1
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Kuebler CA, Paré AC. Striped Expression of Leucine-Rich Repeat Proteins Coordinates Cell Intercalation and Compartment Boundary Formation in the Early Drosophila Embryo. Symmetry (Basel) 2023; 15:1490. [PMID: 38650964 PMCID: PMC11034934 DOI: 10.3390/sym15081490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024] Open
Abstract
Planar polarity is a commonly observed phenomenon in which proteins display a consistent asymmetry in their subcellular localization or activity across the plane of a tissue. During animal development, planar polarity is a fundamental mechanism for coordinating the behaviors of groups of cells to achieve anisotropic tissue remodeling, growth, and organization. Therefore, a primary focus of developmental biology research has been to understand the molecular mechanisms underlying planar polarity in a variety of systems to identify conserved principles of tissue organization. In the early Drosophila embryo, the germband neuroectoderm epithelium rapidly doubles in length along the anterior-posterior axis through a process known as convergent extension (CE); it also becomes subdivided into tandem tissue compartments through the formation of compartment boundaries (CBs). Both processes are dependent on the planar polarity of proteins involved in cellular tension and adhesion. The enrichment of actomyosin-based tension and adherens junction-based adhesion at specific cell-cell contacts is required for coordinated cell intercalation, which drives CE, and the creation of highly stable cell-cell contacts at CBs. Recent studies have revealed a system for rapid cellular polarization triggered by the expression of leucine-rich-repeat (LRR) cell-surface proteins in striped patterns. In particular, the non-uniform expression of Toll-2, Toll-6, Toll-8, and Tartan generates local cellular asymmetries that allow cells to distinguish between cell-cell contacts oriented parallel or perpendicular to the anterior-posterior axis. In this review, we discuss (1) the biomechanical underpinnings of CE and CB formation, (2) how the initial symmetry-breaking events of anterior-posterior patterning culminate in planar polarity, and (3) recent advances in understanding the molecular mechanisms downstream of LRR receptors that lead to planar polarized tension and junctional adhesion.
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Affiliation(s)
- Chloe A. Kuebler
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
| | - Adam C. Paré
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
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2
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Sharrock TE, Evans J, Blanchard GB, Sanson B. Different temporal requirements for tartan and wingless in the formation of contractile interfaces at compartmental boundaries. Development 2022; 149:dev200292. [PMID: 36178136 PMCID: PMC9687003 DOI: 10.1242/dev.200292] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 09/12/2022] [Indexed: 10/21/2023]
Abstract
Compartmental boundaries physically separate developing tissues into distinct regions, which is fundamental for the organisation of the body plan in both insects and vertebrates. In many examples, this physical segregation is caused by a regulated increase in contractility of the actomyosin cortex at boundary cell-cell interfaces, a property important in developmental morphogenesis beyond compartmental boundary formation. We performed an unbiased screening approach to identify cell surface receptors required for actomyosin enrichment and polarisation at parasegmental boundaries (PSBs) in early Drosophila embryos, from the start of germband extension at gastrulation and throughout the germband extended stages (stages 6 to 11). First, we find that Tartan is required during germband extension for actomyosin enrichment at PSBs, confirming an earlier report. Next, by following in real time the dynamics of loss of boundary straightness in tartan mutant embryos compared with wild-type and ftz mutant embryos, we show that Tartan is required during germband extension but not beyond. We identify candidate genes that could take over from Tartan at PSBs and confirm that at germband extended stages, actomyosin enrichment at PSBs requires Wingless signalling.
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Affiliation(s)
- Thomas E. Sharrock
- Departmentof Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Cambridge CB2 3DY, UK
| | - Jenny Evans
- Departmentof Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Cambridge CB2 3DY, UK
| | - Guy B. Blanchard
- Departmentof Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Cambridge CB2 3DY, UK
| | - Bénédicte Sanson
- Departmentof Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Cambridge CB2 3DY, UK
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3
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Davies JA. Synthetic Morphogenesis: introducing IEEE journal readers to programming living mammalian cells to make structures. PROCEEDINGS OF THE IEEE. INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS 2022; 110:688-707. [PMID: 36590991 PMCID: PMC7614003 DOI: 10.1109/jproc.2021.3137077] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Synthetic morphogenesis is a new engineering discipline, in which cells are genetically engineered to make designed shapes and structures. At least in this early phase of the field, devices tend to make use of natural shape-generating processes that operate in embryonic development, but invoke them artificially at times and in orders of a technologist's choosing. This requires construction of genetic control, sequencing and feedback systems that have close parallels to electronic design, which is one reason the field may be of interest to readers of IEEE journals. The other reason is that synthetic morphogenesis allows the construction of two-way interfaces, especially opto-genetic and opto-electronic, between the living and the electronic, allowing unprecedented information flow and control between the two types of 'machine'. This review introduces synthetic morphogenesis, illustrates what has been achieved, drawing parallels wherever possible between biology and electronics, and looks forward to likely next steps and challenges to be overcome.
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Affiliation(s)
- Jamie A Davies
- Professor of Experimental Anatomy at the University of Edinburgh, UK, and a member of the Centre for Mammalian Synthetic Biology at that University
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4
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Berg IC, Mohagheghian E, Habing K, Wang N, Underhill GH. Microtissue Geometry and Cell-Generated Forces Drive Patterning of Liver Progenitor Cell Differentiation in 3D. Adv Healthc Mater 2021; 10:e2100223. [PMID: 33890430 PMCID: PMC8222189 DOI: 10.1002/adhm.202100223] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/27/2021] [Indexed: 01/13/2023]
Abstract
3D microenvironments provide a unique opportunity to investigate the impact of intrinsic mechanical signaling on progenitor cell differentiation. Using a hydrogel-based microwell platform, arrays of 3D, multicellular microtissues in constrained geometries, including toroids and cylinders are produced. These generated distinct mechanical profiles to investigate the impact of geometry and stress on early liver progenitor cell fate using a model liver development system. Image segmentation allows the tracking of individual cell fate and the characterization of distinct patterning of hepatocytic makers to the outer shell of the microtissues, and the exclusion from the inner diameter surface of the toroids. Biliary markers are distributed throughout the interior regions of micropatterned tissues and are increased in toroidal tissues when compared with those in cylindrical tissues. Finite element models of predicted stress distributions, combined with mechanical measurements, demonstrates that intercellular tension correlates with increased hepatocytic fate, while compression correlates with decreased hepatocytic and increased biliary fate. This system, which integrates microfabrication, imaging, mechanical modeling, and quantitative analysis, demonstrates how microtissue geometry can drive patterning of mechanical stresses that regulate cell differentiation trajectories. This approach may serve as a platform for further investigation of signaling mechanisms in the liver and other developmental systems.
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Affiliation(s)
- Ian C. Berg
- University of Illinois at Urbana-Champaign Department of Bioengineering, 1102 Everitt Lab, MC-278, 1406 W. Green Street, Urbana, IL 61801, USA
| | - Erfan Mohagheghian
- University of Illinois at Urbana-Champaign Department of Mechanical Science and Engineering, Mechanical Engineering Building, 1206 W. Green St. MC 244, Urbana, IL, 61801, USA
| | - Krista Habing
- University of Illinois at Urbana-Champaign Department of Bioengineering, 1102 Everitt Lab, MC-278, 1406 W. Green Street, Urbana, IL 61801, USA
| | - Ning Wang
- University of Illinois at Urbana-Champaign Department of Mechanical Science and Engineering, Mechanical Engineering Building, 1206 W. Green St. MC 244, Urbana, IL, 61801, USA
| | - Gregory H. Underhill
- University of Illinois at Urbana-Champaign Department of Bioengineering, 1102 Everitt Lab, MC-278, 1406 W. Green Street, Urbana, IL 61801, USA
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5
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Boot RC, Koenderink GH, Boukany PE. Spheroid mechanics and implications for cell invasion. ADVANCES IN PHYSICS: X 2021. [DOI: 10.1080/23746149.2021.1978316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Affiliation(s)
- Ruben C. Boot
- Department of Chemical Engineering, Delft University of Technology, Delft, The Netherlands
| | - Gijsje H. Koenderink
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, The Netherlands
| | - Pouyan E. Boukany
- Department of Chemical Engineering, Delft University of Technology, Delft, The Netherlands
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6
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Sharrock TE, Sanson B. Cell sorting and morphogenesis in early Drosophila embryos. Semin Cell Dev Biol 2020; 107:147-160. [PMID: 32807642 DOI: 10.1016/j.semcdb.2020.07.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 07/13/2020] [Accepted: 07/14/2020] [Indexed: 12/25/2022]
Abstract
The regionalisation of growing tissues into compartments that do not mix is thought to be a common motif of animal development. Compartments and compartmental boundaries were discovered by lineage studies in the model organism Drosophila. Since then, many compartment boundaries have been identified in developing tissues, from insects to vertebrates. These are important for animal development, because boundaries localize signalling centres that control tissue morphogenesis. Compartment boundaries are boundaries of lineage restriction, where specific mechanisms keep boundaries straight and cells segregated. Here, we review the mechanisms of cell sorting at boundaries found in early Drosophila embryos. The parasegmental boundaries, separating anterior from posterior compartments in the embryo, keep cells segregated by increasing actomyosin contractility at boundary cell-cell interfaces. Differential actomyosin contractility in turn promotes fold formation and orients cell division. Earlier in development, actomyosin differentials are also important for cell sorting during axis extension. Specific cell surface asymmetries and signalling pathways are required to initiate and maintain these actomyosin differentials.
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Affiliation(s)
- Thomas E Sharrock
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Bénédicte Sanson
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
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7
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Wang J, Dahmann C. Establishing compartment boundaries in Drosophila wing imaginal discs: An interplay between selector genes, signaling pathways and cell mechanics. Semin Cell Dev Biol 2020; 107:161-169. [PMID: 32732129 DOI: 10.1016/j.semcdb.2020.07.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 07/13/2020] [Accepted: 07/14/2020] [Indexed: 01/02/2023]
Abstract
The partitioning of cells into groups or 'compartments' separated by straight and sharp boundaries is important for tissue formation in animal development. Cells from neighboring compartments are characterized by distinct fates and functions and their continuous separation at compartment boundaries maintains proper tissue organization. Signaling across compartment boundaries can induce the local expression of morphogens that in turn direct growth and patterning of the surrounding cells. Compartment boundaries play therefore an important role in tissue development. Compartment boundaries were first identified in the early 1970s in the Drosophila wing. Here, we review the role of compartment boundaries in growth and patterning of the developing wing and then discuss the genetic and physical mechanisms underlying cell separation at compartment boundaries in this tissue.
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Affiliation(s)
- Jing Wang
- Institute of Genetics, Technische Universität Dresden, 01062 Dresden, Germany
| | - Christian Dahmann
- Institute of Genetics, Technische Universität Dresden, 01062 Dresden, Germany; Cluster of Excellence Physics of Life, Technische Universität Dresden, 01062 Dresden, Germany.
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8
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Davies JA, Glykofrydis F. Engineering pattern formation and morphogenesis. Biochem Soc Trans 2020; 48:1177-1185. [PMID: 32510150 PMCID: PMC7329343 DOI: 10.1042/bst20200013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/14/2020] [Accepted: 05/18/2020] [Indexed: 12/14/2022]
Abstract
The development of natural tissues, organs and bodies depends on mechanisms of patterning and of morphogenesis, typically (but not invariably) in that order, and often several times at different final scales. Using synthetic biology to engineer patterning and morphogenesis will both enhance our basic understanding of how development works, and provide important technologies for advanced tissue engineering. Focusing on mammalian systems built to date, this review describes patterning systems, both contact-mediated and reaction-diffusion, and morphogenetic effectors. It also describes early attempts to connect the two to create self-organizing physical form. The review goes on to consider how these self-organized systems might be modified to increase the complexity and scale of the order they produce, and outlines some possible directions for future research and development.
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Affiliation(s)
- Jamie A. Davies
- Deanery of Biomedical Sciences and Centre for Mammalian Synthetic Biology, University of Edinburgh, U.K
| | - Fokion Glykofrydis
- Deanery of Biomedical Sciences and Centre for Mammalian Synthetic Biology, University of Edinburgh, U.K
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9
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Paré AC, Naik P, Shi J, Mirman Z, Palmquist KH, Zallen JA. An LRR Receptor-Teneurin System Directs Planar Polarity at Compartment Boundaries. Dev Cell 2019; 51:208-221.e6. [PMID: 31495696 DOI: 10.1016/j.devcel.2019.08.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 04/25/2019] [Accepted: 08/02/2019] [Indexed: 12/28/2022]
Abstract
Epithelial cells dynamically self-organize in response to extracellular spatial cues relayed by cell-surface receptors. During convergent extension in Drosophila, Toll-related receptors direct planar polarized cell rearrangements that elongate the head-to-tail axis. However, many cells establish polarity in the absence of Toll receptor activity, indicating the presence of additional spatial cues. Here we demonstrate that the leucine-rich-repeat receptor Tartan and the teneurin Ten-m provide critical polarity signals at epithelial compartment boundaries. The Tartan and Ten-m extracellular domains interact in vitro, and Tartan promotes Ten-m localization to compartment boundaries in vivo. We show that Tartan and Ten-m are necessary for the planar polarity and organization of compartment boundary cells. Moreover, ectopic stripes of Tartan and Ten-m are sufficient to induce myosin accumulation at stripe boundaries. These results demonstrate that the Tartan/Ten-m and Toll receptor systems together create a high-resolution network of spatial cues that guides cell behavior during convergent extension.
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Affiliation(s)
- Adam C Paré
- Howard Hughes Medical Institute and Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Pooja Naik
- Howard Hughes Medical Institute and Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA; Weill Cornell Graduate School of Medical Sciences, New York, NY, USA
| | - Jay Shi
- Howard Hughes Medical Institute and Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA; Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY, USA
| | - Zachary Mirman
- Howard Hughes Medical Institute and Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Karl H Palmquist
- Howard Hughes Medical Institute and Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Jennifer A Zallen
- Howard Hughes Medical Institute and Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA.
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10
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Urbano JM, Naylor HW, Scarpa E, Muresan L, Sanson B. Suppression of epithelial folding at actomyosin-enriched compartment boundaries downstream of Wingless signalling in Drosophila. Development 2018; 145:dev155325. [PMID: 29691225 PMCID: PMC5964650 DOI: 10.1242/dev.155325] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 03/09/2018] [Indexed: 01/01/2023]
Abstract
Epithelial folding shapes embryos and tissues during development. Here, we investigate the coupling between epithelial folding and actomyosin-enriched compartmental boundaries. The mechanistic relationship between the two is unclear, because actomyosin-enriched boundaries are not necessarily associated with folds. Also, some cases of epithelial folding occur independently of actomyosin contractility. We investigated the shallow folds called parasegment grooves that form at boundaries between anterior and posterior compartments in the early Drosophila embryo. We demonstrate that formation of these folds requires the presence of an actomyosin enrichment along the boundary cell-cell contacts. These enrichments, which require Wingless signalling, increase interfacial tension not only at the level of the adherens junctions but also along the lateral surfaces. We find that epithelial folding is normally under inhibitory control because different genetic manipulations, including depletion of the Myosin II phosphatase Flapwing, increase the depth of folds at boundaries. Fold depth correlates with the levels of Bazooka (Baz), the Par-3 homologue, along the boundary cell-cell contacts. Moreover, Wingless and Hedgehog signalling have opposite effects on fold depth at the boundary that correlate with changes in Baz planar polarity.
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Affiliation(s)
- Jose M Urbano
- Department of Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Downing Street, Cambridge, CB2 3DY, UK
| | - Huw W Naylor
- Department of Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Downing Street, Cambridge, CB2 3DY, UK
| | - Elena Scarpa
- Department of Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Downing Street, Cambridge, CB2 3DY, UK
| | - Leila Muresan
- Department of Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Downing Street, Cambridge, CB2 3DY, UK
- Cambridge Advanced Imaging Centre, University of Cambridge, Anatomy Building, Downing Street, Cambridge, CB2 3DY, UK
| | - Bénédicte Sanson
- Department of Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Downing Street, Cambridge, CB2 3DY, UK
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11
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Taylor HB, Khuong A, Wu Z, Xu Q, Morley R, Gregory L, Poliakov A, Taylor WR, Wilkinson DG. Cell segregation and border sharpening by Eph receptor-ephrin-mediated heterotypic repulsion. J R Soc Interface 2018; 14:rsif.2017.0338. [PMID: 28747399 PMCID: PMC5550979 DOI: 10.1098/rsif.2017.0338] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 06/26/2017] [Indexed: 01/06/2023] Open
Abstract
Eph receptor and ephrin signalling has a major role in cell segregation and border formation, and may act through regulation of cell adhesion, repulsion or tension. To elucidate roles of cell repulsion and adhesion, we combined experiments in cell culture assays with quantitations of cell behaviour which are used in computer simulations. Cells expressing EphB2, or kinase-inactive EphB2 (kiEphB2), segregate and form a sharp border with ephrinB1-expressing cells, and this is disrupted by knockdown of N-cadherin. Measurements of contact inhibition of locomotion reveal that EphB2-, kiEphB2- and ephrinB1-expressing cells have strong heterotypic and weak homotypic repulsion. EphB2 cells have a transient increase in migration after heterotypic activation, which underlies a shift in the EphB2–ephrinB1 border but is not required for segregation or border sharpening. Simulations with the measured values of cell behaviour reveal that heterotypic repulsion can account for cell segregation and border sharpening, and is more efficient than decreased heterotypic adhesion. By suppressing homotypic repulsion, N-cadherin creates a sufficient difference between heterotypic and homotypic repulsion, and enables homotypic cohesion, both of which are required to sharpen borders.
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Affiliation(s)
- Harriet B Taylor
- Neural Development Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.,Previously at MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Anaïs Khuong
- Neural Development Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.,Computational Cell and Molecular Biology Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.,Previously at MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Zhonglin Wu
- Neural Development Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.,Previously at MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Qiling Xu
- Neural Development Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.,Previously at MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Rosalind Morley
- Previously at MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Lauren Gregory
- Previously at MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Alexei Poliakov
- Previously at MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - William R Taylor
- Computational Cell and Molecular Biology Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK .,Previously at MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - David G Wilkinson
- Neural Development Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK .,Previously at MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
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12
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Sussman DM, Schwarz JM, Marchetti MC, Manning ML. Soft yet Sharp Interfaces in a Vertex Model of Confluent Tissue. PHYSICAL REVIEW LETTERS 2018; 120:058001. [PMID: 29481188 DOI: 10.1103/physrevlett.120.058001] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Indexed: 06/08/2023]
Abstract
How can dense biological tissue maintain sharp boundaries between coexisting cell populations? We explore this question within a simple vertex model for cells, focusing on the role of topology and tissue surface tension. We show that the ability of cells to independently regulate adhesivity and tension, together with neighbor-based interaction rules, lets them support strikingly unusual interfaces. In particular, we show that mechanical- and fluctuation-based measurements of the effective surface tension of a cellular aggregate yield different results, leading to mechanically soft interfaces that are nevertheless extremely sharp.
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Affiliation(s)
- Daniel M Sussman
- Department of Physics and Soft Matter Program, Syracuse University, Syracuse, New York 13244, USA
| | - J M Schwarz
- Department of Physics and Soft Matter Program, Syracuse University, Syracuse, New York 13244, USA
| | - M Cristina Marchetti
- Department of Physics and Soft Matter Program, Syracuse University, Syracuse, New York 13244, USA
| | - M Lisa Manning
- Department of Physics and Soft Matter Program, Syracuse University, Syracuse, New York 13244, USA
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13
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Özpolat BD, Handberg-Thorsager M, Vervoort M, Balavoine G. Cell lineage and cell cycling analyses of the 4d micromere using live imaging in the marine annelid Platynereis dumerilii. eLife 2017; 6:30463. [PMID: 29231816 PMCID: PMC5764573 DOI: 10.7554/elife.30463] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 12/11/2017] [Indexed: 11/13/2022] Open
Abstract
Cell lineage, cell cycle, and cell fate are tightly associated in developmental processes, but in vivo studies at single-cell resolution showing the intricacies of these associations are rare due to technical limitations. In this study on the marine annelid Platynereis dumerilii, we investigated the lineage of the 4d micromere, using high-resolution long-term live imaging complemented with a live-cell cycle reporter. 4d is the origin of mesodermal lineages and the germline in many spiralians. We traced lineages at single-cell resolution within 4d and demonstrate that embryonic segmental mesoderm forms via teloblastic divisions, as in clitellate annelids. We also identified the precise cellular origins of the larval mesodermal posterior growth zone. We found that differentially-fated progeny of 4d (germline, segmental mesoderm, growth zone) display significantly different cell cycling. This work has evolutionary implications, sets up the foundation for functional studies in annelid stem cells, and presents newly established techniques for live imaging marine embryos.
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14
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Javaherian S, D'Arcangelo E, Slater B, Londono C, Xu B, McGuigan AP. Modulation of cellular polarization and migration by ephrin/Eph signal-mediated boundary formation. Integr Biol (Camb) 2017; 9:934-946. [PMID: 29120470 DOI: 10.1039/c7ib00176b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Compartment boundaries are essential for ensuring proper cell organization during embryo development and in adult tissues, yet the mechanisms underlying boundary establishment are not completely understood. A number of mechanisms, including (i) differential adhesion, (ii) differential tension, and (iii) cell signaling-mediated cell repulsion, are known to contribute and likely a context-dependent balance of each of these dictates boundary implementation. The ephrin/Eph signaling pathway is known to impact boundary formation in higher animals. In different contexts, ephrin/Eph signaling is known to modulate adhesive properties and migratory behavior of cells. Furthermore it has been proposed that ephrin/Eph signaling may modulate cellular tensile properties, leading to boundary implementation. It remains unclear however, whether, in different contexts, ephrin/Eph act through distinct dominant action modes (e.g. differential adhesion vs. cell repulsion), or whether ephrin/Eph signaling elicits multiple cellular changes simultaneously. Here, using micropatterning of cells over-expressing either EphB3 or ephrinB1, we assess the contribution of each these factors in one model. We show that in this system ephrinB1/EphB3-mediated boundaries are accompanied by modulation of tissue-level architecture and polarization of cell migration. These changes are associated with changes in cell shape and cytoskeletal organization also suggestive of altered cellular tension.
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Affiliation(s)
- Sahar Javaherian
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College St., Toronto, ON M5S 3E5, Canada.
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15
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Nagashima M, Hadidjojo J, Barthel LK, Lubensky DK, Raymond PA. Anisotropic Müller glial scaffolding supports a multiplex lattice mosaic of photoreceptors in zebrafish retina. Neural Dev 2017; 12:20. [PMID: 29141686 PMCID: PMC5688757 DOI: 10.1186/s13064-017-0096-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 10/19/2017] [Indexed: 11/21/2022] Open
Abstract
Background The multiplex, lattice mosaic of cone photoreceptors in the adult fish retina is a compelling example of a highly ordered epithelial cell pattern, with single cell width rows and columns of cones and precisely defined neighbor relationships among different cone types. Cellular mechanisms patterning this multiplex mosaic are not understood. Physical models can provide new insights into fundamental mechanisms of biological patterning. In earlier work, we developed a mathematical model of photoreceptor cell packing in the zebrafish retina, which predicted that anisotropic mechanical tension in the retinal epithelium orients planar polarized adhesive interfaces to align the columns as cone photoreceptors are generated at the retinal margin during post-embryonic growth. Methods With cell-specific fluorescent reporters and in vivo imaging of the growing retinal margin in transparent juvenile zebrafish we provide the first view of how cell packing, spatial arrangement, and cell identity are coordinated to build the lattice mosaic. With targeted laser ablation we probed the tissue mechanics of the retinal epithelium. Results Within the lattice mosaic, planar polarized Crumbs adhesion proteins pack cones into a single cell width column; between columns, N-cadherin-mediated adherens junctions stabilize Müller glial apical processes. The concentration of activated pMyosin II at these punctate adherens junctions suggests that these glial bands are under tension, forming a physical barrier between cone columns and contributing to mechanical stress anisotropies in the epithelial sheet. Unexpectedly, we discovered that the appearance of such parallel bands of Müller glial apical processes precedes the packing of cones into single cell width columns, hinting at a possible role for glia in the initial organization of the lattice mosaic. Targeted laser ablation of Müller glia directly demonstrates that these glial processes support anisotropic mechanical tension in the planar dimension of the retinal epithelium. Conclusions These findings uncovered a novel structural feature of Müller glia associated with alignment of photoreceptors into a lattice mosaic in the zebrafish retina. This is the first demonstration, to our knowledge, of planar, anisotropic mechanical forces mediated by glial cells. Electronic supplementary material The online version of this article (10.1186/s13064-017-0096-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mikiko Nagashima
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 830 North University Avenue, Ann Arbor, MI, 48109-1048, USA
| | - Jeremy Hadidjojo
- Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI, 48109-1040, USA
| | - Linda K Barthel
- Microscopy and Image Analysis Laboratory, University of Michigan, Ann Arbor, MI, USA
| | - David K Lubensky
- Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI, 48109-1040, USA.
| | - Pamela A Raymond
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 830 North University Avenue, Ann Arbor, MI, 48109-1048, USA.
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16
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Davies J. Using synthetic biology to explore principles of development. Development 2017; 144:1146-1158. [PMID: 28351865 DOI: 10.1242/dev.144196] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 02/14/2017] [Indexed: 12/31/2022]
Abstract
Developmental biology is mainly analytical: researchers study embryos, suggest hypotheses and test them through experimental perturbation. From the results of many experiments, the community distils the principles thought to underlie embryogenesis. Verifying these principles, however, is a challenge. One promising approach is to use synthetic biology techniques to engineer simple genetic or cellular systems that follow these principles and to see whether they perform as expected. As I review here, this approach has already been used to test ideas of patterning, differentiation and morphogenesis. It is also being applied to evo-devo studies to explore alternative mechanisms of development and 'roads not taken' by natural evolution.
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Affiliation(s)
- Jamie Davies
- Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XB, UK
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17
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Ku HY, Sun YH. Notch-dependent epithelial fold determines boundary formation between developmental fields in the Drosophila antenna. PLoS Genet 2017; 13:e1006898. [PMID: 28708823 PMCID: PMC5533456 DOI: 10.1371/journal.pgen.1006898] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Revised: 07/28/2017] [Accepted: 06/26/2017] [Indexed: 12/19/2022] Open
Abstract
Compartment boundary formation plays an important role in development by separating adjacent developmental fields. Drosophila imaginal discs have proven valuable for studying the mechanisms of boundary formation. We studied the boundary separating the proximal A1 segment and the distal segments, defined respectively by Lim1 and Dll expression in the eye-antenna disc. Sharp segregation of the Lim1 and Dll expression domains precedes activation of Notch at the Dll/Lim1 interface. By repressing bantam miRNA and elevating the actin regulator Enable, Notch signaling then induces actomyosin-dependent apical constriction and epithelial fold. Disruption of Notch signaling or the actomyosin network reduces apical constriction and epithelial fold, so that Dll and Lim1 cells become intermingled. Our results demonstrate a new mechanism of boundary formation by actomyosin-dependent tissue folding, which provides a physical barrier to prevent mixing of cells from adjacent developmental fields. During development, boundary formation between adjacent developmental fields is important to maintain the integrity of complex organs and tissues. We examined how boundaries become established between adjacent developmental fields—which are defined by expression of distinct selector genes and developmental fates—using the Drosophila eye-antennal disc as a model. We show that boundary formation is a progressive process. We focused our analysis on the antennal A1 fold that separates the A1 and A2-Ar segments, corresponding to the evolutionarily conserved segregation between coxopodite and telopodite segments of arthropod appendages. We describe a clear temporal and causal sequence of events from selector gene expression to establishment of a lineage-restricting boundary. We found that Notch activation at the boundary between adjacent fields of selector gene expression triggers actomyosin-mediated cell apical constriction, which induces the formation of an epithelial fold and prevents intermixing of cells from adjacent fields. Our findings describe a novel mechanism by which epithelial fold provides a physical barrier for cell segregation.
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Affiliation(s)
- Hui-Yu Ku
- Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Y. Henry Sun
- Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- * E-mail:
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18
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Williams ML, Solnica-Krezel L. Regulation of gastrulation movements by emergent cell and tissue interactions. Curr Opin Cell Biol 2017; 48:33-39. [PMID: 28586710 DOI: 10.1016/j.ceb.2017.04.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 04/30/2017] [Indexed: 10/19/2022]
Abstract
It is during gastrulation that the primordial germ layers are specified, embryonic axes become morphologically manifest, and the embryonic body plan begins to take shape. As morphogenetic movements push and pull nascent tissues into position within the gastrula, new interactions are established between neighboring cells and tissues. These interactions represent an emergent property within gastrulating embryos, and serve to regulate and promote ensuing morphogenesis that establishes the next set of cell/tissue contacts, and so on. Several recent studies demonstrate the critical roles of such interactions during gastrulation, including those between germ layers, along embryonic axes, and at tissue boundaries. Emergent tissue interactions result from - and result in - morphogen signaling, cell contacts, and mechanical forces within the gastrula. Together, these comprise a dynamic and complex regulatory cascade that drives gastrulation morphogenesis.
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Affiliation(s)
- Margot Lk Williams
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Lilianna Solnica-Krezel
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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19
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Michel M, Aliee M, Rudolf K, Bialas L, Jülicher F, Dahmann C. The Selector Gene apterous and Notch Are Required to Locally Increase Mechanical Cell Bond Tension at the Drosophila Dorsoventral Compartment Boundary. PLoS One 2016; 11:e0161668. [PMID: 27552097 PMCID: PMC4995041 DOI: 10.1371/journal.pone.0161668] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/09/2016] [Indexed: 11/25/2022] Open
Abstract
The separation of cells with distinct fates and functions is important for tissue and organ formation during animal development. Regions of different fates within tissues are often separated from another along straight boundaries. These compartment boundaries play a crucial role in tissue patterning and growth by stably positioning organizers. In Drosophila, the wing imaginal disc is subdivided into a dorsal and a ventral compartment. Cells of the dorsal, but not ventral, compartment express the selector gene apterous. Apterous expression sets in motion a gene regulatory cascade that leads to the activation of Notch signaling in a few cell rows on either side of the dorsoventral compartment boundary. Both Notch and apterous mutant clones disturb the separation of dorsal and ventral cells. Maintenance of the straight shape of the dorsoventral boundary involves a local increase in mechanical tension at cell bonds along the boundary. The mechanisms by which cell bond tension is locally increased however remain unknown. Here we use a combination of laser ablation of cell bonds, quantitative image analysis, and genetic mutants to show that Notch and Apterous are required to increase cell bond tension along the dorsoventral compartment boundary. Moreover, clonal expression of the Apterous target gene capricious results in cell separation and increased cell bond tension at the clone borders. Finally, using a vertex model to simulate tissue growth, we find that an increase in cell bond tension at the borders of cell clones, but not throughout the cell clone, can lead to cell separation. We conclude that Apterous and Notch maintain the characteristic straight shape of the dorsoventral compartment boundary by locally increasing cell bond tension.
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Affiliation(s)
- Marcus Michel
- Institute of Genetics, Technische Universität Dresden, 01062, Dresden, Germany
| | - Maryam Aliee
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187, Dresden, Germany
| | - Katrin Rudolf
- Institute of Genetics, Technische Universität Dresden, 01062, Dresden, Germany
| | - Lisa Bialas
- Institute of Genetics, Technische Universität Dresden, 01062, Dresden, Germany
| | - Frank Jülicher
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187, Dresden, Germany
- * E-mail: (FJ); (CD)
| | - Christian Dahmann
- Institute of Genetics, Technische Universität Dresden, 01062, Dresden, Germany
- * E-mail: (FJ); (CD)
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20
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McGuigan AP, Javaherian S. Tissue Patterning: Translating Design Principles from In Vivo to In Vitro. Annu Rev Biomed Eng 2016; 18:1-24. [DOI: 10.1146/annurev-bioeng-083115-032943] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Alison P. McGuigan
- Department of Chemical Engineering and Applied Chemistry and
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3E5, Canada;
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21
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Abstract
During animal development, cells with similar function and fate often stay together and sort out from cells with different fates. In Drosophila wing imaginal discs, cells of anterior and posterior fates are separated by a straight compartment boundary. Separation of anterior and posterior cells requires the homeodomain-containing protein Engrailed, which is expressed in posterior cells. Engrailed induces the expression of the short-range signaling molecule Hedgehog in posterior cells and confines Hedgehog signal transduction to anterior cells. Transduction of the Hedgehog signal in anterior cells is required for the separation of anterior and posterior cells. Previous work showed that this separation of cells involves a local increase in mechanical tension at cell junctions along the compartment boundary. However, how mechanical tension was locally increased along the compartment boundary remained unknown. A recent paper now shows that the difference in Hedgehog signal transduction between anterior and posterior cells is necessary and sufficient to increase mechanical tension. The local increase in mechanical tension biases junctional rearrangements during cell intercalations to maintain the straight shape of the compartment boundary. These data highlight how developmental signals can generate patterns of mechanical tension important for tissue organization.
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Affiliation(s)
- Marcus Michel
- a Institute of Genetics, Technische Universität Dresden , Dresden , Germany
| | - Christian Dahmann
- a Institute of Genetics, Technische Universität Dresden , Dresden , Germany
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22
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Tetley RJ, Blanchard GB, Fletcher AG, Adams RJ, Sanson B. Unipolar distributions of junctional Myosin II identify cell stripe boundaries that drive cell intercalation throughout Drosophila axis extension. eLife 2016; 5:e12094. [PMID: 27183005 PMCID: PMC4915814 DOI: 10.7554/elife.12094] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 05/10/2016] [Indexed: 12/21/2022] Open
Abstract
Convergence and extension movements elongate tissues during development. Drosophila germ-band extension (GBE) is one example, which requires active cell rearrangements driven by Myosin II planar polarisation. Here, we develop novel computational methods to analyse the spatiotemporal dynamics of Myosin II during GBE, at the scale of the tissue. We show that initial Myosin II bipolar cell polarization gives way to unipolar enrichment at parasegmental boundaries and two further boundaries within each parasegment, concomitant with a doubling of cell number as the tissue elongates. These boundaries are the primary sites of cell intercalation, behaving as mechanical barriers and providing a mechanism for how cells remain ordered during GBE. Enrichment at parasegment boundaries during GBE is independent of Wingless signaling, suggesting pair-rule gene control. Our results are consistent with recent work showing that a combinatorial code of Toll-like receptors downstream of pair-rule genes contributes to Myosin II polarization via local cell-cell interactions. We propose an updated cell-cell interaction model for Myosin II polarization that we tested in a vertex-based simulation.
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Affiliation(s)
- Robert J Tetley
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Guy B Blanchard
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Alexander G Fletcher
- School of Mathematics and Statistics, University of Sheffield, Sheffield, United Kingdom
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Richard J Adams
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Bénédicte Sanson
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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23
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Cachat E, Liu W, Martin KC, Yuan X, Yin H, Hohenstein P, Davies JA. 2- and 3-dimensional synthetic large-scale de novo patterning by mammalian cells through phase separation. Sci Rep 2016; 6:20664. [PMID: 26857385 PMCID: PMC4746622 DOI: 10.1038/srep20664] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 01/11/2016] [Indexed: 01/09/2023] Open
Abstract
Synthetic biology provides an opportunity for the construction and exploration of alternative solutions to biological problems - solutions different from those chosen by natural life. To this end, synthetic biologists have built new sensory systems, cellular memories, and alternative genetic codes. There is a growing interest in applying synthetic approaches to multicellular systems, especially in relation to multicellular self-organization. Here we describe a synthetic biological system that confers large-scale de novo patterning activity on 2-D and 3-D populations of mammalian cells. Instead of using the reaction-diffusion mechanisms common in real embryos, our system uses cadherin-mediated phase separation, inspired by the known phenomenon of cadherin-based sorting. An engineered self-organizing, large-scale patterning system requiring no prior spatial cue may be a significant step towards the construction of self-assembling synthetic tissues.
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Affiliation(s)
- Elise Cachat
- Centre for Integrative Physiology & Synthsys Centre for Synthetic & Systems Biology, University of Edinburgh, George Square, Edinburgh EH8 9XB, UK
| | - Weijia Liu
- Centre for Integrative Physiology & Synthsys Centre for Synthetic & Systems Biology, University of Edinburgh, George Square, Edinburgh EH8 9XB, UK
| | - Kim C. Martin
- Centre for Integrative Physiology & Synthsys Centre for Synthetic & Systems Biology, University of Edinburgh, George Square, Edinburgh EH8 9XB, UK
| | - Xiaofei Yuan
- School of Engineering, University of Glasgow, Rankine Building, Oakfield Avenue, Glasgow G12 8LT, UK
| | - Huabing Yin
- School of Engineering, University of Glasgow, Rankine Building, Oakfield Avenue, Glasgow G12 8LT, UK
| | - Peter Hohenstein
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK
| | - Jamie A. Davies
- Centre for Integrative Physiology & Synthsys Centre for Synthetic & Systems Biology, University of Edinburgh, George Square, Edinburgh EH8 9XB, UK,
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24
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Rudolf K, Umetsu D, Aliee M, Sui L, Jülicher F, Dahmann C. A local difference in Hedgehog signal transduction increases mechanical cell bond tension and biases cell intercalations along the Drosophila anteroposterior compartment boundary. Development 2015; 142:3845-58. [DOI: 10.1242/dev.125542] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Tissue organization requires the interplay between biochemical signaling and cellular force generation. The formation of straight boundaries separating cells with different fates into compartments is important for growth and patterning during tissue development. In the developing Drosophila wing disc, maintenance of the straight anteroposterior (AP) compartment boundary involves a local increase in mechanical tension at cell bonds along the boundary. The biochemical signals that regulate mechanical tension along the AP boundary, however, remain unknown. Here, we show that a local difference in Hedgehog signal transduction activity between anterior and posterior cells is necessary and sufficient to increase mechanical tension along the AP boundary. This difference in Hedgehog signal transduction is also required to bias cell rearrangements during cell intercalations to keep the characteristic straight shape of the AP boundary. Moreover, severing cell bonds along the AP boundary does not reduce tension at neighboring bonds, implying that active mechanical tension is upregulated, cell bond by cell bond. Finally, differences in the expression of the homeodomain-containing protein Engrailed also contribute to the straight shape of the AP boundary, independently of Hedgehog signal transduction and without modulating cell bond tension. Our data reveal a novel link between local differences in Hedgehog signal transduction and a local increase in active mechanical tension of cell bonds that biases junctional rearrangements. The large-scale shape of the AP boundary thus emerges from biochemical signals inducing patterns of active tension on cell bonds.
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Affiliation(s)
- Katrin Rudolf
- Institute of Genetics, Technische Universität Dresden, Dresden 01062, Germany
| | - Daiki Umetsu
- RIKEN Center for Developmental Biology, Kobe 650-0047, Japan
| | - Maryam Aliee
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, Dresden 01187, Germany
| | - Liyuan Sui
- Institute of Genetics, Technische Universität Dresden, Dresden 01062, Germany
| | - Frank Jülicher
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, Dresden 01187, Germany
| | - Christian Dahmann
- Institute of Genetics, Technische Universität Dresden, Dresden 01062, Germany
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25
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Umetsu D, Dahmann C. Signals and mechanics shaping compartment boundaries in Drosophila. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015; 4:407-17. [PMID: 25755098 DOI: 10.1002/wdev.178] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 12/18/2014] [Accepted: 01/22/2015] [Indexed: 11/06/2022]
Abstract
During animal development groups of cells with similar fates and functions often stay together and separate from cells with different fates. An example for this cellular behavior is the formation of compartments, groups of cells with similar fates that are separated by sharp boundaries from neighboring groups of cells. Compartments play important roles during patterning by serving as units of growth and gene expression. Boundaries between compartments are associated with organizers that secrete signaling molecules instructing growth and differentiation throughout the tissue. The straight shape of the boundary between compartments is important for maintaining the position and shape of the organizer and thus for precise patterning. The straight shape of compartment boundaries, however, is challenged by cell divisions and cell intercalations that take place in many developing tissues. Early work established a role for selector genes and signaling pathways in setting up and keeping boundaries straight. Recent work in Drosophila has now begun to further unravel the physical and cellular mechanisms that maintain compartment boundaries. Key to the separation of compartments is a local increase of actomyosin-dependent mechanical tension at cell junctions along the boundary. Increased mechanical tension acts as a barrier to cell mixing during cell division and influences cell rearrangements during cell intercalations along the compartment boundary in a way that the straight shape of the boundary is maintained. An important question for the future is how the signaling pathways that maintain the straight shape of compartment boundaries control mechanical tension along these boundaries.
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Affiliation(s)
- Daiki Umetsu
- RIKEN Center for Developmental Biology, Kobe, Japan
| | - Christian Dahmann
- Technische Universität Dresden, Institute of Genetics, Dresden, Germany
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26
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Vroomans RMA, Hogeweg P, ten Tusscher KHWJ. Segment-specific adhesion as a driver of convergent extension. PLoS Comput Biol 2015; 11:e1004092. [PMID: 25706823 PMCID: PMC4338282 DOI: 10.1371/journal.pcbi.1004092] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 12/15/2014] [Indexed: 11/19/2022] Open
Abstract
Convergent extension, the simultaneous extension and narrowing of tissues, is a crucial event in the formation of the main body axis during embryonic development. It involves processes on multiple scales: the sub-cellular, cellular and tissue level, which interact via explicit or intrinsic feedback mechanisms. Computational modelling studies play an important role in unravelling the multiscale feedbacks underlying convergent extension. Convergent extension usually operates in tissue which has been patterned or is currently being patterned into distinct domains of gene expression. How such tissue patterns are maintained during the large scale tissue movements of convergent extension has thus far not been investigated. Intriguingly, experimental data indicate that in certain cases these tissue patterns may drive convergent extension rather than requiring safeguarding against convergent extension. Here we use a 2D Cellular Potts Model (CPM) of a tissue prepatterned into segments, to show that convergent extension tends to disrupt this pre-existing segmental pattern. However, when cells preferentially adhere to cells of the same segment type, segment integrity is maintained without any reduction in tissue extension. Strikingly, we demonstrate that this segment-specific adhesion is by itself sufficient to drive convergent extension. Convergent extension is enhanced when we endow our in silico cells with persistence of motion, which in vivo would naturally follow from cytoskeletal dynamics. Finally, we extend our model to confirm the generality of our results. We demonstrate a similar effect of differential adhesion on convergent extension in tissues that can only extend in a single direction (as often occurs due to the inertia of the head region of the embryo), and in tissues prepatterned into a sequence of domains resulting in two opposing adhesive gradients, rather than alternating segments. The process of convergent extension is a major contributor to the formation of the anterior-posterior body axis in the early embryo. Convergent extension refers to the directed movement of cells that leads to the extension of tissue in one direction and narrowing of the tissue in the perpendicular direction. Often, convergent extension occurs in tissue which already contains distinct domains of gene expression such as segments, and it is unclear how these patterns are maintained despite extensive cell movement. Interestingly, experimental evidence suggests that these tissue patterns may drive rather than be compromised by convergent extension. However, existing computational models aimed at unravelling the mechanisms of convergent extension have thus far only studied the process in homogeneous tissues. With our model, we demonstrate that in a segmented tissue, preferential adhesion of cells to other cells within the same segment type is required to maintain the tissue pattern during convergent extension. Furthermore, such segment-specific adhesion is by itself capable of driving convergent extension.
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Affiliation(s)
- Renske M. A. Vroomans
- Theoretical Biology and Bioinformatics, Utrecht University, Utrecht, The Netherlands
- * E-mail:
| | - Paulien Hogeweg
- Theoretical Biology and Bioinformatics, Utrecht University, Utrecht, The Netherlands
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27
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Abstract
The mammalian kidney forms via cell-cell interactions between an epithelial outgrowth of the nephric duct and the surrounding nephrogenic mesenchyme. Initial morphogenetic events include ureteric bud branching to form the collecting duct (CD) tree and mesenchymal-to-epithelial transitions to form the nephrons, requiring reciprocal induction between adjacent mesenchyme and epithelial cells. Within the tips of the branching ureteric epithelium, cells respond to mesenchyme-derived trophic factors by proliferation, migration, and mitosis-associated cell dispersal. Self-inhibition signals from one tip to another play a role in branch patterning. The position, survival, and fate of the nephrogenic mesenchyme are regulated by ECM and secreted signals from adjacent tip and stroma. Signals from the ureteric tip promote mesenchyme self-renewal and trigger nephron formation. Subsequent fusion to the CDs, nephron segmentation and maturation, and formation of a patent glomerular basement membrane also require specialized cell-cell interactions. Differential cadherin, laminin, nectin, and integrin expression, as well as intracellular kinesin and actin-mediated regulation of cell shape and adhesion, underlies these cell-cell interactions. Indeed, the capacity for the kidney to form via self-organization has now been established both via the recapitulation of expected morphogenetic interactions after complete dissociation and reassociation of cellular components during development as well as the in vitro formation of 3D kidney organoids from human pluripotent stem cells. As we understand more about how the many cell-cell interactions required for kidney formation operate, this enables the prospect of bioengineering replacement structures based on these self-organizing properties.
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28
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Tug of war--the influence of opposing physical forces on epithelial cell morphology. Dev Biol 2015; 401:92-102. [PMID: 25576028 DOI: 10.1016/j.ydbio.2014.12.030] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 12/24/2014] [Accepted: 12/28/2014] [Indexed: 01/13/2023]
Abstract
The shape of a single animal cell is determined both by its internal cytoskeleton and through physical interactions with its environment. In a tissue context, this extracellular environment is made up largely of other cells and the extracellular matrix. As a result, the shape of cells residing within an epithelium will be determined both by forces actively generated within the cells themselves and by their deformation in response to forces generated elsewhere in the tissue as they propagate through cell-cell junctions. Together these complex patterns of forces combine to drive epithelial tissue morphogenesis during both development and homeostasis. Here we review the role of both active and passive cell shape changes and mechanical feedback control in tissue morphogenesis in different systems.
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29
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Javaherian S, D'Arcangelo E, Slater B, Zulueta-Coarasa T, Fernandez-Gonzalez R, McGuigan AP. An in vitro model of tissue boundary formation for dissecting the contribution of different boundary forming mechanisms. Integr Biol (Camb) 2015; 7:298-312. [DOI: 10.1039/c4ib00272e] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Separation of phenotypically distinct cell populations is necessary to ensure proper organization and function of tissues and organs therefore understanding fundamental mechanisms that drive this cell segregation is important. In this work, authors present an in vivo model system that accurately recapitulates important aspects of cell segregation in vivo and allows dissection of cell behaviours driving cell segregation.
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Affiliation(s)
- Sahar Javaherian
- University of Toronto
- Department of Chemical Engineering and Applied Chemistry
- Toronto
- Canada
| | - Elisa D'Arcangelo
- Institute of Biomaterials and Biomedical Engineering
- University of Toronto
- Toronto
- Canada
| | - Benjamin Slater
- University of Toronto
- Department of Chemical Engineering and Applied Chemistry
- Toronto
- Canada
| | | | | | - Alison P. McGuigan
- University of Toronto
- Department of Chemical Engineering and Applied Chemistry
- Toronto
- Canada
- Institute of Biomaterials and Biomedical Engineering
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30
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Umetsu D, Dunst S, Dahmann C. An RNA interference screen for genes required to shape the anteroposterior compartment boundary in Drosophila identifies the Eph receptor. PLoS One 2014; 9:e114340. [PMID: 25473846 PMCID: PMC4256218 DOI: 10.1371/journal.pone.0114340] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 11/07/2014] [Indexed: 12/01/2022] Open
Abstract
The formation of straight compartment boundaries separating groups of cells with distinct fates and functions is an evolutionarily conserved strategy during animal development. The physical mechanisms that shape compartment boundaries have recently been further elucidated, however, the molecular mechanisms that underlie compartment boundary formation and maintenance remain poorly understood. Here, we report on the outcome of an RNA interference screen aimed at identifying novel genes involved in maintaining the straight shape of the anteroposterior compartment boundary in Drosophila wing imaginal discs. Out of screening 3114 transgenic RNA interference lines targeting a total of 2863 genes, we identified a single novel candidate that interfered with the formation of a straight anteroposterior compartment boundary. Interestingly, the targeted gene encodes for the Eph receptor tyrosine kinase, an evolutionarily conserved family of signal transducers that has previously been shown to be important for maintaining straight compartment boundaries in vertebrate embryos. Our results identify a hitherto unknown role of the Eph receptor tyrosine kinase in Drosophila and suggest that Eph receptors have important functions in shaping compartment boundaries in both vertebrate and insect development.
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Affiliation(s)
- Daiki Umetsu
- Institute of Genetics, Technische Universität Dresden, Dresden, Germany
| | - Sebastian Dunst
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Christian Dahmann
- Institute of Genetics, Technische Universität Dresden, Dresden, Germany
- * E-mail:
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Local Increases in Mechanical Tension Shape Compartment Boundaries by Biasing Cell Intercalations. Curr Biol 2014; 24:1798-805. [DOI: 10.1016/j.cub.2014.06.052] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Revised: 05/28/2014] [Accepted: 06/19/2014] [Indexed: 01/01/2023]
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Gold KS, Brand AH. Optix defines a neuroepithelial compartment in the optic lobe of the Drosophila brain. Neural Dev 2014; 9:18. [PMID: 25074684 PMCID: PMC4127074 DOI: 10.1186/1749-8104-9-18] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 06/25/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND During early brain development, the organisation of neural progenitors into a neuroepithelial sheet maintains tissue integrity during growth. Neuroepithelial cohesion and patterning is essential for orderly proliferation and neural fate specification. Neuroepithelia are regionalised by the expression of transcription factors and signalling molecules, resulting in the formation of distinct developmental, and ultimately functional, domains. RESULTS We have discovered that the Six3/6 family orthologue Optix is an essential regulator of neuroepithelial maintenance and patterning in the Drosophila brain. Six3 and Six6 are required for mammalian eye and forebrain development, and mutations in humans are associated with severe eye and brain malformation. In Drosophila, Optix is expressed in a sharply defined region of the larval optic lobe, and its expression is reciprocal to that of the transcription factor Vsx1. Optix gain- and loss-of-function affects neuroepithelial adhesion, integrity and polarity. We find restricted cell lineage boundaries that correspond to transcription factor expression domains. CONCLUSION We propose that the optic lobe is compartmentalised by expression of Optix and Vsx1. Our findings provide insight into the spatial patterning of a complex region of the brain, and suggest an evolutionarily conserved principle of visual system development.
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Affiliation(s)
| | - Andrea H Brand
- The Gurdon Institute and Department of Physiology, Development & Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK.
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Abstract
Changes in cell shape are one of the driving forces of tissue morphogenesis. Contractile cytoskeletal assemblies based on actomyosin networks have emerged as a main player that can drive these changes. Different types of actomyosin networks have been identified, with distinct subcellular localizations, including apical junctional and apicomedial actomyosin. A further specialization of junctional actomyosin are so-called actomyosin 'cables', supracellular arrangements that appear to stretch over many cell diameters. Such actomyosin cables have been shown to serve several important functions, in processes such as wound healing, epithelial morphogenesis and maintenance of compartment identities during development. In the Drosophila embryo, we have recently identified a function for a circumferential actomyosin cable in assisting tube formation. Here, I will briefly summarize general principles that have emerged from the analysis of such cables.
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Affiliation(s)
- Katja Röper
- MRC-Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK.
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Lindström NO, Hohenstein P, Davies JA. Nephrons require Rho-kinase for proximal-distal polarity development. Sci Rep 2013; 3:2692. [PMID: 24045698 PMCID: PMC3776198 DOI: 10.1038/srep02692] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 08/29/2013] [Indexed: 12/24/2022] Open
Abstract
Epithelial tubules must have the right length and pattern for proper function. In the nephron, planar cell polarity controls elongation along the proximal-distal axis. As the tubule lengthens, specialized segments (proximal, distal etc.) begin to differentiate along it. Other epithelia need Rho-kinase for planar cell polarity but it is not known whether Rho-kinase is involved in this way in the nephron. We show that Rho-kinase is essential for the morphogenesis of nephrons, specifically for correct cell orientation and volume. We use fluorescent reporter-models and progenitor-specific markers to demonstrate that inhibition of Rho-kinase prevents proper proximal-distal axis formation, causes segments to develop abnormally, and progenitor-cell segregation to fail. Our data demonstrate the importance of Rho-kinase in normal nephron tubulogenesis and patterning.
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Affiliation(s)
- Nils O. Lindström
- Centre for Integrative Physiology, The University of Edinburgh, Hugh Robson Building, EH8 9XB, United Kingdom
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh, EH4 2XU, United Kingdom
- The Roslin Institute, The University of Edinburgh, Easter Bush, EH25 9RG, United Kingdom
| | - Peter Hohenstein
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh, EH4 2XU, United Kingdom
- The Roslin Institute, The University of Edinburgh, Easter Bush, EH25 9RG, United Kingdom
| | - Jamie A. Davies
- Centre for Integrative Physiology, The University of Edinburgh, Hugh Robson Building, EH8 9XB, United Kingdom
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Levayer R. [Regulation of intercellular adhesion during epithelial morphogenesis]. Biol Aujourdhui 2012; 206:219-36. [PMID: 23171844 DOI: 10.1051/jbio/2012021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Indexed: 11/14/2022]
Abstract
The epithelium is one of the most abundant tissues in metazoans. It is required to generate stable chemical and mechanical barriers between physiological compartments (fluid matrix/external environment). This function is based on multiple intercellular junctions, which insulate and stabilize cell-cell contacts in the tissue. Despite this apparent robustness, epithelia can be extensively remodeled during wound healing, embryogenesis and tumor progression. The capacity to be remodeled while keeping tissue cohesion requires a perfect balance between stability and plasticity of intercellular junctions. The balance is partially regulated by intercellular adhesion, which is mostly based on adherens junctions and the transmembrane protein E-cadherin. The aim of this review is to report the molecular basis of the balance between plasticity and robustness in the epithelium. We will first present the minimal physical framework used to describe epithelial cell shape. We will then describe the main processes involved in intercellular adhesion regulation and their functions during epithelial morphogenesis. Eventually, we will analyze the relationship and the coupling between adhesive forces and cortical tension.
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Affiliation(s)
- Romain Levayer
- Institut de Biologie du Developpement de Marseille Luminy, Marseille, France.
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Amack JD, Manning ML. Knowing the boundaries: extending the differential adhesion hypothesis in embryonic cell sorting. Science 2012; 338:212-5. [PMID: 23066072 DOI: 10.1126/science.1223953] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Successful embryogenesis requires proper sorting and compartmentalization of different cell types. Mechanical interactions between cells help govern these processes. In the past, physics-based theories have guided in vitro studies of cell sorting and tissue surface tension. Recent experiments have challenged this approach, indicating that adhesive molecules also act as signaling molecules that initiate local reorganization of actomyosin and demonstrating that cells at the boundary of a colony of initially identical cells become "mechanically polarized." Extending physical models to account for mechanical polarization helps solve a long-standing paradox about magnitudes of tissue surface tensions and potentially explains discrepancies between recent in vivo and in vitro cell-sorting experiments. New experiments are needed to further explore the connection between mechanical polarization and tissue boundary formation in vivo.
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Affiliation(s)
- Jeffrey D Amack
- Department of Cell and Developmental Biology, State University of New York, Upstate Medical University, 309 Weiskotten Hall, Syracuse, NY 13210, USA.
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Aliee M, Röper JC, Landsberg KP, Pentzold C, Widmann TJ, Jülicher F, Dahmann C. Physical mechanisms shaping the Drosophila dorsoventral compartment boundary. Curr Biol 2012; 22:967-76. [PMID: 22560616 DOI: 10.1016/j.cub.2012.03.070] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 02/28/2012] [Accepted: 03/27/2012] [Indexed: 11/27/2022]
Abstract
BACKGROUND Separating cells with distinct identities and fates by straight and sharp compartment boundaries is important for growth and pattern formation during animal development. The physical mechanisms shaping compartment boundaries, however, are not fully understood. RESULTS We combine theory and quantitative experiments to investigate the roles of different mechanisms to shape compartment boundaries. Our theoretical work shows that cell elongation created by anisotropic stress, cell proliferation rate, orientation of cell division, and cell bond tension all have distinct effects on the morphology of compartment boundaries during tissue growth. Our experiments using the developing Drosophila wing reveal that the roughness of the dorsoventral compartment boundary is dynamic and that it decreases during development. By measuring tissue relaxation in response to laser ablation of cell bonds at different developmental times, we demonstrate that decreased boundary roughness correlates with increased cell bond tension along the compartment boundary. Finally, by using experimentally determined values for cell bond tension, cell elongation and bias in orientation of cell division in simulations of tissue growth, we can reproduce the main features of the time evolution of the dorsoventral compartment boundary shape. CONCLUSIONS Local increase of cell bond tension along the boundary as well as global anisotropies in the tissue contribute to shaping boundaries in cell networks. We propose a simple scenario that combines time-dependent cell bond tension at the boundary, oriented cell division, and cell elongation in the tissue that can account for the main features of the dynamics of the shape of the dorsoventral compartment boundary.
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Affiliation(s)
- Maryam Aliee
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187 Dresden, Germany
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Batlle E, Wilkinson DG. Molecular mechanisms of cell segregation and boundary formation in development and tumorigenesis. Cold Spring Harb Perspect Biol 2012; 4:a008227. [PMID: 22214769 PMCID: PMC3249626 DOI: 10.1101/cshperspect.a008227] [Citation(s) in RCA: 137] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The establishment and maintenance of precisely organized tissues requires the formation of sharp borders between distinct cell populations. The maintenance of segregated cell populations is also required for tissue homeostasis in the adult, and deficiencies in segregation underlie the metastatic spreading of tumor cells. Three classes of mechanisms that underlie cell segregation and border formation have been uncovered. The first involves differences in cadherin-mediated cell-cell adhesion that establishes interfacial tension at the border between distinct cell populations. A second mechanism involves the induction of actomyosin-mediated contraction by intercellular signaling, such that cortical tension is generated at the border. Third, activation of Eph receptors and ephrins can lead to both decreased adhesion by triggering cleavage of E-cadherin, and to repulsion of cells by regulation of the actin cytoskeleton, thus preventing intermingling between cell populations. These mechanisms play crucial roles at distinct boundaries during development, and alterations in cadherin or Eph/ephrin expression have been implicated in tumor metastasis.
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Affiliation(s)
- Eduard Batlle
- Oncology Program and ICREA, Institute for Research in Biomedicine, Josep Samitier 1-5, 08028 Barcelona, Spain
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