1
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Herriage HC, Huang YT, Calvi BR. The antagonistic relationship between apoptosis and polyploidy in development and cancer. Semin Cell Dev Biol 2024; 156:35-43. [PMID: 37331841 PMCID: PMC10724375 DOI: 10.1016/j.semcdb.2023.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 05/23/2023] [Accepted: 05/30/2023] [Indexed: 06/20/2023]
Abstract
One of the important functions of regulated cell death is to prevent cells from inappropriately acquiring extra copies of their genome, a state known as polyploidy. Apoptosis is the primary cell death mechanism that prevents polyploidy, and defects in this apoptotic response can result in polyploid cells whose subsequent error-prone chromosome segregation are a major contributor to genome instability and cancer progression. Conversely, some cells actively repress apoptosis to become polyploid as part of normal development or regeneration. Thus, although apoptosis prevents polyploidy, the polyploid state can actively repress apoptosis. In this review, we discuss progress in understanding the antagonistic relationship between apoptosis and polyploidy in development and cancer. Despite recent advances, a key conclusion is that much remains unknown about the mechanisms that link apoptosis to polyploid cell cycles. We suggest that drawing parallels between the regulation of apoptosis in development and cancer could help to fill this knowledge gap and lead to more effective therapies.
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Affiliation(s)
- Hunter C Herriage
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Yi-Ting Huang
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Brian R Calvi
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.
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2
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Berg C, Sieber M, Sun J. Finishing the egg. Genetics 2024; 226:iyad183. [PMID: 38000906 PMCID: PMC10763546 DOI: 10.1093/genetics/iyad183] [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: 07/05/2023] [Accepted: 09/27/2023] [Indexed: 11/26/2023] Open
Abstract
Gamete development is a fundamental process that is highly conserved from early eukaryotes to mammals. As germ cells develop, they must coordinate a dynamic series of cellular processes that support growth, cell specification, patterning, the loading of maternal factors (RNAs, proteins, and nutrients), differentiation of structures to enable fertilization and ensure embryonic survival, and other processes that make a functional oocyte. To achieve these goals, germ cells integrate a complex milieu of environmental and developmental signals to produce fertilizable eggs. Over the past 50 years, Drosophila oogenesis has risen to the forefront as a system to interrogate the sophisticated mechanisms that drive oocyte development. Studies in Drosophila have defined mechanisms in germ cells that control meiosis, protect genome integrity, facilitate mRNA trafficking, and support the maternal loading of nutrients. Work in this system has provided key insights into the mechanisms that establish egg chamber polarity and patterning as well as the mechanisms that drive ovulation and egg activation. Using the power of Drosophila genetics, the field has begun to define the molecular mechanisms that coordinate environmental stresses and nutrient availability with oocyte development. Importantly, the majority of these reproductive mechanisms are highly conserved throughout evolution, and many play critical roles in the development of somatic tissues as well. In this chapter, we summarize the recent progress in several key areas that impact egg chamber development and ovulation. First, we discuss the mechanisms that drive nutrient storage and trafficking during oocyte maturation and vitellogenesis. Second, we examine the processes that regulate follicle cell patterning and how that patterning impacts the construction of the egg shell and the establishment of embryonic polarity. Finally, we examine regulatory factors that control ovulation, egg activation, and successful fertilization.
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Affiliation(s)
- Celeste Berg
- Department of Genome Sciences, University of Washington, Seattle, WA 98195-5065USA
| | - Matthew Sieber
- Department of Physiology, UT Southwestern Medical Center, Dallas, TX 75390USA
| | - Jianjun Sun
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269USA
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3
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Kim HS, Parker DJ, Hardiman MM, Munkácsy E, Jiang N, Rogers AN, Bai Y, Brent C, Mobley JA, Austad SN, Pickering AM. Early-adulthood spike in protein translation drives aging via juvenile hormone/germline signaling. Nat Commun 2023; 14:5021. [PMID: 37596266 PMCID: PMC10439225 DOI: 10.1038/s41467-023-40618-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 08/01/2023] [Indexed: 08/20/2023] Open
Abstract
Protein translation (PT) declines with age in invertebrates, rodents, and humans. It has been assumed that elevated PT at young ages is beneficial to health and PT ends up dropping as a passive byproduct of aging. In Drosophila, we show that a transient elevation in PT during early-adulthood exerts long-lasting negative impacts on aging trajectories and proteostasis in later-life. Blocking the early-life PT elevation robustly improves life-/health-span and prevents age-related protein aggregation, whereas transiently inducing an early-life PT surge in long-lived fly strains abolishes their longevity/proteostasis benefits. The early-life PT elevation triggers proteostatic dysfunction, silences stress responses, and drives age-related functional decline via juvenile hormone-lipid transfer protein axis and germline signaling. Our findings suggest that PT is adaptively suppressed after early-adulthood, alleviating later-life proteostatic burden, slowing down age-related functional decline, and improving lifespan. Our work provides a theoretical framework for understanding how lifetime PT dynamics shape future aging trajectories.
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Affiliation(s)
- Harper S Kim
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
- Medical Scientist Training Program, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
- Medical Scientist Training Program, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Danitra J Parker
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UTHealth, Houston, TX, 77030, USA
| | - Madison M Hardiman
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Erin Munkácsy
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Nisi Jiang
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Aric N Rogers
- MDI Biological Laboratory, Bar Harbor, ME, 04672, USA
| | - Yidong Bai
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Colin Brent
- USDA-ARS Arid Land Agricultural Research Center, Maricopa, AZ, 85138, USA
| | - James A Mobley
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, 35249, USA
| | - Steven N Austad
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
- Nathan Shock Center, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Andrew M Pickering
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, San Antonio, TX, 78229, USA.
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UTHealth, Houston, TX, 77030, USA.
- Department of Molecular Medicine, University of Texas Health San Antonio, San Antonio, TX, 78229, USA.
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4
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Chakraborty A, Peterson NG, King JS, Gross RT, Pla MM, Thennavan A, Zhou KC, DeLuca S, Bursac N, Bowles DE, Wolf MJ, Fox DT. Conserved chamber-specific polyploidy maintains heart function in Drosophila. Development 2023; 150:dev201896. [PMID: 37526609 PMCID: PMC10482010 DOI: 10.1242/dev.201896] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 07/24/2023] [Indexed: 08/02/2023]
Abstract
Developmentally programmed polyploidy (whole-genome duplication) of cardiomyocytes is common across evolution. Functions of such polyploidy are essentially unknown. Here, in both Drosophila larvae and human organ donors, we reveal distinct polyploidy levels in cardiac organ chambers. In Drosophila, differential growth and cell cycle signal sensitivity leads the heart chamber to reach a higher ploidy/cell size relative to the aorta chamber. Cardiac ploidy-reduced animals exhibit reduced heart chamber size, stroke volume and cardiac output, and acceleration of circulating hemocytes. These Drosophila phenotypes mimic human cardiomyopathies. Our results identify productive and likely conserved roles for polyploidy in cardiac chambers and suggest that precise ploidy levels sculpt many developing tissues. These findings of productive cardiomyocyte polyploidy impact efforts to block developmental polyploidy to improve heart injury recovery.
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Affiliation(s)
- Archan Chakraborty
- Department of Pharmacology & Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA
- Duke Regeneration Center, Duke University School of Medicine, Durham, NC 27710, USA
| | - Nora G. Peterson
- Department of Pharmacology & Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Juliet S. King
- Department of Pharmacology & Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Ryan T. Gross
- Department of Surgery, Duke University, Durham, NC 27710, USA
| | | | - Aatish Thennavan
- Department of Systems Biology, UT MD Anderson Cancer Center, Houston, TX 77230, USA
| | - Kevin C. Zhou
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720, USA
| | - Sophia DeLuca
- Department of Biomedical Engineering, Duke University, Durham, NC 27710, USA
| | - Nenad Bursac
- Duke Regeneration Center, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Biomedical Engineering, Duke University, Durham, NC 27710, USA
| | - Dawn E. Bowles
- Department of Surgery, Duke University, Durham, NC 27710, USA
| | - Matthew J. Wolf
- Department of Medicine, University of Virginia, Charlottesville, VA 22903, USA
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22903, USA
| | - Donald T. Fox
- Department of Pharmacology & Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA
- Duke Regeneration Center, Duke University School of Medicine, Durham, NC 27710, USA
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5
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Chakraborty A, Peterson NG, King JS, Gross RT, Pla MM, Thennavan A, Zhou KC, DeLuca S, Bursac N, Bowles DE, Wolf MJ, Fox DT. Conserved Chamber-Specific Polyploidy Maintains Heart Function in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.10.528086. [PMID: 36798187 PMCID: PMC9934670 DOI: 10.1101/2023.02.10.528086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Developmentally programmed polyploidy (whole-genome-duplication) of cardiomyocytes is common across evolution. Functions of such polyploidy are essentially unknown. Here, we reveal roles for precise polyploidy levels in cardiac tissue. We highlight a conserved asymmetry in polyploidy level between cardiac chambers in Drosophila larvae and humans. In Drosophila , differential Insulin Receptor (InR) sensitivity leads the heart chamber to reach a higher ploidy/cell size relative to the aorta chamber. Cardiac ploidy-reduced animals exhibit reduced heart chamber size, stroke volume, cardiac output, and acceleration of circulating hemocytes. These Drosophila phenotypes mimic systemic human heart failure. Using human donor hearts, we reveal asymmetry in nuclear volume (ploidy) and insulin signaling between the left ventricle and atrium. Our results identify productive and likely conserved roles for polyploidy in cardiac chambers and suggest precise ploidy levels sculpt many developing tissues. These findings of productive cardiomyocyte polyploidy impact efforts to block developmental polyploidy to improve heart injury recovery.
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6
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Abstract
In this chapter, we highlight examples of the diverse array of developmental, cellular, and biochemical insights that can be gained by using Drosophila melanogaster oogenesis as a model tissue. We begin with an overview of ovary development and adult oogenesis. Then we summarize how the adult Drosophila ovary continues to advance our understanding of stem cells, cell cycle, cell migration, cytoplasmic streaming, nurse cell dumping, and cell death. We also review emerging areas of study, including the roles of lipid droplets, ribosomes, and nuclear actin in egg development. Finally, we conclude by discussing the growing conservation of processes and signaling pathways that regulate oogenesis and female reproduction from flies to humans.
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7
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Soriano A, Petit C, Ryan S, Jemc JC. Tracking Follicle Cell Development. Methods Mol Biol 2023; 2626:151-177. [PMID: 36715904 DOI: 10.1007/978-1-0716-2970-3_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Somatic follicle cells are critical support cells for Drosophila oogenesis, as they provide signals and molecules needed to produce a mature egg. Throughout this process, the follicle cells differentiate into multiple subpopulations and transition between three different cell cycle programs to support nurse cell and oocyte development. The follicle cells are mitotic in early egg chamber development, as they cover the germline cyst. In mid-oogenesis, follicle cells switch from mitosis to endocycling, increasing their ploidy from 2C to 16C. Finally, in late oogenesis, cells transition from endocycling to gene amplification, increasing the copy number of a small subset of genes, including the genes encoding proteins required for egg maturation. In order to explore the genetic regulation of these cell cycle switches and follicle cell development and specification, clonal analysis and the GAL4/UAS system are used frequently to reduce or increase expression of genes of interest. These genetic approaches combined with immunohistochemistry and in situ hybridization are powerful tools for characterizing the mechanisms regulating follicle cell development and the mitosis/endocycle and endocycle/gene amplification transitions. This chapter describes the genetic tools available to manipulate gene expression in follicle cells, as well as the methods and reagents that can be utilized to explore gene expression throughout follicle cell development.
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Affiliation(s)
- Adrianna Soriano
- Department of Biology, Loyola University Chicago, Chicago, IL, USA.,Houston Baptist University, Houston, TX, USA
| | | | - Savannah Ryan
- Department of Biology, Loyola University Chicago, Chicago, IL, USA
| | - Jennifer C Jemc
- Department of Biology, Loyola University Chicago, Chicago, IL, USA.
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8
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Diegmiller R, Imran Alsous J, Li D, Yamashita YM, Shvartsman SY. Fusome topology and inheritance during insect gametogenesis. PLoS Comput Biol 2023; 19:e1010875. [PMID: 36821548 PMCID: PMC9949678 DOI: 10.1371/journal.pcbi.1010875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 01/16/2023] [Indexed: 02/24/2023] Open
Abstract
From insects to mammals, oocytes and sperm develop within germline cysts comprising cells connected by intercellular bridges (ICBs). In numerous insects, formation of the cyst is accompanied by growth of the fusome-a membranous organelle that permeates the cyst. Fusome composition and function are best understood in Drosophila melanogaster: during oogenesis, the fusome dictates cyst topology and size and facilitates oocyte selection, while during spermatogenesis, the fusome synchronizes the cyst's response to DNA damage. Despite its distinct and sex-specific roles during insect gametogenesis, elucidating fusome growth and inheritance in females and its structure and connectivity in males has remained challenging. Here, we take advantage of advances in three-dimensional (3D) confocal microscopy and computational image processing tools to reconstruct the topology, growth, and distribution of the fusome in both sexes. In females, our experimental findings inform a theoretical model for fusome assembly and inheritance and suggest that oocyte selection proceeds through an 'equivalency with a bias' mechanism. In males, we find that cell divisions can deviate from the maximally branched pattern observed in females, leading to greater topological variability. Our work consolidates existing disjointed experimental observations and contributes a readily generalizable computational approach for quantitative studies of gametogenesis within and across species.
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Affiliation(s)
- Rocky Diegmiller
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey, United States of America
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Jasmin Imran Alsous
- Flatiron Institute, Simons Foundation, New York, New York, United States of America
| | - Duojia Li
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Yukiko M. Yamashita
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Howard Hughes Medical Institute, Cambridge, Massachusetts, United States of America
| | - Stanislav Y. Shvartsman
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- Flatiron Institute, Simons Foundation, New York, New York, United States of America
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
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9
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Inwood SN, Harrop TWR, Dearden PK. The venom composition and parthenogenesis mechanism of the parasitoid wasp Microctonus hyperodae, a declining biocontrol agent. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 153:103897. [PMID: 36584929 DOI: 10.1016/j.ibmb.2022.103897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 06/17/2023]
Abstract
A biocontrol system in New Zealand using the endoparasitoid Microctonus hyperodae is failing, despite once being one of the most successful examples of classical biocontrol worldwide. Though it is of significant economic importance as a control agent, little is known about the genetics of M. hyperodae. In this study, RNA-seq was used to characterise two key traits of M. hyperodae in this system, the venom, critical for the initial success of biocontrol, and the asexual reproduction mode, which influenced biocontrol decline. Expanded characterisation of M. hyperodae venom revealed candidates involved in manipulating the host environment to source nutrition for the parasitoid egg, preventing a host immune response against the egg, as well as two components that may stimulate the host's innate immune system. Notably lacking from the venom-specific expression list was calreticulin, as it also had high expression in the ovaries. In-situ hybridisation revealed this ovarian expression was localised to the follicle cells, which may result in the deposition of calreticulin into the egg exochorion. Investigating the asexual reproduction of M. hyperodae revealed core meiosis-specific genes had conserved expression patterns with the highest expression in the ovaries, suggesting M. hyperodae parthenogenesis involves meiosis and that the potential for sexual reproduction may have been retained. Upregulation of genes involved in endoreduplication provides a potential mechanism for the restoration of diploidy in eggs after meiosis.
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Affiliation(s)
- Sarah N Inwood
- Bioprotection Aotearoa, Genomics Aotearoa, and the Biochemistry Department, University of Otago, Dunedin, Aotearoa, New Zealand
| | - Thomas W R Harrop
- Bioprotection Aotearoa, Genomics Aotearoa, and the Biochemistry Department, University of Otago, Dunedin, Aotearoa, New Zealand; Melbourne Bioinformatics, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Peter K Dearden
- Bioprotection Aotearoa, Genomics Aotearoa, and the Biochemistry Department, University of Otago, Dunedin, Aotearoa, New Zealand.
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10
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Molano-Fernández M, Hickson ID, Herranz H. Cyclin E overexpression in the Drosophila accessory gland induces tissue dysplasia. Front Cell Dev Biol 2023; 10:992253. [PMID: 36704199 PMCID: PMC9871066 DOI: 10.3389/fcell.2022.992253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 12/23/2022] [Indexed: 01/12/2023] Open
Abstract
The regulation of the cell division cycle is governed by a complex network of factors that together ensure that growing or proliferating cells maintain a stable genome. Defects in this system can lead to genomic instability that can affect tissue homeostasis and thus compromise human health. Variations in ploidy and cell heterogeneity are observed frequently in human cancers. Here, we examine the consequences of upregulating the cell cycle regulator Cyclin E in the Drosophila melanogaster male accessory gland. The accessory gland is the functional analog of the human prostate. This organ is composed of a postmitotic epithelium that is emerging as a powerful in vivo system for modelling different aspects of tumor initiation and progression. We show that Cyclin E upregulation in this model is sufficient to drive tissue dysplasia. Cyclin E overexpression drives endoreplication and affects DNA integrity, which results in heterogeneous nuclear and cellular composition and variable degrees of DNA damage. We present evidence showing that, despite the presence of genotoxic stress, those cells are resistant to apoptosis and thus defective cells are not eliminated from the tissue. We also show that Cyclin E-expressing cells in the accessory gland display mitochondrial DNA aggregates that colocalize with Cyclin E protein. Together, the findings presented here show that Cyclin E upregulation in postmitotic cells of the accessory gland organ causes cellular defects such as genomic instability and mitochondrial defects, eventually leading to tissue dysplasia. This study highlights novel mechanisms by which Cyclin E might contribute to disease initiation and progression.
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Affiliation(s)
- Maria Molano-Fernández
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Ian D. Hickson
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark,Department of Cellular and Molecular Medicine, Center for Chromosome Stability and Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Héctor Herranz
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark,*Correspondence: Héctor Herranz,
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11
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Piet Q, Droc G, Marande W, Sarah G, Bocs S, Klopp C, Bourge M, Siljak-Yakovlev S, Bouchez O, Lopez-Roques C, Lepers-Andrzejewski S, Bourgois L, Zucca J, Dron M, Besse P, Grisoni M, Jourda C, Charron C. A chromosome-level, haplotype-phased Vanilla planifolia genome highlights the challenge of partial endoreplication for accurate whole-genome assembly. PLANT COMMUNICATIONS 2022; 3:100330. [PMID: 35617961 PMCID: PMC9482989 DOI: 10.1016/j.xplc.2022.100330] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 04/10/2022] [Accepted: 04/27/2022] [Indexed: 06/02/2023]
Abstract
Vanilla planifolia, the species cultivated to produce one of the world's most popular flavors, is highly prone to partial genome endoreplication, which leads to highly unbalanced DNA content in cells. We report here the first molecular evidence of partial endoreplication at the chromosome scale by the assembly and annotation of an accurate haplotype-phased genome of V. planifolia. Cytogenetic data demonstrated that the diploid genome size is 4.09 Gb, with 16 chromosome pairs, although aneuploid cells are frequently observed. Using PacBio HiFi and optical mapping, we assembled and phased a diploid genome of 3.4 Gb with a scaffold N50 of 1.2 Mb and 59 128 predicted protein-coding genes. The atypical k-mer frequencies and the uneven sequencing depth observed agreed with our expectation of unbalanced genome representation. Sixty-seven percent of the genes were scattered over only 30% of the genome, putatively linking gene-rich regions and the endoreplication phenomenon. By contrast, low-coverage regions (non-endoreplicated) were rich in repeated elements but also contained 33% of the annotated genes. Furthermore, this assembly showed distinct haplotype-specific sequencing depth variation patterns, suggesting complex molecular regulation of endoreplication along the chromosomes. This high-quality, anchored assembly represents 83% of the estimated V. planifolia genome. It provides a significant step toward the elucidation of this complex genome. To support post-genomics efforts, we developed the Vanilla Genome Hub, a user-friendly integrated web portal that enables centralized access to high-throughput genomic and other omics data and interoperable use of bioinformatics tools.
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Affiliation(s)
- Quentin Piet
- CIRAD, UMR PVBMT, 97410 Saint-Pierre, La Réunion, France
| | - Gaetan Droc
- CIRAD, UMR AGAP Institut, 34398 Montpellier, France; UMR AGAP Institut, Univ Montpellier, CIRAD, INRAE, Institut Agro, 34398 Montpellier, France; French Institute of Bioinformatics (IFB) - South Green Bioinformatics Platform, Bioversity, CIRAD, INRAE, IRD, 34398 Montpellier, France.
| | | | - Gautier Sarah
- French Institute of Bioinformatics (IFB) - South Green Bioinformatics Platform, Bioversity, CIRAD, INRAE, IRD, 34398 Montpellier, France; AGAP, Univ. Montpellier, CIRAD, INRAE, Montpellier SupAgro, Montpellier, France
| | - Stéphanie Bocs
- CIRAD, UMR AGAP Institut, 34398 Montpellier, France; UMR AGAP Institut, Univ Montpellier, CIRAD, INRAE, Institut Agro, 34398 Montpellier, France; French Institute of Bioinformatics (IFB) - South Green Bioinformatics Platform, Bioversity, CIRAD, INRAE, IRD, 34398 Montpellier, France
| | - Christophe Klopp
- Plateforme Bioinformatique, Genotoul, BioinfoMics, UR875 Biométrie et Intelligence Artificielle, INRAE, Castanet-Tolosan, France
| | - Mickael Bourge
- Cytometry Facility, Imagerie-Gif, Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Sonja Siljak-Yakovlev
- Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique Evolution (ESE), 91190 Gif-sur-Yvette, France
| | | | | | | | | | - Joseph Zucca
- Département Biotechnologie, V. Mane Fils, 06620 Le Bar Sur Loup, France
| | - Michel Dron
- Université Paris-Saclay, CNRS, INRAE, Univ. Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91405 Orsay, France
| | - Pascale Besse
- Université de la Réunion, UMR PVBMT, Saint-Pierre, La Réunion, France
| | | | - Cyril Jourda
- CIRAD, UMR PVBMT, 97410 Saint-Pierre, La Réunion, France.
| | - Carine Charron
- CIRAD, UMR PVBMT, 97410 Saint-Pierre, La Réunion, France
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12
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Noncanonical function of Capicua as a growth termination signal in Drosophila oogenesis. Proc Natl Acad Sci U S A 2022; 119:e2123467119. [PMID: 35881788 PMCID: PMC9351367 DOI: 10.1073/pnas.2123467119] [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: 01/28/2023] Open
Abstract
Capicua (Cic) proteins are conserved HMG-box transcriptional repressors that control receptor tyrosine kinase (RTK) signaling responses and are implicated in human neurological syndromes and cancer. While Cic is known to exist as short (Cic-S) and long (Cic-L) isoforms with identical HMG-box and associated core regions but distinct N termini, most previous studies have focused on Cic-S, leaving the function of Cic-L unexplored. Here we show that Cic-L acts in two capacities during Drosophila oogenesis: 1) as a canonical sensor of RTK signaling in somatic follicle cells, and 2) as a regulator of postmitotic growth in germline nurse cells. In these latter cells, Cic-L behaves as a temporal signal that terminates endoreplicative growth before they dump their contents into the oocyte. We show that Cic-L is necessary and sufficient for nurse cell endoreplication arrest and induces both stabilization of CycE and down-regulation of Myc. Surprisingly, this function depends mainly on the Cic-L-specific N-terminal module, which is capable of acting independently of the Cic HMG-box-containing core. Mirroring these observations, basal metazoans possess truncated Cic-like proteins composed only of Cic-L N-terminal sequences, suggesting that this module plays unique, ancient roles unrelated to the canonical function of Cic.
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13
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Yun HS, Lee J, Kim JY, Sim YJ, Lee CW, Park JK, Kim JS, Ahn J, Song JY, Baek JH, Hwang SG. A novel function of HRP-3 in regulating cell cycle progression via the HDAC-E2F1-Cyclin E pathway in lung cancer. Cancer Sci 2021; 113:145-155. [PMID: 34714604 PMCID: PMC8748221 DOI: 10.1111/cas.15183] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 10/06/2021] [Accepted: 10/12/2021] [Indexed: 11/29/2022] Open
Abstract
To improve the poor survival rate of lung cancer patients, we investigated the role of HDGF‐related protein 3 (HRP‐3) as a potential biomarker for lung cancer. The expression of endogenous HRP‐3 in human lung cancer tissues and xenograft tumor models is indicative of its clinical relevance in lung cancer. Additionally, we demonstrated that HRP‐3 directly binds to the E2F1 promoter on chromatin. Interestingly, HRP‐3 depletion in A549 cells impedes the binding of HRP‐3 to the E2F1 promoter; this in turn hampers the interaction between Histone H3/H4 and HDAC1/2 on the E2F1 promoter, while concomitantly inducing Histone H3/H4 acetylation around the E2F1 promoter. The enhanced Histone H3/H4 acetylation on the E2F1 promoter through HRP‐3 depletion increases the transcription level of E2F1. Furthermore, the increased E2F1 transcription levels lead to the enhanced transcription of Cyclin E, known as the E2F1‐responsive gene, thus inducing S‐phase accumulation. Therefore, our study provides evidence for the utility of HRP‐3 as a biomarker for the prognosis and treatment of lung cancer. Furthermore, we delineated the capacity of HRP‐3 to regulate the E2F1 transcription level via histone deacetylation.
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Affiliation(s)
- Hong Shik Yun
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Janet Lee
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Ju-Young Kim
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea.,Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Ye-Ji Sim
- Radiation Biology Research Team, Research Center, Dongnam Institute of Radiological and Medical Sciences, Busan, Korea
| | - Chang-Woo Lee
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Jong Kuk Park
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Jae-Sung Kim
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Jiyeon Ahn
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Jie-Young Song
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Jeong-Hwa Baek
- Radiation Biology Research Team, Research Center, Dongnam Institute of Radiological and Medical Sciences, Busan, Korea
| | - Sang-Gu Hwang
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
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14
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Almeida Machado Costa C, Wang XF, Ellsworth C, Deng WM. Polyploidy in development and tumor models in Drosophila. Semin Cancer Biol 2021; 81:106-118. [PMID: 34562587 DOI: 10.1016/j.semcancer.2021.09.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 09/03/2021] [Accepted: 09/18/2021] [Indexed: 12/26/2022]
Abstract
Polyploidy, a cell status defined as more than two sets of genomic DNA, is a conserved strategy across species that can increase cell size and biosynthetic production, but the functional aspects of polyploidy are nuanced and vary across cell types. Throughout Drosophila developmental stages (embryo, larva, pupa and adult), polyploid cells are present in numerous organs and help orchestrate development while contributing to normal growth, well-being and homeostasis of the organism. Conversely, increasing evidence has shown that polyploid cells are prevalent in Drosophila tumors and play important roles in tumor growth and invasiveness. Here, we summarize the genes and pathways involved in polyploidy during normal and tumorigenic development, the mechanisms underlying polyploidization, and the functional aspects of polyploidy in development, homeostasis and tumorigenesis in the Drosophila model.
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Affiliation(s)
- Caique Almeida Machado Costa
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, Tulane Cancer Center, New Orleans, LA 70112, United States
| | - Xian-Feng Wang
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, Tulane Cancer Center, New Orleans, LA 70112, United States
| | - Calder Ellsworth
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, Tulane Cancer Center, New Orleans, LA 70112, United States
| | - Wu-Min Deng
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, Tulane Cancer Center, New Orleans, LA 70112, United States.
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15
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Kim M, Delos Santos K, Moon NS. Proper CycE-Cdk2 activity in endocycling tissues requires regulation of the cyclin-dependent kinase inhibitor Dacapo by dE2F1b in Drosophila. Genetics 2021; 217:1-15. [PMID: 33683365 DOI: 10.1093/genetics/iyaa029] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 12/06/2020] [Indexed: 01/05/2023] Open
Abstract
Polyploidy is an integral part of development and is associated with cellular stress, aging, and pathological conditions. The endocycle, comprised of successive rounds of G and S phases without mitosis, is widely employed to produce polyploid cells in plants and animals. In Drosophila, maintenance of the endocycle is dependent on E2F-governed oscillations of Cyclin E (CycE)-Cdk2 activity, which is known to be largely regulated at the level of transcription. In this study, we report an additional level of E2F-dependent control of CycE-Cdk2 activity during the endocycle. Genetic experiments revealed that an alternative isoform of Drosophila de2f1, dE2F1b, regulates the expression of the p27CIP/KIP-like Cdk inhibitor Dacapo (Dap). We provide evidence showing that dE2F1b-dependent Dap expression in endocycling tissues is necessary for setting proper CycE-Cdk2 activity. Furthermore, we demonstrate that dE2F1b is required for proliferating cell nuclear antigen expression that establishes a negative feedback loop in S phase. Overall, our study reveals previously unappreciated E2F-dependent regulatory networks that are critical for the periodic transition between G and S phases during the endocycle.
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Affiliation(s)
- Minhee Kim
- Department of Biology, Developmental Biology Research Initiative, McGill University, Montreal, Quebec H3A 1B1 Canada
| | - Keemo Delos Santos
- Department of Biology, Developmental Biology Research Initiative, McGill University, Montreal, Quebec H3A 1B1 Canada
| | - Nam-Sung Moon
- Department of Biology, Developmental Biology Research Initiative, McGill University, Montreal, Quebec H3A 1B1 Canada
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16
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Blatt P, Wong-Deyrup SW, McCarthy A, Breznak S, Hurton MD, Upadhyay M, Bennink B, Camacho J, Lee MT, Rangan P. RNA degradation is required for the germ-cell to maternal transition in Drosophila. Curr Biol 2021; 31:2984-2994.e7. [PMID: 33989522 PMCID: PMC8319052 DOI: 10.1016/j.cub.2021.04.052] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 03/26/2021] [Accepted: 04/20/2021] [Indexed: 10/21/2022]
Abstract
In sexually reproducing animals, the oocyte contributes a large supply of RNAs that are essential to launch development upon fertilization. The mechanisms that regulate the composition of the maternal RNA contribution during oogenesis are unclear. Here, we show that a subset of RNAs expressed during the early stages of oogenesis is subjected to regulated degradation during oocyte specification. Failure to remove these RNAs results in oocyte dysfunction and death. We identify the RNA-degrading Super Killer complex and No-Go Decay factor Pelota as key regulators of oogenesis via targeted degradation of specific RNAs expressed in undifferentiated germ cells. These regulators target RNAs enriched for cytidine sequences that are bound by the polypyrimidine tract binding protein Half pint. Thus, RNA degradation helps orchestrate a germ cell-to-maternal transition that gives rise to the maternal contribution to the zygote.
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Affiliation(s)
- Patrick Blatt
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222
| | - Siu Wah Wong-Deyrup
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222
| | - Alicia McCarthy
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222; 10x Genomics, Inc., 6230 Stoneridge Mall Road, Pleasanton, CA, 94588
| | - Shane Breznak
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222
| | - Matthew D Hurton
- University of Pittsburgh, Department of Biological Sciences; 4249 Fifth Avenue, Pittsburgh, PA 15260
| | - Maitreyi Upadhyay
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222; Department of Stem Cell and Regenerative Biology, Sherman Fairchild 100, Harvard University, 7 Divinity Avenue, Cambridge, MA 02138
| | - Benjamin Bennink
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222
| | - Justin Camacho
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222
| | - Miler T Lee
- University of Pittsburgh, Department of Biological Sciences; 4249 Fifth Avenue, Pittsburgh, PA 15260.
| | - Prashanth Rangan
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222.
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17
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Doherty CA, Diegmiller R, Kapasiawala M, Gavis ER, Shvartsman SY. Coupled oscillators coordinate collective germline growth. Dev Cell 2021; 56:860-870.e8. [PMID: 33689691 PMCID: PMC8265018 DOI: 10.1016/j.devcel.2021.02.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 12/03/2020] [Accepted: 02/16/2021] [Indexed: 12/20/2022]
Abstract
Developing oocytes need large supplies of macromolecules and organelles. A conserved strategy for accumulating these products is to pool resources of oocyte-associated germline nurse cells. In Drosophila, these cells grow more than 100-fold to boost their biosynthetic capacity. No previously known mechanism explains how nurse cells coordinate growth collectively. Here, we report a cell cycle-regulating mechanism that depends on bidirectional communication between the oocyte and nurse cells, revealing the oocyte as a critical regulator of germline cyst growth. Transcripts encoding the cyclin-dependent kinase inhibitor, Dacapo, are synthesized by the nurse cells and actively localized to the oocyte. Retrograde movement of the oocyte-synthesized Dacapo protein to the nurse cells generates a network of coupled oscillators that controls the cell cycle of the nurse cells to regulate cyst growth. We propose that bidirectional nurse cell-oocyte communication establishes a growth-sensing feedback mechanism that regulates the quantity of maternal resources loaded into the oocyte.
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Affiliation(s)
- Caroline A Doherty
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA; Lewis-Sigler Institute of Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
| | - Rocky Diegmiller
- Lewis-Sigler Institute of Integrative Genomics, Princeton University, Princeton, NJ 08540, USA; Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08540, USA
| | - Manisha Kapasiawala
- Lewis-Sigler Institute of Integrative Genomics, Princeton University, Princeton, NJ 08540, USA; Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08540, USA
| | - Elizabeth R Gavis
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA.
| | - Stanislav Y Shvartsman
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA; Lewis-Sigler Institute of Integrative Genomics, Princeton University, Princeton, NJ 08540, USA; Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08540, USA; Center for Computational Biology, Flatiron Institute, New York, NY 10010, USA.
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18
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Dai W, Guo X, Cao Y, Mondo JA, Campanale JP, Montell BJ, Burrous H, Streichan S, Gov N, Rappel WJ, Montell DJ. Tissue topography steers migrating Drosophila border cells. Science 2021; 370:987-990. [PMID: 33214282 DOI: 10.1126/science.aaz4741] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 05/11/2020] [Accepted: 09/28/2020] [Indexed: 12/16/2022]
Abstract
Moving cells can sense and respond to physical features of the microenvironment; however, in vivo, the significance of tissue topography is mostly unknown. Here, we used Drosophila border cells, an established model for in vivo cell migration, to study how chemical and physical information influences path selection. Although chemical cues were thought to be sufficient, live imaging, genetics, modeling, and simulations show that microtopography is also important. Chemoattractants promote predominantly posterior movement, whereas tissue architecture presents orthogonal information, a path of least resistance concentrated near the center of the egg chamber. E-cadherin supplies a permissive haptotactic cue. Our results provide insight into how cells integrate and prioritize topographical, adhesive, and chemoattractant cues to choose one path among many.
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Affiliation(s)
- Wei Dai
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Xiaoran Guo
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Yuansheng Cao
- Department of Physics, University of California, San Diego, CA 92093, USA
| | - James A Mondo
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Joseph P Campanale
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | | | - Haley Burrous
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Sebastian Streichan
- Department of Physics, University of California, Santa Barbara, CA 93106, USA
| | - Nir Gov
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Wouter-Jan Rappel
- Department of Physics, University of California, San Diego, CA 92093, USA
| | - Denise J Montell
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA.
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19
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Nandakumar S, Grushko O, Buttitta LA. Polyploidy in the adult Drosophila brain. eLife 2020; 9:e54385. [PMID: 32840209 PMCID: PMC7447450 DOI: 10.7554/elife.54385] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 08/07/2020] [Indexed: 12/12/2022] Open
Abstract
Long-lived cells such as terminally differentiated postmitotic neurons and glia must cope with the accumulation of damage over the course of an animal's lifespan. How long-lived cells deal with ageing-related damage is poorly understood. Here we show that polyploid cells accumulate in the adult fly brain and that polyploidy protects against DNA damage-induced cell death. Multiple types of neurons and glia that are diploid at eclosion, become polyploid in the adult Drosophila brain. The optic lobes exhibit the highest levels of polyploidy, associated with an elevated DNA damage response in this brain region. Inducing oxidative stress or exogenous DNA damage leads to an earlier onset of polyploidy, and polyploid cells in the adult brain are more resistant to DNA damage-induced cell death than diploid cells. Our results suggest polyploidy may serve a protective role for neurons and glia in adult Drosophila melanogaster brains.
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Affiliation(s)
- Shyama Nandakumar
- Molecular, Cellular, and Developmental Biology, University of MichiganAnn ArborUnited States
| | - Olga Grushko
- Molecular, Cellular, and Developmental Biology, University of MichiganAnn ArborUnited States
| | - Laura A Buttitta
- Molecular, Cellular, and Developmental Biology, University of MichiganAnn ArborUnited States
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20
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Evolutionarily Conserved Roles for Apontic in Induction and Subsequent Decline of Cyclin E Expression. iScience 2020; 23:101369. [PMID: 32736066 PMCID: PMC7394757 DOI: 10.1016/j.isci.2020.101369] [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: 02/06/2020] [Revised: 05/24/2020] [Accepted: 07/11/2020] [Indexed: 11/24/2022] Open
Abstract
Cyclin E is a key factor for S phase entry, and deregulation of Cyclin E results in developmental defects and tumors. Therefore, proper cycling of Cyclin E is crucial for normal growth. Here we found that transcription factors Apontic (Apt) and E2f1 cooperate to induce cyclin E in Drosophila. Functional binding motifs of Apt and E2f1 are clustered in the first intron of Drosophila cyclin E and directly contribute to the cyclin E transcription. Knockout of apt and e2f1 together abolished Cyclin E expression. Furthermore, Apt up-regulates Retinoblastoma family protein 1 (Rbf1) for proper chromatin compaction, which is known to repress cyclin E. Notably, Apt-dependent up-regulation of Cyclin E and Rbf1 is evolutionarily conserved in mammalian cells. Our findings reveal a unique mechanism underlying the induction and subsequent decline of Cyclin E expression.
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21
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DeLuca SZ, Ghildiyal M, Pang LY, Spradling AC. Differentiating Drosophila female germ cells initiate Polycomb silencing by regulating PRC2-interacting proteins. eLife 2020; 9:56922. [PMID: 32773039 PMCID: PMC7438113 DOI: 10.7554/elife.56922] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 08/06/2020] [Indexed: 01/18/2023] Open
Abstract
Polycomb silencing represses gene expression and provides a molecular memory of chromatin state that is essential for animal development. We show that Drosophila female germline stem cells (GSCs) provide a powerful system for studying Polycomb silencing. GSCs have a non-canonical distribution of PRC2 activity and lack silenced chromatin like embryonic progenitors. As GSC daughters differentiate into nurse cells and oocytes, nurse cells, like embryonic somatic cells, silence genes in traditional Polycomb domains and in generally inactive chromatin. Developmentally controlled expression of two Polycomb repressive complex 2 (PRC2)-interacting proteins, Pcl and Scm, initiate silencing during differentiation. In GSCs, abundant Pcl inhibits PRC2-dependent silencing globally, while in nurse cells Pcl declines and newly induced Scm concentrates PRC2 activity on traditional Polycomb domains. Our results suggest that PRC2-dependent silencing is developmentally regulated by accessory proteins that either increase the concentration of PRC2 at target sites or inhibit the rate that PRC2 samples chromatin.
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Affiliation(s)
- Steven Z DeLuca
- Howard Hughes Medical Institute Research Laboratories Department of Embryology, Carnegie Institution for Science, Baltimore, United States
| | - Megha Ghildiyal
- Howard Hughes Medical Institute Research Laboratories Department of Embryology, Carnegie Institution for Science, Baltimore, United States
| | - Liang-Yu Pang
- Howard Hughes Medical Institute Research Laboratories Department of Embryology, Carnegie Institution for Science, Baltimore, United States
| | - Allan C Spradling
- Howard Hughes Medical Institute Research Laboratories Department of Embryology, Carnegie Institution for Science, Baltimore, United States
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22
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Kolesnikova TD, Kolodyazhnaya AV, Pokholkova GV, Schubert V, Dovgan VV, Romanenko SA, Prokopov DY, Zhimulev IF. Effects of Mutations in the Drosophila melanogaster Rif1 Gene on the Replication and Underreplication of Pericentromeric Heterochromatin in Salivary Gland Polytene Chromosomes. Cells 2020; 9:cells9061501. [PMID: 32575592 PMCID: PMC7349278 DOI: 10.3390/cells9061501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 01/09/2023] Open
Abstract
In Drosophila salivary gland polytene chromosomes, a substantial portion of heterochromatin is underreplicated. The combination of mutations SuURES and Su(var)3-906 results in the polytenization of a substantial fraction of unique and moderately repeated sequences but has almost no effect on satellite DNA replication. The Rap1 interacting factor 1 (Rif) protein is a conserved regulator of replication timing, and in Drosophila, it affects underreplication in polytene chromosomes. We compared the morphology of pericentromeric regions and labeling patterns of in situ hybridization of heterochromatin-specific DNA probes between wild-type salivary gland polytene chromosomes and the chromosomes of Rif1 mutants and SuUR Su(var)3-906 double mutants. We show that, despite general similarities, heterochromatin zones exist that are polytenized only in the Rif1 mutants, and that there are zones that are under specific control of Su(var)3-9. In the Rif1 mutants, we found additional polytenization of the largest blocks of satellite DNA (in particular, satellite 1.688 of chromosome X and simple satellites in chromosomes X and 4) as well as partial polytenization of chromosome Y. Data on pulsed incorporation of 5-ethynyl-2′-deoxyuridine (EdU) into polytene chromosomes indicated that in the Rif1 mutants, just as in the wild type, most of the heterochromatin becomes replicated during the late S phase. Nevertheless, a significantly increased number of heterochromatin replicons was noted. These results suggest that Rif1 regulates the activation probability of heterochromatic origins in the satellite DNA region.
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Affiliation(s)
- Tatyana D. Kolesnikova
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
- Laboratory of Structural, Functional and Comparative Genomics, Novosibirsk State University, 630090 Novosibirsk, Russia
- Correspondence:
| | - Alexandra V. Kolodyazhnaya
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Galina V. Pokholkova
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466 Seeland, Germany;
| | - Viktoria V. Dovgan
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Svetlana A. Romanenko
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
| | - Dmitry Yu. Prokopov
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
| | - Igor F. Zhimulev
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.V.K.); (G.V.P.); (V.V.D.); (S.A.R.); (D.Y.P.); (I.F.Z.)
- Laboratory of Structural, Functional and Comparative Genomics, Novosibirsk State University, 630090 Novosibirsk, Russia
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23
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Ren D, Song J, Ni M, Kang L, Guo W. Regulatory Mechanisms of Cell Polyploidy in Insects. Front Cell Dev Biol 2020; 8:361. [PMID: 32548115 PMCID: PMC7272692 DOI: 10.3389/fcell.2020.00361] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 04/22/2020] [Indexed: 12/14/2022] Open
Abstract
Polyploidy cells undergo the endocycle to generate DNA amplification without cell division and have important biological functions in growth, development, reproduction, immune response, nutrient support, and conferring resistance to DNA damage in animals. In this paper, we have specially summarized current research progresses in the regulatory mechanisms of cell polyploidy in insects. First, insect hormones including juvenile hormone and 20-hydroxyecdysone regulate the endocycle of variant cells in diverse insect species. Second, cells skip mitotic division in response to developmental programming and conditional stimuli such as wound healing, regeneration, and aging. Third, the reported regulatory pathways of mitotic to endocycle switch (MES), including Notch, Hippo, and JNK signaling pathways, are summarized and constructed into genetic network. Thus, we think that the studies in crosstalk of hormones and their effects on canonical pathways will shed light on the mechanism of cell polyploidy and elucidate the evolutionary adaptions of MES through diverse insect species.
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Affiliation(s)
- Dani Ren
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Juan Song
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Ming Ni
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, Hebei University, Baoding, China
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, Hebei University, Baoding, China
| | - Wei Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
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24
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Armstrong RL, Das S, Hill CA, Duronio RJ, Nordman JT. Rif1 Functions in a Tissue-Specific Manner To Control Replication Timing Through Its PP1-Binding Motif. Genetics 2020; 215:75-87. [PMID: 32144132 PMCID: PMC7198277 DOI: 10.1534/genetics.120.303155] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 03/05/2020] [Indexed: 12/19/2022] Open
Abstract
Replication initiation in eukaryotic cells occurs asynchronously throughout S phase, yielding early- and late-replicating regions of the genome, a process known as replication timing (RT). RT changes during development to ensure accurate genome duplication and maintain genome stability. To understand the relative contributions that cell lineage, cell cycle, and replication initiation regulators have on RT, we utilized the powerful developmental systems available in Drosophila melanogaster We generated and compared RT profiles from mitotic cells of different tissues and from mitotic and endocycling cells of the same tissue. Our results demonstrate that cell lineage has the largest effect on RT, whereas switching from a mitotic to an endoreplicative cell cycle has little to no effect on RT. Additionally, we demonstrate that the RT differences we observed in all cases are largely independent of transcriptional differences. We also employed a genetic approach in these same cell types to understand the relative contribution the eukaryotic RT control factor, Rif1, has on RT control. Our results demonstrate that Rif1 can function in a tissue-specific manner to control RT. Importantly, the Protein Phosphatase 1 (PP1) binding motif of Rif1 is essential for Rif1 to regulate RT. Together, our data support a model in which the RT program is primarily driven by cell lineage and is further refined by Rif1/PP1 to ultimately generate tissue-specific RT programs.
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Affiliation(s)
- Robin L Armstrong
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Souradip Das
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37232
| | - Christina A Hill
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Robert J Duronio
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina 27599
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Jared T Nordman
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37232
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Skorobagatko DA, Mazilov AA, Strashnyuk VY. Endoreduplication in Drosophila melanogaster progeny after exposure to acute γ-irradiation. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2020; 59:211-220. [PMID: 31927628 DOI: 10.1007/s00411-019-00828-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Accepted: 12/21/2019] [Indexed: 06/10/2023]
Abstract
The purpose of this investigation was to study the effect of acute γ-irradiation of parent adults on the endoreduplication of giant chromosomes in F1 generation of Drosophila melanogaster Meig. A wild-type Oregon-R strain was used as the material. Virgin females and males of Drosophila adults at the age of 3 days were irradiated with doses of 8, 16 and 25 Gy. Giant chromosomes were studied by cytomorphometry on squashed preparations of Drosophila salivary glands stained with acetoorsein. The preparations were obtained at late third instar larvae. The mean values of the polyteny degree of chromosomes (PDC) in males increased after 8 Gy by 10.6%, after 25 Gy by 7.4%, and did not change after the dose of 16 Gy. In females, the PDC did not differ from the control irrespective of the irradiation dose. An increase in endoreduplication was also evidenced by the accelerated development of offsprings of both sexes after irradiation of parents with 25 Gy, and in males also at a dose of 16 Gy. The statistical impact of power of radiation on polyteny was 26.8%, while the impact of sex was 4.9%. The impact of power of radiation on the developmental rate of offspring was 4.4% in males and 7.5% in females. The enhancement of endoreduplication is considered as a consequence of increasing selection pressure after irradiation. The possible involvement of epigenetic effects in the effect of ionizing radiation on endoreduplication is discussed.
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Affiliation(s)
- Daria A Skorobagatko
- Department of Genetics and Cytology, VN Karazin Kharkiv National University, Svobody sq., 4, Kharkiv, 61022, Ukraine
- Laboratory of Radiation Research and Environmental Protection, NSC 'Kharkiv Institute of Physics and Technology', Academicheskaya str., 1, Kharkiv, 61108, Ukraine
| | - Alexey A Mazilov
- Laboratory of Radiation Research and Environmental Protection, NSC 'Kharkiv Institute of Physics and Technology', Academicheskaya str., 1, Kharkiv, 61108, Ukraine
| | - Volodymyr Yu Strashnyuk
- Department of Genetics and Cytology, VN Karazin Kharkiv National University, Svobody sq., 4, Kharkiv, 61022, Ukraine.
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Zeng J, Huynh N, Phelps B, King-Jones K. Snail synchronizes endocycling in a TOR-dependent manner to coordinate entry and escape from endoreplication pausing during the Drosophila critical weight checkpoint. PLoS Biol 2020; 18:e3000609. [PMID: 32097403 PMCID: PMC7041797 DOI: 10.1371/journal.pbio.3000609] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 01/28/2020] [Indexed: 12/30/2022] Open
Abstract
The final body size of any given individual underlies both genetic and environmental constraints. Both mammals and insects use target of rapamycin (TOR) and insulin signaling pathways to coordinate growth with nutrition. In holometabolous insects, the growth period is terminated through a cascade of peptide and steroid hormones that end larval feeding behavior and trigger metamorphosis, a nonfeeding stage during which the larval body plan is remodeled to produce an adult. This irreversible decision, termed the critical weight (CW) checkpoint, ensures that larvae have acquired sufficient nutrients to complete and survive development to adulthood. How insects assess body size via the CW checkpoint is still poorly understood on the molecular level. We show here that the Drosophila transcription factor Snail plays a key role in this process. Before and during the CW checkpoint, snail is highly expressed in the larval prothoracic gland (PG), an endocrine tissue undergoing endoreplication and primarily dedicated to the production of the steroid hormone ecdysone. We observed two Snail peaks in the PG, one before and one after the molt from the second to the third instar. Remarkably, these Snail peaks coincide with two peaks of PG cells entering S phase and a slowing of DNA synthesis between the peaks. Interestingly, the second Snail peak occurs at the exit of the CW checkpoint. Snail levels then decline continuously, and endoreplication becomes nonsynchronized in the PG after the CW checkpoint. This suggests that the synchronization of PG cells into S phase via Snail represents the mechanistic link used to terminate the CW checkpoint. Indeed, PG-specific loss of snail function prior to the CW checkpoint causes larval arrest due to a cessation of endoreplication in PG cells, whereas impairing snail after the CW checkpoint no longer affected endoreplication and further development. During the CW window, starvation or loss of TOR signaling disrupted the formation of Snail peaks and endocycle synchronization, whereas later starvation had no effect on snail expression. Taken together, our data demonstrate that insects use the TOR pathway to assess nutrient status during larval development to regulate Snail in ecdysone-producing cells as an effector protein to coordinate endoreplication and CW attainment. During Drosophila development, the time window when larvae assess their readiness for metamorphosis is marked by slowing of cell growth in the prothoracic gland that produces the molting hormone; cell growth (via DNA endoreplication) then increases, allowing the production of the amount of hormone required to trigger metamorphosis. This study shows that these processes depend on the transcription factor Snail.
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Affiliation(s)
- Jie Zeng
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
| | - Nhan Huynh
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
| | - Brian Phelps
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
| | - Kirst King-Jones
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
- * E-mail:
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Jouvence a small nucleolar RNA required in the gut extends lifespan in Drosophila. Nat Commun 2020; 11:987. [PMID: 32080190 PMCID: PMC7033134 DOI: 10.1038/s41467-020-14784-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 01/31/2020] [Indexed: 01/06/2023] Open
Abstract
Longevity is influenced by genetic and environmental factors, but the underlying mechanisms remain elusive. Here, we functionally characterise a Drosophila small nucleolar RNA (snoRNA), named jouvence whose loss of function reduces lifespan. The genomic region of jouvence rescues the longevity in mutant, while its overexpression in wild-type increases lifespan. Jouvence is required in enterocytes. In mutant, the epithelium of the gut presents more hyperplasia, while the overexpression of jouvence prevents it. Molecularly, the mutant lack pseudouridylation on 18S and 28S-rRNA, a function rescued by targeted expression of jouvence in the gut. A transcriptomic analysis performed from the gut reveals that several genes are either up- or down-regulated, while restoring the mRNA level of two genes (ninaD or CG6296) rescue the longevity. Since snoRNAs are structurally and functionally well conserved throughout evolution, we identified putative jouvence orthologue in mammals including humans, suggesting that its function in longevity could be conserved. Small non-coding RNAs contribute to the regulation of aging. Here the authors identify a small nucleolar RNA, the snoRNA jouvence, which extends the lifespan of fruit flies through its function in the gut, and is conserved in humans.
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Grendler J, Lowgren S, Mills M, Losick VP. Wound-induced polyploidization is driven by Myc and supports tissue repair in the presence of DNA damage. Development 2019; 146:dev.173005. [PMID: 31315896 PMCID: PMC6703715 DOI: 10.1242/dev.173005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 07/05/2019] [Indexed: 12/19/2022]
Abstract
Tissue repair usually requires either polyploid cell growth or cell division, but the molecular mechanism promoting polyploidy and limiting cell division remains poorly understood. Here, we find that injury to the adult Drosophila epithelium causes cells to enter the endocycle through the activation of Yorkie-dependent genes (Myc and E2f1). Myc is even sufficient to induce the endocycle in the uninjured post-mitotic epithelium. As result, epithelial cells enter S phase but mitosis is blocked by inhibition of mitotic gene expression. The mitotic cell cycle program can be activated by simultaneously expressing the Cdc25-like phosphatase String (stg), while genetically depleting APC/C E3 ligase fizzy-related (fzr). However, forcing cells to undergo mitosis is detrimental to wound repair as the adult fly epithelium accumulates DNA damage, and mitotic errors ensue when cells are forced to proliferate. In conclusion, we find that wound-induced polyploidization enables tissue repair when cell division is not a viable option.
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Affiliation(s)
- Janelle Grendler
- Kathryn W. Davis Center for Regenerative Biology and Medicine, MDI Biological Laboratory, 159 Old Bar Harbor Rd, Bar Harbor, ME 04609, USA
| | - Sara Lowgren
- Kathryn W. Davis Center for Regenerative Biology and Medicine, MDI Biological Laboratory, 159 Old Bar Harbor Rd, Bar Harbor, ME 04609, USA
| | - Monique Mills
- Kathryn W. Davis Center for Regenerative Biology and Medicine, MDI Biological Laboratory, 159 Old Bar Harbor Rd, Bar Harbor, ME 04609, USA
| | - Vicki P Losick
- Kathryn W. Davis Center for Regenerative Biology and Medicine, MDI Biological Laboratory, 159 Old Bar Harbor Rd, Bar Harbor, ME 04609, USA
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Rotelli MD, Policastro RA, Bolling AM, Killion AW, Weinberg AJ, Dixon MJ, Zentner GE, Walczak CE, Lilly MA, Calvi BR. A Cyclin A-Myb-MuvB-Aurora B network regulates the choice between mitotic cycles and polyploid endoreplication cycles. PLoS Genet 2019; 15:e1008253. [PMID: 31291240 PMCID: PMC6645565 DOI: 10.1371/journal.pgen.1008253] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 07/22/2019] [Accepted: 06/18/2019] [Indexed: 12/30/2022] Open
Abstract
Endoreplication is a cell cycle variant that entails cell growth and periodic genome duplication without cell division, and results in large, polyploid cells. Cells switch from mitotic cycles to endoreplication cycles during development, and also in response to conditional stimuli during wound healing, regeneration, aging, and cancer. In this study, we use integrated approaches in Drosophila to determine how mitotic cycles are remodeled into endoreplication cycles, and how similar this remodeling is between induced and developmental endoreplicating cells (iECs and devECs). Our evidence suggests that Cyclin A / CDK directly activates the Myb-MuvB (MMB) complex to induce transcription of a battery of genes required for mitosis, and that repression of CDK activity dampens this MMB mitotic transcriptome to promote endoreplication in both iECs and devECs. iECs and devECs differed, however, in that devECs had reduced expression of E2F1-dependent genes that function in S phase, whereas repression of the MMB transcriptome in iECs was sufficient to induce endoreplication without a reduction in S phase gene expression. Among the MMB regulated genes, knockdown of AurB protein and other subunits of the chromosomal passenger complex (CPC) induced endoreplication, as did knockdown of CPC-regulated cytokinetic, but not kinetochore, proteins. Together, our results indicate that the status of a CycA-Myb-MuvB-AurB network determines the decision to commit to mitosis or switch to endoreplication in both iECs and devECs, and suggest that regulation of different steps of this network may explain the known diversity of polyploid cycle types in development and disease.
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Affiliation(s)
- Michael D. Rotelli
- Department of Biology. Indiana University, Bloomington, Indiana, United States of America
- Melvin and Bren Simon Cancer Center, Indianapolis, Indiana, United States of America
| | - Robert A. Policastro
- Department of Biology. Indiana University, Bloomington, Indiana, United States of America
- Melvin and Bren Simon Cancer Center, Indianapolis, Indiana, United States of America
| | - Anna M. Bolling
- Department of Biology. Indiana University, Bloomington, Indiana, United States of America
- Melvin and Bren Simon Cancer Center, Indianapolis, Indiana, United States of America
| | - Andrew W. Killion
- Department of Biology. Indiana University, Bloomington, Indiana, United States of America
- Melvin and Bren Simon Cancer Center, Indianapolis, Indiana, United States of America
| | - Abraham J. Weinberg
- Department of Biology. Indiana University, Bloomington, Indiana, United States of America
- Melvin and Bren Simon Cancer Center, Indianapolis, Indiana, United States of America
| | - Michael J. Dixon
- Department of Biology. Indiana University, Bloomington, Indiana, United States of America
- Melvin and Bren Simon Cancer Center, Indianapolis, Indiana, United States of America
| | - Gabriel E. Zentner
- Department of Biology. Indiana University, Bloomington, Indiana, United States of America
- Melvin and Bren Simon Cancer Center, Indianapolis, Indiana, United States of America
| | - Claire E. Walczak
- Melvin and Bren Simon Cancer Center, Indianapolis, Indiana, United States of America
- Indiana University School of Medicine, Bloomington, Indiana, United States of America
| | - Mary A. Lilly
- National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Brian R. Calvi
- Department of Biology. Indiana University, Bloomington, Indiana, United States of America
- Melvin and Bren Simon Cancer Center, Indianapolis, Indiana, United States of America
- Indiana University School of Medicine, Bloomington, Indiana, United States of America
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Kolesnikova TD, Antonenko OV, Makunin IV. Replication timing in Drosophila and its peculiarities in polytene chromosomes. Vavilovskii Zhurnal Genet Selektsii 2019. [DOI: 10.18699/vj19.473] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Drosophila melanogaster is one of the popular model organisms in DNA replication studies. Since the 1960s, DNA replication of polytene chromosomes has been extensively studied by cytological methods. In the recent two decades, the progress in our understanding of DNA replication was associated with new techniques. Use of fluorescent dyes increased the resolution of cytological methods significantly. High-throughput methods allowed analysis of DNA replication on a genome scale, as well as its correlation with chromatin structure and gene activi ty. Precise mapping of the cytological structures of polytene chromosomes to the genome assembly allowed comparison of replication between polytene chromosomes and chromosomes of diploid cells. New features of replication characteristic for D. melanogaster were described for both diploid and polytene chromosomes. Comparison of genomic replication profiles revealed a significant similarity between Drosophila and other well-studi ed eukaryotic species, such as human. Early replication is often confined to intensely transcribed gene-dense regions characterized by multiple replication initiation sites. Features of DNA replication in Drosophila might be explained by a compact genome. The organization of replication in polytene chromosomes has much in common with the organization of replication in chromosomes in diploid cells. The most important feature of replication in polytene chromosomes is its low rate and the dependence of S-phase duration on many factors: external and internal, local and global. The speed of replication forks in D. melanogaster polytene chromosomes is affected by SUUR and Rif1 proteins. It is not known yet how universal the mechanisms associated with these factors are, but their study is very promising.
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Affiliation(s)
- T. D. Kolesnikova
- Institute of Molecular and Cellular Biology, SB RAS. Novosibirsk State University
| | | | - I. V. Makunin
- Institute of Molecular and Cellular Biology, SB RAS; Research Computing Centre, The University of Queensland
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Abstract
Gametogenesis represents the most dramatic cellular differentiation pathways in both female and male flies. At the genome level, meiosis ensures that diploid germ cells become haploid gametes. At the epigenome level, extensive changes are required to turn on and shut off gene expression in a precise spatiotemporally controlled manner. Research applying conventional molecular genetics and cell biology, in combination with rapidly advancing genomic tools have helped us to investigate (1) how germ cells maintain lineage specificity throughout their adult reproductive lifetime; (2) what molecular mechanisms ensure proper oogenesis and spermatogenesis, as well as protect genome integrity of the germline; (3) how signaling pathways contribute to germline-soma communication; and (4) if such communication is important. In this chapter, we highlight recent discoveries that have improved our understanding of these questions. On the other hand, restarting a new life cycle upon fertilization is a unique challenge faced by gametes, raising questions that involve intergenerational and transgenerational epigenetic inheritance. Therefore, we also discuss new developments that link changes during gametogenesis to early embryonic development-a rapidly growing field that promises to bring more understanding to some fundamental questions regarding metazoan development.
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Abstract
Polyploid cells, which contain multiple copies of the typically diploid genome, are widespread in plants and animals. Polyploidization can be developmentally programmed or stress induced, and arises from either cell-cell fusion or a process known as endoreplication, in which cells replicate their DNA but either fail to complete cytokinesis or to progress through M phase entirely. Polyploidization offers cells several potential fitness benefits, including the ability to increase cell size and biomass production without disrupting cell and tissue structure, and allowing improved cell longevity through higher tolerance to genomic stress and apoptotic signals. Accordingly, recent studies have uncovered crucial roles for polyploidization in compensatory cell growth during tissue regeneration in the heart, liver, epidermis and intestine. Here, we review current knowledge of the molecular pathways that generate polyploidy and discuss how polyploidization is used in tissue repair and regeneration.
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Affiliation(s)
| | - Bruce A Edgar
- Huntsman Cancer Institute, Salt Lake City, UT 84112, USA
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Mammalian endoreplication emerges to reveal a potential developmental timer. Cell Death Differ 2018; 25:471-476. [PMID: 29352263 PMCID: PMC5864232 DOI: 10.1038/s41418-017-0040-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 11/07/2017] [Accepted: 11/08/2017] [Indexed: 01/27/2023] Open
Abstract
Among the most intriguing and relevant questions in physiology is how developing tissues correctly coordinate proliferation with differentiation. Endoreplication, in a broad sense, is a consequence of a cell division block in the presence of an active cell cycle, and it typically occurs as cells differentiate terminally to fulfill a specialised function. Until recently, endoreplication was thought to be a rare variation of the cell cycle in mammals, more common in invertebrates and plants. However, in the last years, endoreplication has been uncovered in various tissues in mammalian organisms, including human. A recent report showing that cells in the mammary gland become binucleate at lactation sheds new insight into the importance of mammalian polyploidisation. We here propose that endoreplication is a widespread phenomenon in mammalian developing tissues that results from an automatic, robust and simple self-limiting mechanism coordinating cell multiplication with differentiation. This mechanism might act as a developmental timer. The model has implications for homeostasis control and carcinogenesis.
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Posukh OV, Maksimov DA, Laktionov PP, Koryakov DE, Belyakin SN. Functional dissection of Drosophila melanogaster SUUR protein influence on H3K27me3 profile. Epigenetics Chromatin 2017; 10:56. [PMID: 29191233 PMCID: PMC5709859 DOI: 10.1186/s13072-017-0163-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 11/23/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In eukaryotes, heterochromatin replicates late in S phase of the cell cycle and contains specific covalent modifications of histones. SuUR mutation found in Drosophila makes heterochromatin replicate earlier than in wild type and reduces the level of repressive histone modifications. SUUR protein was shown to be associated with moving replication forks, apparently through the interaction with PCNA. The biological process underlying the effects of SUUR on replication and composition of heterochromatin remains unknown. RESULTS Here we performed a functional dissection of SUUR protein effects on H3K27me3 level. Using hidden Markow model-based algorithm we revealed SuUR-sensitive chromosomal regions that demonstrated unusual characteristics: They do not contain Polycomb and require SUUR function to sustain H3K27me3 level. We tested the role of SUUR protein in the mechanisms that could affect H3K27me3 histone levels in these regions. We found that SUUR does not affect the initial H3K27me3 pattern formation in embryogenesis or Polycomb distribution in the chromosomes. We also ruled out the possible effect of SUUR on histone genes expression and its involvement in DSB repair. CONCLUSIONS Obtained results support the idea that SUUR protein contributes to the heterochromatin maintenance during the chromosome replication. A model that explains major SUUR-associated phenotypes is proposed.
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Affiliation(s)
- Olga V Posukh
- Genomics Lab, Institute of Molecular and Cellular Biology SB RAS, Lavrentyev ave. 8/2, Novosibirsk, Russia, 630090
| | - Daniil A Maksimov
- Genomics Lab, Institute of Molecular and Cellular Biology SB RAS, Lavrentyev ave. 8/2, Novosibirsk, Russia, 630090
| | - Petr P Laktionov
- Genomics Lab, Institute of Molecular and Cellular Biology SB RAS, Lavrentyev ave. 8/2, Novosibirsk, Russia, 630090
| | - Dmitry E Koryakov
- Genomics Lab, Institute of Molecular and Cellular Biology SB RAS, Lavrentyev ave. 8/2, Novosibirsk, Russia, 630090.,Novosibirsk State University, Pirogov str. 2, Novosibirsk, Russia
| | - Stepan N Belyakin
- Genomics Lab, Institute of Molecular and Cellular Biology SB RAS, Lavrentyev ave. 8/2, Novosibirsk, Russia, 630090. .,Novosibirsk State University, Pirogov str. 2, Novosibirsk, Russia.
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Abstract
Ongoing work shows that misplaced epithelial cells have the capacity to reintegrate back into tissue layers. This movement appears to underlie tissue stability and may also control aspects of tissue structure. A recent study reveals that cell reintegration in at least one tissue, the Drosophila follicular epithelium, is based on adhesion molecules that line lateral cell surfaces. In this article we will review these observations, discuss their implications for epithelial tissue development and maintenance, and identify future directions for study.
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Affiliation(s)
- Tyler J Wilson
- Department of Biology, University of Rochester, Rochester, NY, USA
| | - Dan T Bergstralh
- Department of Biology, University of Rochester, Rochester, NY, USA
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Multiple mechanisms contribute to double-strand break repair at rereplication forks in Drosophila follicle cells. Proc Natl Acad Sci U S A 2016; 113:13809-13814. [PMID: 27849606 DOI: 10.1073/pnas.1617110113] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rereplication generates double-strand breaks (DSBs) at sites of fork collisions and causes genomic damage, including repeat instability and chromosomal aberrations. However, the primary mechanism used to repair rereplication DSBs varies across different experimental systems. In Drosophila follicle cells, developmentally regulated rereplication is used to amplify six genomic regions, two of which contain genes encoding eggshell proteins. We have exploited this system to test the roles of several DSB repair pathways during rereplication, using fork progression as a readout for DSB repair efficiency. Here we show that a null mutation in the microhomology-mediated end-joining (MMEJ) component, polymerase θ/mutagen-sensitive 308 (mus308), exhibits a sporadic thin eggshell phenotype and reduced chorion gene expression. Unlike other thin eggshell mutants, mus308 displays normal origin firing but reduced fork progression at two regions of rereplication. We also find that MMEJ compensates for loss of nonhomologous end joining to repair rereplication DSBs in a site-specific manner. Conversely, we show that fork progression is enhanced in the absence of both Drosophila Rad51 homologs, spindle-A and spindle-B, revealing homologous recombination is active and actually impairs fork movement during follicle cell rereplication. These results demonstrate that several DSB repair pathways are used during rereplication in the follicle cells and their contribution to productive fork progression is influenced by genomic position and repair pathway competition. Furthermore, our findings illustrate that specific rereplication DSB repair pathways can have major effects on cellular physiology, dependent upon genomic context.
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Lee H, Cho DY, Whitworth C, Eisman R, Phelps M, Roote J, Kaufman T, Cook K, Russell S, Przytycka T, Oliver B. Effects of Gene Dose, Chromatin, and Network Topology on Expression in Drosophila melanogaster. PLoS Genet 2016; 12:e1006295. [PMID: 27599372 PMCID: PMC5012587 DOI: 10.1371/journal.pgen.1006295] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 08/10/2016] [Indexed: 11/18/2022] Open
Abstract
Deletions, commonly referred to as deficiencies by Drosophila geneticists, are valuable tools for mapping genes and for genetic pathway discovery via dose-dependent suppressor and enhancer screens. More recently, it has become clear that deviations from normal gene dosage are associated with multiple disorders in a range of species including humans. While we are beginning to understand some of the transcriptional effects brought about by gene dosage changes and the chromosome rearrangement breakpoints associated with them, much of this work relies on isolated examples. We have systematically examined deficiencies of the left arm of chromosome 2 and characterize gene-by-gene dosage responses that vary from collapsed expression through modest partial dosage compensation to full or even over compensation. We found negligible long-range effects of creating novel chromosome domains at deletion breakpoints, suggesting that cases of gene regulation due to altered nuclear architecture are rare. These rare cases include trans de-repression when deficiencies delete chromatin characterized as repressive in other studies. Generally, effects of breakpoints on expression are promoter proximal (~100bp) or in the gene body. Effects of deficiencies genome-wide are in genes with regulatory relationships to genes within the deleted segments, highlighting the subtle expression network defects in these sensitized genetic backgrounds.
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Affiliation(s)
- Hangnoh Lee
- Section of Developmental Genomics, Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Kidney and Digestive Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Dong-Yeon Cho
- Computational Biology Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Cale Whitworth
- Section of Developmental Genomics, Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Kidney and Digestive Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Robert Eisman
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Melissa Phelps
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - John Roote
- Department of Genetics and Cambridge Systems Biology Centre, University of Cambridge, Cambridge, United Kingdom
| | - Thomas Kaufman
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Kevin Cook
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Steven Russell
- Department of Genetics and Cambridge Systems Biology Centre, University of Cambridge, Cambridge, United Kingdom
| | - Teresa Przytycka
- Computational Biology Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Brian Oliver
- Section of Developmental Genomics, Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Kidney and Digestive Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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Kelpsch DJ, Groen CM, Fagan TN, Sudhir S, Tootle TL. Fascin regulates nuclear actin during Drosophila oogenesis. Mol Biol Cell 2016; 27:2965-79. [PMID: 27535426 PMCID: PMC5042582 DOI: 10.1091/mbc.e15-09-0634] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 08/02/2016] [Indexed: 01/15/2023] Open
Abstract
Study of Drosophila oogenesis reveals that the nuclear localization of actin is controlled by both development and Fascin. Fascin regulates both endogenous nuclear actin and ectopic nuclear actin rod formation by controlling Cofilin. Drosophila oogenesis provides a developmental system with which to study nuclear actin. During Stages 5–9, nuclear actin levels are high in the oocyte and exhibit variation within the nurse cells. Cofilin and Profilin, which regulate the nuclear import and export of actin, also localize to the nuclei. Expression of GFP-tagged Actin results in nuclear actin rod formation. These findings indicate that nuclear actin must be tightly regulated during oogenesis. One factor mediating this regulation is Fascin. Overexpression of Fascin enhances nuclear GFP-Actin rod formation, and Fascin colocalizes with the rods. Loss of Fascin reduces, whereas overexpression of Fascin increases, the frequency of nurse cells with high levels of nuclear actin, but neither alters the overall nuclear level of actin within the ovary. These data suggest that Fascin regulates the ability of specific cells to accumulate nuclear actin. Evidence indicates that Fascin positively regulates nuclear actin through Cofilin. Loss of Fascin results in decreased nuclear Cofilin. In addition, Fascin and Cofilin genetically interact, as double heterozygotes exhibit a reduction in the number of nurse cells with high nuclear actin levels. These findings are likely applicable beyond Drosophila follicle development, as the localization and functions of Fascin and the mechanisms regulating nuclear actin are widely conserved.
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Affiliation(s)
- Daniel J Kelpsch
- Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA 52242
| | - Christopher M Groen
- Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA 52242
| | - Tiffany N Fagan
- Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA 52242
| | - Sweta Sudhir
- Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA 52242
| | - Tina L Tootle
- Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, IA 52242
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39
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Li YF, Chen XY, Zhang CD, Tang XF, Wang L, Liu TH, Pan MH, Lu C. Effects of starvation and hormones on DNA synthesis in silk gland cells of the silkworm, Bombyx mori. INSECT SCIENCE 2016; 23:569-578. [PMID: 25558018 DOI: 10.1111/1744-7917.12199] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/30/2014] [Indexed: 06/04/2023]
Abstract
Silk gland cells of silkworm larvae undergo multiple cycles of endomitosis for the synthesis of silk proteins during the spinning phase. In this paper, we analyzed the endomitotic DNA synthesis of silk gland cells during larval development, and found that it was a periodic fluctuation, increasing during the vigorous feeding phase and being gradually inhibited in the next molting phase. That means it might be activated by a self-regulating process after molting. The expression levels of cyclin E, cdt1 and pcna were consistent with these developmental changes. Moreover, we further examined whether these changes in endomitotic DNA synthesis resulted from feeding or hormonal stimulation. The results showed that DNA synthesis could be inhibited by starvation and re-activated by re-feeding, and therefore appears to be dependent on nutrition. DNA synthesis was suppressed by in vivo treatment with 20-hydroxyecdysone (20E). However, there was no effect on DNA synthesis by in vitro 20E treatment or by either in vivo or in vitro juvenile hormone treatment. The levels of Akt and 4E-BP phosphorylation in the silk glands were also reduced by starvation and in vivo treatment with 20E. These results indicate that the activation of endomitotic DNA synthesis during the intermolt stages is related to feeding and DNA synthesis is inhibited indirectly by 20E.
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Affiliation(s)
- Yao-Feng Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Xiang-Yun Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Chun-Dong Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing, China
| | - Xiao-Fang Tang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - La Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Tai-Hang Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Min-Hui Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Cheng Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
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40
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Bretscher HS, Fox DT. Proliferation of Double-Strand Break-Resistant Polyploid Cells Requires Drosophila FANCD2. Dev Cell 2016; 37:444-57. [PMID: 27270041 PMCID: PMC4901310 DOI: 10.1016/j.devcel.2016.05.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 02/22/2016] [Accepted: 05/02/2016] [Indexed: 12/17/2022]
Abstract
Conserved DNA-damage responses (DDRs) sense genome damage and prevent mitosis of broken chromosomes. How cells lacking DDRs cope with broken chromosomes during mitosis is poorly understood. DDRs are frequently inactivated in cells with extra genomes (polyploidy), suggesting that study of polyploidy can reveal how cells with impaired DDRs/genome damage continue dividing. Here, we show that continued division and normal organ development occurs in polyploid, DDR-impaired Drosophila papillar cells. As papillar cells become polyploid, they naturally accumulate broken acentric chromosomes but do not apoptose/arrest the cell cycle. To survive mitosis with acentric chromosomes, papillar cells require Fanconi anemia proteins FANCD2 and FANCI, as well as Blm helicase, but not canonical DDR signaling. FANCD2 acts independently of previous S phases to promote alignment and segregation of acentric DNA produced by double-strand breaks, thus avoiding micronuclei and organ malformation. Because polyploidy and impaired DDRs can promote cancer, our findings provide insight into disease-relevant DNA-damage tolerance mechanisms.
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Affiliation(s)
- Heidi S Bretscher
- Department of Pharmacology & Cancer Biology, Duke University School of Medicine, DUMC Box 3813, Durham, NC 27710, USA
| | - Donald T Fox
- Department of Pharmacology & Cancer Biology, Duke University School of Medicine, DUMC Box 3813, Durham, NC 27710, USA.
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41
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Huang F, Saraf A, Florens L, Kusch T, Swanson SK, Szerszen LT, Li G, Dutta A, Washburn MP, Abmayr SM, Workman JL. The Enok acetyltransferase complex interacts with Elg1 and negatively regulates PCNA unloading to promote the G1/S transition. Genes Dev 2016; 30:1198-210. [PMID: 27198229 PMCID: PMC4888840 DOI: 10.1101/gad.271429.115] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 04/29/2016] [Indexed: 11/24/2022]
Abstract
KAT6 histone acetyltransferases (HATs) are highly conserved in eukaryotes and are involved in cell cycle regulation. However, information regarding their roles in regulating cell cycle progression is limited. Here, we report the identification of subunits of the Drosophila Enok complex and demonstrate that all subunits are important for its HAT activity. We further report a novel interaction between the Enok complex and the Elg1 proliferating cell nuclear antigen (PCNA)-unloader complex. Depletion of Enok in S2 cells resulted in a G1/S cell cycle block, and this block can be partially relieved by depleting Elg1. Furthermore, depletion of Enok reduced the chromatin-bound levels of PCNA in both S2 cells and early embryos, suggesting that the Enok complex may interact with the Elg1 complex and down-regulate its PCNA-unloading function to promote the G1/S transition. Supporting this hypothesis, depletion of Enok also partially rescued the endoreplication defects in Elg1-depleted nurse cells. Taken together, our study provides novel insights into the roles of KAT6 HATs in cell cycle regulation through modulating PCNA levels on chromatin.
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Affiliation(s)
- Fu Huang
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA; Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Anita Saraf
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Laurence Florens
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Thomas Kusch
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Selene K Swanson
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Leanne T Szerszen
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Ge Li
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Arnob Dutta
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Michael P Washburn
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA; Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Susan M Abmayr
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Jerry L Workman
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
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42
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Losick VP, Jun AS, Spradling AC. Wound-Induced Polyploidization: Regulation by Hippo and JNK Signaling and Conservation in Mammals. PLoS One 2016; 11:e0151251. [PMID: 26958853 PMCID: PMC4784922 DOI: 10.1371/journal.pone.0151251] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 02/25/2016] [Indexed: 12/13/2022] Open
Abstract
Tissue integrity and homeostasis often rely on the proliferation of stem cells or differentiated cells to replace lost, aged, or damaged cells. Recently, we described an alternative source of cell replacement- the expansion of resident, non-dividing diploid cells by wound-induced polyploidization (WIP). Here we show that the magnitude of WIP is proportional to the extent of cell loss using a new semi-automated assay with single cell resolution. Hippo and JNK signaling regulate WIP; unexpectedly however, JNK signaling through AP-1 limits rather than stimulates the level of Yki activation and polyploidization in the Drosophila epidermis. We found that polyploidization also quantitatively compensates for cell loss in a mammalian tissue, mouse corneal endothelium, where increased cell death occurs with age in a mouse model of Fuchs Endothelial Corneal Dystrophy (FECD). Our results suggest that WIP is an evolutionarily conserved homeostatic mechanism that maintains the size and synthetic capacity of adult tissues.
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Affiliation(s)
- Vicki P. Losick
- Department of Embryology, Carnegie Institution for Science, Howard Hughes Medical Institute, 3250 San Martin Dr., Baltimore, MD 21218, United States of America
| | - Albert S. Jun
- Wilmer Eye Institute, Johns Hopkins School of Medicine, 400 N. Broadway, Baltimore, MD 21231, United States of America
| | - Allan C. Spradling
- Department of Embryology, Carnegie Institution for Science, Howard Hughes Medical Institute, 3250 San Martin Dr., Baltimore, MD 21218, United States of America
- * E-mail:
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43
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Romani P, Gargiulo G, Cavaliere V. The ecdysone receptor signalling regulates microvilli formation in follicular epithelial cells. Cell Mol Life Sci 2016; 73:409-25. [PMID: 26223269 PMCID: PMC11108565 DOI: 10.1007/s00018-015-1999-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 07/03/2015] [Accepted: 07/22/2015] [Indexed: 11/27/2022]
Abstract
Epithelial morphogenesis contributes greatly to the development and homeostasis of the organs and body parts. Here, we analysed the consequences of impaired ecdysone receptor (EcR) signalling in the Drosophila follicular epithelium. Besides governing cell growth, the three EcR isoforms act redundantly in controlling follicle cell positioning. Flattening of the microvilli and an aberrant actin cytoskeleton arise from defective EcR signalling in follicle cells, and these defects impact on the organisation of the oocyte membrane. We found that this signalling governs a complex molecular network since its impairment affects key molecules as atypical protein kinase C and activated Moesin. Interestingly, the activity of the transcription factor Tramtrack69 isoform is required for microvilli and their actin core morphogenesis as well as for follicle cell positioning. In conclusion, our findings provide evidence of novel roles for EcR signalling and Tramtrack69 transcription factor in controlling stage-specific differentiation events that take place in the follicular epithelium.
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Affiliation(s)
- Patrizia Romani
- Dipartimento di Farmacia e Biotecnologie, FaBiT, Università di Bologna, Via Selmi, 3, 40126, Bologna, Italy.
| | - Giuseppe Gargiulo
- Dipartimento di Farmacia e Biotecnologie, FaBiT, Università di Bologna, Via Selmi, 3, 40126, Bologna, Italy
| | - Valeria Cavaliere
- Dipartimento di Farmacia e Biotecnologie, FaBiT, Università di Bologna, Via Selmi, 3, 40126, Bologna, Italy.
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44
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Regulation of CTP Synthase Filament Formation During DNA Endoreplication in Drosophila. Genetics 2015; 201:1511-23. [PMID: 26482795 DOI: 10.1534/genetics.115.180737] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 10/13/2015] [Indexed: 12/20/2022] Open
Abstract
CTP synthase (CTPsyn) plays an essential role in DNA, RNA, and lipid synthesis. Recent studies in bacteria, yeast, and Drosophila all reveal a polymeric CTPsyn structure, which dynamically regulates its enzymatic activity. However, the molecular mechanism underlying the formation of CTPsyn polymers is not completely understood. In this study, we found that reversible ubiquitination regulates the dynamic assembly of the filamentous structures of Drosophila CTPsyn. We further determined that the proto-oncogene Cbl, an E3 ubiquitin ligase, controls CTPsyn filament formation in endocycles. While the E3 ligase activity of Cbl is required for CTPsyn filament formation, Cbl does not affect the protein levels of CTPsyn. It remains unclear whether the regulation of CTPsyn filaments by Cbl is through direct ubiquitination of CTPsyn. In the absence of Cbl or with knockdown of CTPsyn, the progression of the endocycle-associated S phase was impaired. Furthermore, overexpression of wild-type, but not enzymatically inactive CTPsyn, rescued the endocycle defect in Cbl mutant cells. Together, these results suggest that Cbl influences the nucleotide pool balance and controls CTPsyn filament formation in endocycles. This study links Cbl-mediated ubiquitination to the polymerization of a metabolic enzyme and reveals a role for Cbl in endocycles during Drosophila development.
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45
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Neiman M, Beaton MJ, Hessen DO, Jeyasingh PD, Weider LJ. Endopolyploidy as a potential driver of animal ecology and evolution. Biol Rev Camb Philos Soc 2015; 92:234-247. [PMID: 26467853 DOI: 10.1111/brv.12226] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 09/15/2015] [Accepted: 09/16/2015] [Indexed: 01/20/2023]
Abstract
Endopolyploidy - the existence of higher-ploidy cells within organisms that are otherwise of a lower ploidy level (generally diploid) - was discovered decades ago, but remains poorly studied relative to other genomic phenomena, especially in animals. Our synthetic review suggests that endopolyploidy is more common in animals than often recognized and probably influences a number of fitness-related and ecologically important traits. In particular, we argue that endopolyploidy is likely to play a central role in key traits such as gene expression, body and cell size, and growth rate, and in a variety of cell types, including those responsible for tissue regeneration, nutrient storage, and inducible anti-predator defences. We also summarize evidence for intraspecific genetic variation in endopolyploid levels and make the case that the existence of this variation suggests that endopolyploid levels are likely to be heritable and thus a potential target for natural selection. We then discuss why, in light of evident benefits of endopolyploidy, animals remain primarily diploid. We conclude by highlighting key areas for future research such as comprehensive evaluation of the heritability of endopolyploidy and the adaptive scope of endopolyploid-related traits, the extent to which endopolyploid induction incurs costs, and characterization of the relationships between environmental variability and endopolyploid levels.
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Affiliation(s)
- Maurine Neiman
- Department of Biology, University of Iowa, 143 Biology Building, Iowa City, IA 52242, U.S.A
| | - Margaret J Beaton
- Biology Department, Mount Allison University, Sackville, NB E4L 1G7, Canada
| | - Dag O Hessen
- Department of Biosciences, University of Oslo, Box 1066, Blindern, 0316 Oslo, Norway
| | - Punidan D Jeyasingh
- Department of Integrative Biology, Oklahoma State University, 501 Life Sciences West, Stillwater, OK 74078, U.S.A
| | - Lawrence J Weider
- Department of Biology, Program in Ecology and Evolutionary Biology, University of Oklahoma, 730 Van Vleet Oval, Room 304, Norman, OK 73019, U.S.A
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46
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Nordman JT, Orr-Weaver TL. Understanding replication fork progression, stability, and chromosome fragility by exploiting the Suppressor of Underreplication protein. Bioessays 2015; 37:856-61. [PMID: 26059810 DOI: 10.1002/bies.201500021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
There are many layers of regulation governing DNA replication to ensure that genetic information is accurately transmitted from mother cell to daughter cell. While much of the control occurs at the level of origin selection and firing, less is known about how replication fork progression is controlled throughout the genome. In Drosophila polytene cells, specific regions of the genome become repressed for DNA replication, resulting in underreplication and decreased copy number. Importantly, underreplicated domains share properties with common fragile sites. The Suppressor of Underreplication protein SUUR is essential for this repression. Recent work established that SUUR functions by directly inhibiting replication fork progression, raising several interesting questions as to how replication fork progression and stability can be modulated within targeted regions of the genome. Here we discuss potential mechanisms by which replication fork inhibition can be achieved and the consequences this has on genome stability and copy number control.
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Affiliation(s)
- Jared T Nordman
- Department of Biology, Whitehead Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Terry L Orr-Weaver
- Department of Biology, Whitehead Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
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47
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Ovejero-Benito MC, Frade JM. p27(Kip1) participates in the regulation of endoreplication in differentiating chick retinal ganglion cells. Cell Cycle 2015; 14:2311-22. [PMID: 25946375 PMCID: PMC4614947 DOI: 10.1080/15384101.2015.1044175] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Nuclear DNA duplication in the absence of cell division (i.e. endoreplication) leads to somatic polyploidy in eukaryotic cells. In contrast to some invertebrate neurons, whose nuclei may contain up to 200,000-fold the normal haploid DNA amount (C), polyploid neurons in higher vertebrates show only 4C DNA content. To explore the mechanism that prevents extra rounds of DNA synthesis in these latter cells we focused on the chick retina, where a population of tetraploid retinal ganglion cells (RGCs) has been described. We show that differentiating chick RGCs that express the neurotrophic receptors p75 and TrkB while lacking retinoblastoma protein, a feature of tetraploid RGCs, also express p27Kip1. Two different short hairpin RNAs (shRNA) that significantly downregulate p27Kip1 expression facilitated DNA synthesis and increased ploidy in isolated chick RGCs. Moreover, this forced DNA synthesis could not be prevented by Cdk4/6 inhibition, thus suggesting that it is triggered by a mechanism similar to endoreplication. In contrast, p27Kip1 deficiency in mouse RGCs does not lead to increased ploidy despite previous observations have shown ectopic DNA synthesis in RGCs from p27Kip1−/− mice. This suggests that a differential mechanism is used for the regulation of neuronal endoreplication in mammalian versus avian RGCs.
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Affiliation(s)
- María C Ovejero-Benito
- a Department of Molecular , Cellular, and Developmental Neurobiology; Cajal Institute; IC-CSIC ; Madrid , Spain
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48
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Li Y, Chen X, Tang X, Zhang C, Wang L, Chen P, Pan M, Lu C. DNA synthesis during endomitosis is stimulated by insulin via the PI3K/Akt and TOR signaling pathways in the silk gland cells of Bombyx mori. Int J Mol Sci 2015; 16:6266-80. [PMID: 25794286 PMCID: PMC4394531 DOI: 10.3390/ijms16036266] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 03/03/2015] [Accepted: 03/05/2015] [Indexed: 01/23/2023] Open
Abstract
Silk gland cells undergo multiple endomitotic cell cycles during silkworm larval ontogeny. Our previous study demonstrated that feeding is required for continued endomitosis in the silk gland cells of silkworm larvae. Furthermore, the insulin signaling pathway is closely related to nutritional signals. To investigate whether the insulin signaling pathway is involved in endomitosis in silk gland cells, in this study, we initially analyzed the effects of bovine insulin on DNA synthesis in endomitotic silk gland cells using 5-bromo-2'-deoxyuridine (BrdU) labeling technology, and found that bovine insulin can stimulate DNA synthesis. Insulin signal transduction is mainly mediated via phosphoinositide 3-kinase (PI3K)/Akt, the target of rapamycin (TOR) and the extracellular signal-regulated kinase (ERK) pathways in vertebrates. We ascertained that these three pathways are involved in DNA synthesis in endomitotic silk gland cells using specific inhibitors against each pathway. Moreover, we investigated whether these three pathways are involved in insulin-stimulated DNA synthesis in endomitotic silk gland cells, and found that the PI3K/Akt and TOR pathways, but not the ERK pathway, are involved in this process. These results provide an important theoretical foundation for the further investigations of the mechanism underlying efficient endomitosis in silk gland cells.
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Affiliation(s)
- Yaofeng Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
| | - Xiangyun Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
| | - Xiaofang Tang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
| | - Chundong Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
- Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.
| | - La Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
| | - Peng Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
| | - Minhui Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China.
| | - Cheng Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China.
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49
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Matias NR, Mathieu J, Huynh JR. Abscission is regulated by the ESCRT-III protein shrub in Drosophila germline stem cells. PLoS Genet 2015; 11:e1004653. [PMID: 25647097 PMCID: PMC4372032 DOI: 10.1371/journal.pgen.1004653] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 07/31/2014] [Indexed: 11/18/2022] Open
Abstract
Abscission is the final event of cytokinesis that leads to the physical separation of the two daughter cells. Recent technical advances have allowed a better understanding of the cellular and molecular events leading to abscission in isolated yeast or mammalian cells. However, how abscission is regulated in different cell types or in a developing organism remains poorly understood. Here, we characterized the function of the ESCRT-III protein Shrub during cytokinesis in germ cells undergoing a series of complete and incomplete divisions. We found that Shrub is required for complete abscission, and that levels of Shrub are critical for proper timing of abscission. Loss or gain of Shrub delays abscission in germline stem cells (GSCs), and leads to the formation of stem-cysts, where daughter cells share the same cytoplasm as the mother stem cell and cannot differentiate. In addition, our results indicate a negative regulation of Shrub by the Aurora B kinase during GSC abscission. Finally, we found that Lethal giant discs (lgd), known to be required for Shrub function in the endosomal pathway, also regulates the duration of abscission in GSCs. Abscission is the final step of cytokinesis which allows the physical separation of sister cells through the scission of a thin cytoplasmic bridge that links them at the end of mitosis. The duration of abscission varies depending on cell types, indicating that the event is developmentally regulated. Recently, we have identified two kinases, Aurora B and CycB/Cdk-1, which regulate the timing of abscission in germ cells and in mammalian cells. However, these kinases are upstream regulators and do not perform abscission per se. Here, we show that Shrub, a potential target of Aurora B and one of the most downstream effectors of abscission, is required for complete abscission in germline stem cells. In the absence of Shrub, the mother stem cell remains linked to its daughter cells, which then share the same cytoplasm and cannot differentiate. Loss of Shrub and Aurora B have opposite effects on abscission duration suggesting that Aurora B regulates negatively Shrub. We further show that Shrub acts together with its interactor Lethal giant disc to ensure proper abscission timing.
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Affiliation(s)
- Neuza Reis Matias
- Department of Genetics and Developmental Biology, Institut Curie, Paris, France
- CNRS UMR3215, Inserm U934, Paris, France
| | - Juliette Mathieu
- Department of Genetics and Developmental Biology, Institut Curie, Paris, France
- CNRS UMR3215, Inserm U934, Paris, France
- * E-mail: (JM); (JRH)
| | - Jean-René Huynh
- Department of Genetics and Developmental Biology, Institut Curie, Paris, France
- CNRS UMR3215, Inserm U934, Paris, France
- * E-mail: (JM); (JRH)
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50
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Stephenson R, Hosler MR, Gavande NS, Ghosh AK, Weake VM. Characterization of a Drosophila ortholog of the Cdc7 kinase: a role for Cdc7 in endoreplication independent of Chiffon. J Biol Chem 2014; 290:1332-47. [PMID: 25451925 DOI: 10.1074/jbc.m114.597948] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cdc7 is a serine-threonine kinase that phosphorylates components of the pre-replication complex during DNA replication initiation. Cdc7 is highly conserved, and Cdc7 orthologs have been characterized in organisms ranging from yeast to humans. Cdc7 is activated specifically during late G1/S phase by binding to its regulatory subunit, Dbf4. Drosophila melanogaster contains a Dbf4 ortholog, Chiffon, which is essential for chorion amplification in Drosophila egg chambers. However, no Drosophila ortholog of Cdc7 has yet been characterized. Here, we report the functional and biochemical characterization of a Drosophila ortholog of Cdc7. Co-expression of Drosophila Cdc7 and Chiffon is able to complement a growth defect in yeast containing a temperature-sensitive Cdc7 mutant. Cdc7 and Chiffon physically interact and can be co-purified from insect cells. Cdc7 phosphorylates the known Cdc7 substrates Mcm2 and histone H3 in vitro, and Cdc7 kinase activity is stimulated by Chiffon and inhibited by the Cdc7-specific inhibitor XL413. Drosophila egg chamber follicle cells deficient for Cdc7 have a defect in two types of DNA replication, endoreplication and chorion gene amplification. However, follicle cells deficient for Chiffon have a defect in chorion gene amplification but still undergo endocycling. Our results show that Cdc7 interacts with Chiffon to form a functional Dbf4-dependent kinase complex and that Cdc7 is necessary for DNA replication in Drosophila egg chamber follicle cells. Additionally, we show that Chiffon is a member of an expanding subset of DNA replication initiation factors that are not strictly required for endoreplication in Drosophila.
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Affiliation(s)
| | | | | | - Arun K Ghosh
- Chemistry and Medicinal Chemistry, and Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907
| | - Vikki M Weake
- From the Departments of Biochemistry and Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907
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