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Gill HK, Yin S, Lawlor JC, Huycke TR, Nerurkar NL, Tabin CJ, Mahadevan L. The developmental mechanics of divergent buckling patterns in the chick gut. Proc Natl Acad Sci U S A 2024; 121:e2310992121. [PMID: 38968105 PMCID: PMC11252809 DOI: 10.1073/pnas.2310992121] [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: 06/30/2023] [Accepted: 05/06/2024] [Indexed: 07/07/2024] Open
Abstract
Tissue buckling is an increasingly appreciated mode of morphogenesis in the embryo, but it is often unclear how geometric and material parameters are molecularly determined in native developmental contexts to generate diverse functional patterns. Here, we study the link between differential mechanical properties and the morphogenesis of distinct anteroposterior compartments in the intestinal tract-the esophagus, small intestine, and large intestine. These regions originate from a simple, common tube but adopt unique forms. Using measured data from the developing chick gut coupled with a minimal theory and simulations of differential growth, we investigate divergent lumen morphologies along the entire early gut and demonstrate that spatiotemporal geometries, moduli, and growth rates control the segment-specific patterns of mucosal buckling. Primary buckling into wrinkles, folds, and creases along the gut, as well as secondary buckling phenomena, including period-doubling in the foregut and multiscale creasing-wrinkling in the hindgut, are captured and well explained by mechanical models. This study advances our existing knowledge of how identity leads to form in these regions, laying the foundation for future work uncovering the relationship between molecules and mechanics in gut morphological regionalization.
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Affiliation(s)
- Hasreet K. Gill
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA02115
| | - Sifan Yin
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA02138
| | - John C. Lawlor
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA02115
| | - Tyler R. Huycke
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA02115
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA94158
| | - Nandan L. Nerurkar
- The Fu Foundation School of Engineering and Applied Science, Department of Biomedical Engineering, Columbia University, New York, NY10027
| | - Clifford J. Tabin
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA02115
| | - L. Mahadevan
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA02138
- Department of Physics, Harvard University, Cambridge, MA02138
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA02138
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2
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Serrano Nájera G, Plum AM, Steventon B, Weijer CJ, Serra M. Control of Modular Tissue Flows Shaping the Embryo in Avian Gastrulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.04.601785. [PMID: 39026830 PMCID: PMC11257462 DOI: 10.1101/2024.07.04.601785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Avian gastrulation requires coordinated flows of thousands of cells to form the body plan. We quantified these flows using their fundamental kinematic units: one attractor and two repellers constituting its Dynamic Morphoskeleton (DM). We have also elucidated the mechanistic origin of the attractor, marking the primitive streak (PS), and controlled its shape, inducing gastrulation flows in the chick embryo that are typical of other vertebrates. However, the origins of repellers and dynamic embryo shape remain unclear. Here, we address these questions using active matter physics and experiments. Repeller 1, separating the embryo proper (EP) from extraembryonic (EE) tissues, arises from the tug-of-war between EE epiboly and EP isotropic myosin-induced active stress. Repeller 2, bisecting the anterior and posterior PS and associated with embryo shape change, arises from anisotropic myosin-induced active intercalation in the mesendoderm. Combining mechanical confinement with inhibition of mesendoderm induction, we eliminated either one or both repellers, as predicted by our model. Our results reveal a remarkable modularity of avian gastrulation flows delineated by the DM, uncovering the mechanistic roles of EE epiboly, EP active constriction, mesendoderm intercalation and ingression. These findings offer a new perspective for deconstructing morphogenetic flows, uncovering their modular origin, and aiding synthetic morphogenesis.
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Affiliation(s)
| | - Alex M. Plum
- Department of Physics, University of California San Diego, CA 92093, USA
| | - Ben Steventon
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK
| | - Cornelis J. Weijer
- Division of Molec. Cell and Dev. Biology, School of Life Sciences, Univ. of Dundee, UK
| | - Mattia Serra
- Department of Physics, University of California San Diego, CA 92093, USA
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3
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Ray T, Shi D, Harris TJC. Confinement promotes nematic alignment of spindle-shaped cells during Drosophila embryogenesis. Development 2024; 151:dev202577. [PMID: 38864272 PMCID: PMC11234378 DOI: 10.1242/dev.202577] [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: 11/30/2023] [Accepted: 06/05/2024] [Indexed: 06/13/2024]
Abstract
Tissue morphogenesis is often controlled by actomyosin networks pulling on adherens junctions (AJs), but junctional myosin levels vary. At an extreme, the Drosophila embryo amnioserosa forms a horseshoe-shaped strip of aligned, spindle-shaped cells lacking junctional myosin. What are the bases of amnioserosal cell interactions and alignment? Compared with surrounding tissue, we find that amnioserosal AJ continuity has lesser dependence on α-catenin, the mediator of AJ-actomyosin association, and greater dependence on Bazooka/Par-3, a junction-associated scaffold protein. Microtubule bundles also run along amnioserosal AJs and support their long-range curvilinearity. Amnioserosal confinement is apparent from partial overlap of its spindle-shaped cells, its outward bulging from surrounding tissue and from compressive stress detected within the amnioserosa. Genetic manipulations that alter amnioserosal confinement by surrounding tissue also result in amnioserosal cells losing alignment and gaining topological defects characteristic of nematically ordered systems. With Bazooka depletion, confinement by surrounding tissue appears to be relatively normal and amnioserosal cells align despite their AJ fragmentation. Overall, the fully elongated amnioserosa appears to form through tissue-autonomous generation of spindle-shaped cells that nematically align in response to confinement by surrounding tissue.
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Affiliation(s)
- Tirthankar Ray
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
| | - Damo Shi
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
| | - Tony J. C. Harris
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
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4
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Sinigaglia C, Braghin F, Serra M. Optimal Control of Short-Time Attractors in Active Nematics. PHYSICAL REVIEW LETTERS 2024; 132:218302. [PMID: 38856253 DOI: 10.1103/physrevlett.132.218302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 04/17/2024] [Accepted: 04/24/2024] [Indexed: 06/11/2024]
Abstract
Objective Eulerian coherent structures (OECSs) and instantaneous Lyapunov exponents (iLEs) govern short-term material transport in fluid flows as Lagrangian coherent structures and the finite-time Lyapunov exponent do over longer times. Attracting OECSs and iLEs reveal short-time attractors and are computable from the Eulerian rate-of-strain tensor. Here, we devise for the first time an optimal control strategy to create short-time attractors in compressible, viscosity-dominated active nematic flows. By modulating the active stress intensity, our framework achieves a target profile of the minimum eigenvalue of the rate-of-strain tensor, controlling the location and shape of short-time attractors. We show that our optimal control strategy effectively achieves desired short-time attractors while rejecting disturbances. Combining optimal control and coherent structures, our work offers a new perspective to steer material transport in compressible active nematics, with applications to morphogenesis and synthetic active matter.
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Affiliation(s)
- Carlo Sinigaglia
- Politecnico di Milano, Department of Mechanical Engineering, Milan 20156, Italy
| | - Francesco Braghin
- Politecnico di Milano, Department of Mechanical Engineering, Milan 20156, Italy
| | - Mattia Serra
- University of California San Diego, Department of Physics, San Diego, California 92093, USA
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5
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Claussen NH, Brauns F, Shraiman BI. A Geometric Tension Dynamics Model of Epithelial Convergent Extension. ARXIV 2024:arXiv:2311.16384v2. [PMID: 38076522 PMCID: PMC10705598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Epithelial tissue elongation by convergent extension is a key motif of animal morphogenesis. On a coarse scale, cell motion resembles laminar fluid flow; yet in contrast to a fluid, epithelial cells adhere to each other and maintain the tissue layer under actively generated internal tension. To resolve this apparent paradox, we formulate a model in which tissue flow in the tension-dominated regime occurs through adiabatic remodeling of force balance in the network of adherens junctions. We propose that the slow dynamics within the manifold of force-balanced configurations is driven by positive feedback on myosin-generated cytoskeletal tension. Shifting force balance within a tension network causes active cell rearrangements (T1 transitions) resulting in net tissue deformation oriented by initial tension anisotropy. Strikingly, we find that the total extent of tissue deformation depends on the initial cellular packing order. T1s degrade this order so that tissue flow is self-limiting. We explain these findings by showing that coordination of T1s depends on coherence in local tension configurations, quantified by a geometric order parameter in tension space. Our model reproduces the salient tissue- and cell-scale features of germ band elongation during Drosophila gastrulation, in particular the slowdown of tissue flow after approximately twofold elongation concomitant with a loss of order in tension configurations. This suggests local cell geometry contains morphogenetic information and yields experimentally testable predictions. Furthermore, defining biologically controlled active tension dynamics on the manifold of force-balanced states may provide a general approach to the description of morphogenetic flow.
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Affiliation(s)
- Nikolas H. Claussen
- Department of Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Fridtjof Brauns
- Kavli Institute for Theoretical Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Boris I. Shraiman
- Department of Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA
- Kavli Institute for Theoretical Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA
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6
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Lye CM, Blanchard GB, Evans J, Nestor-Bergmann A, Sanson B. Polarised cell intercalation during Drosophila axis extension is robust to an orthogonal pull by the invaginating mesoderm. PLoS Biol 2024; 22:e3002611. [PMID: 38683880 PMCID: PMC11081494 DOI: 10.1371/journal.pbio.3002611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 05/09/2024] [Accepted: 04/03/2024] [Indexed: 05/02/2024] Open
Abstract
As tissues grow and change shape during animal development, they physically pull and push on each other, and these mechanical interactions can be important for morphogenesis. During Drosophila gastrulation, mesoderm invagination temporally overlaps with the convergence and extension of the ectodermal germband; the latter is caused primarily by Myosin II-driven polarised cell intercalation. Here, we investigate the impact of mesoderm invagination on ectoderm extension, examining possible mechanical and mechanotransductive effects on Myosin II recruitment and polarised cell intercalation. We find that the germband ectoderm is deformed by the mesoderm pulling in the orthogonal direction to germband extension (GBE), showing mechanical coupling between these tissues. However, we do not find a significant change in Myosin II planar polarisation in response to mesoderm invagination, nor in the rate of junction shrinkage leading to neighbour exchange events. We conclude that the main cellular mechanism of axis extension, polarised cell intercalation, is robust to the mesoderm invagination pull. We find, however, that mesoderm invagination slows down the rate of anterior-posterior cell elongation that contributes to axis extension, counteracting the tension from the endoderm invagination, which pulls along the direction of GBE.
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Affiliation(s)
- Claire M. Lye
- 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
| | - Jenny Evans
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Alexander Nestor-Bergmann
- 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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7
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Yin X, Liu YQ, Zhang LY, Liang D, Xu GK. Emergence, Pattern, and Frequency of Spontaneous Waves in Spreading Epithelial Monolayers. NANO LETTERS 2024; 24:3631-3637. [PMID: 38466240 DOI: 10.1021/acs.nanolett.3c04876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
A striking phenomenon of collective cell motion is that they can exhibit a spontaneously emerging wave during epithelia expansions. However, the fundamental mechanism, governing the emergence and its crucial characteristics (e.g., the eigenfrequency and the pattern), remains an enigma. By introducing a mechanochemical feedback loop, we develop a highly efficient discrete vertex model to investigate the spatiotemporal evolution of spreading epithelia. We find both numerically and analytically that expanding cell monolayers display a power-law dependence of wave frequency on the local heterogeneities (i.e., cell density) with a scaling exponent of -1/2. Moreover, our study demonstrates the quantitative capability of the proposed model in capturing distinct X-, W-, and V-mode wave patterns. We unveil that the phase transition between these modes is governed by the distribution of active self-propulsion forces. Our work provides an avenue for rigorous quantitative investigations into the collective motion and pattern formation of cell groups.
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Affiliation(s)
- Xu Yin
- Laboratory for Multiscale Mechanics and Medical Science, Department of Engineering Mechanics, SVL, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yong-Quan Liu
- Laboratory for Multiscale Mechanics and Medical Science, Department of Engineering Mechanics, SVL, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Li-Yuan Zhang
- School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Dong Liang
- Laboratory for Multiscale Mechanics and Medical Science, Department of Engineering Mechanics, SVL, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Guang-Kui Xu
- Laboratory for Multiscale Mechanics and Medical Science, Department of Engineering Mechanics, SVL, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China
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8
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Cupo C, Allan C, Ailiani V, Kasza KE. Signatures of structural disorder in developing epithelial tissues. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.12.579900. [PMID: 38405955 PMCID: PMC10888831 DOI: 10.1101/2024.02.12.579900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Epithelial cells generate functional tissues in developing embryos through collective movements and shape changes. In some morphogenetic events, a tissue dramatically reorganizes its internal structure - often generating high degrees of structural disorder - to accomplish changes in tissue shape. However, the origins of structural disorder in epithelia and what roles it might play in morphogenesis are poorly understood. We study this question in the Drosophila germband epithelium, which undergoes dramatic changes in internal structure as cell rearrangements drive elongation of the embryo body axis. Using two order parameters that quantify volumetric and shear disorder, we show that structural disorder increases during body axis elongation and is strongly linked with specific developmental processes. Both disorder metrics begin to increase around the onset of axis elongation, but then plateau at values that are maintained throughout the process. Notably, the disorder plateau values for volumetric disorder are similar to those for random cell packings, suggesting this may reflect a limit on tissue behavior. In mutant embryos with disrupted external stresses from the ventral furrow, both disorder metrics reach wild-type maximum disorder values with a delay, correlating with delays in cell rearrangements. In contrast, in mutants with disrupted internal stresses and cell rearrangements, volumetric disorder is reduced compared to wild type, whereas shear disorder depends on specific external stress patterns. Together, these findings demonstrate that internal and external stresses both contribute to epithelial tissue disorder and suggest that the maximum values of disorder in a developing tissue reflect physical or biological limits on morphogenesis.
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9
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Lefebvre M, Colen J, Claussen N, Brauns F, Raich M, Mitchell N, Fruchart M, Vitelli V, Streichan SJ. Learning a conserved mechanism for early neuroectoderm morphogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.22.573058. [PMID: 38187670 PMCID: PMC10769415 DOI: 10.1101/2023.12.22.573058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Morphogenesis is the process whereby the body of an organism develops its target shape. The morphogen BMP is known to play a conserved role across bilaterian organisms in determining the dorsoventral (DV) axis. Yet, how BMP governs the spatio-temporal dynamics of cytoskeletal proteins driving morphogenetic flow remains an open question. Here, we use machine learning to mine a morphodynamic atlas of Drosophila development, and construct a mathematical model capable of predicting the coupled dynamics of myosin, E-cadherin, and morphogenetic flow. Mutant analysis shows that BMP sets the initial condition of this dynamical system according to the following signaling cascade: BMP establishes DV pair-rule-gene patterns that set-up an E-cadherin gradient which in turn creates a myosin gradient in the opposite direction through mechanochemical feedbacks. Using neural tube organoids, we argue that BMP, and the signaling cascade it triggers, prime the conserved dynamics of neuroectoderm morphogenesis from fly to humans.
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10
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Serra M, Serrano Nájera G, Chuai M, Plum AM, Santhosh S, Spandan V, Weijer CJ, Mahadevan L. A mechanochemical model recapitulates distinct vertebrate gastrulation modes. SCIENCE ADVANCES 2023; 9:eadh8152. [PMID: 38055823 PMCID: PMC10699781 DOI: 10.1126/sciadv.adh8152] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 11/06/2023] [Indexed: 12/08/2023]
Abstract
During vertebrate gastrulation, an embryo transforms from a layer of epithelial cells into a multilayered gastrula. This process requires the coordinated movements of hundreds to tens of thousands of cells, depending on the organism. In the chick embryo, patterns of actomyosin cables spanning several cells drive coordinated tissue flows. Here, we derive a minimal theoretical framework that couples actomyosin activity to global tissue flows. Our model predicts the onset and development of gastrulation flows in normal and experimentally perturbed chick embryos, mimicking different gastrulation modes as an active stress instability. Varying initial conditions and a parameter associated with active cell ingression, our model recapitulates distinct vertebrate gastrulation morphologies, consistent with recently published experiments in the chick embryo. Altogether, our results show how changes in the patterning of critical cell behaviors associated with different force-generating mechanisms contribute to distinct vertebrate gastrulation modes via a self-organizing mechanochemical process.
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Affiliation(s)
- Mattia Serra
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Guillermo Serrano Nájera
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Manli Chuai
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Alex M. Plum
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Sreejith Santhosh
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Vamsi Spandan
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Cornelis J. Weijer
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - L. Mahadevan
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Departments of Physics, and Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
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11
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Ioratim-Uba A, Liverpool TB, Henkes S. Mechanochemical Active Feedback Generates Convergence Extension in Epithelial Tissue. PHYSICAL REVIEW LETTERS 2023; 131:238301. [PMID: 38134807 DOI: 10.1103/physrevlett.131.238301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 11/07/2023] [Indexed: 12/24/2023]
Abstract
Convergence extension, the simultaneous elongation of tissue along one axis while narrowing along a perpendicular axis, occurs during embryonic development. A fundamental process that contributes to shaping the organism, it happens in many different species and tissue types. Here, we present a minimal continuum model, that can be directly linked to the controlling microscopic biochemistry, which shows spontaneous convergence extension. It is comprised of a 2D viscoelastic active material with a mechanochemical active feedback mechanism coupled to a substrate via friction. Robust convergent extension behavior emerges beyond a critical value of the activity parameter and is controlled by the boundary conditions and the coupling to the substrate. Oscillations and spatial patterns emerge in this model when internal dissipation dominates over friction, as well as in the active elastic limit.
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Affiliation(s)
| | | | - Silke Henkes
- School of Mathematics, University of Bristol, Bristol BS8 1UG, United Kingdom
- Lorentz Institute for Theoretical Physics, Leiden University, Leiden 2333 CA, The Netherlands
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12
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Nishizawa K, Lin SZ, Chardès C, Rupprecht JF, Lenne PF. Two-point optical manipulation reveals mechanosensitive remodeling of cell-cell contacts in vivo. Proc Natl Acad Sci U S A 2023; 120:e2212389120. [PMID: 36947511 PMCID: PMC10068846 DOI: 10.1073/pnas.2212389120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 01/17/2023] [Indexed: 03/23/2023] Open
Abstract
Biological tissues acquire reproducible shapes during development through dynamic cell behaviors. Most of these behaviors involve the remodeling of cell-cell contacts. During epithelial morphogenesis, contractile actomyosin networks remodel cell-cell contacts by shrinking and extending junctions between lateral cell surfaces. However, actomyosin networks not only generate mechanical stresses but also respond to them, confounding our understanding of how mechanical stresses remodel cell-cell contacts. Here, we develop a two-point optical manipulation method to impose different stress patterns on cell-cell contacts in the early epithelium of the Drosophila embryo. The technique allows us to produce junction extension and shrinkage through different push and pull manipulations at the edges of junctions. We use these observations to expand classical vertex-based models of tissue mechanics, incorporating negative and positive mechanosensitive feedback depending on the type of remodeling. In particular, we show that Myosin-II activity responds to junction strain rate and facilitates full junction shrinkage. Altogether our work provides insight into how stress produces efficient deformation of cell-cell contacts in vivo and identifies unanticipated mechanosensitive features of their remodeling.
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Affiliation(s)
- Kenji Nishizawa
- Aix Marseille Univ, CNRS, IBDM, Turing Centre for Living systems, Marseille UMR 7288, France
| | - Shao-Zhen Lin
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, Turing Centre for Living systems, Marseille UMR 7332, France
| | - Claire Chardès
- Aix Marseille Univ, CNRS, IBDM, Turing Centre for Living systems, Marseille UMR 7288, France
| | - Jean-François Rupprecht
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, Turing Centre for Living systems, Marseille UMR 7332, France
| | - Pierre-François Lenne
- Aix Marseille Univ, CNRS, IBDM, Turing Centre for Living systems, Marseille UMR 7288, France
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13
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Lefebvre MF, Claussen NH, Mitchell NP, Gustafson HJ, Streichan SJ. Geometric control of myosin II orientation during axis elongation. eLife 2023; 12:78787. [PMID: 36715100 PMCID: PMC9940909 DOI: 10.7554/elife.78787] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 12/13/2022] [Indexed: 01/31/2023] Open
Abstract
The actomyosin cytoskeleton is a crucial driver of morphogenesis. Yet how the behavior of large-scale cytoskeletal patterns in deforming tissues emerges from the interplay of geometry, genetics, and mechanics remains incompletely understood. Convergent extension in Drosophila melanogaster embryos provides the opportunity to establish a quantitative understanding of the dynamics of anisotropic non-muscle myosin II. Cell-scale analysis of protein localization in fixed embryos suggests that gene expression patterns govern myosin anisotropy via complex rules. However, technical limitations have impeded quantitative and dynamic studies of this process at the whole embryo level, leaving the role of geometry open. Here, we combine in toto live imaging with quantitative analysis of molecular dynamics to characterize the distribution of myosin anisotropy and the corresponding genetic patterning. We found pair rule gene expression continuously deformed, flowing with the tissue frame. In contrast, myosin anisotropy orientation remained approximately static and was only weakly deflected from the stationary dorsal-ventral axis of the embryo. We propose that myosin is recruited by a geometrically defined static source, potentially related to the embryo-scale epithelial tension, and account for transient deflections by cytoskeletal turnover and junction reorientation by flow. With only one parameter, this model quantitatively accounts for the time course of myosin anisotropy orientation in wild-type, twist, and even-skipped embryos, as well as embryos with perturbed egg geometry. Geometric patterning of the cytoskeleton suggests a simple physical strategy to ensure a robust flow and formation of shape.
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Affiliation(s)
- Matthew F Lefebvre
- Department of Physics, University of California, Santa BarbaraSanta BarbaraUnited States
| | - Nikolas H Claussen
- Department of Physics, University of California, Santa BarbaraSanta BarbaraUnited States
| | - Noah P Mitchell
- Department of Physics, University of California, Santa BarbaraSanta BarbaraUnited States
- Kavli Institute for Theoretical Physics, University of California, Santa BarbaraSanta BarbaraUnited States
| | - Hannah J Gustafson
- Department of Physics, University of California, Santa BarbaraSanta BarbaraUnited States
- Biomolecular Science and Engineering, University of California, Santa BarbaraSanta BarbaraUnited States
| | - Sebastian J Streichan
- Department of Physics, University of California, Santa BarbaraSanta BarbaraUnited States
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