1
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Jiang L. Cell-Mediated Branch Fusion in the Drosophila Trachea. Results Probl Cell Differ 2024; 71:91-100. [PMID: 37996674 DOI: 10.1007/978-3-031-37936-9_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
The Drosophila trachea is an interconnected network of epithelial tubes, which delivers gases throughout the entire organism. It is the premier model to study the development of tubular organs, such as the human lung, kidney, and blood vessels. The Drosophila embryonic trachea derives from a series of segmentally repeated clusters. The tracheal precursor cells in each cluster migrate out in a stereotyped pattern to form primary branches. Thereafter, the neighboring branches need to fuse to form an interconnected tubular network. The connection between neighboring branches is orchestrated by specialized cells, called fusion cells. These cells fuse with their counterparts to form a tube with a contiguous lumen. Branch fusion is a multi-step process that includes cell migration, cell adhesion, cytoskeleton track formation, vesicle trafficking, membrane fusion, and lumen formation. This review summarizes the current knowledge on fusion process in the Drosophila trachea. These mechanisms will greatly contribute to our understanding of branch fusion in mammalian systems.
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Affiliation(s)
- Lan Jiang
- Department of Biological Sciences, Oakland University, Rochester, MI, USA.
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2
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Glashauser J, Camelo C, Hollmann M, Backer W, Jacobs T, Sanchez JI, Schleutker R, Förster D, Berns N, Riechmann V, Luschnig S. Acute manipulation and real-time visualization of membrane trafficking and exocytosis in Drosophila. Dev Cell 2023; 58:709-723.e7. [PMID: 37023749 DOI: 10.1016/j.devcel.2023.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 01/05/2023] [Accepted: 03/07/2023] [Indexed: 04/08/2023]
Abstract
Intracellular trafficking of secretory proteins plays key roles in animal development and physiology, but so far, tools for investigating the dynamics of membrane trafficking have been limited to cultured cells. Here, we present a system that enables acute manipulation and real-time visualization of membrane trafficking through the reversible retention of proteins in the endoplasmic reticulum (ER) in living multicellular organisms. By adapting the "retention using selective hooks" (RUSH) approach to Drosophila, we show that trafficking of GPI-linked, secreted, and transmembrane proteins can be controlled with high temporal precision in intact animals and cultured organs. We demonstrate the potential of this approach by analyzing the kinetics of ER exit and apical secretion and the spatiotemporal dynamics of tricellular junction assembly in epithelia of living embryos. Furthermore, we show that controllable ER retention enables tissue-specific depletion of secretory protein function. The system is broadly applicable to visualizing and manipulating membrane trafficking in diverse cell types in vivo.
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Affiliation(s)
- Jade Glashauser
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Carolina Camelo
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Manuel Hollmann
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Wilko Backer
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Thea Jacobs
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Jone Isasti Sanchez
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Raphael Schleutker
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Dominique Förster
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany
| | - Nicola Berns
- Department of Cell and Molecular Biology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Veit Riechmann
- Department of Cell and Molecular Biology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Stefan Luschnig
- Institute of Integrative Cell Biology and Physiology, Faculty of Biology and Cells in Motion (CiM) Interfaculty Center, University of Münster, 48149 Münster, Germany.
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3
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Camelo C, Körte A, Jacobs T, Luschnig S. Tracheal tube fusion in Drosophila involves release of extracellular vesicles from multivesicular bodies. J Cell Sci 2022; 135:274235. [PMID: 35019140 DOI: 10.1242/jcs.259590] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/22/2021] [Indexed: 11/20/2022] Open
Abstract
Extracellular vesicles (EVs) comprise diverse types of cell-released membranous structures that are thought to play important roles in intercellular communication. While the formation and functions of EVs have been investigated extensively in cultured cells, studies of EVs in vivo have remained scarce. We report here that EVs are present in the developing lumen of tracheal tubes in Drosophila embryos. We defined two distinct EV subpopulations, one of which contains the Munc13-4 homologue Staccato (Stac) and is spatially and temporally associated with tracheal tube fusion (anastomosis) events. The formation of Stac-positive luminal EVs depends on the tracheal tip-cell-specific GTPase Arl3, which is also required for the formation of Stac-positive multivesicular bodies, suggesting that Stac-EVs derive from fusion of Stac-MVBs with the luminal membrane in tip cells during anastomosis formation. The GTPases Rab27 and Rab35 cooperate downstream of Arl3 to promote Stac-MVB formation and tube fusion. We propose that Stac-MVBs act as membrane reservoirs that facilitate tracheal lumen fusion in a process regulated by Arl3, Rab27, Rab35, and Stac/Munc13-4.
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Affiliation(s)
- Carolina Camelo
- Institute of Integrative Cell Biology and Physiology, University of Münster, D-48143 Münster, Germany.,Cells in Motion (CiM) Interfaculty Centre, D-48149 Münster, Germany
| | - Anna Körte
- Institute of Integrative Cell Biology and Physiology, University of Münster, D-48143 Münster, Germany.,Cells in Motion (CiM) Interfaculty Centre, D-48149 Münster, Germany
| | - Thea Jacobs
- Institute of Integrative Cell Biology and Physiology, University of Münster, D-48143 Münster, Germany.,Cells in Motion (CiM) Interfaculty Centre, D-48149 Münster, Germany
| | - Stefan Luschnig
- Institute of Integrative Cell Biology and Physiology, University of Münster, D-48143 Münster, Germany.,Cells in Motion (CiM) Interfaculty Centre, D-48149 Münster, Germany
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4
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Tsurkan MV, Voronkina A, Khrunyk Y, Wysokowski M, Petrenko I, Ehrlich H. Progress in chitin analytics. Carbohydr Polym 2021; 252:117204. [DOI: 10.1016/j.carbpol.2020.117204] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 09/26/2020] [Accepted: 09/28/2020] [Indexed: 12/25/2022]
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5
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Gross-Thebing S, Truszkowski L, Tenbrinck D, Sánchez-Iranzo H, Camelo C, Westerich KJ, Singh A, Maier P, Prengel J, Lange P, Hüwel J, Gaede F, Sasse R, Vos BE, Betz T, Matis M, Prevedel R, Luschnig S, Diz-Muñoz A, Burger M, Raz E. Using migrating cells as probes to illuminate features in live embryonic tissues. SCIENCE ADVANCES 2020; 6:eabc5546. [PMID: 33277250 PMCID: PMC7821905 DOI: 10.1126/sciadv.abc5546] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 10/21/2020] [Indexed: 05/03/2023]
Abstract
The biophysical and biochemical properties of live tissues are important in the context of development and disease. Methods for evaluating these properties typically involve destroying the tissue or require specialized technology and complicated analyses. Here, we present a novel, noninvasive methodology for determining the spatial distribution of tissue features within embryos, making use of nondirectionally migrating cells and software we termed "Landscape," which performs automatized high-throughput three-dimensional image registration. Using the live migrating cells as bioprobes, we identified structures within the zebrafish embryo that affect the distribution of the cells and studied one such structure constituting a physical barrier, which, in turn, influences amoeboid cell polarity. Overall, this work provides a unique approach for detecting tissue properties without interfering with animal's development. In addition, Landscape allows for integrating data from multiple samples, providing detailed and reliable quantitative evaluation of variable biological phenotypes in different organisms.
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Affiliation(s)
- Sargon Gross-Thebing
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Lukasz Truszkowski
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Daniel Tenbrinck
- Applied Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany.
| | - Héctor Sánchez-Iranzo
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Carolina Camelo
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
- Institute of Animal Physiology, University of Muenster, Schlossplatz 8, 48143 Muenster, Germany
| | - Kim J Westerich
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Amrita Singh
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Paul Maier
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Jonas Prengel
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Pia Lange
- Applied Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany
| | - Jan Hüwel
- Applied Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany
| | - Fjedor Gaede
- Applied Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany
| | - Ramona Sasse
- Applied Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany
- Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany
| | - Bart E Vos
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
- Mechanics of Cellular Systems Group, Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
| | - Timo Betz
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
- Mechanics of Cellular Systems Group, Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
| | - Maja Matis
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Robert Prevedel
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Stefan Luschnig
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
- Institute of Animal Physiology, University of Muenster, Schlossplatz 8, 48143 Muenster, Germany
| | - Alba Diz-Muñoz
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Martin Burger
- Applied Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany
| | - Erez Raz
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany.
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
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6
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The Transmembrane Proteins M6 and Anakonda Cooperate to Initiate Tricellular Junction Assembly in Epithelia of Drosophila. Curr Biol 2020; 30:4254-4262.e5. [DOI: 10.1016/j.cub.2020.08.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 11/18/2022]
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7
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Petri J, Syed MH, Rey S, Klämbt C. Non-Cell-Autonomous Function of the GPI-Anchored Protein Undicht during Septate Junction Assembly. Cell Rep 2019; 26:1641-1653.e4. [DOI: 10.1016/j.celrep.2019.01.046] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/12/2018] [Accepted: 01/10/2019] [Indexed: 11/26/2022] Open
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8
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Kotini MP, Mäe MA, Belting HG, Betsholtz C, Affolter M. Sprouting and anastomosis in the Drosophila trachea and the vertebrate vasculature: Similarities and differences in cell behaviour. Vascul Pharmacol 2019; 112:8-16. [DOI: 10.1016/j.vph.2018.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/21/2018] [Accepted: 11/02/2018] [Indexed: 01/25/2023]
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9
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Development and Function of the Drosophila Tracheal System. Genetics 2018; 209:367-380. [PMID: 29844090 DOI: 10.1534/genetics.117.300167] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 02/12/2018] [Indexed: 12/14/2022] Open
Abstract
The tracheal system of insects is a network of epithelial tubules that functions as a respiratory organ to supply oxygen to various target organs. Target-derived signaling inputs regulate stereotyped modes of cell specification, branching morphogenesis, and collective cell migration in the embryonic stage. In the postembryonic stages, the same set of signaling pathways controls highly plastic regulation of size increase and pattern elaboration during larval stages, and cell proliferation and reprograming during metamorphosis. Tracheal tube morphogenesis is also regulated by physicochemical interaction of the cell and apical extracellular matrix to regulate optimal geometry suitable for air flow. The trachea system senses both the external oxygen level and the metabolic activity of internal organs, and helps organismal adaptation to changes in environmental oxygen level. Cellular and molecular mechanisms underlying the high plasticity of tracheal development and physiology uncovered through research on Drosophila are discussed.
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10
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Schwarz B, Hollfelder D, Scharf K, Hartmann L, Reim I. Diversification of heart progenitor cells by EGF signaling and differential modulation of ETS protein activity. eLife 2018; 7:32847. [PMID: 29869981 PMCID: PMC6033539 DOI: 10.7554/elife.32847] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 06/04/2018] [Indexed: 12/16/2022] Open
Abstract
For coordinated circulation, vertebrate and invertebrate hearts require stereotyped arrangements of diverse cell populations. This study explores the process of cardiac cell diversification in the Drosophila heart, focusing on the two major cardioblast subpopulations: generic working myocardial cells and inflow valve-forming ostial cardioblasts. By screening a large collection of randomly induced mutants, we identified several genes involved in cardiac patterning. Further analysis revealed an unexpected, specific requirement of EGF signaling for the specification of generic cardioblasts and a subset of pericardial cells. We demonstrate that the Tbx20 ortholog Midline acts as a direct target of the EGFR effector Pointed to repress ostial fates. Furthermore, we identified Edl/Mae, an antagonist of the ETS factor Pointed, as a novel cardiac regulator crucial for ostial cardioblast specification. Combining these findings, we propose a regulatory model in which the balance between activation of Pointed and its inhibition by Edl controls cardioblast subtype-specific gene expression. Organs contain many different kinds of cells, each specialised to perform a particular role. The fruit fly heart, for example, has two types of muscle cells: generic heart muscle cells and ostial heart muscle cells. The generic cells contract to force blood around the body, whilst the ostial cells form openings that allow blood to enter the heart. Though both types of cells carry the same genetic information, each uses a different combination of active genes to perform their role. During development, the cells must decide whether to become generic or ostial. They obtain signals from other cells in and near the developing heart, and respond by turning genes on or off. The response uses proteins called transcription factors, which bind to regulatory portions of specific genes. The sequence of signals and transcription factors that control the fate of developing heart muscle cells was not known. So Schwarz et al. examined the process using a technique called a mutagenesis screen. This involved triggering random genetic mutations and looking for flies with defects in their heart muscle cells. Matching the defects to the mutations revealed genes responsible for heart development. Schwarz et al. found that for cells to develop into generic heart muscle cells, a signal called epidermal growth factor (EGF) switches on a transcription factor called Pointed in the cells. Pointed then turns on another transcription factor that switches off the genes for ostial cells. Conversely, ostial heart muscle cells develop when a protein called ‘ETS-domain lacking’ (Edl) interferes with Pointed, allowing the ostial genes to remain on. The balance between Pointed and Edl controls which type of heart cell each cell will become. Many cells in other tissues in fruit flies also produce the Pointed and Edl proteins and respond to EGF signals. This means that this system may help to decide the fate of cells in other organs. The EGF signaling system is also present in other animals, including humans. Future work could reveal whether the same molecular decision making happens in our own hearts.
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Affiliation(s)
- Benjamin Schwarz
- Department of Biology, Division of Developmental Biology, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | - Dominik Hollfelder
- Department of Biology, Division of Developmental Biology, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | - Katharina Scharf
- Department of Biology, Division of Developmental Biology, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | - Leonie Hartmann
- Department of Biology, Division of Developmental Biology, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
| | - Ingolf Reim
- Department of Biology, Division of Developmental Biology, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany
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11
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Sauerwald J, Soneson C, Robinson MD, Luschnig S. Faithful mRNA splicing depends on the Prp19 complex subunit faint sausage and is required for tracheal branching morphogenesis in Drosophila. Development 2017; 144:657-663. [PMID: 28087625 DOI: 10.1242/dev.144535] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 12/30/2016] [Indexed: 01/26/2023]
Abstract
Morphogenesis requires the dynamic regulation of gene expression, including transcription, mRNA maturation and translation. Dysfunction of the general mRNA splicing machinery can cause surprisingly specific cellular phenotypes, but the basis for these effects is not clear. Here, we show that the Drosophila faint sausage (fas) locus, which is implicated in epithelial morphogenesis and has previously been reported to encode a secreted immunoglobulin domain protein, in fact encodes a subunit of the spliceosome-activating Prp19 complex, which is essential for efficient pre-mRNA splicing. Loss of zygotic fas function globally impairs the efficiency of splicing, and is associated with widespread retention of introns in mRNAs and dramatic changes in gene expression. Surprisingly, despite these general effects, zygotic fas mutants show specific defects in tracheal cell migration during mid-embryogenesis when maternally supplied splicing factors have declined. We propose that tracheal branching, which relies on dynamic changes in gene expression, is particularly sensitive for efficient spliceosome function. Our results reveal an entry point to study requirements of the splicing machinery during organogenesis and provide a better understanding of disease phenotypes associated with mutations in general splicing factors.
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Affiliation(s)
- Julia Sauerwald
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany.,Cluster of Excellence EXC 1003, Cells in Motion (CiM), 48149 Münster, Germany.,Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Charlotte Soneson
- Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.,SIB Swiss Institute of Bioinformatics, 8057 Zürich, Switzerland
| | - Mark D Robinson
- Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.,SIB Swiss Institute of Bioinformatics, 8057 Zürich, Switzerland
| | - Stefan Luschnig
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany .,Cluster of Excellence EXC 1003, Cells in Motion (CiM), 48149 Münster, Germany.,Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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12
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Miao G, Hayashi S. Escargot controls the sequential specification of two tracheal tip cell types by suppressing FGF signaling in Drosophila. Development 2016; 143:4261-4271. [PMID: 27742749 PMCID: PMC5117212 DOI: 10.1242/dev.133322] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 10/04/2016] [Indexed: 01/05/2023]
Abstract
Extrinsic branching factors promote the elongation and migration of tubular organs. In the Drosophila tracheal system, Branchless (Drosophila FGF) stimulates the branching program by specifying tip cells that acquire motility and lead branch migration to a specific destination. Tip cells have two alternative cell fates: the terminal cell (TC), which produces long cytoplasmic extensions with intracellular lumen, and the fusion cell (FC), which mediates branch connections to form tubular networks. How Branchless controls this specification of cells with distinct shapes and behaviors is unknown. Here we report that this cell type diversification involves the modulation of FGF signaling by the zinc-finger protein Escargot (Esg), which is expressed in the FC and is essential for its specification. The dorsal branch begins elongation with a pair of tip cells with high FGF signaling. When the branch tip reaches its final destination, one of the tip cells becomes an FC and expresses Esg. FCs and TCs differ in their response to FGF: TCs are attracted by FGF, whereas FCs are repelled. Esg suppresses ERK signaling in FCs to control this differential migratory behavior. Summary: The migratory behavior of tracheal fusion cells is controlled by the FGF-induced expression of the transcription factor Escargot, which subsequently suppresses ERK signaling.
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Affiliation(s)
- Guangxia Miao
- Laboratory for Morphogenetic Signaling, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan.,Department of Biology, Kobe University Graduate School of Science, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8051, Japan
| | - Shigeo Hayashi
- Laboratory for Morphogenetic Signaling, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan .,Department of Biology, Kobe University Graduate School of Science, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8051, Japan
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13
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Caviglia S, Brankatschk M, Fischer EJ, Eaton S, Luschnig S. Staccato/Unc-13-4 controls secretory lysosome-mediated lumen fusion during epithelial tube anastomosis. Nat Cell Biol 2016; 18:727-39. [DOI: 10.1038/ncb3374] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 05/11/2016] [Indexed: 12/12/2022]
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14
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Sundaram MV, Cohen JD. Time to make the doughnuts: Building and shaping seamless tubes. Semin Cell Dev Biol 2016; 67:123-131. [PMID: 27178486 DOI: 10.1016/j.semcdb.2016.05.006] [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] [Received: 12/21/2015] [Revised: 05/04/2016] [Accepted: 05/06/2016] [Indexed: 10/21/2022]
Abstract
A seamless tube is a very narrow-bore tube that is composed of a single cell with an intracellular lumen and no adherens or tight junctions along its length. Many capillaries in the vertebrate vascular system are seamless tubes. Seamless tubes also are found in invertebrate organs, including the Drosophila trachea and the Caenorhabditis elegans excretory system. Seamless tube cells can be less than a micron in diameter, and they can adopt very simple "doughnut-like" shapes or very complex, branched shapes comparable to those of neurons. The unusual topology and varied shapes of seamless tubes raise many basic cell biological questions about how cells form and maintain such structures. The prevalence of seamless tubes in the vascular system means that answering such questions has significant relevance to human health. In this review, we describe selected examples of seamless tubes in animals and discuss current models for how seamless tubes develop and are shaped, focusing particularly on insights that have come from recent studies in Drosophila and C. elegans.
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Affiliation(s)
- Meera V Sundaram
- Dept. of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
| | - Jennifer D Cohen
- Dept. of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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15
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Wright KD, Mahoney Rogers AA, Zhang J, Shim K. Cooperative and independent functions of FGF and Wnt signaling during early inner ear development. BMC DEVELOPMENTAL BIOLOGY 2015; 15:33. [PMID: 26443994 PMCID: PMC4594887 DOI: 10.1186/s12861-015-0083-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 09/18/2015] [Indexed: 12/28/2022]
Abstract
Background In multiple vertebrate organisms, including chick, Xenopus, and zebrafish, Fibroblast Growth Factor (FGF) and Wnt signaling cooperate during formation of the otic placode. However, in the mouse, although FGF signaling induces Wnt8a expression during induction of the otic placode, it is unclear whether these two signaling pathways functionally cooperate. Sprouty (Spry) genes encode intracellular antagonists of receptor tyrosine kinase signaling, including FGF signaling. We previously demonstrated that the Sprouty1 (Spry1) and Sprouty2 (Spry2) genes antagonize FGF signaling during induction of the otic placode. Here, we investigate cross talk between FGF/SPRY and Wnt signaling during otic placode induction and assess whether these two signaling pathways functionally cooperate during early inner ear development in the mouse. Methods Embryos were generated carrying combinations of a Spry1 null allele, Spry2 null allele, β-catenin null allele, or a Wnt reporter transgene. Otic phenotypes were assessed by in situ hybridization, semi-quantitative reverse transcriptase PCR, immunohistochemistry, and morphometric analysis of sectioned tissue. Results Comparison of Spry1, Spry2, and Wnt reporter expression in pre-otic and otic placode cells indicates that FGF signaling precedes and is active in more cells than Wnt signaling. We provide in vivo evidence that FGF signaling activates the Wnt signaling pathway upstream of TCF/Lef transcriptional activation. FGF regulation of Wnt signaling is functional, since early inner ear defects in Spry1 and Spry2 compound mutant embryos can be genetically rescued by reducing the activity of the Wnt signaling pathway. Interestingly, we find that although the entire otic placode increases in size in Spry1 and Spry2 compound mutant embryos, the size of the Wnt-reporter-positive domain does not increase to the same extent as the Wnt-reporter-negative domain. Conclusions This study provides genetic evidence that FGF and Wnt signaling cooperate during early inner ear development in the mouse. Furthermore, our data suggest that although specification of the otic placode may be globally regulated by FGF signaling, otic specification of cells in which both FGF and Wnt signaling are active may be more tightly regulated. Electronic supplementary material The online version of this article (doi:10.1186/s12861-015-0083-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kevin D Wright
- Department of Pediatrics, Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
| | - Amanda A Mahoney Rogers
- Department of Pediatrics, Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
| | - Jian Zhang
- Department of Pediatrics, Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
| | - Katherine Shim
- Department of Pediatrics, Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
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Byri S, Misra T, Syed ZA, Bätz T, Shah J, Boril L, Glashauser J, Aegerter-Wilmsen T, Matzat T, Moussian B, Uv A, Luschnig S. The Triple-Repeat Protein Anakonda Controls Epithelial Tricellular Junction Formation in Drosophila. Dev Cell 2015; 33:535-48. [PMID: 25982676 DOI: 10.1016/j.devcel.2015.03.023] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Revised: 02/09/2015] [Accepted: 03/26/2015] [Indexed: 11/24/2022]
Abstract
In epithelia, specialized tricellular junctions (TCJs) mediate cell contacts at three-cell vertices. TCJs are fundamental to epithelial biology and disease, but only a few TCJ components are known, and how they assemble at tricellular vertices is not understood. Here we describe a transmembrane protein, Anakonda (Aka), which localizes to TCJs and is essential for the formation of tricellular, but not bicellular, junctions in Drosophila. Loss of Aka causes epithelial barrier defects associated with irregular TCJ structure and geometry, suggesting that Aka organizes cell corners. Aka is necessary and sufficient for accumulation of Gliotactin at TCJs, suggesting that Aka initiates TCJ assembly by recruiting other proteins to tricellular vertices. Aka's extracellular domain has an unusual tripartite repeat structure that may mediate self-assembly, directed by the geometry of tricellular vertices. Conversely, Aka's cytoplasmic tail is dispensable for TCJ localization. Thus, extracellular interactions, rather than TCJ-directed intracellular transport, appear to mediate TCJ assembly.
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Affiliation(s)
- Sunitha Byri
- Institute of Biomedicine, University of Gothenburg, Medicinaregatan 9A, 40530 Gothenburg, Sweden
| | - Tvisha Misra
- Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Zulfeqhar A Syed
- Institute of Biomedicine, University of Gothenburg, Medicinaregatan 9A, 40530 Gothenburg, Sweden
| | - Tilmann Bätz
- Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Jimit Shah
- Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Lukas Boril
- Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Jade Glashauser
- Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Tinri Aegerter-Wilmsen
- Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Till Matzat
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany; Cluster of Excellence EXC 1003, Cells in Motion, CiM, 48149 Münster, Germany
| | - Bernard Moussian
- Interfaculty Institute for Cell Biology, University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Anne Uv
- Institute of Biomedicine, University of Gothenburg, Medicinaregatan 9A, 40530 Gothenburg, Sweden.
| | - Stefan Luschnig
- Institute of Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany; Cluster of Excellence EXC 1003, Cells in Motion, CiM, 48149 Münster, Germany; Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
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Matsuda R, Hosono C, Saigo K, Samakovlis C. The intersection of the extrinsic hedgehog and WNT/wingless signals with the intrinsic Hox code underpins branching pattern and tube shape diversity in the drosophila airways. PLoS Genet 2015; 11:e1004929. [PMID: 25615601 PMCID: PMC4304712 DOI: 10.1371/journal.pgen.1004929] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 11/28/2014] [Indexed: 01/04/2023] Open
Abstract
The tubular networks of the Drosophila respiratory system and our vasculature show distinct branching patterns and tube shapes in different body regions. These local variations are crucial for organ function and organismal fitness. Organotypic patterns and tube geometries in branched networks are typically controlled by variations of extrinsic signaling but the impact of intrinsic factors on branch patterns and shapes is not well explored. Here, we show that the intersection of extrinsic hedgehog(hh) and WNT/wingless (wg) signaling with the tube-intrinsic Hox code of distinct segments specifies the tube pattern and shape of the Drosophila airways. In the cephalic part of the airways, hh signaling induces expression of the transcription factor (TF) knirps (kni) in the anterior dorsal trunk (DTa1). kni represses the expression of another TF spalt major (salm), making DTa1 a narrow and long tube. In DTa branches of more posterior metameres, Bithorax Complex (BX-C) Hox genes autonomously divert hh signaling from inducing kni, thereby allowing DTa branches to develop as salm-dependent thick and short tubes. Moreover, the differential expression of BX-C genes is partly responsible for the anterior-to-posterior gradual increase of the DT tube diameter through regulating the expression level of Salm, a transcriptional target of WNT/wg signaling. Thus, our results highlight how tube intrinsic differential competence can diversify tube morphology without changing availabilities of extrinsic factors. Tubes are common structural elements of many internal organs,
facilitating fluid flow and material exchange. To meet the local needs of diverse tissues, the branching patterns and tube shapes vary regionally. Diametric tapering and specialized branch targeting to the brain represent two common examples of variations with organismal benefits in the Drosophila airways and our vascular system. Several extrinsic signals instruct tube diversifications but the impact of intrinsic factors remains underexplored. Here, we show that the local, tube-intrinsic Hox code instructs the pattern and shape of the dorsal trunk (DT), the main Drosophila airway. In the cephalic part (DT1), where Bithorax Complex (BX-C) Hox genes are not expressed, the extrinsic Hedgehog signal is epistatic to WNT/Wingless signals. Hedgehog instructs anterior DT1 cells to take a long and narrow tube fate targeting the brain. In more posterior metameres, BX-C genes make the extrinsic WNT/Wingless signals epistatic over Hedgehog. There, WNT/Wingless instruct all DT cells to take the thick and short tube fate. Moreover, BX-C genes modulate the outputs of WNT/wingless signaling, making the DT tubes thicker in more posterior metameres. We provide a model for how intrinsic factors modify extrinsic signaling to control regional tube morphologies in a network.
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Affiliation(s)
- Ryo Matsuda
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Chie Hosono
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Kaoru Saigo
- Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Tokyo, Japan
| | - Christos Samakovlis
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- ECCPS, University of Giessen, Giessen, Germany
- * E-mail:
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18
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Caviglia S, Luschnig S. Tube fusion: Making connections in branched tubular networks. Semin Cell Dev Biol 2014; 31:82-90. [DOI: 10.1016/j.semcdb.2014.03.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 03/03/2014] [Accepted: 03/14/2014] [Indexed: 11/16/2022]
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Bätz T, Förster D, Luschnig S. The transmembrane protein Macroglobulin complement-related is essential for septate junction formation and epithelial barrier function in Drosophila. Development 2014; 141:899-908. [PMID: 24496626 DOI: 10.1242/dev.102160] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Occluding cell-cell junctions in epithelia form physical barriers that separate different membrane domains, restrict paracellular diffusion and prevent pathogens from spreading across tissues. In invertebrates, these functions are provided by septate junctions (SJs), the functional equivalent of vertebrate tight junctions. How the diverse functions of SJs are integrated and modulated in a multiprotein complex is not clear, and many SJ components are still unknown. Here we report the identification of Macroglobulin complement-related (Mcr), a member of the conserved α-2-macroglobulin (α2M) complement protein family, as a novel SJ-associated protein in Drosophila. Whereas α2M complement proteins are generally known as secreted factors that bind to surfaces of pathogens and target them for phagocytic uptake, Mcr represents an unusual α2M protein with a predicted transmembrane domain. We show that Mcr protein localizes to lateral membranes of epithelial cells, where its distribution overlaps with SJs. Several SJ components are required for the correct localization of Mcr. Conversely, Mcr is required in a cell-autonomous fashion for the correct membrane localization of SJ components, indicating that membrane-bound rather than secreted Mcr isoforms are involved in SJ formation. Finally, we show that loss of Mcr function leads to morphological, ultrastructural and epithelial barrier defects resembling mutants lacking SJ components. Our results, along with previous findings on the role of Mcr in phagocytosis, suggest that Mcr plays dual roles in epithelial barrier formation and innate immunity. Thus, Mcr represents a novel paradigm for investigating functional links between occluding junction formation and pathogen defense mechanisms.
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Affiliation(s)
- Tilmann Bätz
- Institute of Molecular Life Sciences and PhD Program in Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
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Boisclair Lachance JF, Peláez N, Cassidy JJ, Webber JL, Rebay I, Carthew RW. A comparative study of Pointed and Yan expression reveals new complexity to the transcriptional networks downstream of receptor tyrosine kinase signaling. Dev Biol 2013; 385:263-78. [PMID: 24240101 DOI: 10.1016/j.ydbio.2013.11.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 11/05/2013] [Indexed: 11/29/2022]
Abstract
The biochemical regulatory network downstream of receptor tyrosine kinase (RTK) signaling is controlled by two opposing ETS family members: the transcriptional activator Pointed (Pnt) and the transcriptional repressor Yan. A bistable switch model has been invoked to explain how pathway activation can drive differentiation by shifting the system from a high-Yan/low-Pnt activity state to a low-Yan/high-Pnt activity state. Although the model explains yan and pnt loss-of-function phenotypes in several different cell types, how Yan and Pointed protein expression dynamics contribute to these and other developmental transitions remains poorly understood. Toward this goal we have used a functional GFP-tagged Pnt transgene (Pnt-GFP) to perform a comparative study of Yan and Pnt protein expression throughout Drosophila development. Consistent with the prevailing model of the Pnt-Yan network, we found numerous instances where Pnt-GFP and Yan adopt a mutually exclusive pattern of expression. However we also observed many examples of co-expression. While some co-expression occurred in cells where RTK signaling is presumed low, other co-expression occurred in cells with high RTK signaling. The instances of co-expressed Yan and Pnt-GFP in tissues with high RTK signaling cannot be explained by the current model, and thus they provide important contexts for future investigation of how context-specific differences in RTK signaling, network topology, or responsiveness to other signaling inputs, affect the transcriptional response.
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Affiliation(s)
- Jean-François Boisclair Lachance
- Ben May Department for Cancer Research, University of Chicago, Chicago, IL 60637, USA; The Chicago Center for Systems Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Nicolás Peláez
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA; The Chicago Center for Systems Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Justin J Cassidy
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA; The Chicago Center for Systems Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Jemma L Webber
- Ben May Department for Cancer Research, University of Chicago, Chicago, IL 60637, USA; The Chicago Center for Systems Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Ilaria Rebay
- Ben May Department for Cancer Research, University of Chicago, Chicago, IL 60637, USA; The Chicago Center for Systems Biology, The University of Chicago, Chicago, IL 60637, USA.
| | - Richard W Carthew
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA; The Chicago Center for Systems Biology, The University of Chicago, Chicago, IL 60637, USA.
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21
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Kermath BA, Riha PD, Sajjad A, Gore AC. Effects of chronic NMDA-NR2b inhibition in the median eminence of the reproductive senescent female rat. J Neuroendocrinol 2013; 25:887-97. [PMID: 23957788 PMCID: PMC3800684 DOI: 10.1111/jne.12087] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 08/05/2013] [Accepted: 08/10/2013] [Indexed: 01/07/2023]
Abstract
Gonadotrophin-releasing hormone (GnRH) neurones of the hypothalamic-pituitary-gonadal (HPG) axis drive reproductive function and undergo age-related decreases in activation during the transition to reproductive senescence. Decreased GnRH secretion from the median eminence (ME) partially arises from attenuated glutamatergic signalling via the NMDA receptor (NMDAR) and may be a result of changing NMDAR stoichiometry to favour NR2b over NR2a subunit expression with ageing. We have previously shown that the systemic inhibition of NR2b-containing receptors with ifenprodil, an NR2b-specific antagonist, stimulates parameters of luteinising hormone (used as a proxy for GnRH) release in both young and middle-aged females. In the present study, we chronically administered ifenprodil, an NR2b-specific antagonist, at the site of GnRH terminals in the ME or at GnRH perikarya in the preoptic area, in reproductively senescent middle-aged female rats, aiming to determine whether NR2b antagonism could restore aspects of reproductive functionality. Effects on oestrous cyclicity, serum hormones, and protein expression of GnRH, NR2b and phosphorylated NR2b (Tyr-1472) in the ME were measured. Chronic ifenprodil treatment in the ME (but not the preoptic area) altered oestrous cyclicity by increasing the percentage of days spent in pro-oestrus. This was accompanied by increased GnRH fluorescence intensity in the external ME zone and a greater proportion of GnRH terminals that co-labelled with pNR2b with treatment. We also observed changes in the relationships between protein immunofluorescence, serum hormone levels and other aspects of reproductive physiology in acyclic females, as revealed by bionetwork analysis. Together, these data support the hypothesis that NMDAR-NR2b expression and phosphorylation state play a role in reproductive senescence and highlight the ME as a major player in reproductive ageing.
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Affiliation(s)
- Bailey A. Kermath
- Institute for Neuroscience, The University of Texas at Austin, Austin TX 78712 USA
| | - Penny D. Riha
- Division of Pharmacology and Toxicology, The University of Texas at Austin, Austin, TX 78712 USA.F
| | - Ahmar Sajjad
- Institute for Cell and Molecular Biology, The University of Texas at Austin, Austin, TX 78712 USA
| | - Andrea C. Gore
- Institute for Neuroscience, The University of Texas at Austin, Austin TX 78712 USA
- Division of Pharmacology and Toxicology, The University of Texas at Austin, Austin, TX 78712 USA.F
- Institute for Cell and Molecular Biology, The University of Texas at Austin, Austin, TX 78712 USA
- Corresponding author: Andrea C. Gore, The University of Texas at Austin, 107 W. Dean Keeton, C0875, Austin, TX 78712, Phone (512) 471-3669, Fax (512) 471-5002,
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