1
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Deolal P, Scholz J, Ren K, Bragulat-Teixidor H, Otsuka S. Sculpting nuclear envelope identity from the endoplasmic reticulum during the cell cycle. Nucleus 2024; 15:2299632. [PMID: 38238284 PMCID: PMC10802211 DOI: 10.1080/19491034.2023.2299632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 12/21/2023] [Indexed: 01/23/2024] Open
Abstract
The nuclear envelope (NE) regulates nuclear functions, including transcription, nucleocytoplasmic transport, and protein quality control. While the outer membrane of the NE is directly continuous with the endoplasmic reticulum (ER), the NE has an overall distinct protein composition from the ER, which is crucial for its functions. During open mitosis in higher eukaryotes, the NE disassembles during mitotic entry and then reforms as a functional territory at the end of mitosis to reestablish nucleocytoplasmic compartmentalization. In this review, we examine the known mechanisms by which the functional NE reconstitutes from the mitotic ER in the continuous ER-NE endomembrane system during open mitosis. Furthermore, based on recent findings indicating that the NE possesses unique lipid metabolism and quality control mechanisms distinct from those of the ER, we explore the maintenance of NE identity and homeostasis during interphase. We also highlight the potential significance of membrane junctions between the ER and NE.
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Affiliation(s)
- Pallavi Deolal
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
| | - Julia Scholz
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Kaike Ren
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Helena Bragulat-Teixidor
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Shotaro Otsuka
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
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2
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Walsh ME, King GA, Ünal E. Not just binary: embracing the complexity of nuclear division dynamics. Nucleus 2024; 15:2360601. [PMID: 38842147 PMCID: PMC11164224 DOI: 10.1080/19491034.2024.2360601] [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: 02/09/2024] [Accepted: 05/22/2024] [Indexed: 06/07/2024] Open
Abstract
Cell division presents a challenge for eukaryotic cells: how can chromosomes effectively segregate within the confines of a membranous nuclear compartment? Different organisms have evolved diverse solutions by modulating the degree of nuclear compartmentalization, ranging from complete nuclear envelope breakdown to complete maintenance of nuclear compartmentalization via nuclear envelope expansion. Many intermediate forms exist between these extremes, suggesting that nuclear dynamics during cell division are surprisingly plastic. In this review, we highlight the evolutionary diversity of nuclear divisions, focusing on two defining characteristics: (1) chromosome compartmentalization and (2) nucleocytoplasmic transport. Further, we highlight recent evidence that nuclear behavior during division can vary within different cellular contexts in the same organism. The variation observed within and between organisms underscores the dynamic evolution of nuclear divisions tailored to specific contexts and cellular requirements. In-depth investigation of diverse nuclear divisions will enhance our understanding of the nucleus, both in physiological and pathological states.
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Affiliation(s)
- Madison E. Walsh
- Department of Molecular and Cell Biology, Barker Hall, University of California, Berkeley, CA, USA
| | - Grant A. King
- Department of Molecular and Cell Biology, Barker Hall, University of California, Berkeley, CA, USA
| | - Elçin Ünal
- Department of Molecular and Cell Biology, Barker Hall, University of California, Berkeley, CA, USA
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3
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Zych MG, Hatch EM. Small spaces, big problems: The abnormal nucleoplasm of micronuclei and its consequences. Curr Opin Struct Biol 2024; 87:102839. [PMID: 38763098 DOI: 10.1016/j.sbi.2024.102839] [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: 12/22/2023] [Revised: 03/29/2024] [Accepted: 04/26/2024] [Indexed: 05/21/2024]
Abstract
Micronuclei (MN) form from missegregated chromatin that recruits its own nuclear envelope during mitotic exit and are a common consequence of chromosomal instability. MN are unstable due to errors in nuclear envelope organization and frequently rupture, leading to loss of compartmentalization, loss of nuclear functions, and major changes in genome stability and gene expression. However, recent work found that, even prior to rupture, nuclear processes can be severely defective in MN, which may contribute to rupture-associated defects and have lasting consequences for chromatin structure and function. In this review we discuss work that highlights nuclear function defects in intact MN, including their mechanisms and consequences, and how biases in chromosome missegregation into MN may affect the penetrance of these defects. Illuminating the nuclear environment of MN demonstrates that MN formation alone has major consequences for both the genome and cell and provides new insight into how nuclear content is regulated.
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Affiliation(s)
- Molly G Zych
- Molecular and Cellular Biology PhD Program, University of Washington, Seattle, WA, USA; Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA. https://twitter.com/ZychMolly
| | - Emily M Hatch
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA; Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA, USA.
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4
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Clark FE, Greenberg NL, Silva DMZA, Trimm E, Skinner M, Walton RZ, Rosin LF, Lampson MA, Akera T. An egg-sabotaging mechanism drives non-Mendelian transmission in mice. Curr Biol 2024:S0960-9822(24)00901-1. [PMID: 39067449 DOI: 10.1016/j.cub.2024.07.001] [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: 03/08/2024] [Revised: 05/31/2024] [Accepted: 07/01/2024] [Indexed: 07/30/2024]
Abstract
Selfish genetic elements drive in meiosis to distort their transmission ratio and increase their representation in gametes, violating Mendel's law of segregation. The two established paradigms for meiotic drive, gamete killing and biased segregation, are fundamentally different. In gamete killing, typically observed with male meiosis, selfish elements sabotage gametes that do not contain them. By contrast, killing is predetermined in female meiosis, and selfish elements bias their segregation to the single surviving gamete (i.e., the egg in animal meiosis). Here, we show that a selfish element on mouse chromosome 2, Responder to drive 2 (R2d2), drives using a hybrid mechanism in female meiosis, incorporating elements of both killing and biased segregation. We propose that if R2d2 is destined for the polar body, it manipulates segregation to sabotage the egg by causing aneuploidy, which is subsequently lethal in the embryo, ensuring that surviving progeny preferentially contain R2d2. In heterozygous females, R2d2 orients randomly on the metaphase spindle but lags during anaphase and preferentially remains in the egg, regardless of its initial orientation. Thus, the egg genotype is either euploid with R2d2 or aneuploid with both homologs of chromosome 2, with only the former generating viable embryos. Consistent with this model, R2d2 heterozygous females produce eggs with increased aneuploidy for chromosome 2, increased embryonic lethality, and increased transmission of R2d2. In contrast to typical gamete killing of sisters produced as daughter cells in a single meiosis, R2d2 prevents production of any viable gametes from meiotic divisions in which it should have been excluded from the egg.
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Affiliation(s)
- Frances E Clark
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20894, USA
| | - Naomi L Greenberg
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20894, USA
| | - Duilio M Z A Silva
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20894, USA
| | - Emily Trimm
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Morgan Skinner
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20894, USA
| | - R Zaak Walton
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20894, USA
| | - Leah F Rosin
- Unit on Chromosome Dynamics, Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20894, USA
| | - Michael A Lampson
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Takashi Akera
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20894, USA.
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5
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Bastianello G, Kidiyoor GR, Lowndes C, Li Q, Bonnal R, Godwin J, Iannelli F, Drufuca L, Bason R, Orsenigo F, Parazzoli D, Pavani M, Cancila V, Piccolo S, Scita G, Ciliberto A, Tripodo C, Pagani M, Foiani M. Mechanical stress during confined migration causes aberrant mitoses and c-MYC amplification. Proc Natl Acad Sci U S A 2024; 121:e2404551121. [PMID: 38990945 PMCID: PMC11260125 DOI: 10.1073/pnas.2404551121] [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: 03/04/2024] [Accepted: 06/07/2024] [Indexed: 07/13/2024] Open
Abstract
Confined cell migration hampers genome integrity and activates the ATR and ATM mechano-transduction pathways. We investigated whether the mechanical stress generated by metastatic interstitial migration contributes to the enhanced chromosomal instability observed in metastatic tumor cells. We employed live cell imaging, micro-fluidic approaches, and scRNA-seq to follow the fate of tumor cells experiencing confined migration. We found that, despite functional ATR, ATM, and spindle assembly checkpoint (SAC) pathways, tumor cells dividing across constriction frequently exhibited altered spindle pole organization, chromosome mis-segregations, micronuclei formation, chromosome fragility, high gene copy number variation, and transcriptional de-regulation and up-regulation of c-MYC oncogenic transcriptional signature via c-MYC locus amplifications. In vivo tumor settings showed that malignant cells populating metastatic foci or infiltrating the interstitial stroma gave rise to cells expressing high levels of c-MYC. Altogether, our data suggest that mechanical stress during metastatic migration contributes to override the checkpoint controls and boosts genotoxic and oncogenic events. Our findings may explain why cancer aneuploidy often does not correlate with mutations in SAC genes and why c-MYC amplification is strongly linked to metastatic tumors.
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Affiliation(s)
- Giulia Bastianello
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
- Università degli Studi di Milano, Milan20122, Italy
| | - Gururaj Rao Kidiyoor
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
| | - Conor Lowndes
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
| | - Qingsen Li
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
| | - Raoul Bonnal
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
| | - Jeffrey Godwin
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
| | - Fabio Iannelli
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
| | | | - Ramona Bason
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
| | - Fabrizio Orsenigo
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
| | - Dario Parazzoli
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
| | - Mattia Pavani
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
| | - Valeria Cancila
- Tumor Immunology Unit, Department of Health Science, University of Palermo School of Medicine, Palermo90133, Italy
| | - Stefano Piccolo
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
- Department of Molecular Medicine, University of Padua, Padua35123, Italy
| | - Giorgio Scita
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
- Università degli Studi di Milano, Milan20122, Italy
| | - Andrea Ciliberto
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
| | - Claudio Tripodo
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
- Tumor Immunology Unit, Department of Health Science, University of Palermo School of Medicine, Palermo90133, Italy
| | - Massimiliano Pagani
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
- Università degli Studi di Milano, Milan20122, Italy
| | - Marco Foiani
- Istituto Fondazione Italiana per la Ricerca sul Cancro di Oncologia molecolare—the Associazione Italiana per la Ricerca sul Cancro Institute of Molecular Oncology, Milano20139, Italy
- Istituto di Genetica Molecolare, Centro Nazionale Ricerca, Pavia27100, Italy
- Cancer Science Institute of Singapore, National University of Singapore, Singapore117599, Singapore
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6
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Clark FE, Greenberg NL, Silva DM, Trimm E, Skinner M, Walton RZ, Rosin LF, Lampson MA, Akera T. An egg sabotaging mechanism drives non-Mendelian transmission in mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.22.581453. [PMID: 38903120 PMCID: PMC11188085 DOI: 10.1101/2024.02.22.581453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
During meiosis, homologous chromosomes segregate so that alleles are transmitted equally to haploid gametes, following Mendel's Law of Segregation. However, some selfish genetic elements drive in meiosis to distort the transmission ratio and increase their representation in gametes. The established paradigms for drive are fundamentally different for female vs male meiosis. In male meiosis, selfish elements typically kill gametes that do not contain them. In female meiosis, killing is predetermined, and selfish elements bias their segregation to the single surviving gamete (i.e., the egg in animal meiosis). Here we show that a selfish element on mouse chromosome 2, R2d2, drives using a hybrid mechanism in female meiosis, incorporating elements of both male and female drivers. If R2d2 is destined for the polar body, it manipulates segregation to sabotage the egg by causing aneuploidy that is subsequently lethal in the embryo, so that surviving progeny preferentially contain R2d2. In heterozygous females, R2d2 orients randomly on the metaphase spindle but lags during anaphase and preferentially remains in the egg, regardless of its initial orientation. Thus, the egg genotype is either euploid with R2d2 or aneuploid with both homologs of chromosome 2, with only the former generating viable embryos. Consistent with this model, R2d2 heterozygous females produce eggs with increased aneuploidy for chromosome 2, increased embryonic lethality, and increased transmission of R2d2. In contrast to a male meiotic driver, which kills its sister gametes produced as daughter cells in the same meiosis, R2d2 eliminates "cousins" produced from meioses in which it should have been excluded from the egg.
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Affiliation(s)
- Frances E. Clark
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health; Bethesda, Maryland 20894, USA
| | - Naomi L. Greenberg
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health; Bethesda, Maryland 20894, USA
| | - Duilio M.Z.A. Silva
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health; Bethesda, Maryland 20894, USA
| | - Emily Trimm
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Morgan Skinner
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health; Bethesda, Maryland 20894, USA
| | - R Zaak Walton
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health; Bethesda, Maryland 20894, USA
| | - Leah F. Rosin
- Unit on Chromosome Dynamics, Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20894 USA
| | - Michael A. Lampson
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Takashi Akera
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health; Bethesda, Maryland 20894, USA
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7
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Xu Y, Wang B, Bush I, Saunders HAJ, Wildonger J, Han C. Light-induced trapping of endogenous proteins reveals spatiotemporal roles of microtubule and kinesin-1 in dendrite patterning of Drosophila sensory neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.30.560303. [PMID: 37873262 PMCID: PMC10592855 DOI: 10.1101/2023.09.30.560303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Animal development involves numerous molecular events, whose spatiotemporal properties largely determine the biological outcomes. Conventional methods for studying gene function lack the necessary spatiotemporal resolution for precise dissection of developmental mechanisms. Optogenetic approaches are powerful alternatives, but most existing tools rely on exogenous designer proteins that produce narrow outputs and cannot be applied to diverse or endogenous proteins. To address this limitation, we developed OptoTrap, a light-inducible protein trapping system that allows manipulation of endogenous proteins tagged with GFP or split GFP. This system turns on fast and is reversible in minutes or hours. We generated OptoTrap variants optimized for neurons and epithelial cells and demonstrate effective trapping of endogenous proteins of diverse sizes, subcellular locations, and functions. Furthermore, OptoTrap allowed us to instantly disrupt microtubules and inhibit the kinesin-1 motor in specific dendritic branches of Drosophila sensory neurons. Using OptoTrap, we obtained direct evidence that microtubules support the growth of highly dynamic dendrites. Similarly, targeted manipulation of Kinesin heavy chain revealed differential spatiotemporal requirements of kinesin-1 in the patterning of low- and high-order dendritic branches, suggesting that different cargos are needed for the growth of these branches. OptoTrap allows for precise manipulation of endogenous proteins in a spatiotemporal manner and thus holds great promise for studying developmental mechanisms in a wide range of cell types and developmental stages.
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Affiliation(s)
- Yineng Xu
- Weill Institute for Cell and Molecular Biology, Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Bei Wang
- Weill Institute for Cell and Molecular Biology, Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Inle Bush
- Weill Institute for Cell and Molecular Biology, Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Harriet AJ Saunders
- Department of Biochemistry, University of Wisconsin-Madison, 440 Henry Mall, Madison, WI 53706, USA
| | - Jill Wildonger
- Department of Biochemistry, University of Wisconsin-Madison, 440 Henry Mall, Madison, WI 53706, USA
- Pediatrics Department and Biological Sciences Division, Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Chun Han
- Weill Institute for Cell and Molecular Biology, Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
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8
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Bâcle J, Groizard L, Kumanski S, Moriel-Carretero M. Nuclear envelope-remodeling events as models to assess the potential role of membranes on genome stability. FEBS Lett 2023; 597:1946-1956. [PMID: 37339935 DOI: 10.1002/1873-3468.14688] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/31/2023] [Accepted: 05/31/2023] [Indexed: 06/22/2023]
Abstract
The nuclear envelope (NE) encloses the genetic material and functions in chromatin organization and stability. In Saccharomyces cerevisiae, the NE is bound to the ribosomal DNA (rDNA), highly repeated and transcribed, thus prone to genetic instability. While tethering limits instability, it simultaneously triggers notable NE remodeling. We posit here that NE remodeling may contribute to genome integrity maintenance. The NE importance in genome expression, structure, and integrity is well recognized, yet studies mostly focus on peripheral proteins and nuclear pores, not on the membrane itself. We recently characterized a NE invagination drastically obliterating the rDNA, which we propose here as a model to probe if and how membranes play an active role in genome stability preservation.
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Affiliation(s)
- Janélie Bâcle
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Centre National de la Recherche Scientifique, Université de Montpellier, France
| | - Léa Groizard
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Centre National de la Recherche Scientifique, Université de Montpellier, France
| | - Sylvain Kumanski
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Centre National de la Recherche Scientifique, Université de Montpellier, France
| | - María Moriel-Carretero
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Centre National de la Recherche Scientifique, Université de Montpellier, France
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9
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Ferrandiz N, Royle SJ. 3D Ultrastructural Visualization of Mitosis Fidelity in Human Cells Using Serial Block Face Scanning Electron Microscopy (SBF-SEM). Bio Protoc 2023; 13:e4708. [PMID: 37449034 PMCID: PMC10336565 DOI: 10.21769/bioprotoc.4708] [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: 12/22/2022] [Revised: 03/01/2023] [Accepted: 04/19/2023] [Indexed: 07/18/2023] Open
Abstract
Errors in chromosome segregation during mitosis lead to chromosome instability, resulting in an unbalanced number of chromosomes in the daughter cells. Light microscopy has been used extensively to study chromosome missegregation by visualizing errors of the mitotic spindle. However, less attention has been paid to understanding spindle function in the broader context of intracellular structures and organelles during mitosis. Here, we outline a protocol to visualize chromosomes and endomembranes in mitosis, combining light microscopy and 3D volume electron microscopy, serial block-face scanning electron microscopy (SBF-SEM). SBF-SEM provides high-resolution imaging of large volumes and subcellular structures, followed by image analysis and 3D reconstruction. This protocol allows scientists to visualize the whole subcellular context of the spindle during mitosis.
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Affiliation(s)
- Nuria Ferrandiz
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK
| | - Stephen J. Royle
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK
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10
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Sittewelle M, Ferrandiz N, Fesenko M, Royle SJ. Genetically encoded imaging tools for investigating cell dynamics at a glance. J Cell Sci 2023; 136:jcs260783. [PMID: 37039102 DOI: 10.1242/jcs.260783] [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] [Indexed: 04/12/2023] Open
Abstract
The biology of a cell is the sum of many highly dynamic processes, each orchestrated by a plethora of proteins and other molecules. Microscopy is an invaluable approach to spatially and temporally dissect the molecular details of these processes. Hundreds of genetically encoded imaging tools have been developed that allow cell scientists to determine the function of a protein of interest in the context of these dynamic processes. Broadly, these tools fall into three strategies: observation, inhibition and activation. Using examples for each strategy, in this Cell Science at a Glance and the accompanying poster, we provide a guide to using these tools to dissect protein function in a given cellular process. Our focus here is on tools that allow rapid modification of proteins of interest and how observing the resulting changes in cell states is key to unlocking dynamic cell processes. The aim is to inspire the reader's next set of imaging experiments.
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Affiliation(s)
- Méghane Sittewelle
- Centre for Mechanochemical Cell Biology, Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Nuria Ferrandiz
- Centre for Mechanochemical Cell Biology, Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Mary Fesenko
- Centre for Mechanochemical Cell Biology, Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Stephen J Royle
- Centre for Mechanochemical Cell Biology, Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
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11
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Moreno-Andrés D, Holl K, Antonin W. The second half of mitosis and its implications in cancer biology. Semin Cancer Biol 2023; 88:1-17. [PMID: 36436712 DOI: 10.1016/j.semcancer.2022.11.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/16/2022] [Accepted: 11/21/2022] [Indexed: 11/26/2022]
Abstract
The nucleus undergoes dramatic structural and functional changes during cell division. With the entry into mitosis, in human cells the nuclear envelope breaks down, chromosomes rearrange into rod-like structures which are collected and segregated by the spindle apparatus. While these processes in the first half of mitosis have been intensively studied, much less is known about the second half of mitosis, when a functional nucleus reforms in each of the emerging cells. Here we review our current understanding of mitotic exit and nuclear reformation with spotlights on the links to cancer biology.
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Affiliation(s)
- Daniel Moreno-Andrés
- Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany.
| | - Kristin Holl
- Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany
| | - Wolfram Antonin
- Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany
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Tucker JB, Bonema SC, García-Varela R, Denu RA, Hu Y, McGregor SM, Burkard ME, Weaver BA. Misaligned Chromosomes are a Major Source of Chromosomal Instability in Breast Cancer. CANCER RESEARCH COMMUNICATIONS 2023; 3:54-65. [PMID: 36968230 PMCID: PMC10035514 DOI: 10.1158/2767-9764.crc-22-0302] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 10/17/2022] [Accepted: 12/22/2022] [Indexed: 12/31/2022]
Abstract
Chromosomal instability (CIN), the persistent reshuffling of chromosomes during mitosis, is a hallmark of human cancers that contributes to tumor heterogeneity and has been implicated in driving metastasis and altering responses to therapy. Though multiple mechanisms can produce CIN, lagging chromosomes generated from abnormal merotelic attachments are the major cause of CIN in a variety of cell lines, and are expected to predominate in cancer. Here, we quantify CIN in breast cancer using a tumor microarray, matched primary and metastatic samples, and patient-derived organoids from primary breast cancer. Surprisingly, misaligned chromosomes are more common than lagging chromosomes and represent a major source of CIN in primary and metastatic tumors. This feature of breast cancers is conserved in a majority of breast cancer cell lines. Importantly, though a portion of misaligned chromosomes align before anaphase onset, the fraction that remain represents the largest source of CIN in these cells. Metastatic breast cancers exhibit higher rates of CIN than matched primary cancers, primarily due to increases in misaligned chromosomes. Whether CIN causes immune activation or evasion is controversial. We find that misaligned chromosomes result in immune-activating micronuclei substantially less frequently than lagging and bridge chromosomes and that breast cancers with greater frequencies of lagging chromosomes and chromosome bridges recruit more stromal tumor-infiltrating lymphocytes. These data indicate misaligned chromosomes represent a major mechanism of CIN in breast cancer and provide support for differential immunostimulatory effects of specific types of CIN. Significance We surveyed the single-cell landscape of mitotic defects that generate CIN in primary and metastatic breast cancer and relevant models. Misaligned chromosomes predominate, and are less immunostimulatory than other chromosome segregation errors.
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Affiliation(s)
- John B. Tucker
- Cancer Biology Graduate Training Program, University of Wisconsin–Madison, Madison, Wisconsin
| | - Sarah C. Bonema
- Molecular and Cellular Pharmacology Graduate Training Program, University of Wisconsin–Madison, Madison, Wisconsin
| | | | - Ryan A. Denu
- Medical Scientist Training Program, University of Wisconsin–Madison, Madison, Wisconsin
| | - Yang Hu
- Medical Scientist Training Program, University of Wisconsin–Madison, Madison, Wisconsin
| | - Stephanie M. McGregor
- Department of Pathology and Laboratory Medicine, University of Wisconsin–Madison, Madison, Wisconsin
| | - Mark E. Burkard
- Department of Medicine, University of Wisconsin–Madison, Madison, Wisconsin
- Department of Oncology/McArdle Laboratory for Cancer Research, University of Wisconsin–Madison, Madison, Wisconsin
- Carbone Cancer Center, University of Wisconsin–Madison, Madison, Wisconsin
| | - Beth A. Weaver
- Department of Oncology/McArdle Laboratory for Cancer Research, University of Wisconsin–Madison, Madison, Wisconsin
- Carbone Cancer Center, University of Wisconsin–Madison, Madison, Wisconsin
- Department of Cell and Regenerative Biology, University of Wisconsin–Madison, Madison, Wisconsin
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Araújo M, Tavares A, Vieira DV, Telley IA, Oliveira RA. Endoplasmic reticulum membranes are continuously required to maintain mitotic spindle size and forces. Life Sci Alliance 2022; 6:6/1/e202201540. [PMID: 36379670 PMCID: PMC9671068 DOI: 10.26508/lsa.202201540] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 10/27/2022] [Accepted: 10/28/2022] [Indexed: 11/16/2022] Open
Abstract
Membrane organelle function, localization, and proper partitioning upon cell division depend on interactions with the cytoskeleton. Whether membrane organelles also impact the function of cytoskeletal elements remains less clear. Here, we show that acute disruption of the ER around spindle poles affects mitotic spindle size and function in Drosophila syncytial embryos. Acute ER disruption was achieved through the inhibition of ER membrane fusion by the dominant-negative cytoplasmic domain of atlastin. We reveal that when centrosome-proximal ER membranes are disrupted, specifically at metaphase, mitotic spindles become smaller, despite no significant changes in microtubule dynamics. These smaller spindles are still able to mediate sister chromatid separation, yet with decreased velocity. Furthermore, by inducing mitotic exit, we found that nuclear separation and distribution are affected by ER disruption. Our results suggest that ER integrity around spindle poles is crucial for the maintenance of mitotic spindle shape and pulling forces. In addition, ER integrity also ensures nuclear spacing during syncytial divisions.
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Affiliation(s)
| | | | | | - Ivo A Telley
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Raquel A Oliveira
- Instituto Gulbenkian de Ciência, Oeiras, Portugal .,Universidade Católica Portuguesa, Católica Medical School, Católica Biomedical Research Centre, Lisbon, Portugal
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14
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Gomes AM, Orr B, Novais-Cruz M, De Sousa F, Macário-Monteiro J, Lemos C, Ferrás C, Maiato H. Micronuclei from misaligned chromosomes that satisfy the spindle assembly checkpoint in cancer cells. Curr Biol 2022; 32:4240-4254.e5. [PMID: 36057259 PMCID: PMC9559752 DOI: 10.1016/j.cub.2022.08.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 07/22/2022] [Accepted: 08/11/2022] [Indexed: 12/14/2022]
Abstract
Chromosome alignment to the spindle equator is a hallmark of mitosis thought to promote chromosome segregation fidelity in metazoans. Yet chromosome alignment is only indirectly supervised by the spindle assembly checkpoint (SAC) as a byproduct of chromosome bi-orientation, and the consequences of defective chromosome alignment remain unclear. Here, we investigated how human cells respond to chromosome alignment defects of distinct molecular nature by following the fate of live HeLa cells after RNAi-mediated depletion of 125 proteins previously implicated in chromosome alignment. We confirmed chromosome alignment defects upon depletion of 108/125 proteins. Surprisingly, in all confirmed cases, depleted cells frequently entered anaphase after a delay with misaligned chromosomes. Using depletion of prototype proteins resulting in defective chromosome alignment, we show that misaligned chromosomes often satisfy the SAC and directly missegregate without lagging behind in anaphase. In-depth analysis of specific molecular perturbations that prevent proper kinetochore-microtubule attachments revealed that misaligned chromosomes that missegregate frequently result in micronuclei. Higher-resolution live-cell imaging indicated that, contrary to most anaphase lagging chromosomes that correct and reintegrate the main nuclei, misaligned chromosomes are a strong predictor of micronuclei formation in a cancer cell model of chromosomal instability, but not in non-transformed near-diploid cells. We provide evidence supporting that intrinsic differences in kinetochore-microtubule attachment stability on misaligned chromosomes account for this distinct outcome. Thus, misaligned chromosomes that satisfy the SAC may represent a previously overlooked mechanism driving chromosomal/genomic instability during cancer cell division, and we unveil genetic conditions predisposing for these events.
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Affiliation(s)
- Ana Margarida Gomes
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Bernardo Orr
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Marco Novais-Cruz
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Filipe De Sousa
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Joana Macário-Monteiro
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Carolina Lemos
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal; UnIGENe, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Cristina Ferrás
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Helder Maiato
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Cell Division Group, Department of Biomedicine, Faculdade de Medicina, Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
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Donker L, Godinho SA. Too close for comfort? Endomembranes promote missegregation by enclosing lost chromosomes. J Cell Biol 2022; 221:e202204114. [PMID: 35536317 PMCID: PMC9097545 DOI: 10.1083/jcb.202204114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Correct segregation of chromosomes during mitosis is essential to prevent aneuploidy. In this issue, Ferrandiz et al. (2022. J. Cell Biol.https://doi.org/10.1083/jcb.202203021) show that endomembranes can promote chromosome missegregation by "ensheathing" misaligned chromosomes, preventing their integration into the metaphase plate. Their findings point toward endomembranes as a potential risk factor for aneuploidy.
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Affiliation(s)
- Lisa Donker
- Barts Cancer Institute, Queen Mary University of London, London, UK
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Vukušić K, Tolić IM. Polar Chromosomes—Challenges of a Risky Path. Cells 2022; 11:cells11091531. [PMID: 35563837 PMCID: PMC9101661 DOI: 10.3390/cells11091531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/28/2022] [Accepted: 04/30/2022] [Indexed: 12/29/2022] Open
Abstract
The process of chromosome congression and alignment is at the core of mitotic fidelity. In this review, we discuss distinct spatial routes that the chromosomes take to align during prometaphase, which are characterized by distinct biomolecular requirements. Peripheral polar chromosomes are an intriguing case as their alignment depends on the activity of kinetochore motors, polar ejection forces, and a transition from lateral to end-on attachments to microtubules, all of which can result in the delayed alignment of these chromosomes. Due to their undesirable position close to and often behind the spindle pole, these chromosomes may be particularly prone to the formation of erroneous kinetochore-microtubule interactions, such as merotelic attachments. To prevent such errors, the cell employs intricate mechanisms to preposition the spindle poles with respect to chromosomes, ensure the formation of end-on attachments in restricted spindle regions, repair faulty attachments by error correction mechanisms, and delay segregation by the spindle assembly checkpoint. Despite this protective machinery, there are several ways in which polar chromosomes can fail in alignment, mis-segregate, and lead to aneuploidy. In agreement with this, polar chromosomes are present in certain tumors and may even be involved in the process of tumorigenesis.
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