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Jash E, Azhar AA, Mendoza H, Tan ZM, Escher HN, Kaufman DS, Csankovszki G. XOL-1 regulates developmental timing by modulating the H3K9 landscape in C. elegans early embryos. PLoS Genet 2024; 20:e1011238. [PMID: 39146391 PMCID: PMC11349215 DOI: 10.1371/journal.pgen.1011238] [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: 04/01/2024] [Revised: 08/27/2024] [Accepted: 07/30/2024] [Indexed: 08/17/2024] Open
Abstract
Sex determination in the nematode C. elegans is controlled by the master regulator XOL-1 during embryogenesis. Expression of xol-1 is dependent on the ratio of X chromosomes and autosomes, which differs between XX hermaphrodites and XO males. In males, xol-1 is highly expressed and in hermaphrodites, xol-1 is expressed at very low levels. XOL-1 activity is known to be critical for the proper development of C. elegans males, but its low expression was considered to be of minimal importance in the development of hermaphrodite embryos. Our study reveals that XOL-1 plays an important role as a regulator of developmental timing during hermaphrodite embryogenesis. Using a combination of imaging and bioinformatics techniques, we found that hermaphrodite embryos have an accelerated rate of cell division, as well as a more developmentally advanced transcriptional program when xol-1 is lost. Further analyses reveal that XOL-1 is responsible for regulating the timing of initiation of dosage compensation on the X chromosomes, and the appropriate expression of sex-biased transcriptional programs in hermaphrodites. We found that xol-1 mutant embryos overexpress the H3K9 methyltransferase MET-2 and have an altered H3K9me landscape. Some of these effects of the loss of xol-1 gene were reversed by the loss of met-2. These findings demonstrate that XOL-1 plays an important role as a developmental regulator in embryos of both sexes, and that MET-2 acts as a downstream effector of XOL-1 activity in hermaphrodites.
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Affiliation(s)
- Eshna Jash
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Anati Alyaa Azhar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Hector Mendoza
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Zoey M. Tan
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Halle Nicole Escher
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Dalia S. Kaufman
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Györgyi Csankovszki
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
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2
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Das M, Semple JI, Haemmerli A, Volodkina V, Scotton J, Gitchev T, Annan A, Campos J, Statzer C, Dakhovnik A, Ewald CY, Mozziconacci J, Meister P. Condensin I folds the Caenorhabditis elegans genome. Nat Genet 2024; 56:1737-1749. [PMID: 39039278 DOI: 10.1038/s41588-024-01832-5] [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: 04/01/2022] [Accepted: 06/13/2024] [Indexed: 07/24/2024]
Abstract
The structural maintenance of chromosome (SMC) complexes-cohesin and condensins-are crucial for chromosome separation and compaction during cell division. During the interphase, mammalian cohesins additionally fold the genome into loops and domains. Here we show that, in Caenorhabditis elegans, a species with holocentric chromosomes, condensin I is the primary, long-range loop extruder. The loss of condensin I and its X-specific variant, condensin IDC, leads to genome-wide decompaction, chromosome mixing and disappearance of X-specific topologically associating domains, while reinforcing fine-scale epigenomic compartments. In addition, condensin I/IDC inactivation led to the upregulation of X-linked genes and unveiled nuclear bodies grouping together binding sites for the X-targeting loading complex of condensin IDC. C. elegans condensin I/IDC thus uniquely organizes holocentric interphase chromosomes, akin to cohesin in mammals, as well as regulates X-chromosome gene expression.
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Affiliation(s)
- Moushumi Das
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Jennifer I Semple
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Anja Haemmerli
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Valeriia Volodkina
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Janik Scotton
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Todor Gitchev
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Ahrmad Annan
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Julie Campos
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Cyril Statzer
- Eidgenössische Technische Hochschule Zürich, Department of Health Sciences and Technology, Institute of Translational Medicine, Schwerzenbach, Switzerland
| | - Alexander Dakhovnik
- Eidgenössische Technische Hochschule Zürich, Department of Health Sciences and Technology, Institute of Translational Medicine, Schwerzenbach, Switzerland
| | - Collin Y Ewald
- Eidgenössische Technische Hochschule Zürich, Department of Health Sciences and Technology, Institute of Translational Medicine, Schwerzenbach, Switzerland
| | - Julien Mozziconacci
- Laboratoire Structure et Instabilité des Génomes UMR 7196, Muséum National d'Histoire Naturelle, Paris, France
| | - Peter Meister
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, Bern, Switzerland.
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Aharonoff A, Kim J, Washington A, Ercan S. SMC-mediated dosage compensation in C. elegans evolved in the presence of an ancestral nematode mechanism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.21.595224. [PMID: 38826443 PMCID: PMC11142195 DOI: 10.1101/2024.05.21.595224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Mechanisms of X chromosome dosage compensation have been studied extensively in a few model species representing clades of shared sex chromosome ancestry. However, the diversity within each clade as a function of sex chromosome evolution is largely unknown. Here, we anchor ourselves to the nematode Caenorhabditis elegans, for which a well-studied mechanism of dosage compensation occurs through a specialized structural maintenance of chromosomes (SMC) complex, and explore the diversity of dosage compensation in the surrounding phylogeny of nematodes. Through phylogenetic analysis of the C. elegans dosage compensation complex and a survey of its epigenetic signatures, including X-specific topologically associating domains (TADs) and X-enrichment of H4K20me1, we found that the condensin-mediated mechanism evolved recently in the lineage leading to Caenorhabditis through an SMC-4 duplication. Intriguingly, an independent duplication of SMC-4 and the presence of X-specific TADs in Pristionchus pacificus suggest that condensin-mediated dosage compensation arose more than once. mRNA-seq analyses of gene expression in several nematode species indicate that dosage compensation itself is ancestral, as expected from the ancient XO sex determination system. Indicative of the ancestral mechanism, H4K20me1 is enriched on the X chromosomes in Oscheius tipulae, which does not contain X-specific TADs or SMC-4 paralogs. Together, our results indicate that the dosage compensation system in C. elegans is surprisingly new, and condensin may have been co-opted repeatedly in nematodes, suggesting that the process of evolving a chromosome-wide gene regulatory mechanism for dosage compensation is constrained. Significance statement X chromosome dosage compensation mechanisms evolved in response to Y chromosome degeneration during sex chromosome evolution. However, establishment of dosage compensation is not an endpoint. As sex chromosomes change, dosage compensation strategies may have also changed. In this study, we performed phylogenetic and epigenomic analyses surrounding Caenorhabditis elegans and found that the condensin-mediated dosage compensation mechanism in C. elegans is surprisingly new, and has evolved in the presence of an ancestral mechanism. Intriguingly, condensin-based dosage compensation may have evolved more than once in the nematode lineage, the other time in Pristionchus. Together, our work highlights a previously unappreciated diversity of dosage compensation mechanisms within a clade, and suggests constraints in evolving new mechanisms in the presence of an existing one.
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Affiliation(s)
- Avrami Aharonoff
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003
| | - Jun Kim
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003
| | - Aaliyah Washington
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003
| | - Sevinç Ercan
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003
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4
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Breimann L, Bahry E, Zouinkhi M, Kolyvanov K, Street LA, Preibisch S, Ercan S. Analysis of developmental gene expression using smFISH and in silico staging of C. elegans embryos. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.15.594414. [PMID: 38798598 PMCID: PMC11118362 DOI: 10.1101/2024.05.15.594414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Regulation of transcription during embryogenesis is key to development and differentiation. To study transcript expression throughout Caenorhabditis elegans embryogenesis at single-molecule resolution, we developed a high-throughput single-molecule fluorescence in situ hybridization (smFISH) method that relies on computational methods to developmentally stage embryos and quantify individual mRNA molecules in single embryos. We applied our system to sdc-2, a zygotically transcribed gene essential for hermaphrodite development and dosage compensation. We found that sdc-2 is rapidly activated during early embryogenesis by increasing both the number of mRNAs produced per transcription site and the frequency of sites engaged in transcription. Knockdown of sdc-2 and dpy-27, a subunit of the dosage compensation complex (DCC), increased the number of active transcription sites for the X chromosomal gene dpy-23 but not the autosomal gene mdh-1, suggesting that the DCC reduces the frequency of dpy-23 transcription. The temporal resolution from in silico staging of embryos showed that the deletion of a single DCC recruitment element near the dpy-23 gene causes higher dpy-23 mRNA expression after the start of dosage compensation, which could not be resolved using mRNAseq from mixed-stage embryos. In summary, we have established a computational approach to quantify temporal regulation of transcription throughout C. elegans embryogenesis and demonstrated its potential to provide new insights into developmental gene regulation.
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Affiliation(s)
- Laura Breimann
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Ella Bahry
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
- Helmholtz Imaging, Max-Delbrück-Center for Molecular Medicine (MDC), Berlin, Germany
| | - Marwan Zouinkhi
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Klim Kolyvanov
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Lena Annika Street
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY, USA
| | - Stephan Preibisch
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Sevinç Ercan
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY, USA
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5
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Meng Q, Borris RP, Kim HM. Torenia sp. Extracts Contain Multiple Potent Antitumor Compounds with Nematocidal Activity, Triggering an Activated DNA Damage Checkpoint and Defective Meiotic Progression. Pharmaceuticals (Basel) 2024; 17:611. [PMID: 38794181 PMCID: PMC11124231 DOI: 10.3390/ph17050611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/03/2024] [Accepted: 05/07/2024] [Indexed: 05/26/2024] Open
Abstract
Previously, we analyzed 316 herbal extracts to evaluate their potential nematocidal properties in Caenorhabditis elegans. In this study, our attention was directed towards Torenia sp., resulting in reduced survival and heightened larval arrest/lethality, alongside a noticeable decrease in DAPI-stained bivalent structures and disrupted meiotic progression, thus disrupting developmental processes. Notably, Torenia sp. extracts activated a DNA damage checkpoint response via the ATM/ATR and CHK-1 pathways, hindering germline development. LC-MS analysis revealed 13 compounds in the Torenia sp. extracts, including flavonoids, terpenoids, tanshinones, an analog of resveratrol, iridoids, carotenoids, fatty acids, and alkaloids. Of these, 10 are known for their antitumor activity, suggesting the potential of Torenia species beyond traditional gardening, extending into pharmaceutical and therapeutic applications.
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Affiliation(s)
- Qinghao Meng
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China
| | - Robert P. Borris
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China
| | - Hyun-Min Kim
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan 215316, China
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6
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Meng Q, Pathak N, Ren X, Borris RP, Kim HM. Exploring the Impact of Onobrychis cornuta and Veratrum lobelianum Extracts on C. elegans: Implications for MAPK Modulation, Germline Development, and Antitumor Properties. Nutrients 2023; 16:8. [PMID: 38201838 PMCID: PMC10780469 DOI: 10.3390/nu16010008] [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: 10/13/2023] [Revised: 12/12/2023] [Accepted: 12/14/2023] [Indexed: 01/12/2024] Open
Abstract
In an era of increasing interest in the potential health benefits of medicinal foods, the need to assess their safety and potential toxicity remains a critical concern. While these natural remedies have garnered substantial attention for their therapeutic potential, a comprehensive understanding of their effects on living organisms is essential. We examined 316 herbal extracts to determine their potential nematocidal attributes in Caenorhabditis elegans. Approximately 16% of these extracts exhibited the capacity to induce diminished survival rates and larval arrest, establishing a correlation between larval arrest and overall worm viability. Certain extracts led to an unexpected increase in male nematodes, accompanied by a discernible reduction in DAPI-stained bivalent structures and perturbed meiotic advancement, thereby disrupting the conventional developmental processes. Notably, Onobrychis cornuta and Veratrum lobelianum extracts activated a DNA damage checkpoint response via the ATM/ATR and CHK-1 pathways, thus hindering germline development. Our LC-MS analysis revealed jervine in V. lobelianum and nine antitumor compounds in O. cornuta. Interestingly, linoleic acid replicated phenotypes induced by O. cornuta exposure, including an increased level of pCHK-1 foci, apoptosis, and the MAPK pathway. Mutants in the MAPK pathway mitigated the decline in worm survival, underscoring its importance in promoting worm viability. This study reveals complex interactions between herbal extracts and C. elegans processes, shedding light on potential antitumor effects and mechanisms. The findings provide insights into the complex landscape of herbal medicine's impact on a model organism, offering implications for broader applications.
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Affiliation(s)
- Qinghao Meng
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; (Q.M.); (N.P.); (R.P.B.)
| | - Nishit Pathak
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; (Q.M.); (N.P.); (R.P.B.)
| | - Xiaojing Ren
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; (Q.M.); (N.P.); (R.P.B.)
| | - Robert P. Borris
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; (Q.M.); (N.P.); (R.P.B.)
| | - Hyun-Min Kim
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan 215316, China
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7
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Yang Q, Lo TW, Brejc K, Schartner C, Ralston EJ, Lapidus DM, Meyer BJ. X-chromosome target specificity diverged between dosage compensation mechanisms of two closely related Caenorhabditis species. eLife 2023; 12:e85413. [PMID: 36951246 PMCID: PMC10076027 DOI: 10.7554/elife.85413] [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: 12/07/2022] [Accepted: 03/21/2023] [Indexed: 03/24/2023] Open
Abstract
An evolutionary perspective enhances our understanding of biological mechanisms. Comparison of sex determination and X-chromosome dosage compensation mechanisms between the closely related nematode species Caenorhabditis briggsae (Cbr) and Caenorhabditis elegans (Cel) revealed that the genetic regulatory hierarchy controlling both processes is conserved, but the X-chromosome target specificity and mode of binding for the specialized condensin dosage compensation complex (DCC) controlling X expression have diverged. We identified two motifs within Cbr DCC recruitment sites that are highly enriched on X: 13 bp MEX and 30 bp MEX II. Mutating either MEX or MEX II in an endogenous recruitment site with multiple copies of one or both motifs reduced binding, but only removing all motifs eliminated binding in vivo. Hence, DCC binding to Cbr recruitment sites appears additive. In contrast, DCC binding to Cel recruitment sites is synergistic: mutating even one motif in vivo eliminated binding. Although all X-chromosome motifs share the sequence CAGGG, they have otherwise diverged so that a motif from one species cannot function in the other. Functional divergence was demonstrated in vivo and in vitro. A single nucleotide position in Cbr MEX can determine whether Cel DCC binds. This rapid divergence of DCC target specificity could have been an important factor in establishing reproductive isolation between nematode species and contrasts dramatically with the conservation of target specificity for X-chromosome dosage compensation across Drosophila species and for transcription factors controlling developmental processes such as body-plan specification from fruit flies to mice.
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Affiliation(s)
- Qiming Yang
- Howard Hughes Medical InstituteBerkeleyUnited States
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Te-Wen Lo
- Howard Hughes Medical InstituteBerkeleyUnited States
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Katjuša Brejc
- Howard Hughes Medical InstituteBerkeleyUnited States
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Caitlin Schartner
- Howard Hughes Medical InstituteBerkeleyUnited States
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Edward J Ralston
- Howard Hughes Medical InstituteBerkeleyUnited States
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Denise M Lapidus
- Howard Hughes Medical InstituteBerkeleyUnited States
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Barbara J Meyer
- Howard Hughes Medical InstituteBerkeleyUnited States
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
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8
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Combinatorial clustering of distinct DNA motifs directs synergistic binding of Caenorhabditis elegans dosage compensation complex to X chromosomes. Proc Natl Acad Sci U S A 2022; 119:e2211642119. [PMID: 36067293 PMCID: PMC9477397 DOI: 10.1073/pnas.2211642119] [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] [Indexed: 11/23/2022] Open
Abstract
Diverse regulatory mechanisms balance X-chromosome gene expression between sexes in mammals, fruit flies, and nematodes (XY/XO males and XX females/hermaphrodites). We identify DNA motifs on X that recruit dosage compensation complexes (DCCs) in nematode hermaphrodites to reduce X-chromosome expression. Recruitment sites on X, but not regions on autosomes, contain diverse combinations of different motifs or multiple copies of one motif. DCC binding studies in vivo and in vitro of wild-type and mutant X-recruitment sites validate motif usage. We find that clustering of motifs in different combinations with appropriate orientation and spacing promotes synergy in DCC binding, thereby triggering DCC assembly specifically along X. We demonstrate how regulatory complexes can be recruited across an entire chromosome to control its gene expression. Organisms that count X-chromosome number to determine sex utilize dosage compensation mechanisms to balance X-gene expression between sexes. Typically, a regulatory complex is recruited to X chromosomes of one sex to modulate gene expression. A major challenge is to determine the mechanisms that target regulatory complexes specifically to X. Here, we identify critical X-sequence motifs in Caenorhabditis elegans that act synergistically in hermaphrodites to direct X-specific recruitment of the dosage compensation complex (DCC), a condensin complex. We find two DNA motifs that collaborate with a previously defined 12-bp motif called MEX (motif enriched on X) to mediate binding: MEX II, a 26-bp X-enriched motif and Motif C, a 9-bp motif that lacks X enrichment. Inserting both MEX and MEX II into a new location on X creates a DCC binding site equivalent to an endogenous recruitment site, but inserting only MEX or MEX II alone does not. Moreover, mutating MEX, MEX II, or Motif C in endogenous recruitment sites with multiple different motifs dramatically reduces DCC binding in vivo to nearly the same extent as mutating all motifs. Changing the orientation or spacing of motifs also reduces DCC binding. Hence, synergy in DCC binding via combinatorial clustering of motifs triggers DCC assembly specifically on X chromosomes. Using an in vitro DNA binding assay, we refine the features of motifs and flanking sequences that are critical for DCC binding. Our work reveals general principles by which regulatory complexes can be recruited across an entire chromosome to control its gene expression.
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9
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Wang Y, Wu L, Yuen KWY. The roles of transcription, chromatin organisation and chromosomal processes in holocentromere establishment and maintenance. Semin Cell Dev Biol 2022; 127:79-89. [PMID: 35042676 DOI: 10.1016/j.semcdb.2022.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 01/09/2022] [Accepted: 01/09/2022] [Indexed: 12/15/2022]
Abstract
The centromere is a unique functional region on each eukaryotic chromosome where the kinetochore assembles and orchestrates microtubule attachment and chromosome segregation. Unlike monocentromeres that occupy a specific region on the chromosome, holocentromeres are diffused along the length of the chromosome. Despite being less common, holocentromeres have been verified in almost 800 nematode, insect, and plant species. Understanding of the molecular and epigenetic regulation of holocentromeres is lagging that of monocentromeres. Here we review how permissive locations for holocentromeres are determined across the genome, potentially by chromatin organisation, transcription, and non-coding RNAs, specifically in the nematode C. elegans. In addition, we discuss how holocentric CENP-A or CENP-T-containing nucleosomes are recruited and deposited, through the help of histone chaperones, licensing factors, and condensin complexes, both during de novo holocentromere establishment, and in each mitotic cell cycle. The process of resolving sister centromeres after DNA replication in holocentric organisms is also mentioned. Conservation and diversity between holocentric and monocentric organisms are highlighted, and outstanding questions are proposed.
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Affiliation(s)
- Yue Wang
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Lillian Wu
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong; Epigenetics and Genome Stability Team, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom
| | - Karen Wing Yee Yuen
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong.
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10
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Senaratne AP, Cortes-Silva N, Drinnenberg IA. Evolution of holocentric chromosomes: Drivers, diversity, and deterrents. Semin Cell Dev Biol 2022; 127:90-99. [PMID: 35031207 DOI: 10.1016/j.semcdb.2022.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/14/2021] [Accepted: 01/05/2022] [Indexed: 02/06/2023]
Abstract
Centromeres are specialized chromosomal regions that recruit kinetochore proteins and mediate spindle microtubule attachment to ensure faithful chromosome segregation during mitosis and meiosis. Centromeres can be restricted to one region of the chromosome. Named "monocentromere", this type represents the most commonly found centromere organization across eukaryotes. Alternatively, centromeres can also be assembled at sites chromosome-wide. This second type is called "holocentromere". Despite their early description over 100 years ago, research on holocentromeres has lagged behind that of monocentromeres. Nevertheless, the application of next generation sequencing approaches and advanced microscopic technologies enabled recent advances understanding the molecular organization and regulation of holocentromeres in different organisms. Here we review the current state of research on holocentromeres focusing on evolutionary considerations. First, we provide a brief historical perspective on the discovery of holocentric chromosomes. We then discuss models/drivers that have been proposed over the years to explain the evolutionary transition from mono- to holocentric chromosomes. We continue to review the description of holocentric chromosomes in diverse eukaryotic groups and then focus our discussion on a specific and recently characterized type of holocentromere organization in insects that functions independently of the otherwise essential centromeric marker protein CenH3, thus providing novel insights into holocentromere evolution in insects. Finally, we propose reasons to explain why the holocentric trait is not more frequent across eukaryotes despite putative selective advantages.
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Affiliation(s)
| | - Nuria Cortes-Silva
- Wellcome Trust/Cancer Research UK Gurdon Institute, Tennis Court Road, Cambridge CB2 1QN, UK; Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Ines A Drinnenberg
- Institut Curie, PSL Research University, CNRS, UMR3664, F-75005 Paris, France; Sorbonne Université, Institut Curie, CNRS, UMR3664, F-75005 Paris, France.
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11
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Odiba AS, Ezechukwu CS, Liao G, Li S, Chen Z, Liu X, Fang W, Jin C, Wang B. Loss of NSE-4 Perturbs Genome Stability and DNA Repair in Caenorhabditis elegans. Int J Mol Sci 2022; 23:ijms23137202. [PMID: 35806213 PMCID: PMC9266361 DOI: 10.3390/ijms23137202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/15/2022] [Accepted: 05/24/2022] [Indexed: 02/04/2023] Open
Abstract
The Structural Maintenance of Chromosomes (SMC) complex plays an important role in maintaining chromosome integrity, in which the SMC5/6 complex occupies a central position by facilitating mitotic and meiotic processes as well as DNA repair. NSE-4 Kleisin is critical for both the organization and function of the SMC5/6 complex, bridging NSE1 and NSE3 (MAGE related) with the head domains of the SMC5 and SMC6 proteins. Despite the conservation in protein sequence, no functional relevance of the NSE-4 homologous protein (NSE-4) in Caenorhabditis elegans has been reported. Here, we demonstrated the essential role of C. elegans NSE-4 in genome maintenance and DNA repair. Our results showed that NSE-4 is essential for the maintenance of chromosomal structure and repair of a range of chemically induced DNA damage. Furthermore, NSE-4 is involved in inter-sister repair during meiosis. NSE-4 localizes on the chromosome and is indispensable for the localization of NSE-1. Collectively, our data from this study provide further insight into the evolutionary conservation and diversification of NSE-4 function in the SMC-5/6 complex.
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Affiliation(s)
- Arome Solomon Odiba
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- Department of Genetics and Biotechnology, University of Nigeria, Nsukka 410001, Nigeria
| | - Chiemekam Samuel Ezechukwu
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
- Department of Zoology and Environmental Biology, University of Nigeria, Nsukka 410001, Nigeria
| | - Guiyan Liao
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
- Correspondence: (G.L.); (B.W.)
| | - Siqiao Li
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
| | - Zhongliang Chen
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Z.C.); (X.L.)
| | - Xihui Liu
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Z.C.); (X.L.)
| | - Wenxia Fang
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
| | - Cheng Jin
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bin Wang
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Z.C.); (X.L.)
- Correspondence: (G.L.); (B.W.)
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12
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Xu R, Zhou S, Song J, Zhong H, Zhu T, Gong Y, Zhou Y, Bian Y. Comparative Transcriptome Analysis Provides Insights Into the Mechanism by Which 2,4-Dichlorophenoxyacetic Acid Improves Thermotolerance in Lentinula edodes. Front Microbiol 2022; 13:910255. [PMID: 35801117 PMCID: PMC9253865 DOI: 10.3389/fmicb.2022.910255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/31/2022] [Indexed: 12/02/2022] Open
Abstract
As the widest cultivated edible mushroom worldwide, Lentinula edodes suffers serious yield and quality losses from heat stress during growth and development, and in our previous study, exogenous 2,4-Dichlorophenoxyacetic acid (2,4-D) was found to improve the thermotolerance of L. edodes strain YS3357, but the molecular mechanism remains unclear. Here, we explored the potential protective mechanism of exogenous 2,4-D against heat stress by transcriptome analysis. 2,4-D possible improve the thermotolerance of L. edodes through regulating antioxidant genes, transcription factors, energy-provision system, membrane fluidity, and cell wall remodeling. Furthermore, 2,4-D was also found to regulate the saturation levels of fatty acids and ATP content in L. edodes mycelium under heat stress. This study proposed a regulatory network of 2,4-D in regulating L. edodes response to heat stress, providing a theoretical basis for improving L. edodes thermotolerance, and facilitating the understanding of the molecular mechanism of exogenous hormones in alleviating abiotic stress damage to macrofungi.
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13
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Meyer BJ. The X chromosome in C. elegans sex determination and dosage compensation. Curr Opin Genet Dev 2022; 74:101912. [PMID: 35490475 DOI: 10.1016/j.gde.2022.101912] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/17/2022] [Accepted: 03/24/2022] [Indexed: 11/16/2022]
Abstract
Abnormalities in chromosome dose can reduce organismal fitness and viability by disrupting the balance of gene expression. Unlike imbalances in chromosome dose that cause pathologies, differences in X-chromosome dose that determine sex are well tolerated. Dosage compensation mechanisms have evolved in diverse species to balance X-chromosome gene expression between sexes. Mechanisms underlying nematode X-chromosome counting to determine sex revealed how small quantitative differences in molecular signals are translated into dramatically different developmental fates. Mechanisms underlying X-chromosome dosage compensation revealed the interplay between chromatin modification and three-dimensional chromosome structure imposed by an X-specific condensin complex to regulate gene expression over vast chromosomal territories. In a surprising twist of evolution, this dosage-compensation condensin complex also regulates lifespan and tolerance to proteotoxic stress.
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Affiliation(s)
- Barbara J Meyer
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, 16 Barker Hall, Berkeley, CA 94720-3204, USA.
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14
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Davis MB, Jash E, Chawla B, Haines RA, Tushman LE, Troll R, Csankovszki G. Dual roles for nuclear RNAi Argonautes in Caenorhabditis elegans dosage compensation. Genetics 2022; 221:6540857. [PMID: 35234908 PMCID: PMC9071528 DOI: 10.1093/genetics/iyac033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 02/21/2022] [Indexed: 11/14/2022] Open
Abstract
Dosage compensation involves chromosome-wide gene regulatory mechanisms which impact higher order chromatin structure and are crucial for organismal health. Using a genetic approach, we identified Argonaute genes which promote dosage compensation in Caenorhabditis elegans. Dosage compensation in C. elegans hermaphrodites is initiated by the silencing of xol-1 and subsequent activation of the dosage compensation complex which binds to both hermaphrodite X chromosomes and reduces transcriptional output by half. A hallmark phenotype of dosage compensation mutants is decondensation of the X chromosomes. We characterized this phenotype in Argonaute mutants using X chromosome paint probes and fluorescence microscopy. We found that while nuclear Argonaute mutants hrde-1 and nrde-3, as well as mutants for the piRNA Argonaute prg-1, exhibit derepression of xol-1 transcripts, they also affect X chromosome condensation in a xol-1-independent manner. We also characterized the physiological contribution of Argonaute genes to dosage compensation using genetic assays and found that hrde-1 and nrde-3 contribute to healthy dosage compensation both upstream and downstream of xol-1.
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Affiliation(s)
- Michael B Davis
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Eshna Jash
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Bahaar Chawla
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Rebecca A Haines
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lillian E Tushman
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ryan Troll
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Györgyi Csankovszki
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA,Corresponding author: Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 1105 N. University Ave, Ann Arbor, MI 48109-1085, USA.
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15
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Breimann L, Morao AK, Kim J, Sebastian Jimenez D, Maryn N, Bikkasani K, Carrozza MJ, Albritton SE, Kramer M, Street LA, Cerimi K, Schumann VF, Bahry E, Preibisch S, Woehler A, Ercan S. The histone H4 lysine 20 demethylase DPY-21 regulates the dynamics of condensin DC binding. J Cell Sci 2022; 135:jcs258818. [PMID: 34918745 PMCID: PMC8917352 DOI: 10.1242/jcs.258818] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 11/29/2021] [Indexed: 11/26/2022] Open
Abstract
Condensin is a multi-subunit structural maintenance of chromosomes (SMC) complex that binds to and compacts chromosomes. Here, we addressed the regulation of condensin binding dynamics using Caenorhabditis elegans condensin DC, which represses X chromosomes in hermaphrodites for dosage compensation. We established fluorescence recovery after photobleaching (FRAP) using the SMC4 homolog DPY-27 and showed that a well-characterized ATPase mutation abolishes DPY-27 binding to X chromosomes. Next, we performed FRAP in the background of several chromatin modifier mutants that cause varying degrees of X chromosome derepression. The greatest effect was in a null mutant of the H4K20me2 demethylase DPY-21, where the mobile fraction of condensin DC reduced from ∼30% to 10%. In contrast, a catalytic mutant of dpy-21 did not regulate condensin DC mobility. Hi-C sequencing data from the dpy-21 null mutant showed little change compared to wild-type data, uncoupling Hi-C-measured long-range DNA contacts from transcriptional repression of the X chromosomes. Taken together, our results indicate that DPY-21 has a non-catalytic role in regulating the dynamics of condensin DC binding, which is important for transcription repression.
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Affiliation(s)
- Laura Breimann
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 10115 Berlin, Germany
- Institute for Biology, Humboldt University of Berlin, 10099 Berlin, Germany
| | - Ana Karina Morao
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - Jun Kim
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - David Sebastian Jimenez
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - Nina Maryn
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - Krishna Bikkasani
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - Michael J. Carrozza
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - Sarah E. Albritton
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - Maxwell Kramer
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - Lena Annika Street
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - Kustrim Cerimi
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 10115 Berlin, Germany
| | - Vic-Fabienne Schumann
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 10115 Berlin, Germany
| | - Ella Bahry
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 10115 Berlin, Germany
| | - Stephan Preibisch
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 10115 Berlin, Germany
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Andrew Woehler
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 10115 Berlin, Germany
| | - Sevinç Ercan
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, 10115 Berlin, Germany
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16
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Meyer BJ. Mechanisms of sex determination and X-chromosome dosage compensation. Genetics 2022; 220:6498458. [PMID: 35100381 PMCID: PMC8825453 DOI: 10.1093/genetics/iyab197] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 10/25/2021] [Indexed: 12/03/2022] Open
Abstract
Abnormalities in chromosome number have the potential to disrupt the balance of gene expression and thereby decrease organismal fitness and viability. Such abnormalities occur in most solid tumors and also cause severe developmental defects and spontaneous abortions. In contrast to the imbalances in chromosome dose that cause pathologies, the difference in X-chromosome dose used to determine sexual fate across diverse species is well tolerated. Dosage compensation mechanisms have evolved in such species to balance X-chromosome gene expression between the sexes, allowing them to tolerate the difference in X-chromosome dose. This review analyzes the chromosome counting mechanism that tallies X-chromosome number to determine sex (XO male and XX hermaphrodite) in the nematode Caenorhabditis elegans and the associated dosage compensation mechanism that balances X-chromosome gene expression between the sexes. Dissecting the molecular mechanisms underlying X-chromosome counting has revealed how small quantitative differences in intracellular signals can be translated into dramatically different fates. Dissecting the process of X-chromosome dosage compensation has revealed the interplay between chromatin modification and chromosome structure in regulating gene expression over vast chromosomal territories.
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Affiliation(s)
- Barbara J Meyer
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720-3204, USA
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17
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Kim J, Jimenez DS, Ragipani B, Zhang B, Street LA, Kramer M, Albritton SE, Winterkorn LH, Morao AK, Ercan S. Condensin DC loads and spreads from recruitment sites to create loop-anchored TADs in C. elegans. eLife 2022; 11:68745. [PMID: 36331876 PMCID: PMC9635877 DOI: 10.7554/elife.68745] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 10/23/2022] [Indexed: 11/06/2022] Open
Abstract
Condensins are molecular motors that compact DNA via linear translocation. In Caenorhabditis elegans, the X-chromosome harbors a specialized condensin that participates in dosage compensation (DC). Condensin DC is recruited to and spreads from a small number of recruitment elements on the X-chromosome (rex) and is required for the formation of topologically associating domains (TADs). We take advantage of autosomes that are largely devoid of condensin DC and TADs to address how rex sites and condensin DC give rise to the formation of TADs. When an autosome and X-chromosome are physically fused, despite the spreading of condensin DC into the autosome, no TAD was created. Insertion of a strong rex on the X-chromosome results in the TAD boundary formation regardless of sequence orientation. When the same rex is inserted on an autosome, despite condensin DC recruitment, there was no spreading or features of a TAD. On the other hand, when a 'super rex' composed of six rex sites or three separate rex sites are inserted on an autosome, recruitment and spreading of condensin DC led to the formation of TADs. Therefore, recruitment to and spreading from rex sites are necessary and sufficient for recapitulating loop-anchored TADs observed on the X-chromosome. Together our data suggest a model in which rex sites are both loading sites and bidirectional barriers for condensin DC, a one-sided loop-extruder with movable inactive anchor.
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Affiliation(s)
- Jun Kim
- Department of Biology and Center for Genomics and Systems Biology, New York UniversityNew YorkUnited States
| | - David S Jimenez
- Department of Biology and Center for Genomics and Systems Biology, New York UniversityNew YorkUnited States
| | - Bhavana Ragipani
- Department of Biology and Center for Genomics and Systems Biology, New York UniversityNew YorkUnited States
| | - Bo Zhang
- UCSF HSWSan FranciscoUnited States
| | - Lena A Street
- Department of Biology and Center for Genomics and Systems Biology, New York UniversityNew YorkUnited States
| | - Maxwell Kramer
- Department of Biology and Center for Genomics and Systems Biology, New York UniversityNew YorkUnited States
| | - Sarah E Albritton
- Department of Biology and Center for Genomics and Systems Biology, New York UniversityNew YorkUnited States
| | - Lara H Winterkorn
- Department of Biology and Center for Genomics and Systems Biology, New York UniversityNew YorkUnited States
| | - Ana K Morao
- Department of Biology and Center for Genomics and Systems Biology, New York UniversityNew YorkUnited States
| | - Sevinc Ercan
- Department of Biology and Center for Genomics and Systems Biology, New York UniversityNew YorkUnited States
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18
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Yin Y, Liu Q, Shao Y, He X, Zhu Q, Lu S, Liu P. Regulatory mechanism of androgen receptor on NCAPD3 gene expression in prostate cancer. Prostate 2022; 82:26-40. [PMID: 34591337 DOI: 10.1002/pros.24245] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 07/24/2021] [Accepted: 07/30/2021] [Indexed: 12/17/2022]
Abstract
BACKGROUND Androgen receptor (AR) is an essential transcriptional factor that contributes to the development and progression of prostate cancer (PCa). NCAPD3 is a component of the condensin II complex and plays a critical role in cell mitosis by regulating chromosome condensation; however, the relationship between NCAPD3 and AR remains unknown. METHODS Transcriptome sequencing assay is carried out to analyze the expression of the NCAP family in clinic samples. Chromatin immunoprecipitation (ChIP) sequencing, ChIP assay, and dual-luciferase assay are used to identify the androgen-responsive element in NCAPD3 enhancer. Immunohistochemistry, quantitative reverse transcription-polymerase chain reaction, and western-blot assay are employed to check the expression of genes in PCa tissues and in PCa cells. Confocal immunofluorescence microscopy analysis is used for identifying the regulation of AR on NCAPD3-mediated chromosome condensation. Colony formation, cell cycle assay, wound healing assay, and transwell experiments are used to explore the regulation of AR on the functions of NCAPD3. In vivo experiment is employed to identify in vitro experimental results. RESULTS NCAPD3 is an androgen/AR axis-targeted gene and is involved in AR-induced PCa cell proliferation, migration, and invasion in vitro and in vivo. Androgen treatment and AR overexpression increase the expression of NCAPD3 in PCa cell lines. The canonical exist in the enhancer region of NCAPD3. Androgen/AR axis regulates NCAPD3-invovled chromosome condensation during cell mitosis. CONCLUSIONS Our report demonstrated that NCAPD3 is an androgen-responsive gene and upregulated by androgen/AR axis and involved in AR-promoted progression of PCa, suggesting a potential role of NCAPD3 in the PCa development.
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Affiliation(s)
- Yingying Yin
- Department of Biochemistry,Jiangsu Province Key Laboratory for Molecular and Medicine Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Qianmei Liu
- Department of Biochemistry,Jiangsu Province Key Laboratory for Molecular and Medicine Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Yingying Shao
- Department of Biochemistry,Jiangsu Province Key Laboratory for Molecular and Medicine Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Xinyuan He
- Department of Biochemistry,Jiangsu Province Key Laboratory for Molecular and Medicine Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Qingyi Zhu
- Department of Urology Surgery, Central Laboratory, Jiangsu Province Hospital of Chinese Medicine, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Shan Lu
- Department of Biochemistry,Jiangsu Province Key Laboratory for Molecular and Medicine Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Ping Liu
- Department of Biochemistry,Jiangsu Province Key Laboratory for Molecular and Medicine Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
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19
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Wenda JM, Prosée RF, Gabus C, Steiner FA. Mitotic chromosome condensation requires phosphorylation of the centromeric protein KNL-2 in C. elegans. J Cell Sci 2021; 134:272713. [PMID: 34734636 PMCID: PMC8714079 DOI: 10.1242/jcs.259088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 10/25/2021] [Indexed: 11/20/2022] Open
Abstract
Centromeres are chromosomal regions that serve as sites for kinetochore formation and microtubule attachment, processes that are essential for chromosome segregation during mitosis. Centromeres are almost universally defined by the histone variant CENP-A. In the holocentric nematode C. elegans, CENP-A deposition depends on the loading factor KNL-2. Depletion of either CENP-A or KNL-2 results in defects in centromere maintenance, chromosome condensation and kinetochore formation, leading to chromosome segregation failure. Here, we show that KNL-2 is phosphorylated by CDK-1 in vitro, and that mutation of three C-terminal phosphorylation sites causes chromosome segregation defects and an increase in embryonic lethality. In strains expressing phosphodeficient KNL-2, CENP-A and kinetochore proteins are properly localised, indicating that the role of KNL-2 in centromere maintenance is not affected. Instead, the mutant embryos exhibit reduced mitotic levels of condensin II on chromosomes and significant chromosome condensation impairment. Our findings separate the functions of KNL-2 in CENP-A loading and chromosome condensation, and demonstrate that KNL-2 phosphorylation regulates the cooperation between centromeric regions and the condensation machinery in C. elegans. This article has an associated First Person interview with the first author of the paper. Summary: Phosphorylation of the essential centromere protein KNL-2 is required for mitotic chromosome condensation, but not for the role of KNL-2 in centromere maintenance and kinetochore formation.
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Affiliation(s)
- Joanna M Wenda
- Department of Molecular Biology and Institute for Genetics and Genomics in Geneva, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland
| | - Reinier F Prosée
- Department of Molecular Biology and Institute for Genetics and Genomics in Geneva, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland
| | - Caroline Gabus
- Department of Molecular Biology and Institute for Genetics and Genomics in Geneva, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland
| | - Florian A Steiner
- Department of Molecular Biology and Institute for Genetics and Genomics in Geneva, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland
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20
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Abstract
Nuclei are central hubs for information processing in eukaryotic cells. The need to fit large genomes into small nuclei imposes severe restrictions on genome organization and the mechanisms that drive genome-wide regulatory processes. How a disordered polymer such as chromatin, which has vast heterogeneity in its DNA and histone modification profiles, folds into discernibly consistent patterns is a fundamental question in biology. Outstanding questions include how genomes are spatially and temporally organized to regulate cellular processes with high precision and whether genome organization is causally linked to transcription regulation. The advent of next-generation sequencing, super-resolution imaging, multiplexed fluorescent in situ hybridization, and single-molecule imaging in individual living cells has caused a resurgence in efforts to understand the spatiotemporal organization of the genome. In this review, we discuss structural and mechanistic properties of genome organization at different length scales and examine changes in higher-order chromatin organization during important developmental transitions.
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Affiliation(s)
- Rajarshi P Ghosh
- Department of Molecular and Cell Biology and Howard Hughes Medical Institute, University of California, Berkeley, California 94720, USA; ,
| | - Barbara J Meyer
- Department of Molecular and Cell Biology and Howard Hughes Medical Institute, University of California, Berkeley, California 94720, USA; ,
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21
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Lin Z, Yuen KWY. RbAp46/48LIN-53 and HAT-1 are required for initial CENP-AHCP-3 deposition and de novo holocentromere formation on artificial chromosomes in Caenorhabditis elegans embryos. Nucleic Acids Res 2021; 49:9154-9173. [PMID: 33872374 PMCID: PMC8450102 DOI: 10.1093/nar/gkab217] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 03/10/2021] [Accepted: 03/23/2021] [Indexed: 12/17/2022] Open
Abstract
Foreign DNA microinjected into the Caenorhabditis elegans syncytial gonad forms episomal extra-chromosomal arrays, or artificial chromosomes (ACs), in embryos. Short, linear DNA fragments injected concatemerize into high molecular weight (HMW) DNA arrays that are visible as punctate DAPI-stained foci in oocytes, and they undergo chromatinization and centromerization in embryos. The inner centromere, inner kinetochore and spindle checkpoint components, including AIR-2, CENP-AHCP-3, Mis18BP1KNL-2 and BUB-1, respectively, assemble onto the nascent ACs during the first mitosis. The DNA replication efficiency of ACs improves over several cell cycles, which correlates with the improvement of kinetochore bi-orientation and proper segregation of ACs. Depletion of condensin II subunits, like CAPG-2 and SMC-4, but not the replicative helicase component, MCM-2, reduces de novo CENP-AHCP-3 level on nascent ACs. Furthermore, H3K9ac, H4K5ac and H4K12ac are highly enriched on newly chromatinized ACs. RbAp46/48LIN-53 and HAT-1, which affect the acetylation of histone H3 and H4, are essential for chromatinization, de novo centromere formation and segregation competency of nascent ACs. RbAp46/48LIN-53 or HAT-1 depletion causes the loss of both CENP-AHCP-3 and Mis18BP1KNL-2 initial deposition at de novo centromeres on ACs. This phenomenon is different from centromere maintenance on endogenous chromosomes, where Mis18BP1KNL-2 functions upstream of RbAp46/48LIN-53.
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Affiliation(s)
- Zhongyang Lin
- School of Biological Sciences, The University of Hong Kong. Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Karen Wing Yee Yuen
- School of Biological Sciences, The University of Hong Kong. Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
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22
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Paulson JR, Hudson DF, Cisneros-Soberanis F, Earnshaw WC. Mitotic chromosomes. Semin Cell Dev Biol 2021; 117:7-29. [PMID: 33836947 PMCID: PMC8406421 DOI: 10.1016/j.semcdb.2021.03.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/23/2021] [Accepted: 03/23/2021] [Indexed: 01/25/2023]
Abstract
Our understanding of the structure and function of mitotic chromosomes has come a long way since these iconic objects were first recognized more than 140 years ago, though many details remain to be elucidated. In this chapter, we start with the early history of chromosome studies and then describe the path that led to our current understanding of the formation and structure of mitotic chromosomes. We also discuss some of the remaining questions. It is now well established that each mitotic chromatid consists of a central organizing region containing a so-called "chromosome scaffold" from which loops of DNA project radially. Only a few key non-histone proteins and protein complexes are required to form the chromosome: topoisomerase IIα, cohesin, condensin I and condensin II, and the chromokinesin KIF4A. These proteins are concentrated along the axis of the chromatid. Condensins I and II are primarily responsible for shaping the chromosome and the scaffold, and they produce the loops of DNA by an ATP-dependent process known as loop extrusion. Modelling of Hi-C data suggests that condensin II adopts a spiral staircase arrangement with an extruded loop extending out from each step in a roughly helical pattern. Condensin I then forms loops nested within these larger condensin II loops, thereby giving rise to the final compaction of the mitotic chromosome in a process that requires Topo IIα.
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Affiliation(s)
- James R Paulson
- Department of Chemistry, University of Wisconsin Oshkosh, 800 Algoma Boulevard, Oshkosh, WI 54901, USA.
| | - Damien F Hudson
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, VIC 3052, Australia
| | - Fernanda Cisneros-Soberanis
- Wellcome Trust Centre for Cell Biology, ICB, University of Edinburgh, Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, ICB, University of Edinburgh, Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK.
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23
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Farboud B, Novak CS, Nicoll M, Quiogue A, Meyer BJ. Dose-dependent action of the RNA binding protein FOX-1 to relay X-chromosome number and determine C. elegans sex. eLife 2020; 9:62963. [PMID: 33372658 PMCID: PMC7787662 DOI: 10.7554/elife.62963] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/23/2020] [Indexed: 12/25/2022] Open
Abstract
We demonstrate how RNA binding protein FOX-1 functions as a dose-dependent X-signal element to communicate X-chromosome number and thereby determine nematode sex. FOX-1, an RNA recognition motif protein, triggers hermaphrodite development in XX embryos by causing non-productive alternative pre-mRNA splicing of xol-1, the master sex-determination switch gene that triggers male development in XO embryos. RNA binding experiments together with genome editing demonstrate that FOX-1 binds to multiple GCAUG and GCACG motifs in a xol-1 intron, causing intron retention or partial exon deletion, thereby eliminating male-determining XOL-1 protein. Transforming all motifs to GCAUG or GCACG permits accurate alternative splicing, demonstrating efficacy of both motifs. Mutating subsets of both motifs partially alleviates non-productive splicing. Mutating all motifs blocks it, as does transforming them to low-affinity GCUUG motifs. Combining multiple high-affinity binding sites with the twofold change in FOX-1 concentration between XX and XO embryos achieves dose-sensitivity in splicing regulation to determine sex.
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Affiliation(s)
- Behnom Farboud
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, United States.,Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, United States
| | - Catherine S Novak
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, United States.,Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, United States
| | - Monique Nicoll
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, United States.,Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, United States
| | - Alyssa Quiogue
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, United States.,Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, United States
| | - Barbara J Meyer
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, United States.,Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, United States
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Herbette M, Robert V, Bailly A, Gely L, Feil R, Llères D, Palladino F. A Role for Caenorhabditis elegans COMPASS in Germline Chromatin Organization. Cells 2020; 9:cells9092049. [PMID: 32911802 PMCID: PMC7565041 DOI: 10.3390/cells9092049] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/02/2020] [Accepted: 09/03/2020] [Indexed: 02/07/2023] Open
Abstract
Deposition of histone H3 lysine 4 (H3K4) methylation at promoters is catalyzed by the SET1/COMPASS complex and is associated with context-dependent effects on gene expression and local changes in chromatin organization. The role of SET1/COMPASS in shaping chromosome architecture has not been investigated. Here we used Caenorhabditis elegans to address this question through a live imaging approach and genetic analysis. Using quantitative FRET (Förster resonance energy transfer)-based fluorescence lifetime imaging microscopy (FLIM) on germ cells expressing histones eGFP-H2B and mCherry-H2B, we find that SET1/COMPASS influences meiotic chromosome organization, with marked effects on the close proximity between nucleosomes. We further show that inactivation of set-2, encoding the C. elegans SET1 homologue, or CFP-1, encoding the chromatin targeting subunit of COMPASS, enhances germline chromosome organization defects and sterility of condensin-II depleted animals. set-2 loss also aggravates germline defects resulting from conditional inactivation of topoisomerase II, another structural component of chromosomes. Expression profiling of set-2 mutant germlines revealed only minor transcriptional changes, suggesting that the observed effects are at least partly independent of transcription. Altogether, our results are consistent with a role for SET1/COMPASS in shaping meiotic chromosomes in C. elegans, together with the non-histone proteins condensin-II and topoisomerase. Given the high degree of conservation, our findings expand the range of functions attributed to COMPASS and suggest a broader role in genome organization in different species.
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Affiliation(s)
- Marion Herbette
- Laboratory of Biology and Modeling of the Cell (LBMC), CNRS, Ecole Normale Supérieure de Lyon, Université de Lyon, 69007 Lyon, France; (M.H.); (V.R.); (L.G.)
| | - Valérie Robert
- Laboratory of Biology and Modeling of the Cell (LBMC), CNRS, Ecole Normale Supérieure de Lyon, Université de Lyon, 69007 Lyon, France; (M.H.); (V.R.); (L.G.)
| | - Aymeric Bailly
- Centre de Recherche en Biologie cellulaire de Montpellier, CRBM, CNRS, University of Montpellier, 34090 Montpellier, France;
| | - Loïc Gely
- Laboratory of Biology and Modeling of the Cell (LBMC), CNRS, Ecole Normale Supérieure de Lyon, Université de Lyon, 69007 Lyon, France; (M.H.); (V.R.); (L.G.)
| | - Robert Feil
- Institute of Molecular Genetics of Montpellier (IGMM), CNRS, University of Montpellier, 34090 Montpellier, France; (R.F.); (D.L.)
| | - David Llères
- Institute of Molecular Genetics of Montpellier (IGMM), CNRS, University of Montpellier, 34090 Montpellier, France; (R.F.); (D.L.)
| | - Francesca Palladino
- Laboratory of Biology and Modeling of the Cell (LBMC), CNRS, Ecole Normale Supérieure de Lyon, Université de Lyon, 69007 Lyon, France; (M.H.); (V.R.); (L.G.)
- Correspondence: ; Tel.: +33-047-2728-126
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Kleinschnitz K, Vießmann N, Jordan M, Heidmann SK. Condensin I is required for faithful meiosis in Drosophila males. Chromosoma 2020; 129:141-160. [PMID: 32314039 PMCID: PMC7260282 DOI: 10.1007/s00412-020-00733-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 02/17/2020] [Accepted: 02/20/2020] [Indexed: 01/03/2023]
Abstract
The heteropentameric condensin complexes play vital roles in the formation and faithful segregation of mitotic chromosomes in eukaryotes. While the different contributions of the two common condensin complexes, condensin I and condensin II, to chromosome morphology and behavior in mitosis have been thoroughly investigated, much less is known about the specific roles of the two complexes during meiotic divisions. In Drosophila melanogaster, faithful mitotic divisions depend on functional condensin I, but not on condensin II. However, meiotic divisions in Drosophila males require functional condensin II subunits. The role of condensin I during male meiosis in Drosophila has been unresolved. Here, we show that condensin I-specific subunits localize to meiotic chromatin in both meiosis I and II during Drosophila spermatogenesis. Live cell imaging reveals defects during meiotic divisions after RNAi-mediated knockdown of condensin I-specific mRNAs. This phenotype correlates with reduced male fertility and an increase in nondisjunction events both in meiosis I and meiosis II. Consistently, a reduction in male fertility was also observed after proteasome-mediated degradation of the condensin I subunit Barren. Taken together, our results demonstrate an essential role of condensin I during male meiosis in Drosophila melanogaster.
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Affiliation(s)
| | - Nina Vießmann
- Lehrstuhl für Genetik, University of Bayreuth, Bayreuth, Germany
| | - Mareike Jordan
- Lehrstuhl für Genetik, University of Bayreuth, Bayreuth, Germany
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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VanDiepenbos S, Csankovszki G. Difference in phenotypic severity of presumed null alleles of capg-1. MICROPUBLICATION BIOLOGY 2020; 2020:10.17912/micropub.biology.000245. [PMID: 32550486 PMCID: PMC7252267 DOI: 10.17912/micropub.biology.000245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Affiliation(s)
- Sarah VanDiepenbos
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109 USA
| | - Györgyi Csankovszki
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109 USA,
Correspondence to: Györgyi Csankovszki ()
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Beseda T, Cápal P, Kubalová I, Schubert V, Doležel J, Šimková H. Mitotic chromosome organization: General rules meet species-specific variability. Comput Struct Biotechnol J 2020; 18:1311-1319. [PMID: 32612754 PMCID: PMC7305364 DOI: 10.1016/j.csbj.2020.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/13/2020] [Accepted: 01/16/2020] [Indexed: 10/31/2022] Open
Abstract
Research on the formation of mitotic chromosomes from interphase chromatin domains, ongoing for several decades, made significant progress in recent years. It was stimulated by the development of advanced microscopic techniques and implementation of chromatin conformation capture methods that provide new insights into chromosome ultrastructure. This review aims to summarize and compare several models of chromatin fiber folding to form mitotic chromosomes and discusses them in the light of the novel findings. Functional genomics studies in several organisms confirmed condensins and cohesins as the major players in chromosome condensation. Here we compare available data on the role of these proteins across lower and higher eukaryotes and point to differences indicating evolutionary different pathways to shape mitotic chromosomes. Moreover, we discuss a controversial phenomenon of the mitotic chromosome ultrastructure - chromosome cavities - and using our super-resolution microscopy data, we contribute to its elucidation.
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Affiliation(s)
- Tomáš Beseda
- Institute of Experimental Botany, Czech Acad. Sci., Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, CZ-77900 Olomouc, Czech Republic
| | - Petr Cápal
- Institute of Experimental Botany, Czech Acad. Sci., Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, CZ-77900 Olomouc, Czech Republic
| | - Ivona Kubalová
- The Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Corrensstrasse 3, D-06466 Seeland, Germany
| | - Veit Schubert
- The Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Corrensstrasse 3, D-06466 Seeland, Germany
| | - Jaroslav Doležel
- Institute of Experimental Botany, Czech Acad. Sci., Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, CZ-77900 Olomouc, Czech Republic
| | - Hana Šimková
- Institute of Experimental Botany, Czech Acad. Sci., Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, CZ-77900 Olomouc, Czech Republic
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Street LA, Morao AK, Winterkorn LH, Jiao CY, Albritton SE, Sadic M, Kramer M, Ercan S. Binding of an X-Specific Condensin Correlates with a Reduction in Active Histone Modifications at Gene Regulatory Elements. Genetics 2019; 212:729-742. [PMID: 31123040 PMCID: PMC6614895 DOI: 10.1534/genetics.119.302254] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 05/20/2019] [Indexed: 12/13/2022] Open
Abstract
Condensins are evolutionarily conserved protein complexes that are required for chromosome segregation during cell division and genome organization during interphase. In Caenorhabditis elegans, a specialized condensin, which forms the core of the dosage compensation complex (DCC), binds to and represses X chromosome transcription. Here, we analyzed DCC localization and the effect of DCC depletion on histone modifications, transcription factor binding, and gene expression using chromatin immunoprecipitation sequencing and mRNA sequencing. Across the X, the DCC accumulates at accessible gene regulatory sites in active chromatin and not heterochromatin. The DCC is required for reducing the levels of activating histone modifications, including H3K4me3 and H3K27ac, but not repressive modification H3K9me3. In X-to-autosome fusion chromosomes, DCC spreading into the autosomal sequences locally reduces gene expression, thus establishing a direct link between DCC binding and repression. Together, our results indicate that DCC-mediated transcription repression is associated with a reduction in the activity of X chromosomal gene regulatory elements.
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Affiliation(s)
- Lena Annika Street
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York 10003
| | - Ana Karina Morao
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York 10003
| | - Lara Heermans Winterkorn
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York 10003
| | - Chen-Yu Jiao
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York 10003
| | | | - Mohammed Sadic
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York 10003
| | - Maxwell Kramer
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York 10003
| | - Sevinç Ercan
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York 10003
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29
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Spindle assembly and chromosome dynamics during oocyte meiosis. Curr Opin Cell Biol 2019; 60:53-59. [PMID: 31082633 DOI: 10.1016/j.ceb.2019.03.014] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/18/2019] [Accepted: 03/20/2019] [Indexed: 12/26/2022]
Abstract
Organisms that reproduce sexually utilize a specialized form of cell division called meiosis to reduce their chromosome number by half to generate haploid gametes. Meiosis in females is especially error-prone, and this vulnerability has a profound impact on human health: it is estimated that 10-25% of human embryos are chromosomally abnormal, and the vast majority of these defects arise from problems with the female reproductive cells (oocytes). Here, we highlight recent studies that explore how these important cells divide. Although we focus on work in the model organism Caenorhabditis elegans, we also discuss complementary studies in other organisms that together provide new insights into this crucial form of cell division.
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30
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Abstract
Condensins and cohesins are highly conserved complexes that tether together DNA loci within a single DNA molecule to produce DNA loops. Condensin and cohesin structures, however, are different, and the DNA loops produced by each underlie distinct cell processes. Condensin rods compact chromosomes during mitosis, with condensin I and II complexes producing spatially defined and nested looping in metazoan cells. Structurally adaptive cohesin rings produce loops, which organize the genome during interphase. Cohesin-mediated loops, termed topologically associating domains or TADs, antagonize the formation of epigenetically defined but untethered DNA volumes, termed compartments. While condensin complexes formed through cis-interactions must maintain chromatin compaction throughout mitosis, cohesins remain highly dynamic during interphase to allow for transcription-mediated responses to external cues and the execution of developmental programs. Here, I review differences in condensin and cohesin structures, and highlight recent advances regarding the intramolecular or cis-based tetherings through which condensins compact DNA during mitosis and cohesins organize the genome during interphase.
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Affiliation(s)
- Robert V Skibbens
- Department of Biological Sciences, 111 Research Drive, Lehigh University, Bethlehem, PA 18015, USA
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31
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Meyer BJ. Sex and death: from cell fate specification to dynamic control of X-chromosome structure and gene expression. Mol Biol Cell 2018; 29:2616-2621. [PMID: 30376434 PMCID: PMC6249838 DOI: 10.1091/mbc.e18-06-0397] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Determining sex is a binary developmental decision that most metazoans must make. Like many organisms, Caenorhabditis elegans specifies sex (XO male or XX hermaphrodite) by tallying X-chromosome number. We dissected this precise counting mechanism to determine how tiny differences in concentrations of signals are translated into dramatically different developmental fates. Determining sex by counting chromosomes solved one problem but created another-an imbalance in X gene products. We found that nematodes compensate for the difference in X-chromosome dose between sexes by reducing transcription from both hermaphrodite X chromosomes. In a surprising feat of evolution, X-chromosome regulation is functionally related to a structural problem of all mitotic and meiotic chromosomes: achieving ordered compaction of chromosomes before segregation. We showed the dosage compensation complex is a condensin complex that imposes a specific three--dimensional architecture onto hermaphrodite X chromosomes. It also triggers enrichment of histone modification H4K20me1. We discovered the machinery and mechanism underlying H4K20me1 enrichment and demonstrated its pivotal role in regulating higher-order X-chromosome structure and gene expression.
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Affiliation(s)
- Barbara J. Meyer
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3204,*Address correspondence to: Barbara J. Meyer ()
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32
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Condensin action and compaction. Curr Genet 2018; 65:407-415. [PMID: 30361853 DOI: 10.1007/s00294-018-0899-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 10/18/2018] [Accepted: 10/20/2018] [Indexed: 12/20/2022]
Abstract
Condensin is a multi-subunit protein complex that belongs to the family of structural maintenance of chromosomes (SMC) complexes. Condensins regulate chromosome structure in a wide range of processes including chromosome segregation, gene regulation, DNA repair and recombination. Recent research defined the structural features and molecular activities of condensins, but it is unclear how these activities are connected to the multitude of phenotypes and functions attributed to condensins. In this review, we briefly discuss the different molecular mechanisms by which condensins may regulate global chromosome compaction, organization of topologically associated domains, clustering of specific loci such as tRNA genes, rDNA segregation, and gene regulation.
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Davis-Roca AC, Divekar NS, Ng RK, Wignall SM. Dynamic SUMO remodeling drives a series of critical events during the meiotic divisions in Caenorhabditis elegans. PLoS Genet 2018; 14:e1007626. [PMID: 30180169 PMCID: PMC6138424 DOI: 10.1371/journal.pgen.1007626] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/14/2018] [Accepted: 08/13/2018] [Indexed: 11/19/2022] Open
Abstract
Chromosome congression and segregation in C. elegans oocytes depend on a complex of conserved proteins that forms a ring around the center of each bivalent during prometaphase; these complexes are then removed from chromosomes at anaphase onset and disassemble as anaphase proceeds. Here, we uncover mechanisms underlying the dynamic regulation of these ring complexes (RCs), revealing a strategy by which protein complexes can be progressively remodeled during cellular processes. We find that the assembly, maintenance, and stability of RCs is regulated by a balance between SUMO conjugating and deconjugating activity. During prometaphase, the SUMO protease ULP-1 is targeted to the RCs but is counteracted by SUMO E2/E3 enzymes; then in early anaphase the E2/E3 enzymes are removed, enabling ULP-1 to trigger RC disassembly and completion of the meiotic divisions. Moreover, we found that SUMO regulation is essential to properly connect the RCs to the chromosomes and then also to fully release them in anaphase. Altogether, our work demonstrates that dynamic remodeling of SUMO modifications facilitates key meiotic events and highlights how competition between conjugation and deconjugation activity can modulate SUMO homeostasis, protein complex stability, and ultimately, progressive processes such as cell division. Most cells have two sets of chromosomes, one from each parent. Meiosis is a specialized form of cell division where chromosomes are duplicated once and segregated twice, in order to generate eggs (oocytes) or sperm with only one copy of every chromosome. This is necessary so that fertilization will produce an embryo that once again contains two complete copies of the genome. Using C. elegans as a model system, we have uncovered regulatory mechanisms important for the fidelity of these meiotic divisions. C. elegans oocytes use a kinetochore-independent chromosome segregation mechanism that relies on a large protein complex that localizes to the chromosomes. These protein complexes facilitate chromosome congression during metaphase and then are released from chromosomes in anaphase and progressively disassemble as the chromosomes segregate. We find that the stability and disassembly of these complexes is regulated by a protein modification called SUMO and by competition between enzymes that localize to the protein complex to either add or remove SUMO modifications. These findings provide insight into the mechanisms by which SUMO and SUMO enzymes regulate progression through cell division and illustrate a general strategy by which large protein complexes can be rapidly assembled and disassembled during dynamic cellular processes.
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Affiliation(s)
- Amanda C. Davis-Roca
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
| | - Nikita S. Divekar
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
| | - Rachel K. Ng
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
| | - Sarah M. Wignall
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
- * E-mail:
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Hernandez MR, Davis MB, Jiang J, Brouhard EA, Severson AF, Csankovszki G. Condensin I protects meiotic cohesin from WAPL-1 mediated removal. PLoS Genet 2018; 14:e1007382. [PMID: 29768402 PMCID: PMC5973623 DOI: 10.1371/journal.pgen.1007382] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 05/29/2018] [Accepted: 04/27/2018] [Indexed: 11/22/2022] Open
Abstract
Condensin complexes are key determinants of higher-order chromatin structure and are required for mitotic and meiotic chromosome compaction and segregation. We identified a new role for condensin in the maintenance of sister chromatid cohesion during C. elegans meiosis. Using conventional and stimulated emission depletion (STED) microscopy we show that levels of chromosomally-bound cohesin were significantly reduced in dpy-28 mutants, which lack a subunit of condensin I. SYP-1, a component of the synaptonemal complex central region, was also diminished, but no decrease in the axial element protein HTP-3 was observed. Surprisingly, the two key meiotic cohesin complexes of C. elegans were both depleted from meiotic chromosomes following the loss of condensin I, and disrupting condensin I in cohesin mutants increased the frequency of detached sister chromatids. During mitosis and meiosis in many organisms, establishment of cohesion is antagonized by cohesin removal by Wapl, and we found that condensin I binds to C. elegans WAPL-1 and counteracts WAPL-1-dependent cohesin removal. Our data suggest that condensin I opposes WAPL-1 to promote stable binding of cohesin to meiotic chromosomes, thereby ensuring linkages between sister chromatids in early meiosis.
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Affiliation(s)
- Margarita R. Hernandez
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States of America
| | - Michael B. Davis
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States of America
| | - Jianhao Jiang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States of America
| | - Elizabeth A. Brouhard
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States of America
| | - Aaron F. Severson
- Center for Gene Regulation in Health and Disease and Department of Biological, Geological and Environmental Sciences, Cleveland State University, Cleveland, OH, United States of America
| | - Györgyi Csankovszki
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States of America
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35
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Bian Q, Anderson EC, Brejc K, Meyer BJ. Dynamic Control of Chromosome Topology and Gene Expression by a Chromatin Modification. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2018; 82:279-291. [PMID: 29472317 PMCID: PMC6041165 DOI: 10.1101/sqb.2017.82.034439] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The function of chromatin modification in establishing higher-order chromosome structure during gene regulation has been elusive. We dissected the machinery and mechanism underlying the enrichment of histone modification H4K20me1 on hermaphrodite X chromosomes during Caenorhabditis elegans dosage compensation and discovered a key role for H4K20me1 in regulating X-chromosome topology and chromosome-wide gene expression. Structural and functional analysis of the dosage compensation complex (DCC) subunit DPY-21 revealed a novel Jumonji C demethylase subfamily that converts H4K20me2 to H4K20me1 in worms and mammals. Inactivation of demethylase activity in vivo by genome editing eliminated H4K20me1 enrichment on X chromosomes of somatic cells, increased X-linked gene expression, reduced X-chromosome compaction, and disrupted X-chromosome conformation by diminishing the formation of topologically associated domains. H4K20me1 is also enriched on the inactive X of female mice, making our studies directly relevant to mammalian development. Unexpectedly, DPY-21 also associates specifically with autosomes of nematode germ cells in a DCC-independent manner to enrich H4K20me1 and trigger chromosome compaction. Thus, DPY-21 is an adaptable chromatin regulator. Its H4K20me2 demethylase activity can be harnessed during development for distinct biological functions by targeting it to diverse genomic locations through different mechanisms. In both somatic cells and germ cells, H4K20me1 enrichment modulates three-dimensional chromosome architecture, demonstrating the direct link between chromatin modification and higher-order chromosome structure.
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Affiliation(s)
- Qian Bian
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3204
| | - Erika C Anderson
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3204
| | - Katjuša Brejc
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3204
| | - Barbara J Meyer
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3204
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Quantitative FLIM-FRET Microscopy to Monitor Nanoscale Chromatin Compaction In Vivo Reveals Structural Roles of Condensin Complexes. Cell Rep 2017; 18:1791-1803. [PMID: 28199849 DOI: 10.1016/j.celrep.2017.01.043] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 12/21/2016] [Accepted: 01/19/2017] [Indexed: 01/03/2023] Open
Abstract
How metazoan genomes are structured at the nanoscale in living cells and tissues remains unknown. Here, we adapted a quantitative FRET (Förster resonance energy transfer)-based fluorescence lifetime imaging microscopy (FLIM) approach to assay nanoscale chromatin compaction in living organisms. Caenorhabditis elegans was chosen as a model system. By measuring FRET between histone-tagged fluorescent proteins, we visualized distinct chromosomal regions and quantified the different levels of nanoscale compaction in meiotic cells. Using RNAi and repetitive extrachromosomal array approaches, we defined the heterochromatin state and showed that its architecture presents a nanoscale-compacted organization controlled by Heterochromatin Protein-1 (HP1) and SETDB1 H3-lysine-9 methyltransferase homologs in vivo. Next, we functionally explored condensin complexes. We found that condensin I and condensin II are essential for heterochromatin compaction and that condensin I additionally controls lowly compacted regions. Our data show that, in living animals, nanoscale chromatin compaction is controlled not only by histone modifiers and readers but also by condensin complexes.
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37
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Chatterjee RN. Dosage compensation and its roles in evolution of sex chromosomes and phenotypic dimorphism: lessons from Drosophila, C.elegans and mammals. THE NUCLEUS 2017. [DOI: 10.1007/s13237-017-0223-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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Albritton SE, Ercan S. Caenorhabditis elegans Dosage Compensation: Insights into Condensin-Mediated Gene Regulation. Trends Genet 2017; 34:41-53. [PMID: 29037439 DOI: 10.1016/j.tig.2017.09.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 09/19/2017] [Accepted: 09/25/2017] [Indexed: 01/05/2023]
Abstract
Recent work demonstrating the role of chromosome organization in transcriptional regulation has sparked substantial interest in the molecular mechanisms that control chromosome structure. Condensin, an evolutionarily conserved multisubunit protein complex, is essential for chromosome condensation during cell division and functions in regulating gene expression during interphase. In Caenorhabditis elegans, a specialized condensin forms the core of the dosage compensation complex (DCC), which specifically binds to and represses transcription from the hermaphrodite X chromosomes. DCC serves as a clear paradigm for addressing how condensins target large chromosomal domains and how they function to regulate chromosome structure and transcription. Here, we discuss recent research on C. elegans DCC in the context of canonical condensin mechanisms as have been studied in various organisms.
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Affiliation(s)
- Sarah Elizabeth Albritton
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - Sevinç Ercan
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA.
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Albritton SE, Kranz AL, Winterkorn LH, Street LA, Ercan S. Cooperation between a hierarchical set of recruitment sites targets the X chromosome for dosage compensation. eLife 2017; 6. [PMID: 28562241 PMCID: PMC5451215 DOI: 10.7554/elife.23645] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 05/02/2017] [Indexed: 12/17/2022] Open
Abstract
In many organisms, it remains unclear how X chromosomes are specified for dosage compensation, since DNA sequence motifs shown to be important for dosage compensation complex (DCC) recruitment are themselves not X-specific. Here, we addressed this problem in C. elegans. We found that the DCC recruiter, SDC-2, is required to maintain open chromatin at a small number of primary DCC recruitment sites, whose sequence and genomic context are X-specific. Along the X, primary recruitment sites are interspersed with secondary sites, whose function is X-dependent. A secondary site can ectopically recruit the DCC when additional recruitment sites are inserted either in tandem or at a distance (>30 kb). Deletion of a recruitment site on the X results in reduced DCC binding across several megabases surrounded by topologically associating domain (TAD) boundaries. Our work elucidates that hierarchy and long-distance cooperativity between gene-regulatory elements target a single chromosome for regulation. DOI:http://dx.doi.org/10.7554/eLife.23645.001 The DNA inside living cells is organized in structures called chromosomes. In many animals, females have two X chromosomes, whereas males have only one. To ensure that females do not end up with a double dose of the proteins encoded by the genes on the X chromosome, animals use a process called dosage compensation to correct this imbalance. The mechanisms underlying this process vary between species, but they typically involve a regulatory complex that binds to the X chromosomes of one sex to modify gene expression. Caenorhabditis elegans, for example, is a species of nematode worm in which individuals with two X chromosomes are hermaphrodites and those with one X chromosome are males. In C. elegans, a regulatory complex, called the dosage compensation complex, attaches to both X chromosomes of a hermaphrodite, and reduces the expression of the genes on each by half to match the level seen in the males. Previous research has shown that short DNA sequences, known as motifs, recruit the dosage compensation complex to the X chromosomes. However, these sequences are also found on the other chromosomes and, until now, it was not known why the complex was only recruited to the X chromosomes. Albritton et al. now show the X chromosomes have a ‘hierarchical’ recruitment system. A few sites on the X chromosomes contain clusters of a specific DNA motif, which initiate the process and attract the dosage compensation complex more strongly than other sites. These ‘strong’ recruitment sites are placed across the length of the X chromosomes and cooperate with several ‘weaker’ ones located in between. This way, multiple recruitment sites can cooperate over a long distance, while non-sex chromosomes, which have only one or two stronger recruitment sites, do not have thisadvantage. Hierarchy and cooperativity may be general features of gene expression, in which proteins are targeted to chromosomes without the need for having specific motifs at every recruitment site. The way DNA sequences are distributed across the genome may give us clues about their role. Thus, knowing how genomes are structured will help us identify disrupted areas in diseases such as cancer. DOI:http://dx.doi.org/10.7554/eLife.23645.002
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Affiliation(s)
- Sarah Elizabeth Albritton
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, United States
| | - Anna-Lena Kranz
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, United States
| | - Lara Heermans Winterkorn
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, United States
| | - Lena Annika Street
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, United States
| | - Sevinc Ercan
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, United States
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Abstract
Sexual reproduction requires the production of haploid gametes (sperm and egg) with only one copy of each chromosome; fertilization then restores the diploid chromosome content in the next generation. This reduction in genetic content is accomplished during a specialized cell division called meiosis, in which two rounds of chromosome segregation follow a single round of DNA replication. In preparation for the first meiotic division, homologous chromosomes pair and synapse, creating a context that promotes formation of crossover recombination events. These crossovers, in conjunction with sister chromatid cohesion, serve to connect the two homologs and facilitate their segregation to opposite poles during the first meiotic division. During the second meiotic division, which is similar to mitosis, sister chromatids separate; the resultant products are haploid cells that become gametes. In Caenorhabditis elegans (and most other eukaryotes) homologous pairing and recombination are required for proper chromosome inheritance during meiosis; accordingly, the events of meiosis are tightly coordinated to ensure the proper execution of these events. In this chapter, we review the seminal events of meiosis: pairing of homologous chromosomes, the changes in chromosome structure that chromosomes undergo during meiosis, the events of meiotic recombination, the differentiation of homologous chromosome pairs into structures optimized for proper chromosome segregation at Meiosis I, and the ultimate segregation of chromosomes during the meiotic divisions. We also review the regulatory processes that ensure the coordinated execution of these meiotic events during prophase I.
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Affiliation(s)
- Kenneth J Hillers
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, United States
| | - Verena Jantsch
- Department of Chromosome Biology, Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter,1030 Vienna, Austria
| | | | - Judith L Yanowitz
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, United States
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Zhan P, Xi G, Zhang B, Wu Y, Liu H, Liu Y, Xu W, Zhu Q, Cai F, Zhou Z, Miu Y, Wang X, Jin J, Li Q, Lv T, Song Y. NCAPG2 promotes tumour proliferation by regulating G2/M phase and associates with poor prognosis in lung adenocarcinoma. J Cell Mol Med 2017; 21:665-676. [PMID: 27862966 PMCID: PMC5345611 DOI: 10.1111/jcmm.13010] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 09/19/2016] [Indexed: 12/22/2022] Open
Abstract
NCAPG2 is a component of the condensin II complex and contributes to chromosome segregation via microtubule-kinetochore attachment during mitosis. It is well known that NCAPG2 plays a critical role in cell mitosis; however, the role of altered NCAPG2 expression and its transcriptional regulatory function in cancer development remains mostly unknown. Here, for the first time we reported that NCAPG2 was evidently increased in non-small cell lung cancer tissues compared to adjacent normal lung tissues. Clinicopathological data analysis showed that NCAPG2 overexpression was significantly correlated with lymph node metastasis and pathologic-Tumour Nodes Metastasen stages, and was an independent prognostic factor in lung adenocarcinoma patients. Moreover, siRNA-mediated knockdown of NCAPG2 could inhibit tumour cell growth of lung adenocarcinoma cells (A549 and H1299) in vitro and could significantly lead to cell cycle arrest in the G2 phase. Furthermore, we found that NCAPG2 silencing significantly decreased the expression levels of G2/M phase cell cycle-related protein expressions (Cyclin B1, Cdc2) and increased the expression levels of p27 and p21 through Western blot analysis. Taken together, we demonstrated that increased NCAPG2 expression could regulate cell proliferation and identified as a poor prognostic biomarker in lung adenocarcinoma.
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Affiliation(s)
- Ping Zhan
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
- Department of Respiratory MedicineNanjing Chest HospitalMedical School of Southeast UniversityNanjingChina
| | - Guang‐min Xi
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
| | - Bin Zhang
- Department of GastroenterologyThe Affiliated Drum Tower Hospital of Nanjing University, Medical SchoolNanjingJiangsuChina
| | - Ying Wu
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
| | - Hong‐bing Liu
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
| | - Ya‐fang Liu
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
| | - Wu‐jian Xu
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
| | - Qingqing Zhu
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
| | - Feng Cai
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
| | - Ze‐jun Zhou
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
| | - Ying‐ying Miu
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
| | - Xiao‐xia Wang
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
| | - Jia‐jia Jin
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
| | - Qian Li
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
| | - Tang‐feng Lv
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
| | - Yong Song
- Department of Respiratory MedicineJinling HospitalNanjing University School of MedicineNanjingChina
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An SMC-like protein binds and regulates Caenorhabditis elegans condensins. PLoS Genet 2017; 13:e1006614. [PMID: 28301465 PMCID: PMC5373644 DOI: 10.1371/journal.pgen.1006614] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 03/30/2017] [Accepted: 02/01/2017] [Indexed: 01/17/2023] Open
Abstract
Structural Maintenance of Chromosomes (SMC) family proteins participate in multisubunit complexes that govern chromosome structure and dynamics. SMC-containing condensin complexes create chromosome topologies essential for mitosis/meiosis, gene expression, recombination, and repair. Many eukaryotes have two condensin complexes (I and II); C. elegans has three (I, II, and the X-chromosome specialized condensin IDC) and their regulation is poorly understood. Here we identify a novel SMC-like protein, SMCL-1, that binds to C. elegans condensin SMC subunits, and modulates condensin functions. Consistent with a possible role as a negative regulator, loss of SMCL-1 partially rescued the lethal and sterile phenotypes of a hypomorphic condensin mutant, while over-expression of SMCL-1 caused lethality, chromosome mis-segregation, and disruption of condensin IDC localization on X chromosomes. Unlike canonical SMC proteins, SMCL-1 lacks hinge and coil domains, and its ATPase domain lacks conserved amino acids required for ATP hydrolysis, leading to the speculation that it may inhibit condensin ATPase activity. SMCL-1 homologs are apparent only in the subset of Caenorhabditis species in which the condensin I and II subunit SMC-4 duplicated to create the condensin IDC- specific subunit DPY-27, suggesting that SMCL-1 helps this lineage cope with the regulatory challenges imposed by evolution of a third condensin complex. Our findings uncover a new regulator of condensins and highlight how the duplication and divergence of SMC complex components in various lineages has created new proteins with diverse functions in chromosome dynamics.
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43
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Condensin, master organizer of the genome. Chromosome Res 2017; 25:61-76. [PMID: 28181049 DOI: 10.1007/s10577-017-9553-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 12/19/2016] [Accepted: 01/23/2017] [Indexed: 02/06/2023]
Abstract
A fundamental requirement in nature is for a cell to correctly package and divide its replicated genome. Condensin is a mechanical multisubunit complex critical to this process. Condensin uses ATP to power conformational changes in DNA to enable to correct DNA compaction, organization, and segregation of DNA from the simplest bacteria to humans. The highly conserved nature of the condensin complex and the structural similarities it shares with the related cohesin complex have provided important clues as to how it functions in cells. The fundamental requirement for condensin in mitosis and meiosis is well established, yet the precise mechanism of action is still an open question. Mutation or removal of condensin subunits across a range of species disrupts orderly chromosome condensation leading to errors in chromosome segregation and likely death of the cell. There are divergences in function across species for condensin. Once considered to function solely in mitosis and meiosis, an accumulating body of evidence suggests that condensin has key roles in also regulating the interphase genome. This review will examine how condensin organizes our genomes, explain where and how it binds the genome at a mechanical level, and highlight controversies and future directions as the complex continues to fascinate and baffle biologists.
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44
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Rana V, Bosco G. Condensin Regulation of Genome Architecture. J Cell Physiol 2017; 232:1617-1625. [PMID: 27888504 DOI: 10.1002/jcp.25702] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 11/22/2016] [Indexed: 02/06/2023]
Abstract
Condensin complexes exist across all domains of life and are central to the structure and organization of chromatin. As architectural proteins, condensins control chromatin compaction during interphase and mitosis. Condensin activity has been well studied in mitosis but have recently emerged as important regulators of genome organization and gene expression during interphase. Here, we focus our discussion on recent findings on the molecular mechanism and how condensins are used to shape chromosomes during interphase. These findings suggest condensin activity during interphase is required for proper chromosome organization. J. Cell. Physiol. 232: 1617-1625, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Vibhuti Rana
- Department of Molecular Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
| | - Giovanni Bosco
- Department of Molecular Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
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Roles of SMC Complexes During T Lymphocyte Development and Function. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017; 106:17-42. [DOI: 10.1016/bs.apcsb.2016.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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46
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Lau AC, Zhu KP, Brouhard EA, Davis MB, Csankovszki G. An H4K16 histone acetyltransferase mediates decondensation of the X chromosome in C. elegans males. Epigenetics Chromatin 2016; 9:44. [PMID: 27777629 PMCID: PMC5070013 DOI: 10.1186/s13072-016-0097-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/05/2016] [Indexed: 02/08/2023] Open
Abstract
Background In C. elegans, in order to equalize gene expression between the sexes and balance X and autosomal expression, two steps are believed to be required. First, an unknown mechanism is hypothesized to upregulate the X chromosome in both sexes. This mechanism balances the X to autosomal expression in males, but creates X overexpression in hermaphrodites. Therefore, to restore the balance, hermaphrodites downregulate gene expression twofold on both X chromosomes. While many studies have focused on X chromosome downregulation, the mechanism of X upregulation is not known. Results To gain more insight into X upregulation, we studied the effects of chromatin condensation and histone acetylation on gene expression levels in male C. elegans. We have found that the H4K16 histone acetyltransferase MYS-1/Tip60 mediates dramatic decondensation of the male X chromosome as measured by FISH. However, RNA-seq analysis revealed that MYS-1 contributes only slightly to upregulation of gene expression on the X chromosome. These results suggest that the level of chromosome decondensation does not necessarily correlate with the degree of gene expression change in vivo. Furthermore, the X chromosome is more sensitive to MYS-1-mediated decondensation than the autosomes, despite similar levels of H4K16ac on all chromosomes, as measured by ChIP-seq. H4K16ac levels weakly correlate with gene expression levels on both the X and the autosomes, but highly expressed genes on the X chromosome do not contain exceptionally high levels of H4K16ac. Conclusion These results indicate that H4K16ac and chromosome decondensation influence regulation of the male X chromosome; however, they do not fully account for the high levels of gene expression observed on the X chromosomes. Electronic supplementary material The online version of this article (doi:10.1186/s13072-016-0097-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alyssa C Lau
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N. University Ave., Ann Arbor, MI 48109-1048 USA ; Genome Technologies, The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032 USA
| | - Kevin P Zhu
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N. University Ave., Ann Arbor, MI 48109-1048 USA
| | - Elizabeth A Brouhard
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N. University Ave., Ann Arbor, MI 48109-1048 USA
| | - Michael B Davis
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N. University Ave., Ann Arbor, MI 48109-1048 USA
| | - Györgyi Csankovszki
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, 830 N. University Ave., Ann Arbor, MI 48109-1048 USA
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Snyder MJ, Lau AC, Brouhard EA, Davis MB, Jiang J, Sifuentes MH, Csankovszki G. Anchoring of Heterochromatin to the Nuclear Lamina Reinforces Dosage Compensation-Mediated Gene Repression. PLoS Genet 2016; 12:e1006341. [PMID: 27690361 PMCID: PMC5045178 DOI: 10.1371/journal.pgen.1006341] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 09/06/2016] [Indexed: 12/21/2022] Open
Abstract
Higher order chromosome structure and nuclear architecture can have profound effects on gene regulation. We analyzed how compartmentalizing the genome by tethering heterochromatic regions to the nuclear lamina affects dosage compensation in the nematode C. elegans. In this organism, the dosage compensation complex (DCC) binds both X chromosomes of hermaphrodites to repress transcription two-fold, thus balancing gene expression between XX hermaphrodites and XO males. X chromosome structure is disrupted by mutations in DCC subunits. Using X chromosome paint fluorescence microscopy, we found that X chromosome structure and subnuclear localization are also disrupted when the mechanisms that anchor heterochromatin to the nuclear lamina are defective. Strikingly, the heterochromatic left end of the X chromosome is less affected than the gene-rich middle region, which lacks heterochromatic anchors. These changes in X chromosome structure and subnuclear localization are accompanied by small, but significant levels of derepression of X-linked genes as measured by RNA-seq, without any observable defects in DCC localization and DCC-mediated changes in histone modifications. We propose a model in which heterochromatic tethers on the left arm of the X cooperate with the DCC to compact and peripherally relocate the X chromosomes, contributing to gene repression.
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Affiliation(s)
- Martha J. Snyder
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Alyssa C. Lau
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Elizabeth A. Brouhard
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Michael B. Davis
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jianhao Jiang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Margarita H. Sifuentes
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Györgyi Csankovszki
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
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Wheeler BS, Anderson E, Frøkjær-Jensen C, Bian Q, Jorgensen E, Meyer BJ. Chromosome-wide mechanisms to decouple gene expression from gene dose during sex-chromosome evolution. eLife 2016; 5. [PMID: 27572259 PMCID: PMC5047749 DOI: 10.7554/elife.17365] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/29/2016] [Indexed: 11/24/2022] Open
Abstract
Changes in chromosome number impair fitness by disrupting the balance of gene expression. Here we analyze mechanisms to compensate for changes in gene dose that accompanied the evolution of sex chromosomes from autosomes. Using single-copy transgenes integrated throughout the Caenorhabditis elegans genome, we show that expression of all X-linked transgenes is balanced between XX hermaphrodites and XO males. However, proximity of a dosage compensation complex (DCC) binding site (rex site) is neither necessary to repress X-linked transgenes nor sufficient to repress transgenes on autosomes. Thus, X is broadly permissive for dosage compensation, and the DCC acts via a chromosome-wide mechanism to balance transcription between sexes. In contrast, no analogous X-chromosome-wide mechanism balances transcription between X and autosomes: expression of compensated hermaphrodite X-linked transgenes is half that of autosomal transgenes. Furthermore, our results argue against an X-chromosome dosage compensation model contingent upon rex-directed positioning of X relative to the nuclear periphery. DOI:http://dx.doi.org/10.7554/eLife.17365.001 DNA inside cells is packaged into structures called chromosomes, each of which contains numerous genes. Many organisms, including humans, have two copies of most chromosomes in their cells. If the process of cell division goes awry, cells can end up with too many or too few copies of their chromosomes, which can cause serious illnesses. Sex chromosomes pose a conundrum for cells. In humans, females have two copies of the X chromosome, whereas males only have one. This means that males have half the copy number (dose) of genes on the X chromosome. Human cells correct this imbalance by suppressing the activity, or expression, of most of the genes on one of the X chromosomes in females. “Dosage compensation” also occurs in the roundworm species Caenorhabditis elegans, because male worms have one X chromosome whilst hermaphrodites have two. The dosage compensation mechanism in roundworms differs from that in humans. It involves turning down the expression of both hermaphrodite X chromosomes by half. The process is enacted by a dosage compensation complex that binds to specific sites along both hermaphrodite X chromosomes. Dosage compensation mechanisms that reduce X chromosome expression in females cause sex chromosomes to have lower gene expression than non-sex chromosomes. Modern sex chromosomes evolved from a pair of non-sex chromosomes, and males lost one copy of all of the genes located on those ancestral chromosomes. This evolutionary history causes both sexes to have lower gene expression from X chromosomes than the other chromosomes, raising the question of whether a mechanism exists to balance out the difference in gene expression between sex chromosomes and non-sex chromosomes. Wheeler et al. now show that the expression of any foreign gene artificially added to the X chromosomes of C. elegans is equalized between males and hermaphrodites despite the difference in gene dose. The equalization works regardless of where on the X chromosome the new gene is added. The foreign gene does not need to be adjacent to a binding site for the dosage compensation complex. These results indicate that dosage compensation mechanisms regulate gene expression on a chromosome-wide scale. Wheeler et al. also show that genes added to X chromosomes are expressed at half the level as the same genes added to non-sex chromosomes. These results mean that no chromosome-wide mechanism balances gene expression levels between the X chromosome and the non-sex chromosomes. It remains unknown how C. elegans, and many other living organisms, evolved to tolerate a lower level of gene expression from the sex chromosomes. Instead of a chromosome-wide mechanism, it is likely that individual genes evolved different ways to alter their expression levels. Working out what these mechanisms are remains a challenge for further research. DOI:http://dx.doi.org/10.7554/eLife.17365.002
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Affiliation(s)
- Bayly S Wheeler
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | - Erika Anderson
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | - Christian Frøkjær-Jensen
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, United States.,Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - Qian Bian
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | - Erik Jorgensen
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, United States
| | - Barbara J Meyer
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
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Doughty TW, Arsenault HE, Benanti JA. Levels of Ycg1 Limit Condensin Function during the Cell Cycle. PLoS Genet 2016; 12:e1006216. [PMID: 27463097 PMCID: PMC4963108 DOI: 10.1371/journal.pgen.1006216] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Accepted: 07/05/2016] [Indexed: 11/19/2022] Open
Abstract
During mitosis chromosomes are condensed to facilitate their segregation, through a process mediated by the condensin complex. Although several factors that promote maximal condensin activity during mitosis have been identified, the mechanisms that downregulate condensin activity during interphase are largely unknown. Here, we demonstrate that Ycg1, the Cap-G subunit of budding yeast condensin, is cell cycle-regulated with levels peaking in mitosis and decreasing as cells enter G1 phase. This cyclical expression pattern is established by a combination of cell cycle-regulated transcription and constitutive degradation. Interestingly, overexpression of YCG1 and mutations that stabilize Ycg1 each result in delayed cell-cycle entry and an overall proliferation defect. Overexpression of no other condensin subunit impacts the cell cycle, suggesting that Ycg1 is limiting for condensin complex formation. Consistent with this possibility, we find that levels of intact condensin complex are reduced in G1 phase compared to mitosis, and that increased Ycg1 expression leads to increases in both levels of condensin complex and binding to chromatin in G1. Together, these results demonstrate that Ycg1 levels limit condensin function in interphase cells, and suggest that the association of condensin with chromosomes must be reduced following mitosis to enable efficient progression through the cell cycle.
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Affiliation(s)
- Tyler W. Doughty
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Heather E. Arsenault
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Jennifer A. Benanti
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
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50
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Untangling the Contributions of Sex-Specific Gene Regulation and X-Chromosome Dosage to Sex-Biased Gene Expression in Caenorhabditis elegans. Genetics 2016; 204:355-69. [PMID: 27356611 DOI: 10.1534/genetics.116.190298] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 06/27/2016] [Indexed: 01/31/2023] Open
Abstract
Dosage compensation mechanisms equalize the level of X chromosome expression between sexes. Yet the X chromosome is often enriched for genes exhibiting sex-biased, i.e., imbalanced expression. The relationship between X chromosome dosage compensation and sex-biased gene expression remains largely unexplored. Most studies determine sex-biased gene expression without distinguishing between contributions from X chromosome copy number (dose) and the animal's sex. Here, we uncoupled X chromosome dose from sex-specific gene regulation in Caenorhabditis elegans to determine the effect of each on X expression. In early embryogenesis, when dosage compensation is not yet fully active, X chromosome dose drives the hermaphrodite-biased expression of many X-linked genes, including several genes that were shown to be responsible for hermaphrodite fate. A similar effect is seen in the C. elegans germline, where X chromosome dose contributes to higher hermaphrodite X expression, suggesting that lack of dosage compensation in the germline may have a role in supporting higher expression of X chromosomal genes with female-biased functions in the gonad. In the soma, dosage compensation effectively balances X expression between the sexes. As a result, somatic sex-biased expression is almost entirely due to sex-specific gene regulation. These results suggest that lack of dosage compensation in different tissues and developmental stages allow X chromosome copy number to contribute to sex-biased gene expression and function.
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