1
|
Malin J, Rosa-Birriel C, Hatini V. Pten, PI3K, and PtdIns(3,4,5)P 3 dynamics control pulsatile actin branching in Drosophila retina morphogenesis. Dev Cell 2024; 59:1593-1608.e6. [PMID: 38640926 DOI: 10.1016/j.devcel.2024.03.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 11/28/2023] [Accepted: 03/25/2024] [Indexed: 04/21/2024]
Abstract
Epithelial remodeling of the Drosophila retina depends on the pulsatile contraction and expansion of apical contacts between the cells that form its hexagonal lattice. Phosphoinositide PI(3,4,5)P3 (PIP3) accumulates around tricellular adherens junctions (tAJs) during contact expansion and dissipates during contraction, but with unknown function. Here, we found that manipulations of Pten or PI3-kinase (PI3K) that either decreased or increased PIP3 resulted in shortened contacts and a disordered lattice, indicating a requirement for PIP3 dynamics and turnover. These phenotypes are caused by a loss of branched actin, resulting from impaired activity of the Rac1 Rho GTPase and the WAVE regulatory complex (WRC). We additionally found that during contact expansion, PI3K moves into tAJs to promote the cyclical increase of PIP3 in a spatially and temporally precise manner. Thus, dynamic control of PIP3 by Pten and PI3K governs the protrusive phase of junctional remodeling, which is essential for planar epithelial morphogenesis.
Collapse
Affiliation(s)
- Jacob Malin
- Tufts University School of Medicine, Department of Developmental, Molecular & Chemical Biology, Program in Genetics, Molecular and Cellular Biology, and Program in Pharmacology and Experimental Therapeutics, 150 Harrison Avenue, Boston, MA 02111, USA
| | - Christian Rosa-Birriel
- Tufts University School of Medicine, Department of Developmental, Molecular & Chemical Biology, Program in Genetics, Molecular and Cellular Biology, and Program in Pharmacology and Experimental Therapeutics, 150 Harrison Avenue, Boston, MA 02111, USA
| | - Victor Hatini
- Tufts University School of Medicine, Department of Developmental, Molecular & Chemical Biology, Program in Genetics, Molecular and Cellular Biology, and Program in Pharmacology and Experimental Therapeutics, 150 Harrison Avenue, Boston, MA 02111, USA.
| |
Collapse
|
2
|
Firmin J, Ecker N, Rivet Danon D, Özgüç Ö, Barraud Lange V, Turlier H, Patrat C, Maître JL. Mechanics of human embryo compaction. Nature 2024; 629:646-651. [PMID: 38693259 DOI: 10.1038/s41586-024-07351-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/26/2024] [Indexed: 05/03/2024]
Abstract
The shaping of human embryos begins with compaction, during which cells come into close contact1,2. Assisted reproductive technology studies indicate that human embryos fail compaction primarily because of defective adhesion3,4. On the basis of our current understanding of animal morphogenesis5,6, other morphogenetic engines, such as cell contractility, could be involved in shaping human embryos. However, the molecular, cellular and physical mechanisms driving human embryo morphogenesis remain uncharacterized. Using micropipette aspiration on human embryos donated to research, we have mapped cell surface tensions during compaction. This shows a fourfold increase of tension at the cell-medium interface whereas cell-cell contacts keep a steady tension. Therefore, increased tension at the cell-medium interface drives human embryo compaction, which is qualitatively similar to compaction in mouse embryos7. Further comparison between human and mouse shows qualitatively similar but quantitively different mechanical strategies, with human embryos being mechanically least efficient. Inhibition of cell contractility and cell-cell adhesion in human embryos shows that, whereas both cellular processes are required for compaction, only contractility controls the surface tensions responsible for compaction. Cell contractility and cell-cell adhesion exhibit distinct mechanical signatures when faulty. Analysing the mechanical signature of naturally failing embryos, we find evidence that non-compacting or partially compacting embryos containing excluded cells have defective contractility. Together, our study shows that an evolutionarily conserved increase in cell contractility is required to generate the forces driving the first morphogenetic movement shaping the human body.
Collapse
Affiliation(s)
- Julie Firmin
- Institut Curie, Université PSL, CNRS UMR3215, INSERM U934, Paris, France
- Université de Paris, Paris, France
- Service de Biologie de la Reproduction - CECOS, Paris Centre Hospital, APHP centre, FHU Prema, Paris, France
| | - Nicolas Ecker
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, FHU Prema, Paris, France
| | - Diane Rivet Danon
- Service de Biologie de la Reproduction - CECOS, Paris Centre Hospital, APHP centre, FHU Prema, Paris, France
| | - Özge Özgüç
- Institut Curie, Université PSL, CNRS UMR3215, INSERM U934, Paris, France
| | - Virginie Barraud Lange
- Service de Biologie de la Reproduction - CECOS, Paris Centre Hospital, APHP centre, FHU Prema, Paris, France
- Institut Cochin, Université de Paris, CNRS UMR1016, Paris, France
| | - Hervé Turlier
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, FHU Prema, Paris, France
| | - Catherine Patrat
- Service de Biologie de la Reproduction - CECOS, Paris Centre Hospital, APHP centre, FHU Prema, Paris, France
- Institut Cochin, Université de Paris, CNRS UMR1016, Paris, France
| | - Jean-Léon Maître
- Institut Curie, Université PSL, CNRS UMR3215, INSERM U934, Paris, France.
| |
Collapse
|
3
|
de Plater L, Firmin J, Maître JL. Mechanical strengthening of cell-cell adhesion during mouse embryo compaction. Biophys J 2024:S0006-3495(24)00208-X. [PMID: 38528761 DOI: 10.1016/j.bpj.2024.03.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 02/26/2024] [Accepted: 03/22/2024] [Indexed: 03/27/2024] Open
Abstract
Compaction is the first morphogenetic movement of the eutherian mammals and involves a developmentally regulated adhesion process. Previous studies investigated cellular and mechanical aspects of compaction. During mouse and human compaction, cells spread onto each other as a result of a contractility-mediated increase in surface tension pulling at the edges of their cell-cell contacts. However, how compaction may affect the mechanical stability of cell-cell contacts remains unknown. Here, we used a dual pipette aspiration assay on cell doublets to quantitatively analyze the mechanical stability of compacting mouse embryos. We measured increased mechanical stability of contacts with rupture forces growing from 40 to 70 nN, which was highly correlated with cell-cell contact expansion. Analyzing the dynamic molecular reorganization of cell-cell contacts, we find minimal recruitment of the cell-cell adhesion molecule Cdh1 (also known as E-cadherin) to contacts but we observe its reorganization into a peripheral adhesive ring. However, this reorganization is not associated with increased effective bond density, contrary to previous reports in other adhesive systems. Using genetics, we reduce the levels of Cdh1 or replace it with a chimeric adhesion molecule composed of the extracellular domain of Cdh1 and the intracellular domain of Cdh2 (also known as N-cadherin). We find that reducing the levels of Cdh1 impairs the mechanical stability of cell-cell contacts due to reduced contact growth, which nevertheless show higher effective bond density than wild-type contacts of similar size. On the other hand, chimeric adhesion molecules cannot form large or strong contacts indicating that the intracellular domain of Cdh2 is unable to reorganize contacts and/or is mechanically weaker than the one of Cdh1 in mouse embryos. Together, we find that mouse embryo compaction mechanically strengthens cell-cell adhesion via the expansion of Cdh1 adhesive rings that maintain pre-compaction levels of effective bond density.
Collapse
Affiliation(s)
- Ludmilla de Plater
- Institut Curie, Université PSL, CNRS UMR3215, INSERM U934, Paris, France
| | - Julie Firmin
- Institut Curie, Université PSL, CNRS UMR3215, INSERM U934, Paris, France; Service de Biologie de la Reproduction - CECOS, Paris Centre Hospital, APHP Centre, Université Paris Cité, Paris, France
| | - Jean-Léon Maître
- Institut Curie, Université PSL, CNRS UMR3215, INSERM U934, Paris, France.
| |
Collapse
|
4
|
Arslan FN, Hannezo É, Merrin J, Loose M, Heisenberg CP. Adhesion-induced cortical flows pattern E-cadherin-mediated cell contacts. Curr Biol 2024; 34:171-182.e8. [PMID: 38134934 DOI: 10.1016/j.cub.2023.11.067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 10/25/2023] [Accepted: 11/30/2023] [Indexed: 12/24/2023]
Abstract
Metazoan development relies on the formation and remodeling of cell-cell contacts. Dynamic reorganization of adhesion receptors and the actomyosin cell cortex in space and time plays a central role in cell-cell contact formation and maturation. Nevertheless, how this process is mechanistically achieved when new contacts are formed remains unclear. Here, by building a biomimetic assay composed of progenitor cells adhering to supported lipid bilayers functionalized with E-cadherin ectodomains, we show that cortical F-actin flows, driven by the depletion of myosin-2 at the cell contact center, mediate the dynamic reorganization of adhesion receptors and cell cortex at the contact. E-cadherin-dependent downregulation of the small GTPase RhoA at the forming contact leads to both a depletion of myosin-2 and a decrease of F-actin at the contact center. At the contact rim, in contrast, myosin-2 becomes enriched by the retraction of bleb-like protrusions, resulting in a cortical tension gradient from the contact rim to its center. This tension gradient, in turn, triggers centrifugal F-actin flows, leading to further accumulation of F-actin at the contact rim and the progressive redistribution of E-cadherin from the contact center to the rim. Eventually, this combination of actomyosin downregulation and flows at the contact determines the characteristic molecular organization, with E-cadherin and F-actin accumulating at the contact rim, where they are needed to mechanically link the contractile cortices of the adhering cells.
Collapse
Affiliation(s)
- Feyza Nur Arslan
- Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg 3400, Austria; Institute of Bioengineering, École polytechnique fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Édouard Hannezo
- Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg 3400, Austria
| | - Jack Merrin
- Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg 3400, Austria
| | - Martin Loose
- Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg 3400, Austria
| | | |
Collapse
|
5
|
Zhang N, Häring M, Wolf F, Großhans J, Kong D. Dynamics and functions of E-cadherin complexes in epithelial cell and tissue morphogenesis. MARINE LIFE SCIENCE & TECHNOLOGY 2023; 5:585-601. [PMID: 38045551 PMCID: PMC10689684 DOI: 10.1007/s42995-023-00206-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 10/31/2023] [Indexed: 12/05/2023]
Abstract
Cell-cell adhesion is at the center of structure and dynamics of epithelial tissue. E-cadherin-catenin complexes mediate Ca2+-dependent trans-homodimerization and constitute the kernel of adherens junctions. Beyond the basic function of cell-cell adhesion, recent progress sheds light the dynamics and interwind interactions of individual E-cadherin-catenin complex with E-cadherin superclusters, contractile actomyosin and mechanics of the cortex and adhesion. The nanoscale architecture of E-cadherin complexes together with cis-interactions and interactions with cortical actomyosin adjust to junctional tension and mechano-transduction by reinforcement or weakening of specific features of the interactions. Although post-translational modifications such as phosphorylation and glycosylation have been implicated, their role for specific aspects of in E-cadherin function has remained unclear. Here, we provide an overview of the E-cadherin complex in epithelial cell and tissue morphogenesis focusing on nanoscale architectures by super-resolution approaches and post-translational modifications from recent, in particular in vivo, studies. Furthermore, we review the computational modelling in E-cadherin complexes and highlight how computational modelling has contributed to a deeper understanding of the E-cadherin complexes.
Collapse
Affiliation(s)
- Na Zhang
- Department of Biology, Philipps University, 35043 Marburg, Germany
| | - Matthias Häring
- Göttingen Campus Institute for Dynamics of Biological Networks (CIDBN), Georg August University Göttingen, 37073 Göttingen, Germany
| | - Fred Wolf
- Göttingen Campus Institute for Dynamics of Biological Networks (CIDBN), Georg August University Göttingen, 37073 Göttingen, Germany
| | - Jörg Großhans
- Department of Biology, Philipps University, 35043 Marburg, Germany
- Göttingen Campus Institute for Dynamics of Biological Networks (CIDBN), Georg August University Göttingen, 37073 Göttingen, Germany
| | - Deqing Kong
- Department of Biology, Philipps University, 35043 Marburg, Germany
- Göttingen Campus Institute for Dynamics of Biological Networks (CIDBN), Georg August University Göttingen, 37073 Göttingen, Germany
| |
Collapse
|
6
|
Yost PP, Al-Nouman A, Curtiss J. The Rap1 small GTPase affects cell fate or survival and morphogenetic patterning during Drosophila melanogaster eye development. Differentiation 2023; 133:12-24. [PMID: 37437447 PMCID: PMC10528170 DOI: 10.1016/j.diff.2023.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 07/14/2023]
Abstract
The Drosophila melanogaster eye has been instrumental for determining both how cells communicate with one another to determine cell fate, as well as cell morphogenesis and patterning. Here, we describe the effects of the small GTPase Rap1 on the development of multiple cell types in the D. melanogaster eye. Although Rap1 has previously been linked to RTK-Ras-MAPK signaling in eye development, we demonstrate that manipulation of Rap1 activity is modified by increase or decrease of Delta/Notch signaling during several events of cell fate specification in eye development. In addition, we demonstrate that manipulating Rap1 function either in primary pigment cells or in interommatidial cells affects cone cell contact switching, primary pigment cell enwrapment of the ommatidial cluster, and sorting of secondary and tertiary pigment cells. These data suggest that Rap1 has roles in both ommatidial cell recruitment/survival and in ommatidial morphogenesis in the pupal stage. They lay groundwork for future experiments on the role of Rap1 in these events.
Collapse
Affiliation(s)
- Philip P Yost
- New Mexico State University, 1780 E University Ave, Las Cruces, NM, 88003, USA
| | | | - Jennifer Curtiss
- New Mexico State University, 1780 E University Ave, Las Cruces, NM, 88003, USA.
| |
Collapse
|
7
|
Malin J, Rosa Birriel C, Hatini V. Pten, Pi3K and PtdIns(3,4,5)P 3 dynamics modulate pulsatile actin branching in Drosophila retina morphogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.17.533017. [PMID: 36993510 PMCID: PMC10055149 DOI: 10.1101/2023.03.17.533017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Epithelial remodeling of the Drosophila retina depends on the pulsatile contraction and expansion of apical contacts between the cells that form its hexagonal lattice. Phosphoinositide PI(3,4,5)P 3 (PIP 3 ) accumulates around tricellular adherens junctions (tAJs) during contact expansion and dissipates during contraction, but with unknown function. Here we found that manipulations of Pten or Pi3K that either decreased or increased PIP 3 resulted in shortened contacts and a disordered lattice, indicating a requirement for PIP 3 dynamics and turnover. These phenotypes are caused by a loss of protrusive branched actin, resulting from impaired activity of the Rac1 Rho GTPase and the WAVE regulatory complex (WRC). We additionally found that during contact expansion, Pi3K moves into tAJs to promote the cyclical increase of PIP 3 in a spatially and temporally precise manner. Thus, dynamic regulation of PIP 3 by Pten and Pi3K controls the protrusive phase of junctional remodeling, which is essential for planar epithelial morphogenesis.
Collapse
|
8
|
Rathore S, Meece M, Charlton-Perkins M, Cook TA, Buschbeck EK. Probing the conserved roles of cut in the development and function of optically different insect compound eyes. Front Cell Dev Biol 2023; 11:1104620. [PMID: 37065850 PMCID: PMC10102356 DOI: 10.3389/fcell.2023.1104620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/13/2023] [Indexed: 04/03/2023] Open
Abstract
Astonishing functional diversity exists among arthropod eyes, yet eye development relies on deeply conserved genes. This phenomenon is best understood for early events, whereas fewer investigations have focused on the influence of later transcriptional regulators on diverse eye organizations and the contribution of critical support cells, such as Semper cells (SCs). As SCs in Drosophila melanogaster secrete the lens and function as glia, they are critical components of ommatidia. Here, we perform RNAi-based knockdowns of the transcription factor cut (CUX in vertebrates), a marker of SCs, the function of which has remained untested in these cell types. To probe for the conserved roles of cut, we investigate two optically different compound eyes: the apposition optics of D. melanogaster and the superposition optics of the diving beetle Thermonectus marmoratus. In both cases, we find that multiple aspects of ocular formation are disrupted, including lens facet organization and optics as well as photoreceptor morphogenesis. Together, our findings support the possibility of a generalized role for SCs in arthropod ommatidial form and function and introduces Cut as a central player in mediating this role.
Collapse
Affiliation(s)
- Shubham Rathore
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Michael Meece
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Mark Charlton-Perkins
- Division of Developmental Biology and Department of Pediatric Ophthalmology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
| | - Tiffany A. Cook
- Center of Molecular Medicine and Genetics, Department of Ophthalmological, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
- *Correspondence: Tiffany A. Cook, ; Elke K. Buschbeck,
| | - Elke K. Buschbeck
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
- *Correspondence: Tiffany A. Cook, ; Elke K. Buschbeck,
| |
Collapse
|
9
|
Takeichi M. Cell sorting in vitro and in vivo: How are cadherins involved? Semin Cell Dev Biol 2022; 147:2-11. [PMID: 36376196 DOI: 10.1016/j.semcdb.2022.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 11/07/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022]
Abstract
Animal tissues are composed of heterogenous cells, and their sorting into different compartments of the tissue is a pivotal process for organogenesis. Cells accomplish sorting by themselves-it is well known that singly dispersed cells can self-organize into tissue-like structures in vitro. Cell sorting is regulated by both biochemical and physical mechanisms. Adhesive proteins connect cells together, selecting particular partners through their specific binding properties, while physical forces, such as cell-cortical tension, control the cohesiveness between cells and in turn cell assembly patterns in mechanical ways. These processes cooperate in determining the overall cell sorting behavior. This article focuses on the 'cadherin' family of adhesion molecules as a biochemical component of cell-cell interactions, addressing how they regulate cell sorting by themselves or by cooperating with other factors. New ideas beyond the classical models of cell sorting are also discussed.
Collapse
|
10
|
Malin J, Rosa Birriel C, Astigarraga S, Treisman JE, Hatini V. Sidekick dynamically rebalances contractile and protrusive forces to control tissue morphogenesis. J Cell Biol 2022; 221:e202107035. [PMID: 35258563 PMCID: PMC8908789 DOI: 10.1083/jcb.202107035] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 12/28/2021] [Accepted: 02/07/2022] [Indexed: 12/19/2022] Open
Abstract
Contractile actomyosin and protrusive branched F-actin networks interact in a dynamic balance, repeatedly contracting and expanding apical cell contacts to organize the epithelium of the developing fly retina. Previously we showed that the immunoglobulin superfamily protein Sidekick (Sdk) contributes to contraction by recruiting the actin binding protein Polychaetoid (Pyd) to vertices. Here we show that as tension increases during contraction, Sdk progressively accumulates at vertices, where it toggles to recruit the WAVE regulatory complex (WRC) to promote actin branching and protrusion. Sdk alternately interacts with the WRC and Pyd using the same C-terminal motif. With increasing protrusion, levels of Sdk and the WRC decrease at vertices while levels of Pyd increase paving the way for another round of contraction. Thus, by virtue of dynamic association with vertices and interchangeable associations with contractile and protrusive effectors, Sdk is central to controlling the balance between contraction and expansion that shapes this epithelium.
Collapse
Affiliation(s)
- Jacob Malin
- Department of Developmental, Molecular & Chemical Biology, Program in Cell, Molecular and Developmental Biology and Program in Genetics, Tufts University School of Medicine, Boston, MA
| | - Christian Rosa Birriel
- Department of Developmental, Molecular & Chemical Biology, Program in Cell, Molecular and Developmental Biology and Program in Genetics, Tufts University School of Medicine, Boston, MA
| | - Sergio Astigarraga
- Skirball Institute for Biomolecular Medicine, New York, NY
- Department of Cell Biology, New York University School of Medicine, New York, NY
| | - Jessica E. Treisman
- Skirball Institute for Biomolecular Medicine, New York, NY
- Department of Cell Biology, New York University School of Medicine, New York, NY
| | - Victor Hatini
- Department of Developmental, Molecular & Chemical Biology, Program in Cell, Molecular and Developmental Biology and Program in Genetics, Tufts University School of Medicine, Boston, MA
| |
Collapse
|
11
|
Yanagida A, Corujo-Simon E, Revell CK, Sahu P, Stirparo GG, Aspalter IM, Winkel AK, Peters R, De Belly H, Cassani DAD, Achouri S, Blumenfeld R, Franze K, Hannezo E, Paluch EK, Nichols J, Chalut KJ. Cell surface fluctuations regulate early embryonic lineage sorting. Cell 2022; 185:777-793.e20. [PMID: 35196500 PMCID: PMC8896887 DOI: 10.1016/j.cell.2022.01.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 10/22/2021] [Accepted: 01/26/2022] [Indexed: 01/24/2023]
Abstract
In development, lineage segregation is coordinated in time and space. An important example is the mammalian inner cell mass, in which the primitive endoderm (PrE, founder of the yolk sac) physically segregates from the epiblast (EPI, founder of the fetus). While the molecular requirements have been well studied, the physical mechanisms determining spatial segregation between EPI and PrE remain elusive. Here, we investigate the mechanical basis of EPI and PrE sorting. We find that rather than the differences in static cell surface mechanical parameters as in classical sorting models, it is the differences in surface fluctuations that robustly ensure physical lineage sorting. These differential surface fluctuations systematically correlate with differential cellular fluidity, which we propose together constitute a non-equilibrium sorting mechanism for EPI and PrE lineages. By combining experiments and modeling, we identify cell surface dynamics as a key factor orchestrating the correct spatial segregation of the founder embryonic lineages.
Collapse
Affiliation(s)
- Ayaka Yanagida
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Puddicombe Way, Cambridge CB2 0AW, UK; Centre for Trophoblast Research, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK; Living Systems Institute, University of Exeter, Exeter EX4 4QD, UK
| | - Elena Corujo-Simon
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Puddicombe Way, Cambridge CB2 0AW, UK
| | - Christopher K Revell
- Cavendish Laboratory, Department of Physics, University of Cambridge, JJ Thomson Ave, Cambridge CB3 0HE, UK
| | - Preeti Sahu
- Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg 3400, Austria
| | - Giuliano G Stirparo
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Puddicombe Way, Cambridge CB2 0AW, UK
| | - Irene M Aspalter
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Alex K Winkel
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Ruby Peters
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Henry De Belly
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Puddicombe Way, Cambridge CB2 0AW, UK; MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK; Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Davide A D Cassani
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | - Sarra Achouri
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Puddicombe Way, Cambridge CB2 0AW, UK; Centre for Trophoblast Research, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
| | - Raphael Blumenfeld
- Gonville & Caius College, University of Cambridge, Trinity St., Cambridge CB2 1TA, UK
| | - Kristian Franze
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Edouard Hannezo
- Institute of Science and Technology Austria, Am Campus 1, Klosterneuburg 3400, Austria
| | - Ewa K Paluch
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK; Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK.
| | - Jennifer Nichols
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Puddicombe Way, Cambridge CB2 0AW, UK; Centre for Trophoblast Research, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK; Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK.
| | - Kevin J Chalut
- Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Puddicombe Way, Cambridge CB2 0AW, UK; Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK.
| |
Collapse
|
12
|
Paci G, Mao Y. Forced into shape: Mechanical forces in Drosophila development and homeostasis. Semin Cell Dev Biol 2021; 120:160-170. [PMID: 34092509 PMCID: PMC8681862 DOI: 10.1016/j.semcdb.2021.05.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 12/03/2022]
Abstract
Mechanical forces play a central role in shaping tissues during development and maintaining epithelial integrity in homeostasis. In this review, we discuss the roles of mechanical forces in Drosophila development and homeostasis, starting from the interplay of mechanics with cell growth and division. We then discuss several examples of morphogenetic processes where complex 3D structures are shaped by mechanical forces, followed by a closer look at patterning processes. We also review the role of forces in homeostatic processes, including cell elimination and wound healing. Finally, we look at the interplay of mechanics and developmental robustness and discuss open questions in the field, as well as novel approaches that will help tackle them in the future.
Collapse
Affiliation(s)
- Giulia Paci
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK; Institute for the Physics of Living Systems, University College London, Gower Street, London WC1E 6BT, UK
| | - Yanlan Mao
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK; Institute for the Physics of Living Systems, University College London, Gower Street, London WC1E 6BT, UK.
| |
Collapse
|
13
|
Charlton-Perkins MA, Friedrich M, Cook TA. Semper's cells in the insect compound eye: Insights into ocular form and function. Dev Biol 2021; 479:126-138. [PMID: 34343526 PMCID: PMC8410683 DOI: 10.1016/j.ydbio.2021.07.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 11/28/2022]
Abstract
The arthropod compound eye represents one of two major eye types in the animal kingdom and has served as an essential experimental paradigm for defining fundamental mechanisms underlying sensory organ formation, function, and maintenance. One of the most distinguishing features of the compound eye is the highly regular array of lens facets that define individual eye (ommatidial) units. These lens facets are produced by a deeply conserved quartet of cuticle-secreting cells, called Semper cells (SCs). Also widely known as cone cells, SCs were originally identified for their secretion of the dioptric system, i.e. the corneal lens and underlying crystalline cones. Additionally, SCs are now known to execute a diversity of patterning and glial functions in compound eye development and maintenance. Here, we present an integrated account of our current knowledge of SC multifunctionality in the Drosophila compound eye, highlighting emerging gene regulatory modules that may drive the diverse roles for these cells. Drawing comparisons with other deeply conserved retinal glia in the vertebrate single lens eye, this discussion speaks to glial cell origins and opens new avenues for understanding sensory system support programs.
Collapse
Affiliation(s)
- Mark A Charlton-Perkins
- Department of Paediatrics, Wellcome-MRC Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Puddicombe Way, Cambridge, CB2 0AW, United Kingdom
| | - Markus Friedrich
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI, 48202, USA; Department of Ophthalmological, Visual, and Anatomical Sciences, Wayne State University, School of Medicine, 540 East Canfield Avenue, Detroit, MI, 48201, USA
| | - Tiffany A Cook
- Department of Ophthalmological, Visual, and Anatomical Sciences, Wayne State University, School of Medicine, 540 East Canfield Avenue, Detroit, MI, 48201, USA; Center of Molecular Medicine and Genetics, Wayne State University School of Medicine, 540 East Canfield Avenue, Detroit, MI, 48201, USA.
| |
Collapse
|
14
|
Johnson RI. Hexagonal patterning of the Drosophila eye. Dev Biol 2021; 478:173-182. [PMID: 34245727 DOI: 10.1016/j.ydbio.2021.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 07/04/2021] [Accepted: 07/06/2021] [Indexed: 10/24/2022]
Abstract
A complex network of transcription factor interactions propagates across the larval eye disc to establish columns of evenly-spaced R8 precursor cells, the founding cells of Drosophila ommatidia. After the recruitment of additional photoreceptors to each ommatidium, the surrounding cells are organized into their stereotypical pattern during pupal development. These support cells - comprised of pigment and cone cells - are patterned to encapsulate the photoreceptors and separate ommatidia with an hexagonal honeycomb lattice. Since the proteins and processes essential for correct eye patterning are conserved, elucidating how these function and change during Drosophila eye patterning can substantially advance our understanding of transcription factor and signaling networks, cytoskeletal structures, adhesion complexes, and the biophysical properties of complex tissues during their morphogenesis. Our understanding of many of these aspects of Drosophila eye patterning is largely descriptive. Many important questions, especially relating to the regulation and integration of cellular events, remain.
Collapse
Affiliation(s)
- Ruth I Johnson
- Biology Department, Wesleyan University, 52 Lawn Avenue, Middletown, CT, USA.
| |
Collapse
|
15
|
Blackie L, Tozluoglu M, Trylinski M, Walther RF, Schweisguth F, Mao Y, Pichaud F. A combination of Notch signaling, preferential adhesion and endocytosis induces a slow mode of cell intercalation in the Drosophila retina. Development 2021; 148:264928. [PMID: 33999996 PMCID: PMC8180261 DOI: 10.1242/dev.197301] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 04/09/2021] [Indexed: 12/25/2022]
Abstract
Movement of epithelial cells in a tissue occurs through neighbor exchange and drives tissue shape changes. It requires intercellular junction remodeling, a process typically powered by the contractile actomyosin cytoskeleton. This has been investigated mainly in homogeneous epithelia, where intercalation takes minutes. However, in some tissues, intercalation involves different cell types and can take hours. Whether slow and fast intercalation share the same mechanisms remains to be examined. To address this issue, we used the fly eye, where the cone cells exchange neighbors over ∼10 h to shape the lens. We uncovered three pathways regulating this slow mode of cell intercalation. First, we found a limited requirement for MyosinII. In this case, mathematical modeling predicts an adhesion-dominant intercalation mechanism. Genetic experiments support this prediction, revealing a role for adhesion through the Nephrin proteins Roughest and Hibris. Second, we found that cone cell intercalation is regulated by the Notch pathway. Third, we show that endocytosis is required for membrane removal and Notch activation. Taken together, our work indicates that adhesion, endocytosis and Notch can direct slow cell intercalation during tissue morphogenesis.
Collapse
Affiliation(s)
- Laura Blackie
- MRC Laboratory for Molecular Cell Biology (LMCB), University College London, London WC1E 6BT, UK.,MRC London Institute of Medical Sciences (LMS), London W12 0NN, UK
| | - Melda Tozluoglu
- MRC Laboratory for Molecular Cell Biology (LMCB), University College London, London WC1E 6BT, UK
| | - Mateusz Trylinski
- MRC Laboratory for Molecular Cell Biology (LMCB), University College London, London WC1E 6BT, UK.,Department of Developmental and Stem Cell Biology, Pasteur Institute, F-75015 Paris, France
| | - Rhian F Walther
- MRC Laboratory for Molecular Cell Biology (LMCB), University College London, London WC1E 6BT, UK
| | - François Schweisguth
- Department of Developmental and Stem Cell Biology, Pasteur Institute, F-75015 Paris, France.,CNRS, UMR3738, F-75015 Paris, France
| | - Yanlan Mao
- MRC Laboratory for Molecular Cell Biology (LMCB), University College London, London WC1E 6BT, UK.,Institute for the Physics of Living Systems, University College London, London WC1E 6BT, UK
| | - Franck Pichaud
- MRC Laboratory for Molecular Cell Biology (LMCB), University College London, London WC1E 6BT, UK.,Institute for the Physics of Living Systems, University College London, London WC1E 6BT, UK
| |
Collapse
|
16
|
Lavalou J, Mao Q, Harmansa S, Kerridge S, Lellouch AC, Philippe JM, Audebert S, Camoin L, Lecuit T. Formation of polarized contractile interfaces by self-organized Toll-8/Cirl GPCR asymmetry. Dev Cell 2021; 56:1574-1588.e7. [PMID: 33932333 PMCID: PMC8207821 DOI: 10.1016/j.devcel.2021.03.030] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 02/23/2021] [Accepted: 03/25/2021] [Indexed: 12/16/2022]
Abstract
Interfaces between cells with distinct genetic identities elicit signals to organize local cell behaviors driving tissue morphogenesis. The Drosophila embryonic axis extension requires planar polarized enrichment of myosin-II powering oriented cell intercalations. Myosin-II levels are quantitatively controlled by GPCR signaling, whereas myosin-II polarity requires patterned expression of several Toll receptors. How Toll receptors polarize myosin-II and how this involves GPCRs remain unknown. Here, we report that differential expression of a single Toll receptor, Toll-8, polarizes myosin-II through binding to the adhesion GPCR Cirl/latrophilin. Asymmetric expression of Cirl is sufficient to enrich myosin-II, and Cirl localization is asymmetric at Toll-8 expression boundaries. Exploring the process dynamically, we reveal that Toll-8 and Cirl exhibit mutually dependent planar polarity in response to quantitative differences in Toll-8 expression between neighboring cells. Collectively, we propose that the cell surface protein complex Toll-8/Cirl self-organizes to generate local asymmetric interfaces essential for planar polarization of contractility. Asymmetric expression of a single Toll receptor leads to Myo-II polarization The adhesion GPCR Cirl binds to Toll-8 mediating Toll-8-induced Myo-II polarization Toll-8 boundaries generate a Cirl interfacial asymmetry that can polarize Myo-II Differences in Toll-8 levels lead to interdependent Toll-8 and Cirl planar polarity
Collapse
Affiliation(s)
- Jules Lavalou
- Aix-Marseille Université & CNRS, IBDM - UMR7288 & Turing Centre for Living Systems, Marseille, France; Collège de France, Paris, France
| | - Qiyan Mao
- Aix-Marseille Université & CNRS, IBDM - UMR7288 & Turing Centre for Living Systems, Marseille, France.
| | - Stefan Harmansa
- Aix-Marseille Université & CNRS, IBDM - UMR7288 & Turing Centre for Living Systems, Marseille, France
| | - Stephen Kerridge
- Aix-Marseille Université & CNRS, IBDM - UMR7288 & Turing Centre for Living Systems, Marseille, France
| | - Annemarie C Lellouch
- Aix-Marseille Université & CNRS, IBDM - UMR7288 & Turing Centre for Living Systems, Marseille, France
| | - Jean-Marc Philippe
- Aix-Marseille Université & CNRS, IBDM - UMR7288 & Turing Centre for Living Systems, Marseille, France
| | - Stephane Audebert
- Centre de Recherche en Cancérologie de Marseille, Marseille Proteomics, Aix-Marseille Université, Inserm, CNRS, Institut Paoli Calmettes, Marseille, France
| | - Luc Camoin
- Centre de Recherche en Cancérologie de Marseille, Marseille Proteomics, Aix-Marseille Université, Inserm, CNRS, Institut Paoli Calmettes, Marseille, France
| | - Thomas Lecuit
- Aix-Marseille Université & CNRS, IBDM - UMR7288 & Turing Centre for Living Systems, Marseille, France; Collège de France, Paris, France.
| |
Collapse
|
17
|
Lenne PF, Rupprecht JF, Viasnoff V. Cell Junction Mechanics beyond the Bounds of Adhesion and Tension. Dev Cell 2021; 56:202-212. [PMID: 33453154 DOI: 10.1016/j.devcel.2020.12.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/06/2020] [Accepted: 12/21/2020] [Indexed: 12/22/2022]
Abstract
Cell-cell junctions, in particular adherens junctions, are major determinants of tissue mechanics during morphogenesis and homeostasis. In attempts to link junctional mechanics to tissue mechanics, many have utilized explicitly or implicitly equilibrium approaches based on adhesion energy, surface energy, and contractility to determine the mechanical equilibrium at junctions. However, it is increasingly clear that they have significant limitations, such as that it remains challenging to link the dynamics of the molecular components to the resulting physical properties of the junction, to its remodeling ability, and to its adhesion strength. In this perspective, we discuss recent attempts to consider the aspect of energy dissipation at junctions to draw contact points with soft matter physics where energy loss plays a critical role in adhesion theories. We set the grounds for a theoretical framework of the junction mechanics that bridges the dynamics at the molecular scale to the mechanics at the tissue scale.
Collapse
Affiliation(s)
- Pierre-François Lenne
- Aix Marseille Université, CNRS, IBDM, Turing Centre for Living Systems, 13288 Marseille, France.
| | - Jean-François Rupprecht
- Aix Marseille Université, CNRS, CPT, Turing Centre for Living Systems, 13288 Marseille, France.
| | - Virgile Viasnoff
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore; CNRS Biomechanics of Cell Contacts, Singapore 117411, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117411, Singapore.
| |
Collapse
|
18
|
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.
Collapse
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.
| |
Collapse
|
19
|
Blackie L, Walther RF, Staddon MF, Banerjee S, Pichaud F. Cell-type-specific mechanical response and myosin dynamics during retinal lens development in Drosophila. Mol Biol Cell 2020; 31:1355-1369. [PMID: 32320320 PMCID: PMC7353141 DOI: 10.1091/mbc.e19-09-0523] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 04/07/2020] [Accepted: 04/14/2020] [Indexed: 11/11/2022] Open
Abstract
During organogenesis, different cell types need to work together to generate functional multicellular structures. To study this process, we made use of the genetically tractable fly retina, with a focus on the mechanisms that coordinate morphogenesis between the different epithelial cell types that make up the optical lens. Our work shows that these epithelial cells present contractile apical-medial MyosinII meshworks, which control the apical area and junctional geometry of these cells during lens development. Our study also suggests that these MyosinII meshworks drive cell shape changes in response to external forces, and thus they mediate part of the biomechanical coupling that takes place between these cells. Importantly, our work, including mathematical modeling of forces and material stiffness during lens development, raises the possibility that increased cell stiffness acts as a mechanism for limiting this mechanical coupling. We propose this might be required in complex tissues, where different cell types undergo concurrent morphogenesis and where averaging out of forces across cells could compromise individual cell apical geometry and thereby organ function.
Collapse
Affiliation(s)
| | | | - Michael F Staddon
- Department of Physics and Astronomy, and
- Institute for the Physics of Living Systems, University College London, WC1E 6BT London, UK
| | - Shiladitya Banerjee
- Department of Physics and Astronomy, and
- Institute for the Physics of Living Systems, University College London, WC1E 6BT London, UK
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213
| | - Franck Pichaud
- MRC Laboratory for Molecular Cell Biology
- Institute for the Physics of Living Systems, University College London, WC1E 6BT London, UK
| |
Collapse
|
20
|
Hashimoto H, Munro E. Differential Expression of a Classic Cadherin Directs Tissue-Level Contractile Asymmetry during Neural Tube Closure. Dev Cell 2020; 51:158-172.e4. [PMID: 31639367 DOI: 10.1016/j.devcel.2019.10.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 04/23/2019] [Accepted: 09/30/2019] [Indexed: 11/28/2022]
Abstract
Embryos control force generation at tissue boundaries, but how they do so remains poorly understood. Here we show how tissue-specific expression of the type II cadherin, Cadherin2, patterns actomyosin contractility along tissue boundaries to control zippering and neural tube closure in the basal chordate, Ciona robusta. Cadherin2 is differentially expressed and homotypically enriched in neural cells along the neural/epidermal (Ne/Epi) boundary, where RhoA and myosin are activated during zipper progression. Homotypically enriched Cadherin2 sequesters the Rho GTPase-activating protein, Gap21/23, to homotypic junctions. Gap21/23 in turn redirects RhoA/myosin activity to heterotypic Ne/Epi junctions. By activating myosin II along Ne/Epi junctions ahead of the zipper and inhibiting myosin II along newly formed Ne/Ne junctions behind the zipper, Cadherin2 promotes tissue-level contractile asymmetry to drive zipper progression. We propose that dynamic coupling of junction exchange to local changes in contractility may control fusion and separation of epithelia in many other contexts.
Collapse
Affiliation(s)
- Hidehiko Hashimoto
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA.
| | - Edwin Munro
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA; Committee on Development, Regeneration, and Stem Cell Biology, University of Chicago, Chicago, IL 60637, USA; Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA.
| |
Collapse
|
21
|
Sidor C, Stevens TJ, Jin L, Boulanger J, Röper K. Rho-Kinase Planar Polarization at Tissue Boundaries Depends on Phospho-regulation of Membrane Residence Time. Dev Cell 2020; 52:364-378.e7. [PMID: 31902655 PMCID: PMC7008249 DOI: 10.1016/j.devcel.2019.12.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 10/24/2019] [Accepted: 12/09/2019] [Indexed: 12/24/2022]
Abstract
The myosin II activator Rho-kinase (Rok) is planar polarized at the tissue boundary of the Drosophila embryonic salivary gland placode through a negative regulation by the apical polarity protein Crumbs that is anisotropically localized at the boundary. However, in inner cells of the placode, both Crumbs and Rok are isotropically enriched at junctions. We propose that modulation of Rok membrane residence time by Crumbs’ downstream effectors can reconcile both behaviors. Using FRAP combined with in silico simulations, we find that the lower membrane dissociation rate (koff) of Rok at the tissue boundary with low Crumbs explains this boundary-specific effect. The S/T kinase Pak1, recruited by Crumbs and Cdc42, negatively affects Rok membrane association in vivo and in vitro can phosphorylate Rok near the pleckstrin homology (PH) domain that mediates membrane association. These data reveal an important mechanism of the modulation of Rok membrane residence time via affecting the koff that may be widely employed during tissue morphogenesis. Rho-kinase is planar polarized at tissue boundaries, complementary to Crumbs Crumbs and downstream Pak1 modulate Rok residence time by affecting koff Pak1 can phosphorylate Rok near the PH and Rho-binding domains Rok phosphorylation affects residence time and allows polarization at boundaries
Collapse
Affiliation(s)
- Clara Sidor
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK.
| | - Tim J Stevens
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK
| | - Li Jin
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK
| | - Jérôme Boulanger
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK
| | - Katja Röper
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK.
| |
Collapse
|
22
|
Winkley K, Ward S, Reeves W, Veeman M. Iterative and Complex Asymmetric Divisions Control Cell Volume Differences in Ciona Notochord Tapering. Curr Biol 2019; 29:3466-3477.e4. [PMID: 31607534 DOI: 10.1016/j.cub.2019.08.056] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/29/2019] [Accepted: 08/21/2019] [Indexed: 12/12/2022]
Abstract
The notochord of the invertebrate chordate Ciona forms a tapered rod at tailbud stages consisting of only 40 cylindrical cells in a single-file column. This tapered shape involves differences in notochord cell volume along the anterior-posterior axis. Here, we quantify sibling cell volume asymmetry throughout the developing notochord and find that there are distinctive patterns of unequal cleavage in all 4 bilateral pairs of A-line primary notochord founder cells and also in the B-line-derived secondary notochord founder cells. A quantitative model confirms that the observed patterns of unequal cleavage are sufficient to explain all the anterior-posterior variation in notochord cell volume. Many examples are known of cells that divide asymmetrically to give daughter cells of different size and fate. Here, by contrast, a series of subtle but iterative and finely patterned asymmetric divisions controls the shape of an entire organ. Quantitative 3D analysis of cell shape and spindle positioning allows us to infer multiple cellular mechanisms driving these unequal cleavages, including polarized displacements of the mitotic spindle, contributions from the shape of the mother cell, and late changes occurring between anaphase and abscission that potentially involve differential cortical contractility. We infer differential use of these mechanisms between different notochord blastomeres and also between different rounds of cell division. These results demonstrate a new role for asymmetric division in directly shaping a developing organ and point toward complex underlying mechanisms.
Collapse
Affiliation(s)
- Konner Winkley
- Division of Biology, Kansas State University, 1717 Claflin Road, Manhattan, KS 66506, USA
| | - Spencer Ward
- Division of Biology, Kansas State University, 1717 Claflin Road, Manhattan, KS 66506, USA
| | - Wendy Reeves
- Division of Biology, Kansas State University, 1717 Claflin Road, Manhattan, KS 66506, USA
| | - Michael Veeman
- Division of Biology, Kansas State University, 1717 Claflin Road, Manhattan, KS 66506, USA.
| |
Collapse
|
23
|
Kong W, Loison O, Chavadimane Shivakumar P, Chan EH, Saadaoui M, Collinet C, Lenne PF, Clément R. Experimental validation of force inference in epithelia from cell to tissue scale. Sci Rep 2019; 9:14647. [PMID: 31601854 PMCID: PMC6787039 DOI: 10.1038/s41598-019-50690-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 09/13/2019] [Indexed: 11/24/2022] Open
Abstract
Morphogenesis relies on the active generation of forces, and the transmission of these forces to surrounding cells and tissues. Hence measuring forces directly in developing embryos is an essential task to study the mechanics of development. Among the experimental techniques that have emerged to measure forces in epithelial tissues, force inference is particularly appealing. Indeed it only requires a snapshot of the tissue, as it relies on the topology and geometry of cell contacts, assuming that forces are balanced at each vertex. However, establishing force inference as a reliable technique requires thorough validation in multiple conditions. Here we performed systematic comparisons of force inference with laser ablation experiments in four epithelial tissues from two animals, the fruit fly and the quail. We show that force inference accurately predicts single junction tension, tension patterns in stereotyped groups of cells, and tissue-scale stress patterns, in wild type and mutant conditions. We emphasize its ability to capture the distribution of forces at different scales from a single image, which gives it a critical advantage over perturbative techniques such as laser ablation. Overall, our results demonstrate that force inference is a reliable and efficient method to quantify the mechanical state of epithelia during morphogenesis, especially at larger scales when inferred tensions and pressures are binned into a coarse-grained stress tensor.
Collapse
Affiliation(s)
- Weiyuan Kong
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Olivier Loison
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | | | - Eunice HoYee Chan
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Mehdi Saadaoui
- Department of Developmental and Stem Cell Biology, Institut Pasteur, 25 rue du Docteur Roux, 75724, Paris Cedex 15, France
- CNRS URA2578, rue du Dr Roux, 75015, Paris, France
| | - Claudio Collinet
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Pierre-François Lenne
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France.
| | - Raphaël Clément
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France.
| |
Collapse
|
24
|
Abstract
Cell-cell junctions are specializations of the plasma membrane responsible for physically integrating cells into tissues. We are now beginning to appreciate the diverse impacts that mechanical forces exert upon the integrity and function of these junctions. Currently, this is best understood for cadherin-based adherens junctions in epithelia and endothelia, where cell-cell adhesion couples the contractile cytoskeletons of cells together to generate tissue-scale tension. Junctional tension participates in morphogenesis and tissue homeostasis. Changes in tension can also be detected by mechanotransduction pathways that allow cells to communicate with each other. In this review, we discuss progress in characterising the forces present at junctions in physiological conditions; the cellular mechanisms that generate intrinsic tension and detect changes in tension; and, finally, we consider how tissue integrity is maintained in the face of junctional stresses.
Collapse
|
25
|
Matamoro-Vidal A, Levayer R. Multiple Influences of Mechanical Forces on Cell Competition. Curr Biol 2019; 29:R762-R774. [DOI: 10.1016/j.cub.2019.06.030] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|
26
|
Letizia A, He D, Astigarraga S, Colombelli J, Hatini V, Llimargas M, Treisman JE. Sidekick Is a Key Component of Tricellular Adherens Junctions that Acts to Resolve Cell Rearrangements. Dev Cell 2019; 50:313-326.e5. [PMID: 31353315 DOI: 10.1016/j.devcel.2019.07.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/03/2019] [Accepted: 07/02/2019] [Indexed: 11/27/2022]
Abstract
Tricellular adherens junctions are points of high tension that are central to the rearrangement of epithelial cells. However, the molecular composition of these junctions is unknown, making it difficult to assess their role in morphogenesis. Here, we show that Sidekick, an immunoglobulin family cell adhesion protein, is highly enriched at tricellular adherens junctions in Drosophila. This localization is modulated by tension, and Sidekick is itself necessary to maintain normal levels of cell bond tension. Loss of Sidekick causes defects in cell and junctional rearrangements in actively remodeling epithelial tissues like the retina and tracheal system. The adaptor proteins Polychaetoid and Canoe are enriched at tricellular adherens junctions in a Sidekick-dependent manner; Sidekick functionally interacts with both proteins and directly binds to Polychaetoid. We suggest that Polychaetoid and Canoe link Sidekick to the actin cytoskeleton to enable tricellular adherens junctions to maintain or transmit cell bond tension during epithelial cell rearrangements.
Collapse
Affiliation(s)
- Annalisa Letizia
- Institut de Biologia Molecular de Barcelona, CSIC, Parc Científic de Barcelona, Baldiri Reixac, 10-12, Barcelona 08028, Spain
| | - DanQing He
- Kimmel Center for Biology and Medicine at the Skirball Institute and Department of Cell Biology, NYU School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Sergio Astigarraga
- Kimmel Center for Biology and Medicine at the Skirball Institute and Department of Cell Biology, NYU School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Julien Colombelli
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Parc Científic de Barcelona, Baldiri Reixac, 10, Barcelona 08028, Spain
| | - Victor Hatini
- Department of Developmental, Molecular & Chemical Biology, Program in Cell, Molecular and Developmental Biology and Program in Genetics, Tufts University School of Medicine, 150 Harrison Avenue, Jaharis 322, Boston, MA 02111, USA
| | - Marta Llimargas
- Institut de Biologia Molecular de Barcelona, CSIC, Parc Científic de Barcelona, Baldiri Reixac, 10-12, Barcelona 08028, Spain.
| | - Jessica E Treisman
- Kimmel Center for Biology and Medicine at the Skirball Institute and Department of Cell Biology, NYU School of Medicine, 540 First Avenue, New York, NY 10016, USA.
| |
Collapse
|
27
|
DeAngelis MW, Johnson RI. Dissection of the Drosophila Pupal Retina for Immunohistochemistry, Western Analysis, and RNA Isolation. J Vis Exp 2019. [PMID: 30933080 DOI: 10.3791/59299] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The Drosophila pupal retina provides an excellent model system for the study of morphogenetic processes during development. In this paper, we present a reliable protocol for the dissection of the delicate Drosophila pupal retina. Our surgical approach utilizes readily-available microdissection tools to open pupae and precisely extract eye-brain complexes. These can be fixed, subjected to immunohistochemistry, and retinas then mounted onto microscope slides and imaged if the goal is to detect cellular or subcellular structures. Alternatively, unfixed retinas can be isolated from brain tissue, lysed in appropriate buffers and utilized for protein gel electrophoresis or mRNA extraction (to assess protein or gene expression, respectively). Significant practice and patience may be required to master the microdissection protocol described, but once mastered, the protocol enables relatively quick isolation of mainly undamaged retinas.
Collapse
|
28
|
Araya C, Häkkinen HM, Carcamo L, Cerda M, Savy T, Rookyard C, Peyriéras N, Clarke JDW. Cdh2 coordinates Myosin-II dependent internalisation of the zebrafish neural plate. Sci Rep 2019; 9:1835. [PMID: 30755665 PMCID: PMC6372647 DOI: 10.1038/s41598-018-38455-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 12/07/2018] [Indexed: 11/09/2022] Open
Abstract
Tissue internalisation is a key morphogenetic mechanism by which embryonic tissues generate complex internal organs and a number of studies of epithelia have outlined a general view of tissue internalisation. Here we have used quantitative live imaging and mutant analysis to determine whether similar mechanisms are responsible for internalisation in a tissue that apparently does not have a typical epithelial organisation - the zebrafish neural plate. We found that although zebrafish embryos begin neurulation without a conventional epithelium, medially located neural plate cells adopt strategies typical of epithelia in order to constrict their dorsal surface membrane during cell internalisation. Furthermore, we show that Myosin-II activity is a significant driver of this transient cell remodeling which also depends on Cdh2 (N-cadherin). Abrogation of Cdh2 results in defective Myosin-II distribution, mislocalised internalisation events and defective neural plate morphogenesis. Our work suggests Cdh2 coordinates Myosin-II dependent internalisation of the zebrafish neural plate.
Collapse
Affiliation(s)
- Claudio Araya
- Laboratory of Developmental Biology, Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja, 5090000, Valdivia, Chile. .,Centro Interdisciplinario de Estudios del Sistema Nervioso (CISNe), UACh, Valdivia, Chile.
| | - Hanna-Maria Häkkinen
- Laboratory of Developmental Biology, Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja, 5090000, Valdivia, Chile
| | - Luis Carcamo
- Laboratory of Developmental Biology, Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja, 5090000, Valdivia, Chile
| | - Mauricio Cerda
- Anatomy and Developmental Biology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, PO Box 70031, Santiago, Chile.,Biomedical Neuroscience Institute, Independencia, 1027, Santiago, Chile
| | - Thierry Savy
- UPS3611 Complex Systems Institute Paris Ile-de-France (ISC-PIF), CNRS, Paris, France.,USR3695 BioEmergences, CNRS, Paris-Saclay University, Gif-sur- Yvette, France
| | - Christopher Rookyard
- Centre for Developmental Neurobiology, Institute of Psychiatry Psychology and Neuroscience, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, United Kingdom
| | - Nadine Peyriéras
- UPS3611 Complex Systems Institute Paris Ile-de-France (ISC-PIF), CNRS, Paris, France.,USR3695 BioEmergences, CNRS, Paris-Saclay University, Gif-sur- Yvette, France
| | - Jonathan D W Clarke
- Centre for Developmental Neurobiology, Institute of Psychiatry Psychology and Neuroscience, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, United Kingdom
| |
Collapse
|
29
|
Revell C, Blumenfeld R, Chalut KJ. Force-based three-dimensional model predicts mechanical drivers of cell sorting. Proc Biol Sci 2019; 286:20182495. [PMID: 30963946 PMCID: PMC6364585 DOI: 10.1098/rspb.2018.2495] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 01/03/2019] [Indexed: 01/22/2023] Open
Abstract
Many biological processes, including tissue morphogenesis, are driven by cell sorting. However, the primary mechanical drivers of sorting in multicellular aggregates (MCAs) remain controversial, in part because there is no appropriate computational model to probe mechanical interactions between cells. To address this important issue, we developed a three-dimensional, local force-based simulation based on the subcellular element method. In our method, cells are modelled as collections of locally interacting force-bearing elements. We use the method to investigate the effects of tension and cell-cell adhesion on MCA sorting. We predict a minimum level of adhesion to produce inside-out sorting of two cell types, which is in excellent agreement with observations in several developmental systems. We also predict the level of tension asymmetry needed for robust sorting. The generality and flexibility of the method make it applicable to tissue self-organization in a myriad of other biological processes, such as tumorigenesis and embryogenesis.
Collapse
Affiliation(s)
- Christopher Revell
- Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK
| | - Raphael Blumenfeld
- Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK
- Department of Earth Science and Engineering, Imperial College London, London SW7 2BP, UK
| | - Kevin J. Chalut
- Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK
- Wellcome Trust/Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK
| |
Collapse
|
30
|
Wang Y, Wen Q, Zhou Z, Yan N. Cell Modeling Based on Bubbles with Weighted Membranes. J Comput Biol 2019; 26:241-265. [PMID: 30624960 DOI: 10.1089/cmb.2018.0205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mathematicization for cell modeling provides an effective tool to verify the biological theory, and the existing research mainly focuses on the description of cell structures. This article then addresses the pattern question of cell division or morphogenesis by means of bubble model with weighted membranes. In this study, we show that cell shapes including intersection angles at junction points depend on weights on membranes. For convenience, adhesion and contractile force are considered together as a factor in construction of patterning model. This model is also used to compare with experimental data. And the consistency between our model and experiments is also obtained consequently. This system of differential equations with their boundary conditions theorizes the existing experimental models, and improves the rationality of these models.
Collapse
Affiliation(s)
- Yuandi Wang
- 1 Department of Mathematics, Shanghai University, Shanghai, China
| | - Qingmei Wen
- 1 Department of Mathematics, Shanghai University, Shanghai, China
| | - Zhigang Zhou
- 2 College of Aqua-life Sciences and Technology, Shanghai Ocean University, Shanghai, China
| | - Nanjun Yan
- 1 Department of Mathematics, Shanghai University, Shanghai, China
| |
Collapse
|
31
|
Agarwal P, Zaidel-Bar R. Principles of Actomyosin Regulation In Vivo. Trends Cell Biol 2018; 29:150-163. [PMID: 30385150 DOI: 10.1016/j.tcb.2018.09.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/22/2018] [Accepted: 09/25/2018] [Indexed: 12/22/2022]
Abstract
The actomyosin cytoskeleton is responsible for most force-driven processes in cells and tissues. How it assembles into the necessary structures at the right time and place is an important question. Here, we focus on molecular mechanisms of actomyosin regulation recently elucidated in animal models, and highlight several common principles that emerge. The architecture of the actomyosin network - an important determinant of its function - results from actin polymerization, crosslinking and turnover, localized myosin activation, and contractility-driven self-organization. Spatiotemporal regulation is achieved by tissue-specific expression and subcellular localization of Rho GTPase regulators. Subcellular anchor points of actomyosin structures control the outcome of their contraction, and molecular feedback mechanisms dictate whether they are transient, cyclic, or persistent.
Collapse
Affiliation(s)
- Priti Agarwal
- Mechanobiology Institute, National University of Singapore, Singapore
| | - Ronen Zaidel-Bar
- Mechanobiology Institute, National University of Singapore, Singapore; Department of Cell and Developmental Biology, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
| |
Collapse
|
32
|
Sun J, Stathopoulos A. FGF controls epithelial-mesenchymal transitions during gastrulation by regulating cell division and apicobasal polarity. Development 2018; 145:dev.161927. [PMID: 30190277 DOI: 10.1242/dev.161927] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 08/31/2018] [Indexed: 01/06/2023]
Abstract
To support tissue and organ development, cells transition between epithelial and mesenchymal states. Here, we have investigated how mesoderm cells change state in Drosophila embryos and whether fibroblast growth factor (FGF) signaling plays a role. During gastrulation, presumptive mesoderm cells invaginate, undergo an epithelial-to-mesenchymal state transition (EMT) and migrate upon the ectoderm. Our data show that EMT is a prolonged process in which adherens junctions progressively decrease in number throughout the migration of mesoderm cells. FGF influences adherens junction number and promotes mesoderm cell division, which we propose decreases cell-cell attachments to support slow EMT while retaining collective cell movement. We also found that, at the completion of migration, cells form a monolayer and undergo a reverse mesenchymal-to-epithelial transition (MET). FGF activity leads to accumulation of β-integrin Myospheroid basally and cell polarity factor Bazooka apically within mesoderm cells, thereby reestablishing apicobasal cell polarity in an epithelialized state in which cells express both E-Cadherin and N-Cadherin. In summary, FGF plays a dynamic role in supporting mesoderm cell development to ensure collective mesoderm cell movements, as well as proper differentiation of mesoderm cell types.
Collapse
Affiliation(s)
- Jingjing Sun
- California Institute of Technology, Division of Biology and Biological Engineering, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Angelike Stathopoulos
- California Institute of Technology, Division of Biology and Biological Engineering, 1200 East California Boulevard, Pasadena, CA 91125, USA
| |
Collapse
|
33
|
Abstract
During the very first days of mammalian development, the embryo forms a structure called the blastocyst. The blastocyst consists of two cell types: the trophectoderm (TE), which implants the embryo in the uterus and the inner cell mass (ICM), which gives rise to all cells of the mammalian body. Previous works identified how cells differentiate according to their position within the embryo: TE for surface cells and ICM for internal cells. It is therefore essential to understand how cells acquire their position in the first place. During the formation of the blastocyst, cells distort and relocate as a consequence of forces that are generated by the cells themselves. Recently, several important studies have identified the forces and cellular mechanisms leading to the shaping of the ICM. Here, I describe how these studies led us to understand how contractile forces shape the mammalian embryo to position and differentiate the ICM.
Collapse
Affiliation(s)
- Jean-Léon Maître
- Institut Curie, PSL Research University, CNRS UMR3215 Inserm U934, 26 rue d'Ulm, 75248 Paris, France - Équipe mécanique du développement mammifère, Unité Génétique et Biologie du Développement, Institut Curie, 26 rue d'Ulm, 75248 Paris cedex 05, France
| |
Collapse
|
34
|
Maître JL. Mechanics of blastocyst morphogenesis. Biol Cell 2017; 109:323-338. [DOI: 10.1111/boc.201700029] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 06/28/2017] [Accepted: 06/28/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Jean-Léon Maître
- Institut Curie; PSL Research University; CNRS UMR3215, INSERM U934; Paris France
| |
Collapse
|
35
|
Harris TJC. Sculpting epithelia with planar polarized actomyosin networks: Principles from Drosophila. Semin Cell Dev Biol 2017; 81:54-61. [PMID: 28760393 DOI: 10.1016/j.semcdb.2017.07.042] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/25/2017] [Accepted: 07/26/2017] [Indexed: 02/04/2023]
Abstract
Drosophila research has revealed how planar polarized actomyosin networks affect various types of tissue morphogenesis. The networks are positioned by both tissue-wide patterning factors (including Even-skipped, Runt, Engrailed, Invected, Hedgehog, Notch, Wingless, Epidermal Growth Factor, Jun N-terminal kinase, Sex combs reduced and Fork head) and local receptor complexes (including Echinoid, Crumbs and Toll receptors). Networks with differing super-structure and contractile output have been discovered. Their contractility can affect individual cells or can be coordinated across groups of cells, and such contractility can drive or resist physical change. For what seem to be simple tissue changes, multiple types of actomyosin networks can contribute, acting together as contractile elements or braces within the developing structure. This review discusses the positioning and effects of planar polarized actomyosin networks for a number of developmental events in Drosophila, including germband extension, dorsal closure, head involution, tracheal pit formation, salivary gland development, imaginal disc boundary formation, and tissue rotation of the male genitalia and the egg chamber.
Collapse
Affiliation(s)
- Tony J C Harris
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|