenyu Zhang
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Susanna M Dang
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Yeara Jo
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Katrine N Madsen
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Ishan Paranjpe
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Angus Y Lee
- Cancer Research Laboratory, University of California, BerkeleyBerkeleyUnited States
| | - Bryan Chim
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesdaUnited States
| | - Stefan A Muljo
- Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesdaUnited States
| | - David H Raulet
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
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8
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Basilicata MF, Keller Valsecchi CI. The good, the bad, and the ugly: Evolutionary and pathological aspects of gene dosage alterations. PLoS Genet 2021; 17:e1009906. [PMID: 34882671 PMCID: PMC8659298 DOI: 10.1371/journal.pgen.1009906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Diploid organisms contain a maternal and a paternal genome complement that is thought to provide robustness and allow developmental progression despite genetic perturbations that occur in heterozygosity. However, changes affecting gene dosage from the chromosome down to the individual gene level possess a significant pathological potential and can lead to developmental disorders (DDs). This indicates that expression from a balanced gene complement is highly relevant for proper cellular and organismal function in eukaryotes. Paradoxically, gene and whole chromosome duplications are a principal driver of evolution, while heteromorphic sex chromosomes (XY and ZW) are naturally occurring aneuploidies important for sex determination. Here, we provide an overview of the biology of gene dosage at the crossroads between evolutionary benefit and pathogenicity during disease. We describe the buffering mechanisms and cellular responses to alterations, which could provide a common ground for the understanding of DDs caused by copy number alterations.
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