1
|
Sullivan W. Remarkable chromosomes and karyotypes: A top 10 list. Mol Biol Cell 2024; 35:pe1. [PMID: 38517328 PMCID: PMC11064663 DOI: 10.1091/mbc.e23-12-0498] [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: 12/20/2023] [Revised: 02/23/2024] [Accepted: 03/01/2024] [Indexed: 03/23/2024] Open
Abstract
Chromosomes and karyotypes are particularly rich in oddities and extremes. Described below are 10 remarkable chromosomes and karyotypes sprinkled throughout the tree of life. These include variants in chromosome number, structure, and dynamics both natural and engineered. This versatility highlights the robustness and tolerance of the mitotic and meiotic machinery to dramatic changes in chromosome and karyotype architecture. These examples also illustrate that the robustness comes at a cost, enabling the evolution of chromosomes that subvert mitosis and meiosis.
Collapse
Affiliation(s)
- William Sullivan
- Department of MCD Biology, University of California, Santa Cruz, CA 95064
| |
Collapse
|
2
|
Carmo C, Coelho J, Silva RD, Tavares A, Boavida A, Gaetani P, Guilgur LG, Martinho RG, Oliveira RA. A dual-function SNF2 protein drives chromatid resolution and nascent transcripts removal in mitosis. EMBO Rep 2023; 24:e56463. [PMID: 37462213 PMCID: PMC10481674 DOI: 10.15252/embr.202256463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 06/28/2023] [Accepted: 07/03/2023] [Indexed: 09/07/2023] Open
Abstract
Mitotic chromatin is largely assumed incompatible with transcription due to changes in the transcription machinery and chromosome architecture. However, the mechanisms of mitotic transcriptional inactivation and their interplay with chromosome assembly remain largely unknown. By monitoring ongoing transcription in Drosophila early embryos, we reveal that eviction of nascent mRNAs from mitotic chromatin occurs after substantial chromosome compaction and is not promoted by condensin I. Instead, we show that the timely removal of transcripts from mitotic chromatin is driven by the SNF2 helicase-like protein Lodestar (Lds), identified here as a modulator of sister chromatid cohesion defects. In addition to the eviction of nascent transcripts, we uncover that Lds cooperates with Topoisomerase 2 to ensure efficient sister chromatid resolution and mitotic fidelity. We conclude that the removal of nascent transcripts upon mitotic entry is not a passive consequence of cell cycle progression and/or chromosome compaction but occurs via dedicated mechanisms with functional parallelisms to sister chromatid resolution.
Collapse
Affiliation(s)
| | - João Coelho
- Instituto Gulbenkian de CiênciaOeirasPortugal
| | - Rui D Silva
- Algarve Biomedical Center Research Institute (ABC‐RI) and Faculty of Medicine and Biomedical Sciences (FMCB)Universidade do AlgarveFaroPortugal
| | | | - Ana Boavida
- Instituto Gulbenkian de CiênciaOeirasPortugal
- Present address:
Istituto di Biochimica e Biologia Cellulare, Consiglio Nazionale delle RicercheNaplesItaly
| | | | | | - Rui Gonçalo Martinho
- Algarve Biomedical Center Research Institute (ABC‐RI) and Faculty of Medicine and Biomedical Sciences (FMCB)Universidade do AlgarveFaroPortugal
- Department of Medical Sciences (DCM) and Institute for Biomedicine (iBiMED)Universidade de AveiroAveiroPortugal
| | - Raquel A Oliveira
- Instituto Gulbenkian de CiênciaOeirasPortugal
- Católica Biomedical Research Centre, Católica Medical SchoolUniversidade Católica PortuguesaLisbonPortugal
| |
Collapse
|
3
|
Warecki B, Bast I, Tajima M, Sullivan W. Connections between sister and non-sister telomeres of segregating chromatids maintain euploidy. Curr Biol 2023; 33:58-74.e5. [PMID: 36525974 PMCID: PMC9839490 DOI: 10.1016/j.cub.2022.11.038] [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: 05/04/2022] [Revised: 10/05/2022] [Accepted: 11/17/2022] [Indexed: 12/23/2022]
Abstract
The complete separation of sister chromatids during anaphase is a fundamental requirement for successful mitosis. Therefore, divisions with either persistent DNA-based connections or lagging chromosome fragments threaten aneuploidy if unresolved. Here, we demonstrate the existence of an anaphase mechanism in normally dividing cells in which pervasive connections between telomeres of segregating chromosomes aid in rescuing lagging chromosome fragments. We observe that in a large proportion of Drosophila melanogaster neuronal stem cell divisions, early anaphase sister and non-sister chromatids remain connected by thin telomeric DNA threads. Normally, these threads are resolved in mid-to-late anaphase via a spatial mechanism. However, we find that the presence of a nearby unrepaired DNA break recruits histones, BubR1 kinase, Polo kinase, Aurora B kinase, and BAF to the telomeric thread of the broken chromosome, stabilizing it. Stabilized connections then aid lagging chromosome rescue. These results suggest a model in which pervasive anaphase telomere-telomere connections that are normally resolved quickly can instead be stabilized to retain wayward chromosome fragments. Thus, the liability of persistent anaphase inter-chromosomal connections in normal divisions may be offset by their ability to maintain euploidy in the face of chromosome damage and genome loss.
Collapse
Affiliation(s)
- Brandt Warecki
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA.
| | - Ian Bast
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Matthew Tajima
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
| | - William Sullivan
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
| |
Collapse
|
4
|
The Green Valley of Drosophila melanogaster Constitutive Heterochromatin: Protein-Coding Genes Involved in Cell Division Control. Cells 2022; 11:cells11193058. [PMID: 36231024 PMCID: PMC9563267 DOI: 10.3390/cells11193058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 11/25/2022] Open
Abstract
Constitutive heterochromatin represents a significant fraction of eukaryotic genomes (10% in Arabidopsis, 20% in humans, 30% in D. melanogaster, and up to 85% in certain nematodes) and shares similar genetic and molecular properties in animal and plant species. Studies conducted over the last few years on D. melanogaster and other organisms led to the discovery of several functions associated with constitutive heterochromatin. This made it possible to revise the concept that this ubiquitous genomic territory is incompatible with gene expression. The aim of this review is to focus the attention on a group of protein-coding genes resident in D. melanogaster constitutive of heterochromatin, which are implicated in different steps of cell division.
Collapse
|
5
|
Gerbi SA. Non-random chromosome segregation and chromosome eliminations in the fly Bradysia (Sciara). Chromosome Res 2022; 30:273-288. [PMID: 35793056 PMCID: PMC10777868 DOI: 10.1007/s10577-022-09701-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 05/10/2022] [Accepted: 05/23/2022] [Indexed: 11/03/2022]
Abstract
Mendelian inheritance is based upon random segregation of homologous chromosomes during meiosis and perfect duplication and division of chromosomes in mitosis so that the entire genomic content is passed down to the daughter cells. The unusual chromosome mechanics of the fly Bradysia (previously called Sciara) presents many exceptions to the canonical processes. In male meiosis I, there is a monopolar spindle and non-random segregation such that all the paternal homologs move away from the single pole and are eliminated. In male meiosis II, there is a bipolar spindle and segregation of the sister chromatids except for the X dyad that undergoes non-disjunction. The daughter cell that is nullo-X degenerates, whereas the sperm has two copies of the X. Fertilization restores the diploid state, but there are three copies of the X chromosome, of which one or two of the paternally derived X chromosomes will be eliminated in an early cleavage division. Bradysia (Sciara) coprophila also has germ line limited L chromosomes that are eliminated from the soma. Current information and the molecular mechanisms for chromosome imprinting and eliminations, which are just beginning to be studied, will be reviewed here.
Collapse
Affiliation(s)
- Susan A Gerbi
- Department of Molecular Biology, Cell Biology and Biochemistry, Division of Biology and Medicine, Brown University, 185 Meeting Street, Sidney Frank Hall Room 260, Providence, RI, 02912, USA.
| |
Collapse
|
6
|
Warecki B, Sullivan W. The Cell Biology of Heterochromatin. Cells 2022; 11:cells11071247. [PMID: 35406810 PMCID: PMC8997597 DOI: 10.3390/cells11071247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/30/2021] [Accepted: 01/04/2022] [Indexed: 12/10/2022] Open
Abstract
A conserved feature of virtually all higher eukaryotes is that the centromeres are embedded in heterochromatin. Here we provide evidence that this tight association between pericentric heterochromatin and the centromere is essential for proper metaphase exit and progression into telophase. Analysis of chromosome rearrangements that separate pericentric heterochromatin and centromeres indicates that they must remain associated in order to balance Cohesin/DNA catenation-based binding forces and centromere-based pulling forces during the metaphase–anaphase transition. In addition, a centromere embedded in heterochromatin facilitates nuclear envelope assembly around the entire complement of segregating chromosomes. Because the nuclear envelope initially forms on pericentric heterochromatin, nuclear envelope formation proceeds from the pole, thus providing time for incorporation of lagging and trailing chromosome arms into the newly formed nucleus. Additional analysis of noncanonical mitoses provides further insights into the functional significance of the tight association between heterochromatin and centromeres.
Collapse
|
7
|
Warecki B, Bast I, Sullivan W. Visualizing the Dynamics of Cell Division by Live Imaging Drosophila Larval Brain Squashes. Methods Mol Biol 2022; 2415:37-46. [PMID: 34972944 DOI: 10.1007/978-1-0716-1904-9_3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The dramatic changes of subcellular structures during mitosis are best visualized by live imaging. In general, live imaging requires the expression of proteins of interest fused to fluorophores and a model system amenable to live microscopy. Drosophila melanogaster is an attractive model in which to perform live imaging because of the numerous transgenic stocks bearing fluorescently tagged transgenes as well as the ability to precisely manipulate gene expression. Traditionally, the early Drosophila embryo has been used for live fluorescent analysis of mitotic events such as spindle formation and chromosome segregation. More recent studies demonstrate that the Drosophila third instar neuroblasts have a number of properties that make them well suited for live analysis: (1) neuroblasts are distinct cells surrounded by plasma membranes; (2) neuroblasts undergo a complete cell cycle, consisting of G1, S, G2, and M phases; and (3) neuroblasts gene expression is not influenced by maternal load, and so the genetics are therefore relatively more simple. Finally, the Drosophila neuroblast is arguably the best system for live imaging asymmetric stem cell divisions. Here, we detail a method for live imaging Drosophila larval neuroblasts.
Collapse
Affiliation(s)
- Brandt Warecki
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Ian Bast
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - William Sullivan
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA, USA.
| |
Collapse
|
8
|
Vicars H, Karg T, Warecki B, Bast I, Sullivan W. Kinetochore-independent mechanisms of sister chromosome separation. PLoS Genet 2021; 17:e1009304. [PMID: 33513180 PMCID: PMC7886193 DOI: 10.1371/journal.pgen.1009304] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 02/16/2021] [Accepted: 12/08/2020] [Indexed: 11/19/2022] Open
Abstract
Although kinetochores normally play a key role in sister chromatid separation and segregation, chromosome fragments lacking kinetochores (acentrics) can in some cases separate and segregate successfully. In Drosophila neuroblasts, acentric chromosomes undergo delayed, but otherwise normal sister separation, revealing the existence of kinetochore- independent mechanisms driving sister chromosome separation. Bulk cohesin removal from the acentric is not delayed, suggesting factors other than cohesin are responsible for the delay in acentric sister separation. In contrast to intact kinetochore-bearing chromosomes, we discovered that acentrics align parallel as well as perpendicular to the mitotic spindle. In addition, sister acentrics undergo unconventional patterns of separation. For example, rather than the simultaneous separation of sisters, acentrics oriented parallel to the spindle often slide past one another toward opposing poles. To identify the mechanisms driving acentric separation, we screened 117 RNAi gene knockdowns for synthetic lethality with acentric chromosome fragments. In addition to well-established DNA repair and checkpoint mutants, this candidate screen identified synthetic lethality with X-chromosome-derived acentric fragments in knockdowns of Greatwall (cell cycle kinase), EB1 (microtubule plus-end tracking protein), and Map205 (microtubule-stabilizing protein). Additional image-based screening revealed that reductions in Topoisomerase II levels disrupted sister acentric separation. Intriguingly, live imaging revealed that knockdowns of EB1, Map205, and Greatwall preferentially disrupted the sliding mode of sister acentric separation. Based on our analysis of EB1 localization and knockdown phenotypes, we propose that in the absence of a kinetochore, microtubule plus-end dynamics provide the force to resolve DNA catenations required for sister separation.
Collapse
Affiliation(s)
- Hannah Vicars
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California, United States of America
| | - Travis Karg
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California, United States of America
| | - Brandt Warecki
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California, United States of America
| | - Ian Bast
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California, United States of America
| | - William Sullivan
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California, United States of America
| |
Collapse
|
9
|
Finardi A, Massari LF, Visintin R. Anaphase Bridges: Not All Natural Fibers Are Healthy. Genes (Basel) 2020; 11:genes11080902. [PMID: 32784550 PMCID: PMC7464157 DOI: 10.3390/genes11080902] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 02/07/2023] Open
Abstract
At each round of cell division, the DNA must be correctly duplicated and distributed between the two daughter cells to maintain genome identity. In order to achieve proper chromosome replication and segregation, sister chromatids must be recognized as such and kept together until their separation. This process of cohesion is mainly achieved through proteinaceous linkages of cohesin complexes, which are loaded on the sister chromatids as they are generated during S phase. Cohesion between sister chromatids must be fully removed at anaphase to allow chromosome segregation. Other (non-proteinaceous) sources of cohesion between sister chromatids consist of DNA linkages or sister chromatid intertwines. DNA linkages are a natural consequence of DNA replication, but must be timely resolved before chromosome segregation to avoid the arising of DNA lesions and genome instability, a hallmark of cancer development. As complete resolution of sister chromatid intertwines only occurs during chromosome segregation, it is not clear whether DNA linkages that persist in mitosis are simply an unwanted leftover or whether they have a functional role. In this review, we provide an overview of DNA linkages between sister chromatids, from their origin to their resolution, and we discuss the consequences of a failure in their detection and processing and speculate on their potential role.
Collapse
Affiliation(s)
- Alice Finardi
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, 20139 Milan, Italy;
| | - Lucia F. Massari
- The Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK;
| | - Rosella Visintin
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, 20139 Milan, Italy;
- Correspondence: ; Tel.: +39-02-5748-9859; Fax: +39-02-9437-5991
| |
Collapse
|
10
|
Palladino J, Chavan A, Sposato A, Mason TD, Mellone BG. Targeted De Novo Centromere Formation in Drosophila Reveals Plasticity and Maintenance Potential of CENP-A Chromatin. Dev Cell 2020; 52:379-394.e7. [PMID: 32049040 DOI: 10.1016/j.devcel.2020.01.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 10/17/2019] [Accepted: 01/06/2020] [Indexed: 11/25/2022]
Abstract
Centromeres are essential for accurate chromosome segregation and are marked by centromere protein A (CENP-A) nucleosomes. Mis-targeted CENP-A chromatin has been shown to seed centromeres at non-centromeric DNA. However, the requirements for such de novo centromere formation and transmission in vivo remain unknown. Here, we employ Drosophila melanogaster and the LacI/lacO system to investigate the ability of targeted de novo centromeres to assemble and be inherited through development. De novo centromeres form efficiently at six distinct genomic locations, which include actively transcribed chromatin and heterochromatin, and cause widespread chromosomal instability. During tethering, de novo centromeres sometimes prevail, causing the loss of the endogenous centromere via DNA breaks and HP1-dependent epigenetic inactivation. Transient induction of de novo centromeres and chromosome healing in early embryogenesis show that, once established, these centromeres can be maintained through development. Our results underpin the ability of CENP-A chromatin to establish and sustain mitotic centromere function in Drosophila.
Collapse
Affiliation(s)
- Jason Palladino
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Ankita Chavan
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Anthony Sposato
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Timothy D Mason
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Barbara G Mellone
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA; Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269, USA.
| |
Collapse
|
11
|
Martins NMC, Cisneros-Soberanis F, Pesenti E, Kochanova NY, Shang WH, Hori T, Nagase T, Kimura H, Larionov V, Masumoto H, Fukagawa T, Earnshaw WC. H3K9me3 maintenance on a human artificial chromosome is required for segregation but not centromere epigenetic memory. J Cell Sci 2020; 133:jcs242610. [PMID: 32576667 PMCID: PMC7390644 DOI: 10.1242/jcs.242610] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 06/11/2020] [Indexed: 12/24/2022] Open
Abstract
Most eukaryotic centromeres are located within heterochromatic regions. Paradoxically, heterochromatin can also antagonize de novo centromere formation, and some centromeres lack it altogether. In order to investigate the importance of heterochromatin at centromeres, we used epigenetic engineering of a synthetic alphoidtetO human artificial chromosome (HAC), to which chimeric proteins can be targeted. By tethering the JMJD2D demethylase (also known as KDM4D), we removed heterochromatin mark H3K9me3 (histone 3 lysine 9 trimethylation) specifically from the HAC centromere. This caused no short-term defects, but long-term tethering reduced HAC centromere protein levels and triggered HAC mis-segregation. However, centromeric CENP-A was maintained at a reduced level. Furthermore, HAC centromere function was compatible with an alternative low-H3K9me3, high-H3K27me3 chromatin signature, as long as residual levels of H3K9me3 remained. When JMJD2D was released from the HAC, H3K9me3 levels recovered over several days back to initial levels along with CENP-A and CENP-C centromere levels, and mitotic segregation fidelity. Our results suggest that a minimal level of heterochromatin is required to stabilize mitotic centromere function but not for maintaining centromere epigenetic memory, and that a homeostatic pathway maintains heterochromatin at centromeres.This article has an associated First Person interview with the first authors of the paper.
Collapse
Affiliation(s)
| | | | - Elisa Pesenti
- Wellcome Trust Centre for Cell Biology, Edinburgh, UK
| | | | - Wei-Hao Shang
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Tetsuya Hori
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | | | - Hiroshi Kimura
- Cell Biology Unit, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Vladimir Larionov
- National Cancer Institute, National Institutes of Health, Bethesda, USA
| | | | - Tatsuo Fukagawa
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | | |
Collapse
|
12
|
Kochanova NY, Schauer T, Mathias GP, Lukacs A, Schmidt A, Flatley A, Schepers A, Thomae AW, Imhof A. A multi-layered structure of the interphase chromocenter revealed by proximity-based biotinylation. Nucleic Acids Res 2020; 48:4161-4178. [PMID: 32182352 PMCID: PMC7192626 DOI: 10.1093/nar/gkaa145] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 02/18/2020] [Accepted: 02/25/2020] [Indexed: 12/26/2022] Open
Abstract
During interphase centromeres often coalesce into a small number of chromocenters, which can be visualized as distinct, DAPI dense nuclear domains. Intact chromocenters play a major role in maintaining genome stability as they stabilize the transcriptionally silent state of repetitive DNA while ensuring centromere function. Despite its biological importance, relatively little is known about the molecular composition of the chromocenter or the processes that mediate chromocenter formation and maintenance. To provide a deeper molecular insight into the composition of the chromocenter and to demonstrate the usefulness of proximity-based biotinylation as a tool to investigate those questions, we performed super resolution microscopy and proximity-based biotinylation experiments of three distinct proteins associated with the chromocenter in Drosophila. Our work revealed an intricate internal architecture of the chromocenter suggesting a complex multilayered structure of this intranuclear domain.
Collapse
Affiliation(s)
- Natalia Y Kochanova
- Biomedical Center, Chromatin Proteomics Group, Department of Molecular Biology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| | - Tamas Schauer
- Biomedical Center, Bioinformatics Core Facility, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| | - Grusha Primal Mathias
- Biomedical Center, Core Facility Bioimaging, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| | - Andrea Lukacs
- Biomedical Center, Chromatin Proteomics Group, Department of Molecular Biology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| | - Andreas Schmidt
- Biomedical Center, Protein Analysis Unit, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| | - Andrew Flatley
- Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Institute for Diabetes and Obesity, Monoclonal Antibody Core Facility and Research Group Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Aloys Schepers
- Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Institute for Diabetes and Obesity, Monoclonal Antibody Core Facility and Research Group Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Andreas W Thomae
- Biomedical Center, Core Facility Bioimaging, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| | - Axel Imhof
- Biomedical Center, Chromatin Proteomics Group, Department of Molecular Biology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
- Biomedical Center, Protein Analysis Unit, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| |
Collapse
|
13
|
Mirkovic M, Oliveira RA. Centromeric Cohesin: Molecular Glue and Much More. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2019; 56:485-513. [PMID: 28840250 DOI: 10.1007/978-3-319-58592-5_20] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sister chromatid cohesion, mediated by the cohesin complex, is a prerequisite for faithful chromosome segregation during mitosis. Premature release of sister chromatid cohesion leads to random segregation of the genetic material and consequent aneuploidy. Multiple regulatory mechanisms ensure proper timing for cohesion establishment, concomitant with DNA replication, and cohesion release during the subsequent mitosis. Here we summarize the most important phases of the cohesin cycle and the coordination of cohesion release with the progression through mitosis. We further discuss recent evidence that has revealed additional functions for centromeric localization of cohesin in the fidelity of mitosis in metazoans. Beyond its well-established role as "molecular glue", centromeric cohesin complexes are now emerging as a scaffold for multiple fundamental processes during mitosis, including the formation of correct chromosome and kinetochore architecture, force balance with the mitotic spindle, and the association with key molecules that regulate mitotic fidelity, particularly at the chromosomal inner centromere. Centromeric chromatin may be thus seen as a dynamic place where cohesin ensures mitotic fidelity by multiple means.
Collapse
Affiliation(s)
- Mihailo Mirkovic
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 2780-156, Oeiras, Portugal
| | - Raquel A Oliveira
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 2780-156, Oeiras, Portugal.
| |
Collapse
|
14
|
Mirkovic M, Guilgur LG, Tavares A, Passagem-Santos D, Oliveira RA. Induced aneuploidy in neural stem cells triggers a delayed stress response and impairs adult life span in flies. PLoS Biol 2019; 17:e3000016. [PMID: 30794535 PMCID: PMC6402706 DOI: 10.1371/journal.pbio.3000016] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 03/06/2019] [Accepted: 01/31/2019] [Indexed: 02/07/2023] Open
Abstract
Studying aneuploidy during organism development has strong limitations because chronic mitotic perturbations used to generate aneuploidy usually result in lethality. We developed a genetic tool to induce aneuploidy in an acute and time-controlled manner during Drosophila development. This is achieved by reversible depletion of cohesin, a key molecule controlling mitotic fidelity. Larvae challenged with aneuploidy hatch into adults with severe motor defects shortening their life span. Neural stem cells, despite being aneuploid, display a delayed stress response and continue proliferating, resulting in the rapid appearance of chromosomal instability, a complex array of karyotypes, and cellular abnormalities. Notably, when other brain-cell lineages are forced to self-renew, aneuploidy-associated stress response is significantly delayed. Protecting only the developing brain from induced aneuploidy is sufficient to rescue motor defects and adult life span, suggesting that neural tissue is the most ill-equipped to deal with developmental aneuploidy.
Collapse
|
15
|
Silva RD, Mirkovic M, Guilgur LG, Rathore OS, Martinho RG, Oliveira RA. Absence of the Spindle Assembly Checkpoint Restores Mitotic Fidelity upon Loss of Sister Chromatid Cohesion. Curr Biol 2018; 28:2837-2844.e3. [PMID: 30122528 PMCID: PMC6191932 DOI: 10.1016/j.cub.2018.06.062] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 05/30/2018] [Accepted: 06/22/2018] [Indexed: 12/28/2022]
Abstract
The fidelity of mitosis depends on cohesive forces that keep sister chromatids together. This is mediated by cohesin that embraces sister chromatid fibers from the time of their replication until the subsequent mitosis [1, 2, 3]. Cleavage of cohesin marks anaphase onset, where single chromatids are dragged to the poles by the mitotic spindle [4, 5, 6]. Cohesin cleavage should only occur when all chromosomes are properly bio-oriented to ensure equal genome distribution and prevent random chromosome segregation. Unscheduled loss of sister chromatid cohesion is prevented by a safeguard mechanism known as the spindle assembly checkpoint (SAC) [7, 8]. To identify specific conditions capable of restoring defects associated with cohesion loss, we screened for genes whose depletion modulates Drosophila wing development when sister chromatid cohesion is impaired. Cohesion deficiency was induced by knockdown of the acetyltransferase separation anxiety (San)/Naa50, a cohesin complex stabilizer [9, 10, 11, 12]. Several genes whose function impacts wing development upon cohesion loss were identified. Surprisingly, knockdown of key SAC proteins, Mad2 and Mps1, suppressed developmental defects associated with San depletion. SAC impairment upon cohesin removal, triggered by San depletion or artificial removal of the cohesin complex, prevented extensive genome shuffling, reduced segregation defects, and restored cell survival. This counterintuitive phenotypic suppression was caused by an intrinsic bias for efficient chromosome biorientation at mitotic entry, coupled with slow engagement of error-correction reactions. Thus, in contrast to SAC’s role as a safeguard mechanism for mitotic fidelity, removal of this checkpoint alleviates mitotic errors when sister chromatid cohesion is compromised. A Drosophila screen identifies SAC genes as suppressors of cohesion-related defects SAC removal enhances mitotic fidelity upon premature cohesion loss SAC inactivation enhances cell survival and tissue homeostasis upon cohesion loss
Collapse
Affiliation(s)
- Rui D Silva
- Departamento de Ciências Biomédicas e Medicina and Center for Biomedical Research, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - Mihailo Mirkovic
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal
| | - Leonardo G Guilgur
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal
| | - Om S Rathore
- Departamento de Ciências Biomédicas e Medicina and Center for Biomedical Research, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - Rui Gonçalo Martinho
- Departamento de Ciências Biomédicas e Medicina and Center for Biomedical Research, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal; Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; Institute of Biomedicine-iBiMED and Department of Medical Sciences, University of Aveiro, Campus Universitario de Santiago, Agra do Crasto-Ed. 30, 3810-193 Aveiro, Portugal.
| | - Raquel A Oliveira
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal.
| |
Collapse
|
16
|
Carvalhal S, Tavares A, Santos MB, Mirkovic M, Oliveira RA. A quantitative analysis of cohesin decay in mitotic fidelity. J Cell Biol 2018; 217:3343-3353. [PMID: 30002073 PMCID: PMC6168270 DOI: 10.1083/jcb.201801111] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 06/05/2018] [Accepted: 06/28/2018] [Indexed: 12/29/2022] Open
Abstract
Sister chromatid cohesion mediated by cohesin is essential for mitotic fidelity. It counteracts spindle forces to prevent premature chromatid individualization and random genome segregation. However, it is unclear what effects a partial decline of cohesin may have on chromosome organization. In this study, we provide a quantitative analysis of cohesin decay by inducing acute removal of defined amounts of cohesin from metaphase-arrested chromosomes. We demonstrate that sister chromatid cohesion is very resistant to cohesin loss as chromatid disjunction is only observed when chromosomes lose >80% of bound cohesin. Removal close to this threshold leads to chromosomes that are still cohered but display compromised chromosome alignment and unstable spindle attachments. Partial cohesin decay leads to increased duration of mitosis and susceptibility to errors in chromosome segregation. We propose that high cohesin density ensures centromeric chromatin rigidity necessary to maintain a force balance with the mitotic spindle. Partial cohesin loss may lead to chromosome segregation errors even when sister chromatid cohesion is fulfilled.
Collapse
|
17
|
Lopez S, Bermudez B, Montserrat-de la Paz S, Abia R, Muriana FJ. A microRNA expression signature of the postprandial state in response to a high-saturated-fat challenge. J Nutr Biochem 2018; 57:45-55. [DOI: 10.1016/j.jnutbio.2018.03.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 01/23/2018] [Accepted: 03/07/2018] [Indexed: 12/13/2022]
|
18
|
Piskadlo E, Oliveira RA. A Topology-Centric View on Mitotic Chromosome Architecture. Int J Mol Sci 2017; 18:E2751. [PMID: 29258269 PMCID: PMC5751350 DOI: 10.3390/ijms18122751] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 02/04/2023] Open
Abstract
Mitotic chromosomes are long-known structures, but their internal organization and the exact process by which they are assembled are still a great mystery in biology. Topoisomerase II is crucial for various aspects of mitotic chromosome organization. The unique ability of this enzyme to untangle topologically intertwined DNA molecules (catenations) is of utmost importance for the resolution of sister chromatid intertwines. Although still controversial, topoisomerase II has also been proposed to directly contribute to chromosome compaction, possibly by promoting chromosome self-entanglements. These two functions raise a strong directionality issue towards topoisomerase II reactions that are able to disentangle sister DNA molecules (in trans) while compacting the same DNA molecule (in cis). Here, we review the current knowledge on topoisomerase II role specifically during mitosis, and the mechanisms that directly or indirectly regulate its activity to ensure faithful chromosome segregation. In particular, we discuss how the activity or directionality of this enzyme could be regulated by the SMC (structural maintenance of chromosomes) complexes, predominantly cohesin and condensin, throughout mitosis.
Collapse
Affiliation(s)
- Ewa Piskadlo
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal.
| | - Raquel A Oliveira
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal.
| |
Collapse
|
19
|
Pitchai GP, Kaulich M, Bizard AH, Mesa P, Yao Q, Sarlos K, Streicher WW, Nigg EA, Montoya G, Hickson ID. A novel TPR-BEN domain interaction mediates PICH-BEND3 association. Nucleic Acids Res 2017; 45:11413-11424. [PMID: 28977671 PMCID: PMC5737856 DOI: 10.1093/nar/gkx792] [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: 06/26/2017] [Accepted: 08/31/2017] [Indexed: 12/20/2022] Open
Abstract
PICH is a DNA translocase required for the maintenance of chromosome stability in human cells. Recent data indicate that PICH co-operates with topoisomerase IIα to suppress pathological chromosome missegregation through promoting the resolution of ultra-fine anaphase bridges (UFBs). Here, we identify the BEN domain-containing protein 3 (BEND3) as an interaction partner of PICH in human cells in mitosis. We have purified full length PICH and BEND3 and shown that they exhibit a functional biochemical interaction in vitro. We demonstrate that the PICH–BEND3 interaction occurs via a novel interface between a TPR domain in PICH and a BEN domain in BEND3, and have determined the crystal structure of this TPR–BEN complex at 2.2 Å resolution. Based on the structure, we identified amino acids important for the TPR–BEN domain interaction, and for the functional interaction of the full-length proteins. Our data reveal a proposed new function for BEND3 in association with PICH, and the first example of a specific protein–protein interaction mediated by a BEN domain.
Collapse
Affiliation(s)
- Ganesha P Pitchai
- Novo Nordisk Foundation Center for Protein Research, Protein Structure & Function Programme, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.,Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Manuel Kaulich
- Biozentrum, University of Basel, CH-4056, Basel, Switzerland
| | - Anna H Bizard
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Pablo Mesa
- Novo Nordisk Foundation Center for Protein Research, Protein Structure & Function Programme, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Qi Yao
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Kata Sarlos
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Werner W Streicher
- Novo Nordisk Foundation Center for Protein Research, Protein Structure & Function Programme, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Erich A Nigg
- Biozentrum, University of Basel, CH-4056, Basel, Switzerland
| | - Guillermo Montoya
- Novo Nordisk Foundation Center for Protein Research, Protein Structure & Function Programme, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Ian D Hickson
- Center for Chromosome Stability and Center for Healthy Aging, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| |
Collapse
|
20
|
The Hybrid Incompatibility Genes Lhr and Hmr Are Required for Sister Chromatid Detachment During Anaphase but Not for Centromere Function. Genetics 2017; 207:1457-1472. [PMID: 29046402 DOI: 10.1534/genetics.117.300390] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 10/13/2017] [Indexed: 11/18/2022] Open
Abstract
Crosses between Drosophila melanogaster females and Drosophila simulans males produce hybrid sons that die at the larval stage. This hybrid lethality is suppressed by loss-of-function mutations in the D. melanogaster Hybrid male rescue (Hmr) or in the D. simulans Lethal hybrid rescue (Lhr) genes. Previous studies have shown that Hmr and Lhr interact with heterochromatin proteins and suppress expression of transposable elements within D. melanogaster It also has been proposed that Hmr and Lhr function at the centromere. We examined mitotic divisions in larval brains from Hmr and Lhr single mutants and Hmr; Lhr double mutants in D. melanogaster In none of the mutants did we observe defects in metaphase chromosome alignment or hyperploid cells, which are hallmarks of centromere or kinetochore dysfunction. In addition, we found that Hmr-HA and Lhr-HA do not colocalize with centromeres either during interphase or mitotic division. However, all mutants displayed anaphase bridges and chromosome aberrations resulting from the breakage of these bridges, predominantly at the euchromatin-heterochromatin junction. The few dividing cells present in hybrid males showed fuzzy and irregularly condensed chromosomes with unresolved sister chromatids. Despite this defect in condensation, chromosomes in hybrids managed to align on the metaphase plate and undergo anaphase. We conclude that there is no evidence for a centromeric function of Hmr and Lhr within D. melanogaster nor for a centromere defect causing hybrid lethality. Instead, we find that Hmr and Lhr are required in D. melanogaster for detachment of sister chromatids during anaphase.
Collapse
|
21
|
Yamada T, Tahara E, Kanke M, Kuwata K, Nishiyama T. Drosophila Dalmatian combines sororin and shugoshin roles in establishment and protection of cohesion. EMBO J 2017; 36:1513-1527. [PMID: 28483815 DOI: 10.15252/embj.201695607] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 04/04/2017] [Accepted: 04/06/2017] [Indexed: 11/09/2022] Open
Abstract
Sister chromatid cohesion is crucial to ensure chromosome bi-orientation and equal chromosome segregation. Cohesin removal via mitotic kinases and Wapl has to be prevented in pericentromeric regions in order to protect cohesion until metaphase, but the mechanisms of mitotic cohesion protection remain elusive in Drosophila Here, we show that dalmatian (Dmt), an ortholog of the vertebrate cohesin-associated protein sororin, is required for protection of mitotic cohesion in flies. Dmt is essential for cohesion establishment during interphase and is enriched on pericentromeric heterochromatin. Dmt is recruited through direct association with heterochromatin protein-1 (HP1), and this interaction is required for cohesion. During mitosis, Dmt interdependently recruits protein phosphatase 2A (PP2A) to pericentromeric regions, and PP2A binding is required for Dmt to protect cohesion. Intriguingly, Dmt is sufficient to protect cohesion upon heterologous expression in human cells. Our findings of a hybrid system, in which Dmt exerts both sororin-like establishment functions and shugoshin-like heterochromatin-based protection roles, provide clues to the evolutionary modulation of eukaryotic cohesion regulation systems.
Collapse
Affiliation(s)
- Takashi Yamada
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho Chikusa-ku Nagoya, Japan
| | - Eri Tahara
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho Chikusa-ku Nagoya, Japan
| | - Mai Kanke
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho Chikusa-ku Nagoya, Japan
| | - Keiko Kuwata
- Institute of Transformative Bio-Molecules, Nagoya University, Furo-cho Chikusa-ku Nagoya, Japan
| | - Tomoko Nishiyama
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho Chikusa-ku Nagoya, Japan
| |
Collapse
|
22
|
Kirov IV, Kiseleva AV, Van Laere K, Van Roy N, Khrustaleva LI. Tandem repeats of Allium fistulosum associated with major chromosomal landmarks. Mol Genet Genomics 2017; 292:453-464. [PMID: 28150039 DOI: 10.1007/s00438-016-1286-9] [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: 06/05/2016] [Accepted: 12/30/2016] [Indexed: 01/22/2023]
Abstract
Tandem repeats are often associated with important chromosomal landmarks, such as centromeres, telomeres, subtelomeric, and other heterochromatic regions, and can be good candidates for molecular cytogenetic markers. Tandem repeats present in many plant species demonstrate dramatic differences in unit length, proportion in the genome, and chromosomal organization. Members of genus Allium with their large genomes represent a challenging task for current genetics. Using the next generation sequencing data, molecular, and cytogenetic methods, we discovered two tandemly organized repeats in the Allium fistulosum genome (2n = 2C = 16), HAT58 and CAT36. Together, these repeats comprise 0.25% of the bunching onion genome with 160,000 copies/1 C of HAT58 and 93,000 copies/1 C of CAT36. Fluorescent in situ hybridization (FISH) and C-banding showed that HAT58 and CAT36 associated with the interstitial and pericentromeric heterochromatin of the A. fistulosum chromosomes 5, 6, 7, and 8. FISH with HAT58 and CAT36 performed on A. cepa (2n = 2C = 16) and A. wakegi (2n = 2C = 16), a natural allodiploid hybrid between A. fistulosum and A. cepa, revealed that these repeats are species specific and produced specific hybridization patterns only on A. fistulosum chromosomes. Thus, the markers can be used in interspecific breeding programs for monitoring of alien genetic material. We applied Non-denaturing FISH that allowed detection of the repeat bearing chromosomes within 3 h. A polymorphism of the HAT58 chromosome location was observed. This finding suggests that the rapid evolution of the HAT58 repeat is still ongoing.
Collapse
Affiliation(s)
- Ilya V Kirov
- Center of Molecular Biotechnology, Russian State Agrarian University-Moscow Timiryazev Agricultural Academy, Moscow, Russia. .,Department of Genetics, Biotechnology and Plant Breeding, Russian State Agrarian University-Moscow Timiryazev Agricultural Academy, Moscow, Russia. .,Plant Sciences Unit, Applied Genetics and Breeding, Institute for Agricultural and Fisheries Research (ILVO), Melle, Belgium.
| | - Anna V Kiseleva
- Center of Molecular Biotechnology, Russian State Agrarian University-Moscow Timiryazev Agricultural Academy, Moscow, Russia.,Department of Genetics, Biotechnology and Plant Breeding, Russian State Agrarian University-Moscow Timiryazev Agricultural Academy, Moscow, Russia
| | - Katrijn Van Laere
- Plant Sciences Unit, Applied Genetics and Breeding, Institute for Agricultural and Fisheries Research (ILVO), Melle, Belgium
| | - Nadine Van Roy
- Faculty of Medicine and Health Sciences, Center of Medical Genetics, Ghent University, Ghent, Belgium
| | - Ludmila I Khrustaleva
- Center of Molecular Biotechnology, Russian State Agrarian University-Moscow Timiryazev Agricultural Academy, Moscow, Russia. .,Department of Genetics, Biotechnology and Plant Breeding, Russian State Agrarian University-Moscow Timiryazev Agricultural Academy, Moscow, Russia.
| |
Collapse
|
23
|
A Simplified Strategy for Introducing Genetic Variants into Drosophila Compound Autosome Stocks. G3 (BETHESDA, MD.) 2016; 6:3749-3755. [PMID: 27672111 PMCID: PMC5100873 DOI: 10.1534/g3.116.035634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Drosophila stocks bearing compound chromosomes, single molecules of DNA that carry the genomic complement of two chromosomes, are useful tools for studying meiosis and mitosis. However, these stocks cannot easily be crossed to stocks with regular chromosomes, due to the lethality of the resulting whole-chromosome aneuploidy. This prevents the examination of interesting genetic variants in a compound chromosome background. Methods to circumvent this difficulty have included the use of triploid females or nondisjunction (caused by either cold-induced microtubule depolymerization or meiotic mutants). Here, we present a new approach for crossing compound chromosomes that takes advantage of the nonhomologous segregations that result when multiple chromosomes in the same genome are prevented from meiotic crossing over by heterozygosity for balancer chromosomes. This approach gives higher yields of the desired progeny in fewer generations of crossing. Using this technique, we have created and validated stocks carrying both a compound-X and compound-2, as well as compound-2 stocks carrying the meiotic mutant nod.
Collapse
|
24
|
Cipressa F, Morciano P, Bosso G, Mannini L, Galati A, Raffa GD, Cacchione S, Musio A, Cenci G. A role for Separase in telomere protection. Nat Commun 2016; 7:10405. [PMID: 26778495 PMCID: PMC4735636 DOI: 10.1038/ncomms10405] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 12/08/2015] [Indexed: 12/04/2022] Open
Abstract
Drosophila telomeres are elongated by transposition of specialized retroelements rather than telomerase activity and are assembled independently of the sequence. Fly telomeres are protected by the terminin complex that localizes and functions exclusively at telomeres and by non-terminin proteins that do not serve telomere-specific functions. We show that mutations in the Drosophila Separase encoding gene Sse lead not only to endoreduplication but also telomeric fusions (TFs), suggesting a role for Sse in telomere capping. We demonstrate that Separase binds terminin proteins and HP1, and that it is enriched at telomeres. Furthermore, we show that loss of Sse strongly reduces HP1 levels, and that HP1 overexpression in Sse mutants suppresses TFs, suggesting that TFs are caused by a HP1 diminution. Finally, we find that siRNA-induced depletion of ESPL1, the Sse human orthologue, causes telomere dysfunction and HP1 level reduction in primary fibroblasts, highlighting a conserved role of Separase in telomere protection. Drosophila telomeres are elongated by transposition of specialized retroelements rather than telomerase activity. Here, the authors show that Separase is enriched at Drosophila telomeres and loss of Sse, the gene encoding Separase, leads to telomere defects, suggesting a role for Separase in telomere protection.
Collapse
Affiliation(s)
- Francesca Cipressa
- Department of Biology and Biotechnology "Charles Darwin" Section of Genetics, SAPIENZA University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.,Istituto Pasteur, Fondazione Cenci-Bolognetti, Viale Regina Elena 291, 00185 Rome, Italy
| | - Patrizia Morciano
- Department of Biology and Biotechnology "Charles Darwin" Section of Genetics, SAPIENZA University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.,Istituto Pasteur, Fondazione Cenci-Bolognetti, Viale Regina Elena 291, 00185 Rome, Italy
| | - Giuseppe Bosso
- Department of Biology and Biotechnology "Charles Darwin" Section of Genetics, SAPIENZA University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.,Istituto Pasteur, Fondazione Cenci-Bolognetti, Viale Regina Elena 291, 00185 Rome, Italy
| | - Linda Mannini
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, c/o Area di Ricerca di S. Cataldo Via G. Moruzzi 1, 56124 Pisa, Italy
| | - Alessandra Galati
- Department of Biology and Biotechnology "Charles Darwin" Section of Genetics, SAPIENZA University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.,Istituto Pasteur, Fondazione Cenci-Bolognetti, Viale Regina Elena 291, 00185 Rome, Italy
| | - Grazia Daniela Raffa
- Department of Biology and Biotechnology "Charles Darwin" Section of Genetics, SAPIENZA University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.,Istituto Pasteur, Fondazione Cenci-Bolognetti, Viale Regina Elena 291, 00185 Rome, Italy
| | - Stefano Cacchione
- Department of Biology and Biotechnology "Charles Darwin" Section of Genetics, SAPIENZA University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.,Istituto Pasteur, Fondazione Cenci-Bolognetti, Viale Regina Elena 291, 00185 Rome, Italy
| | - Antonio Musio
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, c/o Area di Ricerca di S. Cataldo Via G. Moruzzi 1, 56124 Pisa, Italy.,Istituto Toscano Tumori, Via T. Alderotti 26N, 50139 Firenze, Italy
| | - Giovanni Cenci
- Department of Biology and Biotechnology "Charles Darwin" Section of Genetics, SAPIENZA University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.,Istituto Pasteur, Fondazione Cenci-Bolognetti, Viale Regina Elena 291, 00185 Rome, Italy
| |
Collapse
|
25
|
Mirkovic M, Hutter LH, Novák B, Oliveira RA. Premature Sister Chromatid Separation Is Poorly Detected by the Spindle Assembly Checkpoint as a Result of System-Level Feedback. Cell Rep 2015; 13:469-478. [PMID: 26456822 DOI: 10.1016/j.celrep.2015.09.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 07/24/2015] [Accepted: 09/08/2015] [Indexed: 12/20/2022] Open
Abstract
Sister chromatid cohesion, mediated by the cohesin complex, is essential for faithful mitosis. Nevertheless, evidence suggests that the surveillance mechanism that governs mitotic fidelity, the spindle assembly checkpoint (SAC), is not robust enough to halt cell division when cohesion loss occurs prematurely. The mechanism behind this poor response is not properly understood. Using developing Drosophila brains, we show that full sister chromatid separation elicits a weak checkpoint response resulting in abnormal mitotic exit after a short delay. Quantitative live-cell imaging approaches combined with mathematical modeling indicate that weak SAC activation upon cohesion loss is caused by weak signal generation. This is further attenuated by several feedback loops in the mitotic signaling network. We propose that multiple feedback loops involving cyclin-dependent kinase 1 (Cdk1) gradually impair error-correction efficiency and accelerate mitotic exit upon premature loss of cohesion. Our findings explain how cohesion defects may escape SAC surveillance.
Collapse
Affiliation(s)
- Mihailo Mirkovic
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 2780-156 Oeiras, Portugal
| | - Lukas H Hutter
- Department of Biochemistry, Oxford Center for Integrative Systems Biology, University of Oxford, Oxford OX1 3QU, UK
| | - Béla Novák
- Department of Biochemistry, Oxford Center for Integrative Systems Biology, University of Oxford, Oxford OX1 3QU, UK
| | - Raquel A Oliveira
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 2780-156 Oeiras, Portugal.
| |
Collapse
|
26
|
Hinshaw SM, Makrantoni V, Kerr A, Marston AL, Harrison SC. Structural evidence for Scc4-dependent localization of cohesin loading. eLife 2015; 4:e06057. [PMID: 26038942 PMCID: PMC4471937 DOI: 10.7554/elife.06057] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 06/01/2015] [Indexed: 01/21/2023] Open
Abstract
The cohesin ring holds newly replicated sister chromatids together until their separation at anaphase. Initiation of sister chromatid cohesion depends on a separate complex, Scc2(NIPBL)/Scc4(Mau2) (Scc2/4), which loads cohesin onto DNA and determines its localization across the genome. Proper cohesin loading is essential for cell division, and partial defects cause chromosome missegregation and aberrant transcriptional regulation, leading to severe developmental defects in multicellular organisms. We present here a crystal structure showing the interaction between Scc2 and Scc4. Scc4 is a TPR array that envelops an extended Scc2 peptide. Using budding yeast, we demonstrate that a conserved patch on the surface of Scc4 is required to recruit Scc2/4 to centromeres and to build pericentromeric cohesion. These findings reveal the role of Scc4 in determining the localization of cohesin loading and establish a molecular basis for Scc2/4 recruitment to centromeres.
Collapse
Affiliation(s)
- Stephen M Hinshaw
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
| | - Vasso Makrantoni
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Alastair Kerr
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Adèle L Marston
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Stephen C Harrison
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
- Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| |
Collapse
|
27
|
Karg T, Warecki B, Sullivan W. Aurora B-mediated localized delays in nuclear envelope formation facilitate inclusion of late-segregating chromosome fragments. Mol Biol Cell 2015; 26:2227-41. [PMID: 25877868 PMCID: PMC4462941 DOI: 10.1091/mbc.e15-01-0026] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/09/2015] [Indexed: 01/30/2023] Open
Abstract
Acentric chromosomes exhibit delayed segregation during mitosis. How these delays affect nuclear envelope reassembly is not fully understood. Lagging acentrics coated with Aurora B induce a highly localized gap in the nuclear envelope to allow acentric entry into daughter nuclei. Gap formation is decreased upon reduction of Aurora B. To determine how chromosome segregation is coordinated with nuclear envelope formation (NEF), we examined the dynamics of NEF in the presence of lagging acentric chromosomes in Drosophila neuroblasts. Acentric chromosomes often exhibit delayed but ultimately successful segregation and incorporation into daughter nuclei. However, it is unknown whether these late-segregating acentric fragments influence NEF to ensure their inclusion in daughter nuclei. Through live analysis, we show that acentric chromosomes induce highly localized delays in the reassembly of the nuclear envelope. These delays result in a gap in the nuclear envelope that facilitates the inclusion of lagging acentrics into telophase daughter nuclei. Localized delays of nuclear envelope reassembly require Aurora B kinase activity. In cells with reduced Aurora B activity, there is a decrease in the frequency of local nuclear envelope reassembly delays, resulting in an increase in the frequency of acentric-bearing, lamin-coated micronuclei. These studies reveal a novel role of Aurora B in maintaining genomic integrity by promoting the formation of a passageway in the nuclear envelope through which late-segregating acentric chromosomes enter the telophase daughter nucleus.
Collapse
Affiliation(s)
- Travis Karg
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Brandt Warecki
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - William Sullivan
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| |
Collapse
|