1
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Ciabrelli F, Atinbayeva N, Pane A, Iovino N. Epigenetic inheritance and gene expression regulation in early Drosophila embryos. EMBO Rep 2024; 25:4131-4152. [PMID: 39285248 PMCID: PMC11467379 DOI: 10.1038/s44319-024-00245-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 05/13/2024] [Accepted: 08/21/2024] [Indexed: 10/12/2024] Open
Abstract
Precise spatiotemporal regulation of gene expression is of paramount importance for eukaryotic development. The maternal-to-zygotic transition (MZT) during early embryogenesis in Drosophila involves the gradual replacement of maternally contributed mRNAs and proteins by zygotic gene products. The zygotic genome is transcriptionally activated during the first 3 hours of development, in a process known as "zygotic genome activation" (ZGA), by the orchestrated activities of a few pioneer factors. Their decisive role during ZGA has been characterized in detail, whereas the contribution of chromatin factors to this process has been historically overlooked. In this review, we aim to summarize the current knowledge of how chromatin regulation impacts the first stages of Drosophila embryonic development. In particular, we will address the following questions: how chromatin factors affect ZGA and transcriptional silencing, and how genome architecture promotes the integration of these processes early during development. Remarkably, certain chromatin marks can be intergenerationally inherited, and their presence in the early embryo becomes critical for the regulation of gene expression at later stages. Finally, we speculate on the possible roles of these chromatin marks as carriers of epialleles during transgenerational epigenetic inheritance (TEI).
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Affiliation(s)
- Filippo Ciabrelli
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Nazerke Atinbayeva
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Attilio Pane
- Institute of Biomedical Sciences/UFRJ, 21941902, Rio de Janeiro, Brazil
| | - Nicola Iovino
- Max Planck Institute of Immunobiology and Epigenetics, 79108, Freiburg im Breisgau, Germany.
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2
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Kwizera R, Xie J, Nurse N, Yuan C, Kirchmaier AL. Impacts of Nucleosome Positioning Elements and Pre-Assembled Chromatin States on Expression and Retention of Transgenes. Genes (Basel) 2024; 15:1232. [PMID: 39336823 PMCID: PMC11431089 DOI: 10.3390/genes15091232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2024] [Revised: 09/14/2024] [Accepted: 09/17/2024] [Indexed: 09/30/2024] Open
Abstract
BACKGROUND/OBJECTIVES Transgene applications, ranging from gene therapy to the development of stable cell lines and organisms, rely on maintaining the expression of transgenes. To date, the use of plasmid-based transgenes has been limited by the loss of their expression shortly after their delivery into the target cells. The short-lived expression of plasmid-based transgenes has been largely attributed to host-cell-mediated degradation and/or silencing of transgenes. The development of chromatin-based strategies for gene delivery has the potential to facilitate defining the requirements for establishing epigenetic states and to enhance transgene expression for numerous applications. METHODS To assess the impact of "priming" plasmid-based transgenes to adopt accessible chromatin states to promote gene expression, nucleosome positioning elements were introduced at promoters of transgenes, and vectors were pre-assembled into nucleosomes containing unmodified histones or mutants mimicking constitutively acetylated states at residues 9 and 14 of histone H3 or residue 16 of histone H4 prior to their introduction into cells, then the transgene expression was monitored over time. RESULTS DNA sequences capable of positioning nucleosomes could positively impact the expression of adjacent transgenes in a distance-dependent manner in the absence of their pre-assembly into chromatin. Intriguingly, the pre-assembly of plasmids into chromatin facilitated the prolonged expression of transgenes relative to plasmids that were not pre-packaged into chromatin. Interactions between pre-assembled chromatin states and nucleosome positioning-derived effects on expression were also assessed and, generally, nucleosome positioning played the predominant role in influencing gene expression relative to priming with hyperacetylated chromatin states. CONCLUSIONS Strategies incorporating nucleosome positioning elements and the pre-assembly of plasmids into chromatin prior to nuclear delivery can modulate the expression of plasmid-based transgenes.
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Affiliation(s)
- Ronard Kwizera
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Junkai Xie
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Nathan Nurse
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Chongli Yuan
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Ann L Kirchmaier
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
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3
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Crain AT, Nevil M, Leatham-Jensen MP, Reeves KB, Matera AG, McKay DJ, Duronio RJ. Redesigning the Drosophila histone gene cluster: an improved genetic platform for spatiotemporal manipulation of histone function. Genetics 2024; 228:iyae117. [PMID: 39039029 PMCID: PMC11373521 DOI: 10.1093/genetics/iyae117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 07/09/2024] [Accepted: 07/12/2024] [Indexed: 07/24/2024] Open
Abstract
Mutating replication-dependent (RD) histone genes is an important tool for understanding chromatin-based epigenetic regulation. Deploying this tool in metazoans is particularly challenging because RD histones in these organisms are typically encoded by many genes, often located at multiple loci. Such gene arrangements make the ability to generate homogenous histone mutant genotypes by site-specific gene editing quite difficult. Drosophila melanogaster provides a solution to this problem because the RD histone genes are organized into a single large tandem array that can be deleted and replaced with transgenes containing mutant histone genes. In the last ∼15 years several different RD histone gene replacement platforms were developed using this simple strategy. However, each platform contains weaknesses that preclude full use of the powerful developmental genetic capabilities available to Drosophila researchers. Here we describe the development of a newly engineered platform that rectifies many of these weaknesses. We used CRISPR to precisely delete the RD histone gene array (HisC), replacing it with a multifunctional cassette that permits site-specific insertion of either one or two synthetic gene arrays using selectable markers. We designed this cassette with the ability to selectively delete each of the integrated gene arrays in specific tissues using site-specific recombinases. We also present a method for rapidly synthesizing histone gene arrays of any genotype using Golden Gate cloning technologies. These improvements facilitate the generation of histone mutant cells in various tissues at different stages of Drosophila development and provide an opportunity to apply forward genetic strategies to interrogate chromatin structure and gene regulation.
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Affiliation(s)
- Aaron T Crain
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599USA
| | - Markus Nevil
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599USA
- Seeding Postdoctoral Innovators in Research & Education, University of North Carolina, Chapel Hill, NC 27599USA
| | - Mary P Leatham-Jensen
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599USA
| | - Katherine B Reeves
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599USA
| | - A Gregory Matera
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599USA
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, 27599USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599USA
| | - Daniel J McKay
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599USA
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, 27599USA
| | - Robert J Duronio
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599USA
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, 27599USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599USA
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4
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Lin L, Huang Y, McIntyre J, Chang CH, Colmenares S, Lee YCG. Prevalent Fast Evolution of Genes Involved in Heterochromatin Functions. Mol Biol Evol 2024; 41:msae181. [PMID: 39189646 PMCID: PMC11408610 DOI: 10.1093/molbev/msae181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 08/14/2024] [Accepted: 08/20/2024] [Indexed: 08/28/2024] Open
Abstract
Heterochromatin is a gene-poor and repeat-rich genomic compartment universally found in eukaryotes. Despite its low transcriptional activity, heterochromatin plays important roles in maintaining genome stability, organizing chromosomes, and suppressing transposable elements. Given the importance of these functions, it is expected that genes involved in heterochromatin regulation would be highly conserved. Yet, a handful of these genes were found to evolve rapidly. To investigate whether these previous findings are anecdotal or general to genes modulating heterochromatin, we compile an exhaustive list of 106 candidate genes involved in heterochromatin functions and investigate their evolution over short and long evolutionary time scales in Drosophila. Our analyses find that these genes exhibit significantly more frequent evolutionary changes, both in the forms of amino acid substitutions and gene copy number change, when compared to genes involved in Polycomb-based repressive chromatin. While positive selection drives amino acid changes within both structured domains with diverse functions and intrinsically disordered regions, purifying selection may have maintained the proportions of intrinsically disordered regions of these proteins. Together with the observed negative associations between the evolutionary rate of these genes and the genomic abundance of transposable elements, we propose an evolutionary model where the fast evolution of genes involved in heterochromatin functions is an inevitable outcome of the unique functional roles of heterochromatin, while the rapid evolution of transposable elements may be an effect rather than cause. Our study provides an important global view of the evolution of genes involved in this critical cellular domain and provides insights into the factors driving the distinctive evolution of heterochromatin.
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Affiliation(s)
- Leila Lin
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, USA
| | - Yuheng Huang
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, USA
| | - Jennifer McIntyre
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, USA
| | - Ching-Ho Chang
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Serafin Colmenares
- Department of Cell and Molecular Biology, University of California, Berkeley, CA, USA
| | - Yuh Chwen G Lee
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, USA
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5
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Pipkin HJJ, Lindsay HL, Smiley AT, Jurmu JD, Arsham AM. An accessible digital imaging workflow for multiplexed quantitative analysis of adult eye phenotypes in Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.26.577286. [PMID: 39253516 PMCID: PMC11383053 DOI: 10.1101/2024.01.26.577286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/11/2024]
Abstract
The compound eye of Drosophila melanogaster has long been a model for studying genetics, development, neurodegeneration, and heterochromatin. Imaging and morphometry of adult Drosophila and other insects is hampered by the low throughput, narrow focal plane, and small image sensors typical of stereomicroscope cameras. When data collection is distributed among many individuals or extended time periods, these limitations are compounded by inter-operator variability in lighting, sample positioning, focus, and post-acquisition processing. To address these limitations we developed a method for multiplexed quantitative analysis of adult Drosophila melanogaster phenotypes. Efficient data collection and analysis of up to 60 adult flies in a single image with standardized conditions eliminates inter-operator variability and enables precise quantitative comparison of morphology. Semi-automated data analysis using ImageJ and R reduces image manipulations, facilitates reproducibility, and supports emerging automated segmentation methods, as well as a wide range of graphical and statistical tools. These methods also serve as a low-cost hands-on introduction to imaging, data visualization, and statistical analysis for students and trainees.
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Affiliation(s)
- Heidi J J Pipkin
- Bemidji State University and North Hennepin Community College, 7411 85 Ave N, Brooklyn Park, MN 55445
| | - Hunter L Lindsay
- Bemidji State University and North Hennepin Community College, 7411 85 Ave N, Brooklyn Park, MN 55445
| | - Adam T Smiley
- Bemidji State University and North Hennepin Community College, 7411 85 Ave N, Brooklyn Park, MN 55445
| | - Jack D Jurmu
- Bemidji State University and North Hennepin Community College, 7411 85 Ave N, Brooklyn Park, MN 55445
| | - Andrew M Arsham
- Bemidji State University and North Hennepin Community College, 7411 85 Ave N, Brooklyn Park, MN 55445
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6
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Aldrich JC, Vanderlinden LA, Jacobsen TL, Wood C, Saba LM, Britt SG. Genome-Wide Association Study and transcriptome analysis reveals a complex gene network that regulates opsin gene expression and cell fate determination in Drosophila R7 photoreceptor cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.05.606616. [PMID: 39149333 PMCID: PMC11326169 DOI: 10.1101/2024.08.05.606616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Background An animal's ability to discriminate between differing wavelengths of light (i.e., color vision) is mediated, in part, by a subset of photoreceptor cells that express opsins with distinct absorption spectra. In Drosophila R7 photoreceptors, expression of the rhodopsin molecules, Rh3 or Rh4, is determined by a stochastic process mediated by the transcription factor spineless. The goal of this study was to identify additional factors that regulate R7 cell fate and opsin choice using a Genome Wide Association Study (GWAS) paired with transcriptome analysis via RNA-Seq. Results We examined Rh3 and Rh4 expression in a subset of fully-sequenced inbred strains from the Drosophila Genetic Reference Panel and performed a GWAS to identify 42 naturally-occurring polymorphisms-in proximity to 28 candidate genes-that significantly influence R7 opsin expression. Network analysis revealed multiple potential interactions between the associated candidate genes, spineless and its partners. GWAS candidates were further validated in a secondary RNAi screen which identified 12 lines that significantly reduce the proportion of Rh3 expressing R7 photoreceptors. Finally, using RNA-Seq, we demonstrated that all but four of the GWAS candidates are expressed in the pupal retina at a critical developmental time point and that five are among the 917 differentially expressed genes in sevenless mutants, which lack R7 cells. Conclusions Collectively, these results suggest that the relatively simple, binary cell fate decision underlying R7 opsin expression is modulated by a larger, more complex network of regulatory factors. Of particular interest are a subset of candidate genes with previously characterized neuronal functions including neurogenesis, neurodegeneration, photoreceptor development, axon growth and guidance, synaptogenesis, and synaptic function.
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Affiliation(s)
- John C. Aldrich
- Department of Neurology, Department of Ophthalmology, Dell Medical School; University of Texas at Austin, Austin, TX 78712
- Department of Psychology, University of Texas at Austin, Austin, TX 78712
| | - Lauren A. Vanderlinden
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Thomas L. Jacobsen
- Department of Neurology, Department of Ophthalmology, Dell Medical School; University of Texas at Austin, Austin, TX 78712
| | - Cheyret Wood
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Laura M. Saba
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Steven G. Britt
- Department of Neurology, Department of Ophthalmology, Dell Medical School; University of Texas at Austin, Austin, TX 78712
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7
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Cappucci U, Proietti M, Casale AM, Schiavo S, Chiavarini S, Accardo S, Manzo S, Piacentini L. Assessing genotoxic effects of plastic leachates in Drosophila melanogaster. CHEMOSPHERE 2024; 361:142440. [PMID: 38821133 DOI: 10.1016/j.chemosphere.2024.142440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 05/16/2024] [Accepted: 05/24/2024] [Indexed: 06/02/2024]
Abstract
Plastic polymers were largely added with chemical substances to be utilized in the items and product manufacturing. The leachability of these substances is a matter of concern given the wide amount of plastic waste, particularly in terrestrial environments, where soil represents a sink for these novel contaminants and a possible pathway of human health risk. In this study, we integrated genetic, molecular, and behavioral approaches to comparatively evaluate toxicological effects of plastic leachates, virgin and oxodegradable polypropylene (PP) and polyethylene (PE), in Drosophila melanogaster, a novel in vivo model organism for environmental monitoring studies and (eco)toxicological research. The results of this study revealed that while conventional toxicological endpoints such as developmental times and longevity remain largely unaffected, exposure to plastic leachates induces chromosomal abnormalities and transposable element (TE) activation in neural tissues. The combined effects of DNA damage and TE mobilization contribute to genome instability and increase the likelihood of LOH events, thus potentiating tumor growth and metastatic behavior ofRasV12 clones. Collectively, these findings indicate that plastic leachates exert genotoxic effects in Drosophila thus highlighting potential risks associated with leachate-related plastic pollution and their implications for ecosystems and human health.
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Affiliation(s)
- Ugo Cappucci
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, P. le A. Moro 5, 00185 Rome, Italy
| | - Mirena Proietti
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, P. le A. Moro 5, 00185 Rome, Italy
| | - Assunta Maria Casale
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, P. le A. Moro 5, 00185 Rome, Italy
| | - Simona Schiavo
- ENEA, Department for Sustainability, Division Protection and Enhancement of the Natural Capital, P. le E. Fermi 1, 80055 Portici, Na, Italy
| | - Salvatore Chiavarini
- ENEA, Department for Sustainability, Division Protection and Enhancement of the Natural Capital, P. le E. Fermi 1, 80055 Portici, Na, Italy
| | - Sara Accardo
- ENEA, Department for Sustainability, Division Protection and Enhancement of the Natural Capital, P. le E. Fermi 1, 80055 Portici, Na, Italy
| | - Sonia Manzo
- ENEA, Department for Sustainability, Division Protection and Enhancement of the Natural Capital, P. le E. Fermi 1, 80055 Portici, Na, Italy.
| | - Lucia Piacentini
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, P. le A. Moro 5, 00185 Rome, Italy.
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8
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Lin L, Huang Y, McIntyre J, Chang CH, Colmenares S, Lee YCG. Prevalent fast evolution of genes involved in heterochromatin functions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.03.583199. [PMID: 38496614 PMCID: PMC10942301 DOI: 10.1101/2024.03.03.583199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Heterochromatin is a gene-poor and repeat-rich genomic compartment universally found in eukaryotes. Despite its low transcriptional activity, heterochromatin plays important roles in maintaining genome stability, organizing chromosomes, and suppressing transposable elements (TEs). Given the importance of these functions, it is expected that the genes involved in heterochromatin regulation would be highly conserved. Yet, a handful of these genes were found to evolve rapidly. To investigate whether these previous findings are anecdotal or general to genes modulating heterochromatin, we compile an exhaustive list of 106 candidate genes involved in heterochromatin functions and investigate their evolution over short and long evolutionary time scales in Drosophila. Our analyses find that these genes exhibit significantly more frequent evolutionary changes, both in the forms of amino acid substitutions and gene copy number change, when compared to genes involved in Polycomb-based repressive chromatin. While positive selection drives amino acid changes within both structured domains with diverse functions and intrinsically disordered regions (IDRs), purifying selection may have maintained the proportions of IDRs of these proteins. Together with the observed negative associations between evolutionary rates of these genes and genomic TE abundance, we propose an evolutionary model where the fast evolution of genes involved in heterochromatin functions is an inevitable outcome of the unique functional roles of heterochromatin, while the rapid evolution of TEs may be an effect rather than cause. Our study provides an important global view of the evolution of genes involved in this critical cellular domain and provides insights into the factors driving the distinctive evolution of heterochromatin.
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9
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Liang X, Duan Q, Li B, Wang Y, Bu Y, Zhang Y, Kuang Z, Mao L, An X, Wang H, Yang X, Wan N, Feng Z, Shen W, Miao W, Chen J, Liu S, Storz JF, Liu J, Nevo E, Li K. Genomic structural variation contributes to evolved changes in gene expression in high-altitude Tibetan sheep. Proc Natl Acad Sci U S A 2024; 121:e2322291121. [PMID: 38913905 PMCID: PMC11228492 DOI: 10.1073/pnas.2322291121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 05/06/2024] [Indexed: 06/26/2024] Open
Abstract
Tibetan sheep were introduced to the Qinghai Tibet plateau roughly 3,000 B.P., making this species a good model for investigating genetic mechanisms of high-altitude adaptation over a relatively short timescale. Here, we characterize genomic structural variants (SVs) that distinguish Tibetan sheep from closely related, low-altitude Hu sheep, and we examine associated changes in tissue-specific gene expression. We document differentiation between the two sheep breeds in frequencies of SVs associated with genes involved in cardiac function and circulation. In Tibetan sheep, we identified high-frequency SVs in a total of 462 genes, including EPAS1, PAPSS2, and PTPRD. Single-cell RNA-Seq data and luciferase reporter assays revealed that the SVs had cis-acting effects on the expression levels of these three genes in specific tissues and cell types. In Tibetan sheep, we identified a high-frequency chromosomal inversion that exhibited modified chromatin architectures relative to the noninverted allele that predominates in Hu sheep. The inversion harbors several genes with altered expression patterns related to heart protection, brown adipocyte proliferation, angiogenesis, and DNA repair. These findings indicate that SVs represent an important source of genetic variation in gene expression and may have contributed to high-altitude adaptation in Tibetan sheep.
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Affiliation(s)
- Xiaolong Liang
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Qijiao Duan
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Bowen Li
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Yinjia Wang
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Yueting Bu
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Yonglu Zhang
- Fengjia Town Health Center, Rushan City, Weihai City264200, China
| | - Zhuoran Kuang
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Leyan Mao
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Xuan An
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Huihua Wang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing100193, China
| | - Xiaojie Yang
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Na Wan
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Zhilong Feng
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Wei Shen
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Weilan Miao
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Jiaqi Chen
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Sanyuan Liu
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Jay F. Storz
- School of Biological Sciences, University of Nebraska, Lincoln, NE68588
| | - Jianquan Liu
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
| | - Eviatar Nevo
- Institute of Evolution, University of Haifa, Haifa3498838, Israel
| | - Kexin Li
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, China
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Yabe K, Kamio A, Oya S, Kakutani T, Hirayama M, Tanaka Y, Inagaki S. H3K9 methylation regulates heterochromatin silencing through incoherent feedforward loops. SCIENCE ADVANCES 2024; 10:eadn4149. [PMID: 38924413 PMCID: PMC11204290 DOI: 10.1126/sciadv.adn4149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 05/22/2024] [Indexed: 06/28/2024]
Abstract
Histone H3 lysine-9 methylation (H3K9me) is a hallmark of the condensed and transcriptionally silent heterochromatin. It remains unclear how H3K9me controls transcription silencing and how cells delimit H3K9me domains to avoid silencing essential genes. Here, using Arabidopsis genetic systems that induce H3K9me2 in genes and transposons de novo, we show that H3K9me2 accumulation paradoxically also causes the deposition of the euchromatic mark H3K36me3 by a SET domain methyltransferase, ASHH3. ASHH3-induced H3K36me3 confers anti-silencing by preventing the demethylation of H3K4me1 by LDL2, which mediates transcriptional silencing downstream of H3K9me2. These results demonstrate that H3K9me2 not only facilitates but orchestrates silencing by actuating antagonistic silencing and anti-silencing pathways, providing insights into the molecular basis underlying proper partitioning of chromatin domains and the creation of metastable epigenetic variation.
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Affiliation(s)
| | | | - Satoyo Oya
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | | | - Mami Hirayama
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yuriko Tanaka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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11
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Stutzman AV, Hill CA, Armstrong RL, Gohil R, Duronio RJ, Dowen JM, McKay DJ. Heterochromatic 3D genome organization is directed by HP1a- and H3K9-dependent and independent mechanisms. Mol Cell 2024; 84:2017-2035.e6. [PMID: 38795706 PMCID: PMC11185254 DOI: 10.1016/j.molcel.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 03/07/2024] [Accepted: 05/02/2024] [Indexed: 05/28/2024]
Abstract
Whether and how histone post-translational modifications and the proteins that bind them drive 3D genome organization remains unanswered. Here, we evaluate the contribution of H3K9-methylated constitutive heterochromatin to 3D genome organization in Drosophila tissues. We find that the predominant organizational feature of wild-type tissues is the segregation of euchromatic chromosome arms from heterochromatic pericentromeres. Reciprocal perturbation of HP1a⋅H3K9me binding, using a point mutation in the HP1a chromodomain or replacement of the replication-dependent histone H3 with H3K9R mutant histones, revealed that HP1a binding to methylated H3K9 in constitutive heterochromatin is required to limit contact frequency between pericentromeres and chromosome arms and regulate the distance between arm and pericentromeric regions. Surprisingly, the self-association of pericentromeric regions is largely preserved despite the loss of H3K9 methylation and HP1a occupancy. Thus, the HP1a⋅H3K9 interaction contributes to but does not solely drive the segregation of euchromatin and heterochromatin inside the nucleus.
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Affiliation(s)
- Alexis V Stutzman
- Curriculum in Genetics & Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Christina A Hill
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Robin L Armstrong
- Curriculum in Genetics & Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Riya Gohil
- Curriculum in Genetics & Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Robert J Duronio
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Jill M Dowen
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Biochemistry & Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Daniel J McKay
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA.
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12
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Akilli N, Cheutin T, Cavalli G. Phase separation and inheritance of repressive chromatin domains. Curr Opin Genet Dev 2024; 86:102201. [PMID: 38701672 DOI: 10.1016/j.gde.2024.102201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 04/04/2024] [Accepted: 04/16/2024] [Indexed: 05/05/2024]
Abstract
Polycomb-associated chromatin and pericentromeric heterochromatin form genomic domains important for the epigenetic regulation of gene expression. Both Polycomb complexes and heterochromatin factors rely on 'read and write' mechanisms, which, on their own, are not sufficient to explain the formation and the maintenance of these epigenetic domains. Microscopy has revealed that they form specific nuclear compartments separated from the rest of the genome. Recently, some subunits of these molecular machineries have been shown to undergo phase separation, both in vitro and in vivo, suggesting that phase separation might play important roles in the formation and the function of these two kinds of repressive chromatin. In this review, we will present the recent advances in the field of facultative and constitutive heterochromatin formation and maintenance through phase separation.
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Affiliation(s)
- Nazli Akilli
- Institute of Human Genetics, CNRS, University of Montpellier, Montpellier, France. https://twitter.com/@sinmerank
| | - Thierry Cheutin
- Institute of Human Genetics, CNRS, University of Montpellier, Montpellier, France
| | - Giacomo Cavalli
- Institute of Human Genetics, CNRS, University of Montpellier, Montpellier, France.
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13
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Castilho RM, Castilho LS, Palomares BH, Squarize CH. Determinants of Chromatin Organization in Aging and Cancer-Emerging Opportunities for Epigenetic Therapies and AI Technology. Genes (Basel) 2024; 15:710. [PMID: 38927646 PMCID: PMC11202709 DOI: 10.3390/genes15060710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 05/21/2024] [Accepted: 05/26/2024] [Indexed: 06/28/2024] Open
Abstract
This review article critically examines the pivotal role of chromatin organization in gene regulation, cellular differentiation, disease progression and aging. It explores the dynamic between the euchromatin and heterochromatin, coded by a complex array of histone modifications that orchestrate essential cellular processes. We discuss the pathological impacts of chromatin state misregulation, particularly in cancer and accelerated aging conditions such as progeroid syndromes, and highlight the innovative role of epigenetic therapies and artificial intelligence (AI) in comprehending and harnessing the histone code toward personalized medicine. In the context of aging, this review explores the use of AI and advanced machine learning (ML) algorithms to parse vast biological datasets, leading to the development of predictive models for epigenetic modifications and providing a framework for understanding complex regulatory mechanisms, such as those governing cell identity genes. It supports innovative platforms like CEFCIG for high-accuracy predictions and tools like GridGO for tailored ChIP-Seq analysis, which are vital for deciphering the epigenetic landscape. The review also casts a vision on the prospects of AI and ML in oncology, particularly in the personalization of cancer therapy, including early diagnostics and treatment optimization for diseases like head and neck and colorectal cancers by harnessing computational methods, AI advancements and integrated clinical data for a transformative impact on healthcare outcomes.
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Affiliation(s)
- Rogerio M. Castilho
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1078, USA; (L.S.C.); (C.H.S.)
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI 48109-1078, USA
| | - Leonard S. Castilho
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1078, USA; (L.S.C.); (C.H.S.)
| | - Bruna H. Palomares
- Oral Diagnosis Department, Piracicaba School of Dentistry, State University of Campinas, Piracicaba 13414-903, Sao Paulo, Brazil;
| | - Cristiane H. Squarize
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1078, USA; (L.S.C.); (C.H.S.)
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI 48109-1078, USA
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14
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Ono M, Ito T, Yamaki S, Hori Y, Zhou Q, Zhao X, Muramoto S, Yamamoto R, Furuyama T, Sakata-Haga H, Hatta T, Hamaguchi T, Kato N. Spatiotemporal development of the neuronal accumulation of amyloid precursor protein and the amyloid plaque formation in the brain of 3xTg-AD mice. Heliyon 2024; 10:e28821. [PMID: 38596059 PMCID: PMC11002285 DOI: 10.1016/j.heliyon.2024.e28821] [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: 08/28/2023] [Revised: 03/25/2024] [Accepted: 03/25/2024] [Indexed: 04/11/2024] Open
Abstract
The amyloid plaque is a hallmark of Alzheimer's disease. The accumulation of the amyloid precursor protein (APP) in the neuronal structure is assumed to lead to amyloid plaque formation through the excessive production of β-amyloid protein. To study the relationship between the neuronal accumulation of APP and amyloid plaque formation, we histologically analyzed their development in the different brain regions in 3xTg-AD mice, which express Swedish mutated APP (APPSWE) in the neurons. Observation throughout the brain revealed APPSWE-positive somata in the broad regions. Quantitative model analysis showed that the somatic accumulation of APPSWE developed firstly in the hippocampus from a very early age (<1 month) and proceeded slower in the isocortex. In line with this, the hippocampus was the first region to form amyloid plaques at the age of 9-12 months, while amyloid plaques were rarely observed in the isocortex. Females had more APPSWE-positive somata and plaques than males. Furthermore, amyloid plaques were observed in the lateral septum and pontine grey, which did not contain APPSWE-positive somata but only the APPSWE-positive fibers. These results suggested that neuronal accumulation of APPSWE, both in somatodendritic and axonal domains, is closely related to the formation of amyloid plaques.
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Affiliation(s)
- Munenori Ono
- Department of Physiology, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Tetsufumi Ito
- Systems Function and Morphology, University of Toyama, Toyama, 930-0194, Japan
| | - Sachiko Yamaki
- Department of Physiology, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Yoshie Hori
- Department of Physiology, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Qing Zhou
- Department of Physiology, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Xirun Zhao
- Department of Physiology, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Shinji Muramoto
- Department of Physiology, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Ryo Yamamoto
- Department of Physiology, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Takafumi Furuyama
- Department of Physiology, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Hiromi Sakata-Haga
- Department of Anatomy, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Toshihisa Hatta
- Department of Anatomy, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Tsuyoshi Hamaguchi
- Department of Neurology, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Nobuo Kato
- Department of Physiology, Kanazawa Medical University, Ishikawa, 920-0293, Japan
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15
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Huang Y, Lee YCG. Blessing or curse: how the epigenetic resolution of host-transposable element conflicts shapes their evolutionary dynamics. Proc Biol Sci 2024; 291:20232775. [PMID: 38593848 PMCID: PMC11003778 DOI: 10.1098/rspb.2023.2775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 03/01/2024] [Indexed: 04/11/2024] Open
Abstract
Transposable elements (TEs) are selfish genetic elements whose antagonistic interactions with hosts represent a common genetic conflict in eukaryotes. To resolve this conflict, hosts have widely adopted epigenetic silencing that deposits repressive marks at TEs. However, this mechanism is imperfect and fails to fully halt TE replication. Furthermore, TE epigenetic silencing can inadvertently spread repressive marks to adjacent functional sequences, a phenomenon considered a 'curse' of this conflict resolution. Here, we used forward simulations to explore how TE epigenetic silencing and its harmful side effects shape the evolutionary dynamics of TEs and their hosts. Our findings reveal that epigenetic silencing allows TEs and their hosts to stably coexist under a wide range of conditions, because the underlying molecular mechanisms give rise to copy-number dependency of the strength of TE silencing. Interestingly, contrary to intuitive expectations that TE epigenetic silencing should evolve to be as strong as possible, we found a selective benefit for modifier alleles that weaken TE silencing under biologically feasible conditions. These results reveal that the dual nature of TE epigenetic silencing, with both positive and negative effects, complicates its evolutionary trajectory and makes it challenging to determine whether TE epigenetic silencing is a 'blessing' or a 'curse'.
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Affiliation(s)
- Yuheng Huang
- Department of Ecology and Evolutionary Biology, University of California, Irvine, USA
| | - Yuh Chwen G. Lee
- Department of Ecology and Evolutionary Biology, University of California, Irvine, USA
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16
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Koestler SA, Ball ML, Muresan L, Dinakaran V, White R. Transcriptionally active chromatin loops contain both 'active' and 'inactive' histone modifications that exhibit exclusivity at the level of nucleosome clusters. Epigenetics Chromatin 2024; 17:8. [PMID: 38528624 DOI: 10.1186/s13072-024-00535-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Accepted: 03/14/2024] [Indexed: 03/27/2024] Open
Abstract
Chromatin state is thought to impart regulatory function to the underlying DNA sequence. This can be established through histone modifications and chromatin organisation, but exactly how these factors relate to one another to regulate gene expression is unclear. In this study, we have used super-resolution microscopy to image the Y loops of Drosophila melanogaster primary spermatocytes, which are enormous transcriptionally active chromatin fibres, each representing single transcription units that are individually resolvable in the nuclear interior. We previously found that the Y loops consist of regular clusters of nucleosomes, with an estimated median of 54 nucleosomes per cluster with wide variation.In this study, we report that the histone modifications H3K4me3, H3K27me3, and H3K36me3 are also clustered along the Y loops, with H3K4me3 more associated with diffuse chromatin compared to H3K27me3. These histone modifications form domains that can be stretches of Y loop chromatin micrometres long, or can be in short alternating domains. The different histone modifications are associated with different sizes of chromatin clusters and unique morphologies. Strikingly, a single chromatin cluster almost always only contains only one type of the histone modifications that were labelled, suggesting exclusivity, and therefore regulation at the level of individual chromatin clusters. The active mark H3K36me3 is more associated with actively elongating RNA polymerase II than H3K27me3, with polymerase often appearing on what are assumed to be looping regions on the periphery of chromatin clusters.These results provide a foundation for understanding the relationship between chromatin state, chromatin organisation, and transcription regulation - with potential implications for pause-release dynamics, splicing complex organisation and chromatin dynamics during polymerase progression along a gene.
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Affiliation(s)
- Stefan A Koestler
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3DY, UK
| | - Madeleine L Ball
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3DY, UK
| | - Leila Muresan
- Cambridge Advanced Imaging Centre, University of Cambridge, Downing Site, Cambridge, CB2 3DY, UK
| | - Vineet Dinakaran
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3DY, UK
| | - Robert White
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3DY, UK.
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17
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Flynn JM, Yamashita YM. The implications of satellite DNA instability on cellular function and evolution. Semin Cell Dev Biol 2024; 156:152-159. [PMID: 37852904 DOI: 10.1016/j.semcdb.2023.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 09/21/2023] [Accepted: 10/11/2023] [Indexed: 10/20/2023]
Abstract
Abundant tandemly repeated satellite DNA is present in most eukaryotic genomes. Previous limitations including a pervasive view that it was uninteresting junk DNA, combined with challenges in studying it, are starting to dissolve - and recent studies have found important functions for satellite DNAs. The observed rapid evolution and implied instability of satellite DNA now has important significance for their functions and maintenance within the genome. In this review, we discuss the processes that lead to satellite DNA copy number instability, and the importance of mechanisms to manage the potential negative effects of instability. Satellite DNA is vulnerable to challenges during replication and repair, since it forms difficult-to-process secondary structures and its homology within tandem arrays can result in various types of recombination. Satellite DNA instability may be managed by DNA or chromatin-binding proteins ensuring proper nuclear localization and repair, or by proteins that process aberrant structures that satellite DNAs tend to form. We also discuss the pattern of satellite DNA mutations from recent mutation accumulation (MA) studies that have tracked changes in satellite DNA for up to 1000 generations with minimal selection. Finally, we highlight examples of satellite evolution from studies that have characterized satellites across millions of years of Drosophila fruit fly evolution, and discuss possible ways that selection might act on the satellite DNA composition.
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Affiliation(s)
- Jullien M Flynn
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Howard Hughes Medical Institute, Cambridge, MA, USA.
| | - Yukiko M Yamashita
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Howard Hughes Medical Institute, Cambridge, MA, USA; Massachusetts Institute of Technology, Cambridge, MA, USA.
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18
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Clot C, Hudry B, Delanoue R. [The Y chromosome has no impact on sex-specific longevity]. Med Sci (Paris) 2024; 40:143-145. [PMID: 38411420 DOI: 10.1051/medsci/2023203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024] Open
Affiliation(s)
- Charlène Clot
- Université Côte d'Azur, CNRS, Inserm, Institut de biologie Valrose, Nice, France
| | - Bruno Hudry
- Université Côte d'Azur, CNRS, Inserm, Institut de biologie Valrose, Nice, France
| | - Rénald Delanoue
- Université Côte d'Azur, CNRS, Inserm, Institut de biologie Valrose, Nice, France
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19
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Roy A, Ghosh A. Epigenetic Restriction Factors (eRFs) in Virus Infection. Viruses 2024; 16:183. [PMID: 38399958 PMCID: PMC10892949 DOI: 10.3390/v16020183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
The ongoing arms race between viruses and their hosts is constantly evolving. One of the ways in which cells defend themselves against invading viruses is by using restriction factors (RFs), which are cell-intrinsic antiviral mechanisms that block viral replication and transcription. Recent research has identified a specific group of RFs that belong to the cellular epigenetic machinery and are able to restrict the gene expression of certain viruses. These RFs can be referred to as epigenetic restriction factors or eRFs. In this review, eRFs have been classified into two categories. The first category includes eRFs that target viral chromatin. So far, the identified eRFs in this category include the PML-NBs, the KRAB/KAP1 complex, IFI16, and the HUSH complex. The second category includes eRFs that target viral RNA or, more specifically, the viral epitranscriptome. These epitranscriptomic eRFs have been further classified into two types: those that edit RNA bases-adenosine deaminase acting on RNA (ADAR) and pseudouridine synthases (PUS), and those that covalently modify viral RNA-the N6-methyladenosine (m6A) writers, readers, and erasers. We delve into the molecular machinery of eRFs, their role in limiting various viruses, and the mechanisms by which viruses have evolved to counteract them. We also examine the crosstalk between different eRFs, including the common effectors that connect them. Finally, we explore the potential for new discoveries in the realm of epigenetic networks that restrict viral gene expression, as well as the future research directions in this area.
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Affiliation(s)
- Arunava Roy
- Department of Molecular Medicine, University of South Florida, Tampa, FL 33612, USA;
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20
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Li B. Unwrap RAP1's Mystery at Kinetoplastid Telomeres. Biomolecules 2024; 14:67. [PMID: 38254667 PMCID: PMC10813129 DOI: 10.3390/biom14010067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 12/27/2023] [Accepted: 12/27/2023] [Indexed: 01/24/2024] Open
Abstract
Although located at the chromosome end, telomeres are an essential chromosome component that helps maintain genome integrity and chromosome stability from protozoa to mammals. The role of telomere proteins in chromosome end protection is conserved, where they suppress various DNA damage response machineries and block nucleolytic degradation of the natural chromosome ends, although the detailed underlying mechanisms are not identical. In addition, the specialized telomere structure exerts a repressive epigenetic effect on expression of genes located at subtelomeres in a number of eukaryotic organisms. This so-called telomeric silencing also affects virulence of a number of microbial pathogens that undergo antigenic variation/phenotypic switching. Telomere proteins, particularly the RAP1 homologs, have been shown to be a key player for telomeric silencing. RAP1 homologs also suppress the expression of Telomere Repeat-containing RNA (TERRA), which is linked to their roles in telomere stability maintenance. The functions of RAP1s in suppressing telomere recombination are largely conserved from kinetoplastids to mammals. However, the underlying mechanisms of RAP1-mediated telomeric silencing have many species-specific features. In this review, I will focus on Trypanosoma brucei RAP1's functions in suppressing telomeric/subtelomeric DNA recombination and in the regulation of monoallelic expression of subtelomere-located major surface antigen genes. Common and unique mechanisms will be compared among RAP1 homologs, and their implications will be discussed.
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Affiliation(s)
- Bibo Li
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Arts and Sciences, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA;
- Case Comprehensive Cancer Center, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
- Center for RNA Science and Therapeutics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
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21
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Ye JC, Heng HH. The New Era of Cancer Cytogenetics and Cytogenomics. Methods Mol Biol 2024; 2825:3-37. [PMID: 38913301 DOI: 10.1007/978-1-0716-3946-7_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/25/2024]
Abstract
The promises of the cancer genome sequencing project, combined with various -omics technologies, have raised questions about the importance of cancer cytogenetic analyses. It is suggested that DNA sequencing provides high resolution, speed, and automation, potentially replacing cytogenetic testing. We disagree with this reductionist prediction. On the contrary, various sequencing projects have unexpectedly challenged gene theory and highlighted the importance of the genome or karyotype in organizing gene network interactions. Consequently, profiling the karyotype can be more meaningful than solely profiling gene mutations, especially in cancer where karyotype alterations mediate cellular macroevolution dominance. In this chapter, recent studies that illustrate the ultimate importance of karyotype in cancer genomics and evolution are briefly reviewed. In particular, the long-ignored non-clonal chromosome aberrations or NCCAs are linked to genome or chromosome instability, genome chaos is linked to genome reorganization under cellular crisis, and the two-phased cancer evolution reconciles the relationship between genome alteration-mediated punctuated macroevolution and gene mutation-mediated stepwise microevolution. By further synthesizing, the concept of karyotype coding is discussed in the context of information management. Altogether, we call for a new era of cancer cytogenetics and cytogenomics, where an array of technical frontiers can be explored further, which is crucial for both basic research and clinical implications in the cancer field.
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Affiliation(s)
- Jing Christine Ye
- Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Henry H Heng
- Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA.
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22
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Courret C, Larracuente AM. High levels of intra-strain structural variation in Drosophila simulans X pericentric heterochromatin. Genetics 2023; 225:iyad176. [PMID: 37768175 PMCID: PMC10697818 DOI: 10.1093/genetics/iyad176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 08/12/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Large genome structural variations can impact genome regulation and integrity. Repeat-rich regions like pericentric heterochromatin are vulnerable to structural rearrangements although we know little about how often these rearrangements occur over evolutionary time. Repetitive genome regions are particularly difficult to study with genomic approaches, as they are missing from most genome assemblies. However, cytogenetic approaches offer a direct way to detect large rearrangements involving pericentric heterochromatin. Here, we use a cytogenetic approach to reveal large structural rearrangements associated with the X pericentromeric region of Drosophila simulans. These rearrangements involve large blocks of satellite DNA-the 500-bp and Rsp-like satellites-which colocalize in the X pericentromeric heterochromatin. We find that this region is polymorphic not only among different strains, but between isolates of the same strain from different labs, and even within individual isolates. On the one hand, our observations raise questions regarding the potential impact of such variation at the phenotypic level and our ability to control for such genetic variability. On the other hand, this highlights the very rapid turnover of the pericentric heterochromatin most likely associated with genomic instability of the X pericentromere. It represents a unique opportunity to study the dynamics of pericentric heterochromatin, the evolution of associated satellites on a very short time scale, and to better understand how structural variation arises.
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Affiliation(s)
- Cécile Courret
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
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23
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Yarinich LA, Ogienko AA, Pindyurin AV, Omelina ES. Analysis of the transcriptional activity of model piggyBac transgenes stably integrated into different loci of the genome of CHO cells in the absence of selection pressure. Vavilovskii Zhurnal Genet Selektsii 2023; 27:906-915. [PMID: 38213697 PMCID: PMC10777298 DOI: 10.18699/vjgb-23-105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 09/21/2023] [Accepted: 09/27/2023] [Indexed: 01/13/2024] Open
Abstract
CHO cells are most commonly used for the synthesis of recombinant proteins in biopharmaceutical production. When stable producer cell lines are obtained, the locus of transgene integration into the genome has a great influence on the level of its expression. Therefore, the identification of genomic loci ensuring a high level of protein production is very important. Here, we used the TRIP assay to study the influence of the local chromatin environment on the activity of transgenes in CHO cells. For this purpose, reporter constructs encoding eGFP under the control of four promoters were stably integrated into the genome of CHO cells using the piggyBac transposon. Each individual transgene contained a unique tag, a DNA barcode, and the resulting polyclonal cell population was cultured for almost a month without any selection. Next, using the high-throughput sequencing, genomic localizations of barcodes, as well as their abundances in the population and transcriptional activities were identified. In total, ~640 transgenes more or less evenly distributed across all chromosomes of CHO cells were characterized. More than half of the transgenes were completely silent. The most active transgenes were identified to be inserted in gene promoters and 5' UTRs. Transgenes carrying Chinese hamster full-length promoter of the EF-1α gene showed the highest activity. Transgenes with a truncated version of the same promoter and with the mouse PGK gene promoter were on average 10 and 19 times less active, respectively. In total, combinations of genomic loci of CHO cells and transgene promoters that together provide different levels of transcriptional activity of the model reporter construct were described.
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Affiliation(s)
- L A Yarinich
- Institute of Molecular and Cellular Biology of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - A A Ogienko
- Institute of Molecular and Cellular Biology of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - A V Pindyurin
- Institute of Molecular and Cellular Biology of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - E S Omelina
- Institute of Molecular and Cellular Biology of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
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24
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Solodovnikov AA, Lavrov SA, Shatskikh AS, Gvozdev VA. Effects of Chromatin Structure Modifiers on the trans-Acting Heterochromatin Position Effect in Drosophila melanogaster. DOKL BIOCHEM BIOPHYS 2023; 513:S75-S81. [PMID: 38379078 DOI: 10.1134/s160767292470073x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 12/30/2023] [Accepted: 01/02/2024] [Indexed: 02/22/2024]
Abstract
The heterochromatin position effect is manifested in the inactivation of euchromatin genes transferred to heterochromatin. In chromosomal rearrangements, genes located near the new eu-heterochromatin boundary in the rearrangement (cis-inactivation) and, in rare cases, genes of a region of the normal chromosome homologous to the region of the eu-heterochromatin boundary of the chromosome with the rearrangement (trans-inactivation) are subject to inactivation. The In(2)A4 inversion is able to trans-inactivate the UAS-eGFP reporter gene located on the normal chromosome. We knockdown a number of chromatin proteins using temperature-controlled RNA interference and investigated the effect of knockdown on trans-inactivation of the reporter. We found suppression of trans-inactivation by knockdowns of Su(var)2-HP2, a protein that binds to the key heterochromatin protein HP1a, SAYP, a subunit of the chromatin remodelling complex, and Eggless histone methyltransferase (SETDB1), which introduces a H3K9me3 histone mark, recognized by the HP1a protein. The method of studying the effects of gene knockdown on heterochromatin position effects presented in this work is of independent methodological interest.
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Affiliation(s)
| | - S A Lavrov
- National Research Center "Kurchatov Institute", Moscow, Russia.
| | - A S Shatskikh
- National Research Center "Kurchatov Institute", Moscow, Russia
| | - V A Gvozdev
- National Research Center "Kurchatov Institute", Moscow, Russia
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25
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Owen JA, Osmanović D, Mirny L. Design principles of 3D epigenetic memory systems. Science 2023; 382:eadg3053. [PMID: 37972190 PMCID: PMC11075759 DOI: 10.1126/science.adg3053] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 09/28/2023] [Indexed: 11/19/2023]
Abstract
Cells remember their identities, in part, by using epigenetic marks-chemical modifications placed along the genome. How can mark patterns remain stable over cell generations despite their constant erosion by replication and other processes? We developed a theoretical model that reveals that three-dimensional (3D) genome organization can stabilize epigenetic memory as long as (i) there is a large density difference between chromatin compartments, (ii) modifying "reader-writer" enzymes spread marks in three dimensions, and (iii) the enzymes are limited in abundance relative to their histone substrates. Analogous to an associative memory that encodes memory in neuronal connectivity, mark patterns are encoded in a 3D network of chromosomal contacts. Our model provides a unified account of diverse observations and reveals a key role of 3D genome organization in epigenetic memory.
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Affiliation(s)
- Jeremy A. Owen
- Department of Physics, Massachusetts Institute of Technology; Cambridge, USA
| | - Dino Osmanović
- Department of Mechanical and Aeronautical Engineering, UCLA; Los Angeles, USA
| | - Leonid Mirny
- Department of Physics, Massachusetts Institute of Technology; Cambridge, USA
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26
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Martí E, Larracuente AM. Genetic conflict and the origin of multigene families: implications for sex chromosome evolution. Proc Biol Sci 2023; 290:20231823. [PMID: 37909083 PMCID: PMC10618873 DOI: 10.1098/rspb.2023.1823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Accepted: 10/10/2023] [Indexed: 11/02/2023] Open
Abstract
Sex chromosomes are havens for intragenomic conflicts. The absence of recombination between sex chromosomes creates the opportunity for the evolution of segregation distorters: selfish genetic elements that hijack different aspects of an individual's reproduction to increase their own transmission. Biased (non-Mendelian) segregation, however, often occurs at a detriment to their host's fitness, and therefore can trigger evolutionary arms races that can have major consequences for genome structure and regulation, gametogenesis, reproductive strategies and even speciation. Here, we review an emerging feature from comparative genomic and sex chromosome evolution studies suggesting that meiotic drive is pervasive: the recurrent evolution of paralogous sex-linked gene families. Sex chromosomes of several species independently acquire and co-amplify rapidly evolving gene families with spermatogenesis-related functions, consistent with a history of intragenomic conflict over transmission. We discuss Y chromosome features that might contribute to the tempo and mode of evolution of X/Y co-amplified gene families, as well as their implications for the evolution of complexity in the genome. Finally, we propose a framework that explores the conditions that might allow for recurrent bouts of fixation of drivers and suppressors, in a dosage-sensitive fashion, and therefore the co-amplification of multigene families on sex chromosomes.
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Affiliation(s)
- Emiliano Martí
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
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27
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Hamali B, Amine AAA, Al-Sady B. Regulation of the heterochromatin spreading reaction by trans-acting factors. Open Biol 2023; 13:230271. [PMID: 37935357 PMCID: PMC10645111 DOI: 10.1098/rsob.230271] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 10/03/2023] [Indexed: 11/09/2023] Open
Abstract
Heterochromatin is a gene-repressive protein-nucleic acid ultrastructure that is initially nucleated by DNA sequences. However, following nucleation, heterochromatin can then propagate along the chromatin template in a sequence-independent manner in a reaction termed spreading. At the heart of this process are enzymes that deposit chemical information on chromatin, which attracts the factors that execute chromatin compaction and transcriptional or co/post-transcriptional gene silencing. Given that these enzymes deposit guiding chemical information on chromatin they are commonly termed 'writers'. While the processes of nucleation and central actions of writers have been extensively studied and reviewed, less is understood about how the spreading process is regulated. We discuss how the chromatin substrate is prepared for heterochromatic spreading, and how trans-acting factors beyond writer enzymes regulate it. We examine mechanisms by which trans-acting factors in Suv39, PRC2, SETDB1 and SIR writer systems regulate spreading of the respective heterochromatic marks across chromatin. While these systems are in some cases evolutionarily and mechanistically quite distant, common mechanisms emerge which these trans-acting factors exploit to tune the spreading reaction.
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Affiliation(s)
- Bulut Hamali
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA
- The G. W. Hooper Foundation, San Francisco, CA 94143, USA
- College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Ahmed A A Amine
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA
- The G. W. Hooper Foundation, San Francisco, CA 94143, USA
| | - Bassem Al-Sady
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA
- The G. W. Hooper Foundation, San Francisco, CA 94143, USA
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28
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Murphy PJ, Berger F. The chromatin source-sink hypothesis: a shared mode of chromatin-mediated regulations. Development 2023; 150:dev201989. [PMID: 38771301 PMCID: PMC10629678 DOI: 10.1242/dev.201989] [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: 05/13/2023] [Accepted: 09/12/2023] [Indexed: 11/05/2023]
Abstract
We propose that several chromatin-mediated regulatory processes are dominated by source-sink relationships in which factors operate as 'sources' to produce or provide a resource and compete with each other to occupy separate 'sinks'. In this model, large portions of genomic DNA operate as 'sinks', which are filled by 'sources', such as available histone variants, covalent modifications to histones, the readers of these modifications and non-coding RNAs. Competing occupation for the sinks by different sources leads to distinct states of genomic equilibrium in differentiated cells. During dynamic developmental events, such as sexual reproduction, we propose that dramatic and rapid reconfiguration of source-sink relationships modifies chromatin states. We envision that re-routing of sources could occur by altering the dimensions of the sink, by reconfiguration of existing sink occupation or by varying the size of the source, providing a central mechanism to explain a plethora of epigenetic phenomena, which contribute to phenotypic variegation, zygotic genome activation and nucleolar dominance.
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Affiliation(s)
- Patrick J. Murphy
- University of Rochester, Department of Biomedical Genetics and Department of Biology, 601 Elmwood Ave., Rochester NY 14620, USA
| | - Frédéric Berger
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter; Dr. Bohr-Gasse 3, 1030 Vienna, Austria
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29
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Sidhwani P, Straight AF. Epigenetic inheritance and boundary maintenance at human centromeres. Curr Opin Struct Biol 2023; 82:102694. [PMID: 37657353 PMCID: PMC10530090 DOI: 10.1016/j.sbi.2023.102694] [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: 02/27/2023] [Revised: 07/31/2023] [Accepted: 08/07/2023] [Indexed: 09/03/2023]
Abstract
Centromeres are chromosomal regions that provide the foundation for microtubule attachment during chromosome segregation. Centromeres are epigenetically defined by nucleosomes containing the histone H3 variant centromere protein A (CENP-A) and, in many organisms, are surrounded by transcriptionally repressed pericentromeric chromatin marked by trimethylation of histone H3 lysine 9 (H3K9me3). Pericentromeric regions facilitate sister chromatid cohesion during mitosis, thereby supporting centromere function. Heterochromatin has a known propensity to spread into adjacent euchromatic domains unless it is properly bounded. Heterochromatin spreading into the centromere can disrupt kinetochore function, perturbing chromosome segregation and genome stability. In the fission yeast Schizosaccharomyces pombe, tRNA genes provide barriers to heterochromatin spread at the centromere, the absence of which results in abnormal meiotic chromosome segregation. How heterochromatin-centromere boundaries are established in humans is not understood. We propose models for stable epigenetic inheritance of centromeric domains in humans and discuss advances that will enable the discovery of novel regulators of this process.
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Affiliation(s)
- Pragya Sidhwani
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, United States. https://twitter.com/@pra_sidh
| | - Aaron F Straight
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, United States.
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30
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Tapia Del Fierro A, den Hamer B, Benetti N, Jansz N, Chen K, Beck T, Vanyai H, Gurzau AD, Daxinger L, Xue S, Ly TTN, Wanigasuriya I, Iminitoff M, Breslin K, Oey H, Krom YD, van der Hoorn D, Bouwman LF, Johanson TM, Ritchie ME, Gouil QA, Reversade B, Prin F, Mohun T, van der Maarel SM, McGlinn E, Murphy JM, Keniry A, de Greef JC, Blewitt ME. SMCHD1 has separable roles in chromatin architecture and gene silencing that could be targeted in disease. Nat Commun 2023; 14:5466. [PMID: 37749075 PMCID: PMC10519958 DOI: 10.1038/s41467-023-40992-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 08/07/2023] [Indexed: 09/27/2023] Open
Abstract
The interplay between 3D chromatin architecture and gene silencing is incompletely understood. Here, we report a novel point mutation in the non-canonical SMC protein SMCHD1 that enhances its silencing capacity at endogenous developmental targets. Moreover, it also results in enhanced silencing at the facioscapulohumeral muscular dystrophy associated macrosatellite-array, D4Z4, resulting in enhanced repression of DUX4 encoded by this repeat. Heightened SMCHD1 silencing perturbs developmental Hox gene activation, causing a homeotic transformation in mice. Paradoxically, the mutant SMCHD1 appears to enhance insulation against other epigenetic regulators, including PRC2 and CTCF, while depleting long range chromatin interactions akin to what is observed in the absence of SMCHD1. These data suggest that SMCHD1's role in long range chromatin interactions is not directly linked to gene silencing or insulating the chromatin, refining the model for how the different levels of SMCHD1-mediated chromatin regulation interact to bring about gene silencing in normal development and disease.
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Affiliation(s)
- Andres Tapia Del Fierro
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- The Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Bianca den Hamer
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Natalia Benetti
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- The Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Natasha Jansz
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- The Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Kelan Chen
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- The Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Tamara Beck
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Hannah Vanyai
- Crick Advanced Light Microscopy Facility, The Francis Crick Institute, London, UK
| | - Alexandra D Gurzau
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- The Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Lucia Daxinger
- Queensland Institute of Medical Research, Brisbane, QLD, Australia
| | - Shifeng Xue
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Institute of Molecular and Cell Biology, A*STAR, Singapore, Singapore
| | - Thanh Thao Nguyen Ly
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Institute of Molecular and Cell Biology, A*STAR, Singapore, Singapore
| | - Iromi Wanigasuriya
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- The Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Megan Iminitoff
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- The Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Kelsey Breslin
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Harald Oey
- Queensland Institute of Medical Research, Brisbane, QLD, Australia
| | - Yvonne D Krom
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Dinja van der Hoorn
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Linde F Bouwman
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Timothy M Johanson
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- The Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Matthew E Ritchie
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- The Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Quentin A Gouil
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- The Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Bruno Reversade
- Institute of Molecular and Cell Biology, A*STAR, Singapore, Singapore
- Genome Institute of Singapore, A*STAR, Singapore, Singapore
| | - Fabrice Prin
- Crick Advanced Light Microscopy Facility, The Francis Crick Institute, London, UK
| | - Timothy Mohun
- Crick Advanced Light Microscopy Facility, The Francis Crick Institute, London, UK
| | | | - Edwina McGlinn
- EMBL Australia, Monash University, Clayton, VIC, Australia
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
| | - James M Murphy
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- The Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Andrew Keniry
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
- The Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Jessica C de Greef
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Marnie E Blewitt
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.
- The Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.
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31
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Chaux F, Agier N, Garrido C, Fischer G, Eberhard S, Xu Z. Telomerase-independent survival leads to a mosaic of complex subtelomere rearrangements in Chlamydomonas reinhardtii. Genome Res 2023; 33:1582-1598. [PMID: 37580131 PMCID: PMC10620057 DOI: 10.1101/gr.278043.123] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 08/09/2023] [Indexed: 08/16/2023]
Abstract
Telomeres and subtelomeres, the genomic regions located at chromosome extremities, are essential for genome stability in eukaryotes. In the absence of the canonical maintenance mechanism provided by telomerase, telomere shortening induces genome instability. The landscape of the ensuing genome rearrangements is not accessible by short-read sequencing. Here, we leverage Oxford Nanopore Technologies long-read sequencing to survey the extensive repertoire of genome rearrangements in telomerase mutants of the model green microalga Chlamydomonas reinhardtii In telomerase-mutant strains grown for hundreds of generations, most chromosome extremities were capped by short telomere sequences that were either recruited de novo from other loci or maintained in a telomerase-independent manner. Other extremities did not end with telomeres but only with repeated subtelomeric sequences. The subtelomeric elements, including rDNA, were massively rearranged and involved in breakage-fusion-bridge cycles, translocations, recombinations, and chromosome circularization. These events were established progressively over time and displayed heterogeneity at the subpopulation level. New telomere-capped extremities composed of sequences originating from more internal genomic regions were associated with high DNA methylation, suggesting that de novo heterochromatin formation contributes to the restoration of chromosome end stability in C. reinhardtii The diversity of alternative strategies present in the same organism to maintain chromosome integrity and the variety of rearrangements found in telomerase mutants are remarkable, and illustrate genome plasticity at short timescales.
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Affiliation(s)
- Frédéric Chaux
- Sorbonne Université, CNRS, UMR7238, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, 75005 Paris, France
| | - Nicolas Agier
- Sorbonne Université, CNRS, UMR7238, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, 75005 Paris, France
| | - Clotilde Garrido
- Sorbonne Université, CNRS, UMR7238, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, 75005 Paris, France
| | - Gilles Fischer
- Sorbonne Université, CNRS, UMR7238, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, 75005 Paris, France
| | - Stephan Eberhard
- Sorbonne Université, CNRS, UMR7141, Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light-Sensing in Microalgae, 75005 Paris, France
| | - Zhou Xu
- Sorbonne Université, CNRS, UMR7238, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, 75005 Paris, France;
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32
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Jangam SV, Briere LC, Jay KL, Andrews JC, Walker MA, Rodan LH, High FA, Yamamoto S, Sweetser DA, Wangler MF. A de novo missense variant in EZH1 associated with developmental delay exhibits functional deficits in Drosophila melanogaster. Genetics 2023; 224:iyad110. [PMID: 37314226 PMCID: PMC10411565 DOI: 10.1093/genetics/iyad110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 01/13/2023] [Accepted: 05/31/2023] [Indexed: 06/15/2023] Open
Abstract
EZH1, a polycomb repressive complex-2 component, is involved in a myriad of cellular processes. EZH1 represses transcription of downstream target genes through histone 3 lysine27 (H3K27) trimethylation (H3K27me3). Genetic variants in histone modifiers have been associated with developmental disorders, while EZH1 has not yet been linked to any human disease. However, the paralog EZH2 is associated with Weaver syndrome. Here we report a previously undiagnosed individual with a novel neurodevelopmental phenotype identified to have a de novo missense variant in EZH1 through exome sequencing. The individual presented in infancy with neurodevelopmental delay and hypotonia and was later noted to have proximal muscle weakness. The variant, p.A678G, is in the SET domain, known for its methyltransferase activity, and an analogous somatic or germline mutation in EZH2 has been reported in patients with B-cell lymphoma or Weaver syndrome, respectively. Human EZH1/2 are homologous to fly Enhancer of zeste (E(z)), an essential gene in Drosophila, and the affected residue (p.A678 in humans, p.A691 in flies) is conserved. To further study this variant, we obtained null alleles and generated transgenic flies expressing wildtype [E(z)WT] and the variant [E(z)A691G]. When expressed ubiquitously the variant rescues null-lethality similar to the wildtype. Overexpression of E(z)WT induces homeotic patterning defects but notably the E(z)A691G variant leads to dramatically stronger morphological phenotypes. We also note a dramatic loss of H3K27me2 and a corresponding increase in H3K27me3 in flies expressing E(z)A691G, suggesting this acts as a gain-of-function allele. In conclusion, here we present a novel EZH1 de novo variant associated with a neurodevelopmental disorder. Furthermore, we found that this variant has a functional impact in Drosophila.
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Affiliation(s)
- Sharayu V Jangam
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Lauren C Briere
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Kristy L Jay
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Jonathan C Andrews
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Melissa A Walker
- Department of Neurology, Division of Neurogenetics, Child Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Lance H Rodan
- Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Frances A High
- Division of Medical Genetics and Metabolism, Massachusetts General Hospital for Children, Boston, MA 02114, USA
| | | | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - David A Sweetser
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Division of Medical Genetics and Metabolism, Massachusetts General Hospital for Children, Boston, MA 02114, USA
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
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33
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Delanoue R, Clot C, Leray C, Pihl T, Hudry B. Y chromosome toxicity does not contribute to sex-specific differences in longevity. Nat Ecol Evol 2023; 7:1245-1256. [PMID: 37308701 PMCID: PMC10406604 DOI: 10.1038/s41559-023-02089-7] [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: 10/12/2022] [Accepted: 04/14/2023] [Indexed: 06/14/2023]
Abstract
While sex chromosomes carry sex-determining genes, they also often differ from autosomes in size and composition, consisting mainly of silenced heterochromatic repetitive DNA. Even though Y chromosomes show structural heteromorphism, the functional significance of such differences remains elusive. Correlative studies suggest that the amount of Y chromosome heterochromatin might be responsible for several male-specific traits, including sex-specific differences in longevity observed across a wide spectrum of species, including humans. However, experimental models to test this hypothesis have been lacking. Here we use the Drosophila melanogaster Y chromosome to investigate the relevance of sex chromosome heterochromatin in somatic organs in vivo. Using CRISPR-Cas9, we generated a library of Y chromosomes with variable levels of heterochromatin. We show that these different Y chromosomes can disrupt gene silencing in trans, on other chromosomes, by sequestering core components of the heterochromatin machinery. This effect is positively correlated to the level of Y heterochromatin. However, we also find that the ability of the Y chromosome to affect genome-wide heterochromatin does not generate physiological sex differences, including sexual dimorphism in longevity. Instead, we discovered that it is the phenotypic sex, female or male, that controls sex-specific differences in lifespan, rather than the presence of a Y chromosome. Altogether, our findings dismiss the 'toxic Y' hypothesis that postulates that the Y chromosome leads to reduced lifespan in XY individuals.
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Affiliation(s)
- Rénald Delanoue
- Institut de Biologie Valrose, Université Côte d'Azur, CNRS, INSERM, Nice, France.
| | - Charlène Clot
- Institut de Biologie Valrose, Université Côte d'Azur, CNRS, INSERM, Nice, France
| | - Chloé Leray
- Institut de Biologie Valrose, Université Côte d'Azur, CNRS, INSERM, Nice, France
| | - Thomas Pihl
- Institut de Biologie Valrose, Université Côte d'Azur, CNRS, INSERM, Nice, France
| | - Bruno Hudry
- Institut de Biologie Valrose, Université Côte d'Azur, CNRS, INSERM, Nice, France.
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34
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Tav C, Fournier É, Fournier M, Khadangi F, Baguette A, Côté MC, Silveira MAD, Bérubé-Simard FA, Bourque G, Droit A, Bilodeau S. Glucocorticoid stimulation induces regionalized gene responses within topologically associating domains. Front Genet 2023; 14:1237092. [PMID: 37576549 PMCID: PMC10413275 DOI: 10.3389/fgene.2023.1237092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/07/2023] [Indexed: 08/15/2023] Open
Abstract
Transcription-factor binding to cis-regulatory regions regulates the gene expression program of a cell, but occupancy is often a poor predictor of the gene response. Here, we show that glucocorticoid stimulation led to the reorganization of transcriptional coregulators MED1 and BRD4 within topologically associating domains (TADs), resulting in active or repressive gene environments. Indeed, we observed a bias toward the activation or repression of a TAD when their activities were defined by the number of regions gaining and losing MED1 and BRD4 following dexamethasone (Dex) stimulation. Variations in Dex-responsive genes at the RNA levels were consistent with the redistribution of MED1 and BRD4 at the associated cis-regulatory regions. Interestingly, Dex-responsive genes without the differential recruitment of MED1 and BRD4 or binding by the glucocorticoid receptor were found within TADs, which gained or lost MED1 and BRD4, suggesting a role of the surrounding environment in gene regulation. However, the amplitude of the response of Dex-regulated genes was higher when the differential recruitment of the glucocorticoid receptor and transcriptional coregulators was observed, reaffirming the role of transcription factor-driven gene regulation and attributing a lesser role to the TAD environment. These results support a model where a signal-induced transcription factor induces a regionalized effect throughout the TAD, redefining the notion of direct and indirect effects of transcription factors on target genes.
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Affiliation(s)
- Christophe Tav
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
| | - Éric Fournier
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
| | - Michèle Fournier
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Fatemeh Khadangi
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Audrey Baguette
- Department of Human Genetics, Faculty of Medicine, McGill University, Montréal, QC, Canada
| | - Maxime C. Côté
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Maruhen A. D. Silveira
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Félix-Antoine Bérubé-Simard
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Guillaume Bourque
- Department of Human Genetics, Faculty of Medicine, McGill University, Montréal, QC, Canada
- Canadian Center for Computational Genomics, McGill University, Montréal, QC, Canada
| | - Arnaud Droit
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
- Centre de Recherche du CHU de Québec—Université Laval, Axe Endocrinologie et Néphrologie, Québec, QC, Canada
- Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Steve Bilodeau
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
- Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
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35
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Carotti E, Carducci F, Barucca M, Canapa A, Biscotti MA. Transposable Elements: Epigenetic Silencing Mechanisms or Modulating Tools for Vertebrate Adaptations? Two Sides of the Same Coin. Int J Mol Sci 2023; 24:11591. [PMID: 37511347 PMCID: PMC10380595 DOI: 10.3390/ijms241411591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
Transposable elements constitute one of the main components of eukaryotic genomes. In vertebrates, they differ in content, typology, and family diversity and played a crucial role in the evolution of this taxon. However, due to their transposition ability, TEs can be responsible for genome instability, and thus silencing mechanisms were evolved to allow the coexistence between TEs and eukaryotic host-coding genes. Several papers are highlighting in TEs the presence of regulatory elements involved in regulating nearby genes in a tissue-specific fashion. This suggests that TEs are not sequences merely to silence; rather, they can be domesticated for the regulation of host-coding gene expression, permitting species adaptation and resilience as well as ensuring human health. This review presents the main silencing mechanisms acting in vertebrates and the importance of exploiting these mechanisms for TE control to rewire gene expression networks, challenging the general view of TEs as threatening elements.
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Affiliation(s)
| | - Federica Carducci
- Dipartimento di Scienze della Vita e dell’Ambiente, Università Politecnica delle Marche, 60131 Ancona, Italy; (E.C.); (M.B.); (A.C.); (M.A.B.)
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36
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Grewal SIS. The molecular basis of heterochromatin assembly and epigenetic inheritance. Mol Cell 2023; 83:1767-1785. [PMID: 37207657 PMCID: PMC10309086 DOI: 10.1016/j.molcel.2023.04.020] [Citation(s) in RCA: 51] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 04/10/2023] [Accepted: 04/20/2023] [Indexed: 05/21/2023]
Abstract
Heterochromatin plays a fundamental role in gene regulation, genome integrity, and silencing of repetitive DNA elements. Histone modifications are essential for the establishment of heterochromatin domains, which is initiated by the recruitment of histone-modifying enzymes to nucleation sites. This leads to the deposition of histone H3 lysine-9 methylation (H3K9me), which provides the foundation for building high-concentration territories of heterochromatin proteins and the spread of heterochromatin across extended domains. Moreover, heterochromatin can be epigenetically inherited during cell division in a self-templating manner. This involves a "read-write" mechanism where pre-existing modified histones, such as tri-methylated H3K9 (H3K9me3), support chromatin association of the histone methyltransferase to promote further deposition of H3K9me. Recent studies suggest that a critical density of H3K9me3 and its associated factors is necessary for the propagation of heterochromatin domains across multiple generations. In this review, I discuss the key experiments that have highlighted the importance of modified histones for epigenetic inheritance.
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Affiliation(s)
- Shiv I S Grewal
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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37
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Cittadino GM, Andrews J, Purewal H, Estanislao Acuña Avila P, Arnone JT. Functional Clustering of Metabolically Related Genes Is Conserved across Dikarya. J Fungi (Basel) 2023; 9:jof9050523. [PMID: 37233234 DOI: 10.3390/jof9050523] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/08/2023] [Accepted: 04/27/2023] [Indexed: 05/27/2023] Open
Abstract
Transcriptional regulation is vital for organismal survival, with many layers and mechanisms collaborating to balance gene expression. One layer of this regulation is genome organization, specifically the clustering of functionally related, co-expressed genes along the chromosomes. Spatial organization allows for position effects to stabilize RNA expression and balance transcription, which can be advantageous for a number of reasons, including reductions in stochastic influences between the gene products. The organization of co-regulated gene families into functional clusters occurs extensively in Ascomycota fungi. However, this is less characterized within the related Basidiomycota fungi despite the many uses and applications for the species within this clade. This review will provide insight into the prevalence, purpose, and significance of the clustering of functionally related genes across Dikarya, including foundational studies from Ascomycetes and the current state of our understanding throughout representative Basidiomycete species.
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Affiliation(s)
- Gina M Cittadino
- Department of Biological and Environmental Sciences, Le Moyne College, Syracuse, NY 13214, USA
| | - Johnathan Andrews
- Department of Biological and Environmental Sciences, Le Moyne College, Syracuse, NY 13214, USA
| | - Harpreet Purewal
- Department of Biological and Environmental Sciences, Le Moyne College, Syracuse, NY 13214, USA
| | | | - James T Arnone
- Department of Biological and Environmental Sciences, Le Moyne College, Syracuse, NY 13214, USA
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38
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Casier K, Autaa J, Gueguen N, Delmarre V, Marie PP, Ronsseray S, Carré C, Brasset E, Teysset L, Boivin A. The histone demethylase Kdm3 prevents auto-immune piRNAs production in Drosophila. SCIENCE ADVANCES 2023; 9:eade3872. [PMID: 37027460 PMCID: PMC10081847 DOI: 10.1126/sciadv.ade3872] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 03/08/2023] [Indexed: 06/19/2023]
Abstract
Genome integrity of the animal germline is protected from transposable element activity by PIWI-interacting RNAs (piRNAs). While piRNA biogenesis is intensively explored, little is known about the genetical determination of piRNA clusters, the genomic sources of piRNAs. Using a bimodal epigenetic state piRNA cluster (BX2), we identified the histone demethylase Kdm3 as being able to prevent a cryptic piRNA production. In the absence of Kdm3, dozens of coding gene-containing regions become genuine germline dual-strand piRNA clusters. Eggs laid by Kdm3 mutant females show developmental defects phenocopying loss of function of genes embedded into the additional piRNA clusters, suggesting an inheritance of functional ovarian "auto-immune" piRNAs. Antagonizing piRNA cluster determination through chromatin modifications appears crucial to prevent auto-immune genic piRNAs production.
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Affiliation(s)
- Karine Casier
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Julie Autaa
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Nathalie Gueguen
- iGReD, CNRS, INSERM, Faculté de Médecine, Université Clermont Auvergne, 63000 Clermont-Ferrand, France
| | - Valérie Delmarre
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Pauline P. Marie
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Stéphane Ronsseray
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Clément Carré
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Emilie Brasset
- iGReD, CNRS, INSERM, Faculté de Médecine, Université Clermont Auvergne, 63000 Clermont-Ferrand, France
| | - Laure Teysset
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
| | - Antoine Boivin
- Transgenerational Epigenetics and Small RNA Biology, Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratoire Biologie du Développement, UMR7622, F-75005 Paris, France
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Seczynska M, Lehner PJ. The sound of silence: mechanisms and implications of HUSH complex function. Trends Genet 2023; 39:251-267. [PMID: 36754727 DOI: 10.1016/j.tig.2022.12.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/14/2022] [Accepted: 12/30/2022] [Indexed: 02/08/2023]
Abstract
The vertebrate genome is under constant threat of invasion by genetic parasites. Whether the host can immediately recognize and respond to invading elements has been unclear. The discovery of the human silencing hub (HUSH) complex, and the finding that it provides immediate protection from genome invasion by silencing products of reverse transcription, have important implications for mammalian genome evolution. In this review, we summarize recent insights into HUSH function and describe how cellular introns provide a novel means of self-nonself discrimination, allowing HUSH to recognize and transcriptionally repress a broad range of intronless genetic elements. We discuss how HUSH contributes to genome evolution, and highlight studies reporting the critical role of HUSH in development and implicating HUSH in the control of immune signaling and cancer progression.
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Affiliation(s)
- Marta Seczynska
- Cambridge Institute for Therapeutic Immunology & Infectious Disease, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge CB2 0AW, UK.
| | - Paul J Lehner
- Cambridge Institute for Therapeutic Immunology & Infectious Disease, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge CB2 0AW, UK.
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40
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Han D, Schaffner SH, Davies JP, Lauren Benton M, Plate L, Nordman JT. BRWD3 promotes KDM5 degradation to maintain H3K4 methylation levels. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.28.534572. [PMID: 37034668 PMCID: PMC10081218 DOI: 10.1101/2023.03.28.534572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Histone modifications are critical for regulating chromatin structure and gene expression. Dysregulation of histone modifications likely contributes to disease states and cancer. Depletion of the chromatin-binding protein BRWD3, a known substrate-specificity factor of the Cul4-DDB1 E3 ubiquitin ligase complex, results in increased in H3K4me1 levels. The underlying mechanism linking BRWD3 and H3K4 methylation, however, has yet to be defined. Here, we show that depleting BRWD3 not only causes an increase in H3K4me1 levels, but also causes a decrease in H3K4me3 levels, indicating that BRWD3 influences H3K4 methylation more broadly. Using immunoprecipitation coupled to quantitative mass spectrometry, we identified an interaction between BRWD3 and the H3K4-specific demethylase 5 (KDM5/Lid), an enzyme that removes tri- and di- methyl marks from H3K4. Moreover, analysis of ChIP-seq data revealed that BRWD3 and KDM5 are significantly co- localized throughout the genome and that sites of H3K4me3 are highly enriched at BRWD3 binding sites. We show that BRWD3 promotes K48-linked polyubiquitination and degradation of KDM5 and that KDM5 degradation is dependent on both BRWD3 and Cul4. Critically, depleting KDM5 fully restores altered H3K4me3 levels and partially restores H3K4me1 levels upon BRWD3 depletion. Together, our results demonstrate that BRWD3 regulates KDM5 activity to balance H3K4 methylation levels.
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Affiliation(s)
- Dongsheng Han
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, 37212, USA
| | | | - Jonathan P. Davies
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, 37212, USA
| | | | - Lars Plate
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, 37212, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37212, USA
| | - Jared T. Nordman
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, 37212, USA
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41
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Jangam S, Briere LC, Jay K, Andrews JC, Walker MA, Rodan LH, High FA, Yamamoto S, Sweetser DA, Wangler M. A de novo missense variant in EZH1 associated with developmental delay exhibits functional deficits in Drosophila melanogaster. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.01.31.23285113. [PMID: 36778246 PMCID: PMC9915809 DOI: 10.1101/2023.01.31.23285113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
EZH1 ( Enhancer of Zeste, homolog 1) , a Polycomb Repressive Complex-2 (PRC2) component, is involved in a myriad of cellular processes through modifying histone 3 lysine27 (H3K27) residues. EZH1 represses transcription of downstream target genes through H3K27 trimethylation (H3K27me3). Genetic mutations in histone modifiers have been associated with developmental disorders, while EZH1 has not yet been linked to any human disease. However, the paralog EZH2 is associated with Weaver syndrome. Here we report a previously undiagnosed individual with a novel neurodevelopmental phenotype identified to have a de novo variant in EZH1 , p.Ala678Gly, through exome sequencing. The individual presented in infancy with neurodevelopmental delay and hypotonia and was later noted to have proximal muscle weakness. The variant, p.A678G, is in the SET domain, known for its methyltransferase activity, and was the best candidate variant found in the exome. Human EZH1 / 2 are homologous to fly Enhancer of zeste E(z) , an essential gene in flies, and the residue (A678 in humans, A691 in Drosophila ) is conserved. To further study this variant, we obtained Drosophila null alleles and generated transgenic flies expressing wild-type (E(z) WT ) and the variant (E(z) A691G ) . The E(z) A691G variant led to hyper H3K27me3 while the E(z) WT did not, suggesting this is as a gain-of-function allele. When expressed under the tubulin promotor in vivo the variant rescued null-lethality similar to wild-type but the E(z) A691G flies exhibit bang sensitivity and shortened lifespan. In conclusion, here we present a novel EZH1 de novo variant associated with a neurodevelopmental disorder. Furthermore, we found that this variant has a functional impact in Drosophila . Biochemically this allele leads to increased H3K27me3 suggesting gain-of-function, but when expressed in adult flies the E(z) A691G has some characteristics of partial loss-of-function which may suggest it is a more complex allele in vivo .
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Affiliation(s)
- Sharayu Jangam
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030 USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, 77030 USA
| | - Lauren C Briere
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Kristy Jay
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030 USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, 77030 USA
- Genetics and Genomics program, Baylor College of Medicine, Houston, Texas, 77030 USA
| | - Jonathan C Andrews
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030 USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, 77030 USA
| | - Melissa A Walker
- Department of Neurology, Division of Neurogenetics, Child Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Lance H Rodan
- Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Frances A High
- Division of Medical Genetics & Metabolism, Massachusetts General Hospital for Children, Boston, MA 02114, USA
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030 USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, 77030 USA
- Genetics and Genomics program, Baylor College of Medicine, Houston, Texas, 77030 USA
| | - David A Sweetser
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Division of Medical Genetics & Metabolism, Massachusetts General Hospital for Children, Boston, MA 02114, USA
| | - Michael Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030 USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, 77030 USA
- Genetics and Genomics program, Baylor College of Medicine, Houston, Texas, 77030 USA
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42
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Messina G, Celauro E, Marsano RM, Prozzillo Y, Dimitri P. Epigenetic Silencing of P-Element Reporter Genes Induced by Transcriptionally Active Domains of Constitutive Heterochromatin in Drosophila melanogaster. Genes (Basel) 2022; 14:genes14010012. [PMID: 36672753 PMCID: PMC9858095 DOI: 10.3390/genes14010012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/12/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Reporter genes inserted via P-element integration into different locations of the Drosophila melanogaster genome have been routinely used to monitor the functional state of chromatin domains. It is commonly thought that P-element-derived reporter genes are subjected to position effect variegation (PEV) when transposed into constitutive heterochromatin because they acquire heterochromatin-like epigenetic modifications that promote silencing. However, sequencing and annotation of the D. melanogaster genome have shown that constitutive heterochromatin is a genetically and molecularly heterogeneous compartment. In fact, in addition to repetitive DNAs, it harbors hundreds of functional genes, together accounting for a significant fraction of its entire genomic territory. Notably, most of these genes are actively transcribed in different developmental stages and tissues, irrespective of their location in heterochromatin. An open question in the genetic and molecular studies on PEV in D. melanogaster is whether functional heterochromatin domains, i.e., heterochromatin harboring active genes, are able to silence reporter genes therein transposed or, on the contrary, can drive their expression. In this work, we provide experimental evidence showing that strong silencing of the Pw+ reporters is induced even when they are integrated within or near actively transcribed loci in the pericentric regions of chromosome 2. Interestingly, some Pw+ reporters were found insensitive to the action of a known PEV suppressor. Two of them are inserted within Yeti, a gene expressed in the deep heterochromatin of chromosome 2 which carries active chromatin marks. The difference sensitivity to suppressors-exhibited Pw+ reporters supports the view that different epigenetic regulators or mechanisms control different regions of heterochromatin. Together, our results suggest that there may be more complexity regarding the molecular mechanisms underlying PEV.
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Affiliation(s)
- Giovanni Messina
- Dipartimento di Biologia e Biotecnologie “Charles Darwin”, Sapienza Università di Roma, 00185 Roma, Italy
| | - Emanuele Celauro
- Dipartimento di Biologia e Biotecnologie “Charles Darwin”, Sapienza Università di Roma, 00185 Roma, Italy
| | | | - Yuri Prozzillo
- Dipartimento di Biologia e Biotecnologie “Charles Darwin”, Sapienza Università di Roma, 00185 Roma, Italy
| | - Patrizio Dimitri
- Dipartimento di Biologia e Biotecnologie “Charles Darwin”, Sapienza Università di Roma, 00185 Roma, Italy
- Correspondence:
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43
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Cabrera A, Edelstein HI, Glykofrydis F, Love KS, Palacios S, Tycko J, Zhang M, Lensch S, Shields CE, Livingston M, Weiss R, Zhao H, Haynes KA, Morsut L, Chen YY, Khalil AS, Wong WW, Collins JJ, Rosser SJ, Polizzi K, Elowitz MB, Fussenegger M, Hilton IB, Leonard JN, Bintu L, Galloway KE, Deans TL. The sound of silence: Transgene silencing in mammalian cell engineering. Cell Syst 2022; 13:950-973. [PMID: 36549273 PMCID: PMC9880859 DOI: 10.1016/j.cels.2022.11.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 09/22/2022] [Accepted: 11/22/2022] [Indexed: 12/24/2022]
Abstract
To elucidate principles operating in native biological systems and to develop novel biotechnologies, synthetic biology aims to build and integrate synthetic gene circuits within native transcriptional networks. The utility of synthetic gene circuits for cell engineering relies on the ability to control the expression of all constituent transgene components. Transgene silencing, defined as the loss of expression over time, persists as an obstacle for engineering primary cells and stem cells with transgenic cargos. In this review, we highlight the challenge that transgene silencing poses to the robust engineering of mammalian cells, outline potential molecular mechanisms of silencing, and present approaches for preventing transgene silencing. We conclude with a perspective identifying future research directions for improving the performance of synthetic gene circuits.
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Affiliation(s)
- Alan Cabrera
- Department of Bioengineering, Rice University, Houston, TX 77005, USA; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Hailey I Edelstein
- Center for Synthetic Biology, Northwestern University, Evanston, IL 60208, USA; The Eli and Edythe Broad CIRM Center, Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Fokion Glykofrydis
- Department of Stem Cell Biology and Regenerative Medicine, University of Southern California, Los Angeles, CA 90033-9080, USA
| | - Kasey S Love
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sebastian Palacios
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Josh Tycko
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Meng Zhang
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Champaign, Urbana, IL 61801, USA
| | - Sarah Lensch
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Cara E Shields
- Wallace H. Coulter Department of Biomedical Engineering, Emory University, Atlanta, GA 30322, USA
| | - Mark Livingston
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA
| | - Ron Weiss
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Huimin Zhao
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Champaign, Urbana, IL 61801, USA
| | - Karmella A Haynes
- Wallace H. Coulter Department of Biomedical Engineering, Emory University, Atlanta, GA 30322, USA
| | - Leonardo Morsut
- Department of Stem Cell Biology and Regenerative Medicine, University of Southern California, Los Angeles, CA 90033-9080, USA
| | - Yvonne Y Chen
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA; Parker Institute for Cancer Immunotherapy Center at UCLA, Los Angeles, CA 90095, USA
| | - Ahmad S Khalil
- Biological Design Center and Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Wilson W Wong
- Biological Design Center and Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - James J Collins
- Department of Stem Cell Biology and Regenerative Medicine, University of Southern California, Los Angeles, CA 90033-9080, USA; Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA; Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA; Harvard-MIT Program in Health Sciences and Technology, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
| | - Susan J Rosser
- School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Karen Polizzi
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London, UK; Imperial College Centre for Synthetic Biology, South Kensington Campus, London, UK
| | - Michael B Elowitz
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA
| | - Martin Fussenegger
- Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, Basel 4058, Switzerland; Faculty of Science, University of Basel, Mattenstrasse 26, Basel 4058, Switzerland
| | - Isaac B Hilton
- Department of Bioengineering, Rice University, Houston, TX 77005, USA
| | - Joshua N Leonard
- Center for Synthetic Biology, Northwestern University, Evanston, IL 60208, USA; The Eli and Edythe Broad CIRM Center, Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Lacramioara Bintu
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Kate E Galloway
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Tara L Deans
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA.
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44
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Her C, Phan TM, Jovic N, Kapoor U, Ackermann BE, Rizuan A, Kim Y, Mittal J, Debelouchina G. Molecular interactions underlying the phase separation of HP1α: role of phosphorylation, ligand and nucleic acid binding. Nucleic Acids Res 2022; 50:12702-12722. [PMID: 36537242 PMCID: PMC9825191 DOI: 10.1093/nar/gkac1194] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 11/04/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
Heterochromatin protein 1α (HP1α) is a crucial element of chromatin organization. It has been proposed that HP1α functions through liquid-liquid phase separation (LLPS), which allows it to compact chromatin into transcriptionally repressed heterochromatin regions. In vitro, HP1α can undergo phase separation upon phosphorylation of its N-terminus extension (NTE) and/or through interactions with DNA and chromatin. Here, we combine computational and experimental approaches to elucidate the molecular interactions that drive these processes. In phosphorylation-driven LLPS, HP1α can exchange intradimer hinge-NTE interactions with interdimer contacts, which also leads to a structural change from a compacted to an extended HP1α dimer conformation. This process can be enhanced by the presence of positively charged HP1α peptide ligands and disrupted by the addition of negatively charged or neutral peptides. In DNA-driven LLPS, both positively and negatively charged peptide ligands can perturb phase separation. Our findings demonstrate the importance of electrostatic interactions in HP1α LLPS where binding partners can modulate the overall charge of the droplets and screen or enhance hinge region interactions through specific and non-specific effects. Our study illuminates the complex molecular framework that can fine-tune the properties of HP1α and that can contribute to heterochromatin regulation and function.
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Affiliation(s)
| | | | - Nina Jovic
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | - Utkarsh Kapoor
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | - Bryce E Ackermann
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA
| | - Azamat Rizuan
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | - Young C Kim
- Center for Materials Physics and Technology, Naval Research Laboratory, WA, DC, USA
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45
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WiFi Related Radiofrequency Electromagnetic Fields Promote Transposable Element Dysregulation and Genomic Instability in Drosophila melanogaster. Cells 2022; 11:cells11244036. [PMID: 36552798 PMCID: PMC9776602 DOI: 10.3390/cells11244036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/02/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
Exposure to artificial radio frequency electromagnetic fields (RF-EMFs) has greatly increased in recent years, thus promoting a growing scientific and social interest in deepening the biological impact of EMFs on living organisms. The current legislation governing the exposure to RF-EMFs is based exclusively on their thermal effects, without considering the possible non-thermal adverse health effects from long term exposure to EMFs. In this study we investigated the biological non-thermal effects of low-level indoor exposure to RF-EMFs produced by WiFi wireless technologies, using Drosophila melanogaster as the model system. Flies were exposed to 2.4 GHz radiofrequency in a Transverse Electromagnetic (TEM) cell device to ensure homogenous controlled fields. Signals were continuously monitored during the experiments and regulated at non thermal levels. The results of this study demonstrate that WiFi electromagnetic radiation causes extensive heterochromatin decondensation and thus a general loss of transposable elements epigenetic silencing in both germinal and neural tissues. Moreover, our findings provide evidence that WiFi related radiofrequency electromagnetic fields can induce reactive oxygen species (ROS) accumulation, genomic instability, and behavioural abnormalities. Finally, we demonstrate that WiFi radiation can synergize with RasV12 to drive tumor progression and invasion. All together, these data indicate that radiofrequency radiation emitted from WiFi devices could exert genotoxic effects in Drosophila and set the stage to further explore the biological effects of WiFi electromagnetic radiation on living organisms.
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46
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Levinsky AJ, McEdwards G, Sethna N, Currie MA. Targets of histone H3 lysine 9 methyltransferases. Front Cell Dev Biol 2022; 10:1026406. [PMID: 36568972 PMCID: PMC9768651 DOI: 10.3389/fcell.2022.1026406] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 10/05/2022] [Indexed: 12/12/2022] Open
Abstract
Histone H3 lysine 9 di- and trimethylation are well-established marks of constitutively silenced heterochromatin domains found at repetitive DNA elements including pericentromeres, telomeres, and transposons. Loss of heterochromatin at these sites causes genomic instability in the form of aberrant DNA repair, chromosome segregation defects, replication stress, and transposition. H3K9 di- and trimethylation also regulate cell type-specific gene expression during development and form a barrier to cellular reprogramming. However, the role of H3K9 methyltransferases extends beyond histone methylation. There is a growing list of non-histone targets of H3K9 methyltransferases including transcription factors, steroid hormone receptors, histone modifying enzymes, and other chromatin regulatory proteins. Additionally, two classes of H3K9 methyltransferases modulate their own function through automethylation. Here we summarize the structure and function of mammalian H3K9 methyltransferases, their roles in genome regulation and constitutive heterochromatin, as well as the current repertoire of non-histone methylation targets including cases of automethylation.
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Affiliation(s)
- Aidan J. Levinsky
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Gregor McEdwards
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Nasha Sethna
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Mark A. Currie
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada,*Correspondence: Mark A. Currie,
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47
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Kolesnikova TD, Klenov MS, Nokhova AR, Lavrov SA, Pokholkova GV, Schubert V, Maltseva SV, Cook KR, Dixon MJ, Zhimulev IF. A Spontaneous Inversion of the X Chromosome Heterochromatin Provides a Tool for Studying the Structure and Activity of the Nucleolus in Drosophila melanogaster. Cells 2022; 11:cells11233872. [PMID: 36497131 PMCID: PMC9736023 DOI: 10.3390/cells11233872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 11/24/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022] Open
Abstract
The pericentromeric heterochromatin is largely composed of repetitive sequences, making it difficult to analyze with standard molecular biological methods. At the same time, it carries many functional elements with poorly understood mechanisms of action. The search for new experimental models for the analysis of heterochromatin is an urgent task. In this work, we used the Rif1 mutation, which suppresses the underreplication of all types of repeated sequences, to analyze heterochromatin regions in polytene chromosomes of Drosophila melanogaster. In the Rif1 background, we discovered and described in detail a new inversion, In(1)19EHet, which arose on a chromosome already carrying the In(1)sc8 inversion and transferred a large part of X chromosome heterochromatin, including the nucleolar organizer to a new euchromatic environment. Using nanopore sequencing and FISH, we have identified the eu- and heterochromatin breakpoints of In(1)19EHet. The combination of the new inversion and the Rif1 mutation provides a promising tool for studies of X chromosome heterochromatin structure, nucleolar organization, and the nucleolar dominance phenomenon. In particular, we found that, with the complete polytenization of rDNA repeats, the nucleolus consists of a cloud-like structure corresponding to the classical nucleolus of polytene chromosomes, as well as an unusual intrachromosomal structure containing alternating transcriptionally active and inactive regions.
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Affiliation(s)
- Tatyana D. Kolesnikova
- Institute of Molecular and Cellular Biology SB RAS, 630090 Novosibirsk, Russia
- Faculty of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
- Correspondence:
| | - Mikhail S. Klenov
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre “Kurchatov Institute”, 123182 Moscow, Russia
| | - Alina R. Nokhova
- Faculty of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Sergey A. Lavrov
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre “Kurchatov Institute”, 123182 Moscow, Russia
| | | | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research Gatersleben, 06466 Seeland, Germany
| | - Svetlana V. Maltseva
- Faculty of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Kevin R. Cook
- Bloomington Drosophila Stock Center, Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Michael J. Dixon
- Bloomington Drosophila Stock Center, Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Igor F. Zhimulev
- Institute of Molecular and Cellular Biology SB RAS, 630090 Novosibirsk, Russia
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48
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Shevchenko AI, Rifel NA, Zakian SM, Zakharova IS. Constitutive heterochromatin propagation contributes to the X chromosome inactivation. Chromosome Res 2022; 30:289-307. [PMID: 35920963 DOI: 10.1007/s10577-022-09706-4] [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: 04/27/2022] [Revised: 07/08/2022] [Accepted: 07/15/2022] [Indexed: 01/25/2023]
Abstract
Imprinted X chromosome inactivation (iXCI) balances the expression of X-linked genes in preimplantation embryos and extraembryonic tissues in rodents. Long noncoding Xist RNA drives iXCI, silencing genes and recruiting Xist-dependent chromatin repressors. Some domains on the inactive X chromosome include repressive modifications specific to constitutive heterochromatin, which show no direct link to Xist RNA. We explored the relationship between Xist RNA and chromatin silencing during iXCI in vole Microtus levis. We performed locus-specific activation of Xist transcription on the only active X chromosome using the dCas9-SAM system in XO vole trophoblast stem cells (TSCs), which allow modeling iXCI events to some extent. The artificially activated endogenous vole Xist transcript is truncated and restricted ~ 6.6 kb of the exon 1. Ectopic Xist RNA accumulates on the X chromosome and recruits Xist-dependent modifications during TSC differentiation, yet is incapable by itself repressing X-linked genes. Transcriptional silencing occurs upon ectopic Xist upregulation only when repressive marks spread from the massive telomeric constitutive heterochromatin to the X chromosome region containing genes. We hypothesize that the Xist RNA-induced propagation of repressive marks from the constitutive heterochromatin could be a mechanism involved in X chromosome inactivation.
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Affiliation(s)
- Alexander I Shevchenko
- Federal Research Center, "Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences", Novosibirsk, 630090, Russia.,Institute of Chemical Biology and Fundamental Medicine of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.,E.N. Meshalkin National Medical Research Center, Ministry of Health Care of Russian Federation, Novosibirsk, 630055, Russia
| | - Nikita A Rifel
- Federal Research Center, "Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences", Novosibirsk, 630090, Russia
| | - Suren M Zakian
- Federal Research Center, "Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences", Novosibirsk, 630090, Russia.,Institute of Chemical Biology and Fundamental Medicine of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.,E.N. Meshalkin National Medical Research Center, Ministry of Health Care of Russian Federation, Novosibirsk, 630055, Russia
| | - Irina S Zakharova
- Federal Research Center, "Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences", Novosibirsk, 630090, Russia. .,Institute of Chemical Biology and Fundamental Medicine of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia. .,E.N. Meshalkin National Medical Research Center, Ministry of Health Care of Russian Federation, Novosibirsk, 630055, Russia.
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49
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Goupil A, Heinen JP, Salame R, Rossi F, Reina J, Pennetier C, Simon A, Skorski P, Louzao A, Bardin AJ, Basto R, Gonzalez C. Illuminati: a form of gene expression plasticity in Drosophila neural stem cells. Development 2022; 149:282932. [PMID: 36399062 PMCID: PMC9845751 DOI: 10.1242/dev.200808] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 10/06/2022] [Indexed: 11/21/2022]
Abstract
While testing for genome instability in Drosophila as reported by unscheduled upregulation of UAS-GFP in cells that co-express GAL80 and GAL4, we noticed that, as expected, background levels were low in most developing tissues. However, GFP-positive clones were frequent in the larval brain. Most of these clones originated from central brain neural stem cells. Using imaging-based approaches and genome sequencing, we show that these unscheduled clones do not result from chromosome loss or mutations in GAL80. We have named this phenomenon 'Illuminati'. Illuminati is strongly enhanced in brat tumors and is also sensitive to environmental conditions such as food content and temperature. Illuminati is suppressed by Su(var)2-10, but it is not significantly affected by several modifiers of position effect variegation or Gal4::UAS variegation. We conclude that Illuminati identifies a previously unknown type of functional instability that may have important implications in development and disease.
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Affiliation(s)
- Alix Goupil
- Institut Curie, Paris Science et Lettres Research University, Centre National de la Recherche Scientifique, Unité Mixte de Recherche UMR144, Biology of Centrosomes and Genetic Instability Laboratory, 75005 Paris, France
| | - Jan Peter Heinen
- Institute for Research in Biomedicine (IRB Barcelona), Cell Division Laboratory, Cancer Science Programme, The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain
| | - Riham Salame
- Institut Curie, Paris Science et Lettres Research University, Centre National de la Recherche Scientifique, Unité Mixte de Recherche UMR144, Biology of Centrosomes and Genetic Instability Laboratory, 75005 Paris, France
| | - Fabrizio Rossi
- Institute for Research in Biomedicine (IRB Barcelona), Cell Division Laboratory, Cancer Science Programme, The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain
| | - Jose Reina
- Institute for Research in Biomedicine (IRB Barcelona), Cell Division Laboratory, Cancer Science Programme, The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain
| | - Carole Pennetier
- Institut Curie, Paris Science et Lettres Research University, Centre National de la Recherche Scientifique, Unité Mixte de Recherche UMR144, Biology of Centrosomes and Genetic Instability Laboratory, 75005 Paris, France
| | - Anthony Simon
- Institut Curie, Paris Science et Lettres Research University, Centre National de la Recherche Scientifique, Unité Mixte de Recherche UMR144, Biology of Centrosomes and Genetic Instability Laboratory, 75005 Paris, France
| | - Patricia Skorski
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, 75005 Paris, France
| | - Anxela Louzao
- Institute for Research in Biomedicine (IRB Barcelona), Cell Division Laboratory, Cancer Science Programme, The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain
| | - Allison J. Bardin
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, 75005 Paris, France
| | - Renata Basto
- Institut Curie, Paris Science et Lettres Research University, Centre National de la Recherche Scientifique, Unité Mixte de Recherche UMR144, Biology of Centrosomes and Genetic Instability Laboratory, 75005 Paris, France,Authors for correspondence (; )
| | - Cayetano Gonzalez
- Institute for Research in Biomedicine (IRB Barcelona), Cell Division Laboratory, Cancer Science Programme, The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, 08028 Barcelona, Spain,Catalan Institution for Research and Advanced Studies (ICREA), 08010 Barcelona, Spain,Authors for correspondence (; )
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50
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Ohhara Y, Kato Y, Kamiyama T, Yamakawa-Kobayashi K. Su(var)2-10- and Su(var)205-dependent upregulation of the heterochromatic gene neverland is required for developmental transition in Drosophila. Genetics 2022; 222:iyac137. [PMID: 36149288 PMCID: PMC9630985 DOI: 10.1093/genetics/iyac137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 08/29/2022] [Indexed: 11/14/2022] Open
Abstract
Animals develop from juveniles to sexually mature adults through the action of steroid hormones. In insect metamorphosis, a surge of the steroid hormone ecdysone prompts the transition from the larval to the adult stage. Ecdysone is synthesized by a series of biosynthetic enzymes that are specifically expressed in an endocrine organ, the prothoracic gland. At the late larval stage, the expression levels of ecdysone biosynthetic enzymes are upregulated through the action of numerous transcription factors, thus initiating metamorphosis. In contrast, the mechanism by which chromatin regulators support the expression of ecdysone biosynthetic genes is largely unknown. Here, we demonstrate that Su(var)2-10 and Su(var)205, suppressor of variegation [Su(var)] genes encoding a chromatin regulator Su(var)2-10 and nonhistone heterochromatic protein 1a, respectively, regulate the transcription of one of the heterochromatic ecdysone biosynthetic genes, neverland, in Drosophila melanogaster. Knockdown of Su(var)2-10 and Su(var)205 in the prothoracic gland caused a decrease in neverland expression, resulting in a defect in larval-to-prepupal transition. Furthermore, overexpression of neverland and administration of 7-dehydrocholesterol, a biosynthetic precursor of ecdysone produced by Neverland, rescued developmental defects in Su(var)2-10 and Su(var)205 knockdown animals. These results indicate that Su(var)2-10- and Su(var)205-mediated proper expression of neverland is required for the initiation of metamorphosis. Given that Su(var)2-10-positive puncta are juxtaposed with the pericentromeric heterochromatic region, we propose that Su(var)2-10- and Su(var)205-dependent regulation of inherent heterochromatin structure at the neverland gene locus is essential for its transcriptional activation.
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Affiliation(s)
- Yuya Ohhara
- School of Food and Nutritional Sciences, University of Shizuoka, Shizuoka, Shizuoka 422-8526, Japan
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka, Shizuoka 422-8526, Japan
| | - Yuki Kato
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka, Shizuoka 422-8526, Japan
| | - Takumi Kamiyama
- College of Biological Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Kimiko Yamakawa-Kobayashi
- School of Food and Nutritional Sciences, University of Shizuoka, Shizuoka, Shizuoka 422-8526, Japan
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka, Shizuoka 422-8526, Japan
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