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Shaikh U, Sherlock K, Wilson J, Gilliland W, Lewellyn L. Lineage-based scaling of germline intercellular bridges during oogenesis. Development 2024; 151:dev202676. [PMID: 39190553 PMCID: PMC11385318 DOI: 10.1242/dev.202676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 07/19/2024] [Indexed: 08/29/2024]
Abstract
The size of subcellular structures must be tightly controlled to maintain normal cell function. Despite its importance, few studies have determined how the size of organelles or other structures is maintained during development, when cells are growing, dividing and rearranging. The developing Drosophila egg chamber is a powerful model in which to study the relative growth rates of subcellular structures. The egg chamber contains a cluster of 16 germline cells, which are connected through intercellular bridges called ring canals. As the egg chamber grows, the germline cells and the ring canals that connect them increase in size. Here, we demonstrate that ring canal size scaling is related to lineage; the largest, 'first-born' ring canals increase in size at a relatively slower rate than ring canals derived from subsequent mitotic divisions. This lineage-based scaling relationship is maintained even if directed transport is reduced, ring canal size is altered, or in egg chambers with twice as many germline cells. Analysis of lines that produce larger or smaller mature eggs reveals that different strategies could be used to alter final egg size.
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Affiliation(s)
- Umayr Shaikh
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA
| | - Kathleen Sherlock
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA
| | - Julia Wilson
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA
| | - William Gilliland
- Department of Biological Sciences, DePaul University, Chicago, IL 60614, USA
| | - Lindsay Lewellyn
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA
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2
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Shaikh U, Sherlock K, Wilson J, Gilliland W, Lewellyn L. Lineage-based scaling of germline intercellular bridges during oogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.18.553876. [PMID: 37645982 PMCID: PMC10462136 DOI: 10.1101/2023.08.18.553876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
The size of subcellular structures must be tightly controlled to maintain normal cell function. Despite its importance, few studies have determined how the size of organelles or other structures is maintained during development, when cells are growing, dividing, and rearranging. The developing egg chamber is a powerful model in which to study the relative growth rates of subcellular structures. The egg chamber contains a cluster of sixteen germline cells, which are connected through intercellular bridges called ring canals. As the egg chamber grows, the germline cells and the ring canals that connect them increase in size. Here, we demonstrate that ring canal size scaling is related to lineage; the largest, "first born" ring canals increase in size at a relatively slower rate than ring canals derived from subsequent mitotic divisions. This lineage-based scaling relationship is maintained even if directed transport is reduced, ring canal size is altered, or in egg chambers with twice as many germline cells. Analysis of lines that produce larger or smaller mature eggs reveals different strategies could be used to alter final egg size. Summary Statement Using the fruit fly egg chamber as a model, this study demonstrates that the size and scaling of germline intercellular bridges vary based on lineage.
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3
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Price KL, Tharakan DM, Cooley L. Evolutionarily conserved midbody remodeling precedes ring canal formation during gametogenesis. Dev Cell 2023; 58:474-488.e5. [PMID: 36898376 PMCID: PMC10059090 DOI: 10.1016/j.devcel.2023.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 11/18/2022] [Accepted: 02/10/2023] [Indexed: 03/12/2023]
Abstract
How canonical cytokinesis is altered during germ cell division to produce stable intercellular bridges, called "ring canals," is poorly understood. Here, using time-lapse imaging in Drosophila, we observe that ring canal formation occurs through extensive remodeling of the germ cell midbody, a structure classically associated with its function in recruiting abscission-regulating proteins in complete cytokinesis. Germ cell midbody cores reorganize and join the midbody ring rather than being discarded, and this transition is accompanied by changes in centralspindlin dynamics. The midbody-to-ring canal transformation is conserved in the Drosophila male and female germlines and during mouse and Hydra spermatogenesis. In Drosophila, ring canal formation depends on Citron kinase function to stabilize the midbody, similar to its role during somatic cell cytokinesis. Our results provide important insights into the broader functions of incomplete cytokinesis events across biological systems, such as those observed during development and disease states.
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Affiliation(s)
- Kari L Price
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Dyuthi M Tharakan
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Lynn Cooley
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA; Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA; Department of Molecular, Cellular & Developmental Biology, Yale University, New Haven, CT, USA.
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4
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Singh J, Imran Alsous J, Garikipati K, Shvartsman SY. Mechanics of stabilized intercellular bridges. Biophys J 2022; 121:3162-3171. [PMID: 35778841 PMCID: PMC9463629 DOI: 10.1016/j.bpj.2022.06.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/04/2022] [Accepted: 06/27/2022] [Indexed: 11/02/2022] Open
Abstract
Numerous engineered and natural systems form through reinforcement and stabilization of a deformed configuration that was generated by a transient force. An important class of such structures arises during gametogenesis, when a dividing cell undergoes incomplete cytokinesis, giving rise to daughter cells that remain connected through a stabilized intercellular bridge (ICB). ICBs can form through arrest of the contractile cytokinetic furrow and its subsequent stabilization. Despite knowledge of the molecular components, the mechanics underlying robust ICB assembly and the interplay between ring contractility and stiffening are poorly understood. Here, we report joint experimental and theoretical work that explores the physics underlying robust ICB assembly. We develop a continuum mechanics model that reveals the minimal requirements for the formation of stable ICBs, and validate the model's equilibrium predictions through a tabletop experimental analog. With insight into the equilibrium states, we turn to the dynamics: we demonstrate that contractility and stiffening are in dynamic competition and that the time intervals of their action must overlap to ensure assembly of ICBs of biologically observed proportions. Our results highlight a mechanism in which deformation and remodeling are tightly coordinated-one that is applicable to several mechanics-based applications and is a common theme in biological systems spanning several length scales.
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Affiliation(s)
- Jaspreet Singh
- Center for Computational Biology, Flatiron Institute, New York, New York
| | | | - Krishna Garikipati
- Departments of Mechanical Engineering, and Mathematics, Michigan Institute for Computational Discovery & Engineering, University of Michigan, Ann Arbor, Michigan.
| | - Stanislav Y Shvartsman
- Department of Molecular Biology, Princeton University, Princeton, New Jersey; The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey.
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5
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Incomplete abscission and cytoplasmic bridges in the evolution of eukaryotic multicellularity. Curr Biol 2022; 32:R385-R397. [DOI: 10.1016/j.cub.2022.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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6
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Ciocanel MV, Juenemann R, Dawes AT, McKinley SA. Topological Data Analysis Approaches to Uncovering the Timing of Ring Structure Onset in Filamentous Networks. Bull Math Biol 2021; 83:21. [PMID: 33452960 PMCID: PMC7811524 DOI: 10.1007/s11538-020-00847-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Accepted: 12/11/2020] [Indexed: 11/30/2022]
Abstract
In developmental biology as well as in other biological systems, emerging structure and organization can be captured using time-series data of protein locations. In analyzing this time-dependent data, it is a common challenge not only to determine whether topological features emerge, but also to identify the timing of their formation. For instance, in most cells, actin filaments interact with myosin motor proteins and organize into polymer networks and higher-order structures. Ring channels are examples of such structures that maintain constant diameters over time and play key roles in processes such as cell division, development, and wound healing. Given the limitations in studying interactions of actin with myosin in vivo, we generate time-series data of protein polymer interactions in cells using complex agent-based models. Since the data has a filamentous structure, we propose sampling along the actin filaments and analyzing the topological structure of the resulting point cloud at each time. Building on existing tools from persistent homology, we develop a topological data analysis (TDA) method that assesses effective ring generation in this dynamic data. This method connects topological features through time in a path that corresponds to emergence of organization in the data. In this work, we also propose methods for assessing whether the topological features of interest are significant and thus whether they contribute to the formation of an emerging hole (ring channel) in the simulated protein interactions. In particular, we use the MEDYAN simulation platform to show that this technique can distinguish between the actin cytoskeleton organization resulting from distinct motor protein binding parameters.
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Affiliation(s)
| | - Riley Juenemann
- Department of Mathematics, Tulane University, New Orleans, USA
| | - Adriana T Dawes
- Department of Mathematics and Department of Molecular Genetics, The Ohio State University, Columbus, USA
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7
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Zeledon C, Sun X, Plutoni C, Emery G. The ArfGAP Drongo Promotes Actomyosin Contractility during Collective Cell Migration by Releasing Myosin Phosphatase from the Trailing Edge. Cell Rep 2020; 28:3238-3248.e3. [PMID: 31533044 DOI: 10.1016/j.celrep.2019.08.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 07/26/2019] [Accepted: 08/13/2019] [Indexed: 02/07/2023] Open
Abstract
Collective cell migration is involved in various developmental and pathological processes, including the dissemination of various cancer cells. During Drosophila melanogaster oogenesis, a group of cells called border cells migrate collectively toward the oocyte. Herein, we show that members of the Arf family of small GTPases and some of their regulators are required for normal border cell migration. Notably, we found that the ArfGAP Drongo and its GTPase-activating function are essential for the initial detachment of the border cell cluster from the basal lamina. We demonstrate through protein localization and genetic interactions that Drongo controls the localization of the myosin phosphatase in order to regulate myosin II activity at the back of the cluster. Moreover, we show that toward the class III Arf, Drongo acts antagonistically to the guanine exchange factor Steppke. Overall, our work describes a mechanistic pathway that promotes the local actomyosin contractility necessary for border cell detachment.
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Affiliation(s)
- Carlos Zeledon
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, QC, Canada
| | - Xiaojuan Sun
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, QC, Canada
| | - Cédric Plutoni
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, QC, Canada
| | - Gregory Emery
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, QC, Canada; Department of Pathology and Cell Biology, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada.
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8
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Morphology of Mitochondria in Syncytial Annelid Female Germ-Line Cyst Visualized by Serial Block-Face SEM. Int J Cell Biol 2020; 2020:7483467. [PMID: 32395131 PMCID: PMC7199535 DOI: 10.1155/2020/7483467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 07/11/2019] [Accepted: 08/04/2019] [Indexed: 11/23/2022] Open
Abstract
Mitochondria change their morphology and distribution depending on the metabolism and functional state of a cell. Here, we analyzed the mitochondria and selected structures in female germ-line cysts in a representative of clitellate annelids – the white worm Enchytraeus albidus in which each germ cell has one cytoplasmic bridge that connects it to a common cytoplasmic mass. Using serial block-face scanning electron microscopy (SBEM), we prepared three-dimensional ultrastructural reconstructions of the entire selected compartments of a cyst at the advanced stage of oogenesis, i.e. the nurse cell, cytophore, and cytoplasmic bridges of all 16 cells (15 nurse cells and oocyte). We revealed extensive mitochondrial networks in the nurse cells, cytophore and mitochondria that pass through the cytoplasmic bridges, which indicates that a mitochondrial network can extend throughout the entire cyst. The dynamic hyperfusion state was suggested for such mitochondrial aggregations. We measured the mitochondria distribution and revealed their polarized distribution in the nurse cells and more abundant accumulation within the cytophore compared to the nurse cell. A close association of mitochondrial networks with dispersed nuage material, which seems to be the structural equivalent of a Balbiani body, not described in clitellate annelids so far, was also revealed.
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9
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Chen Y, Kotian N, Aranjuez G, Chen L, Messer CL, Burtscher A, Sawant K, Ramel D, Wang X, McDonald JA. Protein phosphatase 1 activity controls a balance between collective and single cell modes of migration. eLife 2020; 9:52979. [PMID: 32369438 PMCID: PMC7200163 DOI: 10.7554/elife.52979] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 04/23/2020] [Indexed: 12/12/2022] Open
Abstract
Collective cell migration is central to many developmental and pathological processes. However, the mechanisms that keep cell collectives together and coordinate movement of multiple cells are poorly understood. Using the Drosophila border cell migration model, we find that Protein phosphatase 1 (Pp1) activity controls collective cell cohesion and migration. Inhibition of Pp1 causes border cells to round up, dissociate, and move as single cells with altered motility. We present evidence that Pp1 promotes proper levels of cadherin-catenin complex proteins at cell-cell junctions within the cluster to keep border cells together. Pp1 further restricts actomyosin contractility to the cluster periphery rather than at individual internal border cell contacts. We show that the myosin phosphatase Pp1 complex, which inhibits non-muscle myosin-II (Myo-II) activity, coordinates border cell shape and cluster cohesion. Given the high conservation of Pp1 complexes, this study identifies Pp1 as a major regulator of collective versus single cell migration.
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Affiliation(s)
- Yujun Chen
- Division of Biology, Kansas State University, Manhattan, United States
| | - Nirupama Kotian
- Division of Biology, Kansas State University, Manhattan, United States
| | - George Aranjuez
- Lerner Research Institute, Cleveland Clinic, Cleveland, United States
| | - Lin Chen
- LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - C Luke Messer
- Division of Biology, Kansas State University, Manhattan, United States
| | - Ashley Burtscher
- Lerner Research Institute, Cleveland Clinic, Cleveland, United States
| | - Ketki Sawant
- Division of Biology, Kansas State University, Manhattan, United States
| | - Damien Ramel
- LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Xiaobo Wang
- LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
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10
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The Arp2/3 complex and the formin, Diaphanous, are both required to regulate the size of germline ring canals in the developing egg chamber. Dev Biol 2020; 461:75-85. [PMID: 31945342 DOI: 10.1016/j.ydbio.2020.01.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 01/10/2020] [Accepted: 01/10/2020] [Indexed: 01/30/2023]
Abstract
Intercellular bridges are an essential structural feature found in both germline and somatic cells throughout the animal kingdom. Because of their large size, the germline intercellular bridges, or ring canals, in the developing fruit fly egg chamber are an excellent model to study the formation, stabilization, and growth of these structures. Within the egg chamber, the germline ring canals connect 15 supporting nurse cells to the developing oocyte, facilitating the transfer of materials required for successful oogenesis. The ring canals are derived from a stalled actomyosin contractile ring; once formed, additional actin and actin-binding proteins are recruited to the ring to support the 20-fold growth that accompanies oogenesis. These behaviors provide a unique model system to study the actin regulators that control incomplete cytokinesis, intercellular bridge formation, and growth. By temporally controlling their expression in the germline, we have demonstrated that the Arp2/3 complex and the formin, Diaphanous (Dia), coordinately regulate ring canal size and growth throughout oogenesis. Dia is required for successful incomplete cytokinesis and the initial stabilization of the germline ring canals. Once ring canals have formed, the Arp2/3 complex and Dia cooperate to determine ring canal size and maintain stability. Our data suggest that nurse cells must maintain a precise balance between the activity of these two nucleators during oogenesis.
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11
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Syncytial germline architecture is actively maintained by contraction of an internal actomyosin corset. Nat Commun 2018; 9:4694. [PMID: 30410005 PMCID: PMC6224597 DOI: 10.1038/s41467-018-07149-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 10/09/2018] [Indexed: 01/13/2023] Open
Abstract
Syncytial architecture is an evolutionarily-conserved feature of the germline of many species and plays a crucial role in their fertility. However, the mechanism supporting syncytial organization is largely unknown. Here, we identify a corset-like actomyosin structure within the syncytial germline of Caenorhabditis elegans, surrounding the common rachis. Using laser microsurgery, we demonstrate that actomyosin contractility within this structure generates tension both in the plane of the rachis surface and perpendicular to it, opposing membrane tension. Genetic and pharmacological perturbations, as well as mathematical modeling, reveal a balance of forces within the gonad and show how changing the tension within the actomyosin corset impinges on syncytial germline structure, leading, in extreme cases, to sterility. Thus, our work highlights a unique tissue-level cytoskeletal structure, and explains the critical role of actomyosin contractility in the preservation of a functional germline. Germline cells in many species are fused to form a syncytium but the mechanics behind the maintenance of these structures are poorly defined. Here, the authors propose an inner contractile actomyosin corset provides a supportive framework to maintain germline architecture in C. elegans.
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12
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Subcellular Specialization and Organelle Behavior in Germ Cells. Genetics 2018; 208:19-51. [PMID: 29301947 DOI: 10.1534/genetics.117.300184] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 08/17/2017] [Indexed: 11/18/2022] Open
Abstract
Gametes, eggs and sperm, are the highly specialized cell types on which the development of new life solely depends. Although all cells share essential organelles, such as the ER (endoplasmic reticulum), Golgi, mitochondria, and centrosomes, germ cells display unique regulation and behavior of organelles during gametogenesis. These germ cell-specific functions of organelles serve critical roles in successful gamete production. In this chapter, I will review the behaviors and roles of organelles during germ cell differentiation.
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13
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Kline A, Curry T, Lewellyn L. The Misshapen kinase regulates the size and stability of the germline ring canals in the Drosophila egg chamber. Dev Biol 2018; 440:99-112. [PMID: 29753016 DOI: 10.1016/j.ydbio.2018.05.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 04/06/2018] [Accepted: 05/08/2018] [Indexed: 11/30/2022]
Abstract
Intercellular bridges are conserved structures that allow neighboring cells to exchange cytoplasmic material; defects in intercellular bridges can lead to infertility in many organisms. Here, we use the Drosophila egg chamber to study the mechanisms that regulate intercellular bridges. Within the developing egg chamber, the germ cells (15 nurse cells and 1 oocyte) are connected to each other through intercellular bridges called ring canals, which expand over the course of oogenesis to support the transfer of materials from the nurse cells to the oocyte. The ring canals are enriched in actin and actin binding proteins, and many proteins have been identified that localize to the germline ring canals and control their expansion and stability. Here, we demonstrate a novel role for the Ste20 family kinase, Misshapen (Msn), in regulation of the size of the germline ring canals. Msn localizes to ring canals throughout most of oogenesis, and depletion of Msn led to the formation of larger ring canals. Over-expression of Msn decreased ring canal diameter, and expression of a membrane tethered form of Msn caused ring canal detachment and nurse cell fusion. Altering the levels or localization of Msn also led to changes in the actin cytoskeleton and altered the localization of E-cadherin, which suggests that Msn could be indirectly limiting ring canal size by altering the structure or dynamics of the actin cytoskeleton and/or adherens junctions.
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Affiliation(s)
- Ashley Kline
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA
| | - Travis Curry
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA
| | - Lindsay Lewellyn
- Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA.
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14
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Goldstein B, Zallen JA. Cell polarity and morphogenesis: new technologies and new findings. Mol Biol Cell 2017; 28:699-700. [PMID: 28292911 PMCID: PMC5349773 DOI: 10.1091/mbc.e16-11-0797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Bob Goldstein
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Jennifer A Zallen
- Howard Hughes Medical Institute and Developmental Biology Program, Sloan Kettering Institute, New York, NY 10065
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15
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Rehain-Bell K, Love A, Werner ME, MacLeod I, Yates JR, Maddox AS. A Sterile 20 Family Kinase and Its Co-factor CCM-3 Regulate Contractile Ring Proteins on Germline Intercellular Bridges. Curr Biol 2017; 27:860-867. [PMID: 28285996 DOI: 10.1016/j.cub.2017.01.058] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 12/18/2016] [Accepted: 01/27/2017] [Indexed: 11/19/2022]
Abstract
Germ cells in most animals are connected by intercellular bridges, actin-based rings that form stable cytoplasmic connections between cells promoting communication and coordination [1]. Moreover, these connections are required for fertility [1, 2]. Intercellular bridges are proposed to arise from stabilization of the cytokinetic ring during incomplete cytokinesis [1]. Paradoxically, proteins that promote closure of cytokinetic rings are enriched on stably open intercellular bridges [1, 3, 4]. Given this inconsistency, the mechanism of intercellular bridge stabilization is unclear. Here, we used the C. elegans germline as a model for identifying molecular mechanisms regulating intercellular bridges. We report that bridges are actually highly dynamic, changing size at precise times during germ cell development. We focused on the regulation of bridge stability by anillins, key regulators of cytokinetic rings and cytoplasmic bridges [1, 4-7]. We identified GCK-1, a conserved serine/threonine kinase [8], as a putative novel anillin interactor. GCK-1 works together with CCM-3, a known binding partner [9], to promote intercellular bridge stability and limit localization of both canonical anillin and non-muscle myosin II (NMM-II) to intercellular bridges. Additionally, we found that a shorter anillin, known to stabilize bridges [4, 7], also regulates NMM-II levels at bridges. Consistent with these results, negative regulators of NMM-II stabilize intercellular bridges in the Drosophila egg chamber [10, 11]. Together with our findings, this suggests that tuning of myosin levels is a conserved mechanism for the stabilization of intercellular bridges that can occur by diverse molecular mechanisms.
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Affiliation(s)
- Kathryn Rehain-Bell
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Curriculum in Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Andrew Love
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Michael E Werner
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ian MacLeod
- The Scripps Research Institute, La Jolla, CA 92037, USA
| | - John R Yates
- The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Amy Shaub Maddox
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Curriculum in Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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16
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Vasquez CG, Heissler SM, Billington N, Sellers JR, Martin AC. Drosophila non-muscle myosin II motor activity determines the rate of tissue folding. eLife 2016; 5. [PMID: 28035903 PMCID: PMC5201417 DOI: 10.7554/elife.20828] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 12/08/2016] [Indexed: 12/15/2022] Open
Abstract
Non-muscle cell contractility is critical for tissues to adopt shape changes. Although, the non-muscle myosin II holoenzyme (myosin) is a molecular motor that powers contraction of actin cytoskeleton networks, recent studies have questioned the importance of myosin motor activity cell and tissue shape changes. Here, combining the biochemical analysis of enzymatic and motile properties for purified myosin mutants with in vivo measurements of apical constriction for the same mutants, we show that in vivo constriction rate scales with myosin motor activity. We show that so-called phosphomimetic mutants of the Drosophila regulatory light chain (RLC) do not mimic the phosphorylated RLC state in vitro. The defect in the myosin motor activity in these mutants is evident in developing Drosophila embryos where tissue recoil following laser ablation is decreased compared to wild-type tissue. Overall, our data highlights that myosin activity is required for rapid cell contraction and tissue folding in developing Drosophila embryos. DOI:http://dx.doi.org/10.7554/eLife.20828.001
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Affiliation(s)
- Claudia G Vasquez
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
| | - Sarah M Heissler
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Neil Billington
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - James R Sellers
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Adam C Martin
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
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17
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Xue Z, Sokac AM. -Back-to-back mechanisms drive actomyosin ring closure during Drosophila embryo cleavage. J Cell Biol 2016; 215:335-344. [PMID: 27799369 PMCID: PMC5100295 DOI: 10.1083/jcb.201608025] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/10/2016] [Indexed: 12/30/2022] Open
Abstract
The mechanisms mediating actomyosin ring contraction during Drosophila cellularization, a developmental division that resembles cytokinesis, are unclear. Xue and Sokac delineate the contribution of cytoskeletal motors and actin-binding proteins to actomyosin ring constriction as Drosophila embryos undergo cleavage. Contraction of actomyosin rings during cytokinesis is typically attributed to actin filaments sliding toward each other via Myosin-2 motor activity. However, rings constrict in some cells in the absence of Myosin-2 activity. Thus, ring closure uses Myosin-2–dependent and –independent mechanisms. But what the Myosin-2–independent mechanisms are, and to what extent they are sufficient to drive closure, remains unclear. During cleavage in Drosophila melanogaster embryos, actomyosin rings constrict in two sequential and mechanistically distinct phases. We show that these phases differ in constriction speed and are genetically and pharmacologically separable. Further, Myosin-2 activity is required for slow constriction in “phase 1” but is largely dispensable for fast constriction in “phase 2,” and F-actin disassembly is only required for fast constriction in phase 2. Switching from phase 1 to phase 2 seemingly relies on the spatial organization of F-actin as controlled by Cofilin, Anillin, and Septin. Our work shows that fly embryos present a singular opportunity to compare separable ring constriction mechanisms, with varying Myosin-2 dependencies, in one cell type and in vivo.
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Affiliation(s)
- Zenghui Xue
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Anna Marie Sokac
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
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18
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Eikenes ÅH, Malerød L, Lie-Jensen A, Sem Wegner C, Brech A, Liestøl K, Stenmark H, Haglund K. Src64 controls a novel actin network required for proper ring canal formation in the Drosophila male germline. Development 2016; 142:4107-18. [PMID: 26628094 DOI: 10.1242/dev.124370] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In many organisms, germ cells develop as cysts in which cells are interconnected via ring canals (RCs) as a result of incomplete cytokinesis. However, the molecular mechanisms of incomplete cytokinesis remain poorly understood. Here, we address the role of tyrosine phosphorylation of RCs in the Drosophila male germline. We uncover a hierarchy of tyrosine phosphorylation within germline cysts that positively correlates with RC age. The kinase Src64 is responsible for mediating RC tyrosine phosphorylation, and loss of Src64 causes a reduction in RC diameter within germline cysts. Mechanistically, we show that Src64 controls an actin network around the RCs that depends on Abl and the Rac/SCAR/Arp2/3 pathway. The actin network around RCs is required for correct RC diameter in cysts of developing germ cells. We also identify that Src64 is required for proper germ cell differentiation in the Drosophila male germline independent of its role in RC regulation. In summary, we report that Src64 controls actin dynamics to mediate proper RC formation during incomplete cytokinesis during germline cyst development in vivo.
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Affiliation(s)
- Åsmund Husabø Eikenes
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
| | - Lene Malerød
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
| | - Anette Lie-Jensen
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
| | - Catherine Sem Wegner
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
| | - Andreas Brech
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
| | - Knut Liestøl
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway Department of Informatics, University of Oslo, Oslo N-0316, Norway
| | - Harald Stenmark
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
| | - Kaisa Haglund
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo N-0379, Norway Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, Oslo N-0379, Norway
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19
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Øvrebø JI, Campsteijn C, Kourtesis I, Hausen H, Raasholm M, Thompson EM. Functional specialization of chordate CDK1 paralogs during oogenic meiosis. Cell Cycle 2015; 14:880-93. [PMID: 25714331 DOI: 10.1080/15384101.2015.1006000] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cyclin-dependent kinases (CDKs) are central regulators of eukaryotic cell cycle progression. In contrast to interphase CDKs, the mitotic phase CDK1 is the only CDK capable of driving the entire cell cycle and it can do so from yeast to mammals. Interestingly, plants and the marine chordate, Oikopleura dioica, possess paralogs of the highly conserved CDK1 regulator. However, whereas in plants the 2 CDK1 paralogs replace interphase CDK functions, O. dioica has a full complement of interphase CDKs in addition to its 5 odCDK1 paralogs. Here we show specific sub-functionalization of odCDK1 paralogs during oogenesis. Differential spatiotemporal dynamics of the odCDK1a, d and e paralogs and the meiotic polo-like kinase 1 (Plk1) and aurora kinase determine the subset of meiotic nuclei in prophase I arrest that will seed growing oocytes and complete meiosis. Whereas we find odCDK1e to be non-essential, knockdown of the odCDK1a paralog resulted in the spawning of non-viable oocytes of reduced size. Knockdown of odCDK1d also resulted in the spawning of non-viable oocytes. In this case, the oocytes were of normal size, but were unable to extrude polar bodies upon exposure to sperm, because they were unable to resume meiosis from prophase I arrest, a classical function of the sole CDK1 during meiosis in other organisms. Thus, we reveal specific sub-functionalization of CDK1 paralogs, during the meiotic oogenic program.
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Key Words
- CDK, Cyclin Dependent Kinase
- DMYPT, Drosophila myosin phosphatase
- GVBD, germinal vesicle breakdown
- MAPK, Mitogen-Activated Protein Kinase
- MTOC
- MTOC, microtubule organizing center
- NEBD, nuclear envelope breakdown
- NPC, Nuclear Pore Complex
- OC, Organizing Center
- Plk1, Polo-like kinase 1
- aurora kinase
- centrosome
- cmRNA, capped messenger RNA
- dsRNA, double-stranded RNA
- endocycle
- polo-like kinase
- syncytium
- urochordate
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Affiliation(s)
- Jan Inge Øvrebø
- a Department of Biology ; University of Bergen ; Bergen , Norway
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20
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Vasquez CG, Tworoger M, Martin AC. Dynamic myosin phosphorylation regulates contractile pulses and tissue integrity during epithelial morphogenesis. ACTA ACUST UNITED AC 2014; 206:435-50. [PMID: 25092658 PMCID: PMC4121972 DOI: 10.1083/jcb.201402004] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Apical constriction is a cell shape change that promotes epithelial bending. Activation of nonmuscle myosin II (Myo-II) by kinases such as Rho-associated kinase (Rok) is important to generate contractile force during apical constriction. Cycles of Myo-II assembly and disassembly, or pulses, are associated with apical constriction during Drosophila melanogaster gastrulation. It is not understood whether Myo-II phosphoregulation organizes contractile pulses or whether pulses are important for tissue morphogenesis. Here, we show that Myo-II pulses are associated with pulses of apical Rok. Mutants that mimic Myo-II light chain phosphorylation or depletion of myosin phosphatase inhibit Myo-II contractile pulses, disrupting both actomyosin coalescence into apical foci and cycles of Myo-II assembly/disassembly. Thus, coupling dynamic Myo-II phosphorylation to upstream signals organizes contractile Myo-II pulses in both space and time. Mutants that mimic Myo-II phosphorylation undergo continuous, rather than incremental, apical constriction. These mutants fail to maintain intercellular actomyosin network connections during tissue invagination, suggesting that Myo-II pulses are required for tissue integrity during morphogenesis.
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Affiliation(s)
- Claudia G Vasquez
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142
| | - Mike Tworoger
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142
| | - Adam C Martin
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142
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21
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Mandal A, Datta AK, Gupta S, Paul R, Saha A, Ghosh BK, Bhattacharya A, Iqbal M. Cytomixis--a unique phenomenon in animal and plant. PROTOPLASMA 2013; 250:985-996. [PMID: 23475075 DOI: 10.1007/s00709-013-0493-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 02/27/2013] [Indexed: 06/01/2023]
Abstract
Cytomixis is reported to be a uniform phenomenon in the context of fertilization during spermatogenesis of animals and in some lower groups of plants where oogamous reproduction prevails. However, the phenomenon is versatile in flowering taxa as it lacks uniformity in occurrences, causes, formation of intercellular bridges, involvement of number of cells in a cluster, evolutionary significance among others. A review on cytomixis is conducted with an objective that it may offer a scope to unravel some of the ambiguities associated with it and provide further information on cell, reproductive, structural and evolutionary biology.
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Affiliation(s)
- Aninda Mandal
- Department of Botany, Cytogenetics, Genetics and Plant Breeding Section, University of Kalyani, Kalyani, 741235, West Bengal, India
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22
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Yamamoto S, Bayat V, Bellen HJ, Tan C. Protein phosphatase 1ß limits ring canal constriction during Drosophila germline cyst formation. PLoS One 2013; 8:e70502. [PMID: 23936219 PMCID: PMC3723691 DOI: 10.1371/journal.pone.0070502] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 06/20/2013] [Indexed: 12/15/2022] Open
Abstract
Germline cyst formation is essential for the propagation of many organisms including humans and flies. The cytoplasm of germline cyst cells communicate with each other directly via large intercellular bridges called ring canals. Ring canals are often derived from arrested contractile rings during incomplete cytokinesis. However how ring canal formation, maintenance and growth are regulated remains unclear. To better understand this process, we carried out an unbiased genetic screen in Drosophila melanogaster germ cells and identified multiple alleles of flapwing (flw), a conserved serine/threonine-specific protein phosphatase. Flw had previously been reported to be unnecessary for early D. melanogaster oogenesis using a hypomorphic allele. We found that loss of Flw leads to over-constricted nascent ring canals and subsequently tiny mature ring canals, through which cytoplasmic transfer from nurse cells to the oocyte is impaired, resulting in small, non-functional eggs. Flw is expressed in germ cells undergoing incomplete cytokinesis, completely colocalized with the Drosophila myosin binding subunit of myosin phosphatase (DMYPT). This colocalization, together with genetic interaction studies, suggests that Flw functions together with DMYPT to negatively regulate myosin activity during ring canal formation. The identification of two subunits of the tripartite myosin phosphatase as the first two main players required for ring canal constriction indicates that tight regulation of myosin activity is essential for germline cyst formation and reproduction in D. melanogaster and probably other species as well.
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Affiliation(s)
- Shinya Yamamoto
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute, Baylor College of Medicine and Texas Children’s Hospital, Houston, Texas, United States of America
| | - Vafa Bayat
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas, United States of America
| | - Hugo J. Bellen
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Jan and Dan Duncan Neurological Research Institute, Baylor College of Medicine and Texas Children’s Hospital, Houston, Texas, United States of America
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas, United States of America
| | - Change Tan
- Division of Biological Sciences, Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- * E-mail:
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23
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Eikenes ÅH, Brech A, Stenmark H, Haglund K. Spatiotemporal control of Cindr at ring canals during incomplete cytokinesis in the Drosophila male germline. Dev Biol 2013; 377:9-20. [PMID: 23499247 DOI: 10.1016/j.ydbio.2013.02.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 02/25/2013] [Accepted: 02/26/2013] [Indexed: 01/08/2023]
Abstract
During male and female gametogenesis in species ranging from insects to mammals, germ cell cyst formation by incomplete cytokinesis involves the stabilization of cleavage furrows and the formation of stable intercellular bridges called ring canals. Accurate regulation of incomplete cytokinesis is required for both female and male fertility in Drosophila melanogaster. Nevertheless, the molecular mechanisms controlling complete versus incomplete cytokinesis are largely unknown. Here, we show that the scaffold protein Cindr is a novel component of both mitotic and meiotic ring canals during Drosophila spermatogenesis. Strikingly, unlike other male germline ring canal components, including Anillin and Pavarotti, Cindr and contractile ring F-actin dissociate from mitotic ring canals and translocate to the fusome upon completion of the mitotic germ cell divisions. We provide evidence that the loss of Cindr from mitotic ring canals is coordinated by signals that mediate the transition from germ cell mitosis to differentiation. Interestingly, Cindr loss from ring canals coincides with completion of the mitotic germ cell divisions in both Drosophila females and males, thus marking a common step of gametogenesis. We also show that Cindr co-localizes with Anillin at mitotic and meiotic ring canals and is recruited to the contractile ring by Anillin during male germ cell meiotic cytokinesis. Taken together, our analyses reveal a key step of incomplete cytokinesis at the endpoint of the mitotic germ cell divisions in D. melanogaster.
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Affiliation(s)
- Åsmund H Eikenes
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo, Norway
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24
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Zhou K, Rolls MM, Hanna-Rose W. A postmitotic function and distinct localization mechanism for centralspindlin at a stable intercellular bridge. Dev Biol 2013; 376:13-22. [PMID: 23370148 DOI: 10.1016/j.ydbio.2013.01.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 01/17/2013] [Accepted: 01/19/2013] [Indexed: 10/27/2022]
Abstract
Centralspindlin, a complex composed of the subunits ZEN-4 and CYK-4, recruits and regulates proteins that modulate the actin cytoskeleton to promote cleavage furrow formation and progression during cytokinesis. The ZEN-4 subunit is a kinesin that is proposed to function primarily by bundling microtubules and promoting transport of the complex to the midzone. ZEN-4 and CYK-4 are mutually dependent for localization to the midzone during cytokinesis. Once at the midzone, the CYK-4 subunit functions to recruit actin regulators and the scaffold anillin as well as to regulate RhoA and Rac via its intrinsic GAP domain, ultimately promoting actomyosin contractile ring assembly. We have revealed a distinct mechanism for centralspindlin localization and function at a stable, postmitotic intercellular bridge in the Caenorhabditis elegans gonad. Loss of zen-4 or cyk-4 function disrupts germ cell progression postmitotically. In contrast to the localization and recruitment relationships during mitosis, centralspindlin is maintained at the intercellular bridge by anillin, and CYK-4 is localized independently of ZEN-4 but not vice versa. We present evidence that centralspindlin function at the rachis bridge involves ZEN-4 action on the microtubules as opposed to the regulation of the actin cytoskeleton mediated by CYK-4 during cytokinesis.
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Affiliation(s)
- Kang Zhou
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
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25
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Haglund K, Nezis IP, Stenmark H. Structure and functions of stable intercellular bridges formed by incomplete cytokinesis during development. Commun Integr Biol 2011; 4:1-9. [PMID: 21509167 DOI: 10.4161/cib.4.1.13550] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2010] [Accepted: 09/08/2010] [Indexed: 01/12/2023] Open
Abstract
Cytokinesis, the final step of cell division, normally proceeds to completion in living organisms, so that daughter cells physically separate by abscission. In certain tissues and developmental stages, on the other hand, the cytokinesis process is incomplete, giving rise to cells interconnected in syncytia by stable intercellular bridges. This evolutionarily conserved physiological process occurs in the female and male germline in species ranging from insects to humans, and has also been observed in some somatic tissues in invertebrates. Stable intercellular bridges have fascinated cell biologists ever since they were first described more than 50 years ago, and even though substantial progress has been made concerning their ultrastructure and molecular composition, much remains to be understood about their biological functions. Another major question is by which mechanisms complete versus incomplete cytokinesis is determined. In this mini-review we will try to give an overview of the current knowledge about the structure, composition and functions of stable intercellular bridges, and discuss recent insights into the molecular control of the incomplete cytokinesis process.
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Affiliation(s)
- Kaisa Haglund
- Department of Biochemistry; Institute for Cancer Research; Oslo University Hospital; Centre for Cancer Biomedicine; Faculty of Medicine; University of Oslo; Montebello, Oslo, Norway
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26
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Matsumura F, Yamakita Y, Yamashiro S. Myosin light chain kinases and phosphatase in mitosis and cytokinesis. Arch Biochem Biophys 2011; 510:76-82. [PMID: 21396909 PMCID: PMC3114266 DOI: 10.1016/j.abb.2011.03.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 03/02/2011] [Accepted: 03/03/2011] [Indexed: 01/23/2023]
Abstract
At mitosis, cells undergo drastic alterations in morphology and cytoskeletal organization including cell rounding during prophase, mitotic spindle assembly during prometaphase and metaphase, chromatid segregation in anaphase, and cytokinesis during telophase. It is well established that myosin II is a motor responsible for cytokinesis. Recent reports have indicated that myosin II is also involved in spindle assembly and karyokinesis. In this review, we summarize current understanding of the functions of myosin II in mitosis and cytokinesis of higher eukaryotes, and discuss the roles of possible upstream molecules that control myosin II in these mitotic events.
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Affiliation(s)
- Fumio Matsumura
- Department of Molecular Biology & Biochemistry, Rutgers, Piscataway, NJ 08854, USA.
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