1
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Campàs O, Noordstra I, Yap AS. Adherens junctions as molecular regulators of emergent tissue mechanics. Nat Rev Mol Cell Biol 2024; 25:252-269. [PMID: 38093099 DOI: 10.1038/s41580-023-00688-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2023] [Indexed: 03/28/2024]
Abstract
Tissue and organ development during embryogenesis relies on the collective and coordinated action of many cells. Recent studies have revealed that tissue material properties, including transitions between fluid and solid tissue states, are controlled in space and time to shape embryonic structures and regulate cell behaviours. Although the collective cellular flows that sculpt tissues are guided by tissue-level physical changes, these ultimately emerge from cellular-level and subcellular-level molecular mechanisms. Adherens junctions are key subcellular structures, built from clusters of classical cadherin receptors. They mediate physical interactions between cells and connect biochemical signalling to the physical characteristics of cell contacts, hence playing a fundamental role in tissue morphogenesis. In this Review, we take advantage of the results of recent, quantitative measurements of tissue mechanics to relate the molecular and cellular characteristics of adherens junctions, including adhesion strength, tension and dynamics, to the emergent physical state of embryonic tissues. We focus on systems in which cell-cell interactions are the primary contributor to morphogenesis, without significant contribution from cell-matrix interactions. We suggest that emergent tissue mechanics is an important direction for future research, bridging cell biology, developmental biology and mechanobiology to provide a holistic understanding of morphogenesis in health and disease.
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Affiliation(s)
- Otger Campàs
- Cluster of Excellence Physics of Life, TU Dresden, Dresden, Germany.
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
- Center for Systems Biology Dresden, Dresden, Germany.
| | - Ivar Noordstra
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
| | - Alpha S Yap
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia.
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2
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Tam R, Harris TJC. Reshaping the Syncytial Drosophila Embryo with Cortical Actin Networks: Four Main Steps of Early Development. Results Probl Cell Differ 2024; 71:67-90. [PMID: 37996673 DOI: 10.1007/978-3-031-37936-9_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
Drosophila development begins as a syncytium. The large size of the one-cell embryo makes it ideal for studying the structure, regulation, and effects of the cortical actin cytoskeleton. We review four main steps of early development that depend on the actin cortex. At each step, dynamic remodelling of the cortex has specific effects on nuclei within the syncytium. During axial expansion, a cortical actomyosin network assembles and disassembles with the cell cycle, generating cytoplasmic flows that evenly distribute nuclei along the ovoid cell. When nuclei move to the cell periphery, they seed Arp2/3-based actin caps which grow into an array of dome-like compartments that house the nuclei as they divide at the cell cortex. To separate germline nuclei from the soma, posterior germ plasm induces full cleavage of mono-nucleated primordial germ cells from the syncytium. Finally, zygotic gene expression triggers formation of the blastoderm epithelium via cellularization and simultaneous division of ~6000 mono-nucleated cells from a single internal yolk cell. During these steps, the cortex is regulated in space and time, gains domain and sub-domain structure, and undergoes mesoscale interactions that lay a structural foundation of animal development.
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Affiliation(s)
- Rebecca Tam
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Tony J C Harris
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada.
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3
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Fei C, Dunkel J. Fly embryo nuclei riding on two-fluid flow. Proc Natl Acad Sci U S A 2023; 120:e2317219120. [PMID: 37939065 PMCID: PMC10665796 DOI: 10.1073/pnas.2317219120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2023] Open
Affiliation(s)
- Chenyi Fei
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Jörn Dunkel
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA02139
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4
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Scott S, Weiss M, Selhuber-Unkel C, Barooji YF, Sabri A, Erler JT, Metzler R, Oddershede LB. Extracting, quantifying, and comparing dynamical and biomechanical properties of living matter through single particle tracking. Phys Chem Chem Phys 2023; 25:1513-1537. [PMID: 36546878 DOI: 10.1039/d2cp01384c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A panoply of new tools for tracking single particles and molecules has led to an explosion of experimental data, leading to novel insights into physical properties of living matter governing cellular development and function, health and disease. In this Perspective, we present tools to investigate the dynamics and mechanics of living systems from the molecular to cellular scale via single-particle techniques. In particular, we focus on methods to measure, interpret, and analyse complex data sets that are associated with forces, materials properties, transport, and emergent organisation phenomena within biological and soft-matter systems. Current approaches, challenges, and existing solutions in the associated fields are outlined in order to support the growing community of researchers at the interface of physics and the life sciences. Each section focuses not only on the general physical principles and the potential for understanding living matter, but also on details of practical data extraction and analysis, discussing limitations, interpretation, and comparison across different experimental realisations and theoretical frameworks. Particularly relevant results are introduced as examples. While this Perspective describes living matter from a physical perspective, highlighting experimental and theoretical physics techniques relevant for such systems, it is also meant to serve as a solid starting point for researchers in the life sciences interested in the implementation of biophysical methods.
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Affiliation(s)
- Shane Scott
- Institute of Physiology, Kiel University, Hermann-Rodewald-Straße 5, 24118 Kiel, Germany
| | - Matthias Weiss
- Experimental Physics I, University of Bayreuth, Universitätsstr. 30, D-95447 Bayreuth, Germany
| | - Christine Selhuber-Unkel
- Institute for Molecular Systems Engineering, Heidelberg University, D-69120 Heidelberg, Germany.,Max Planck School Matter to Life, Jahnstraße 29, D-69120 Heidelberg, Germany
| | - Younes F Barooji
- Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen, Denmark.
| | - Adal Sabri
- Experimental Physics I, University of Bayreuth, Universitätsstr. 30, D-95447 Bayreuth, Germany
| | - Janine T Erler
- BRIC, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark.
| | - Ralf Metzler
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht Str. 24/25, D-14476 Potsdam, Germany.,Asia Pacific Center for Theoretical Physics, Pohang 37673, Republic of Korea
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5
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Sokac AM, Biel N, De Renzis S. Membrane-actin interactions in morphogenesis: Lessons learned from Drosophila cellularization. Semin Cell Dev Biol 2023; 133:107-122. [PMID: 35396167 PMCID: PMC9532467 DOI: 10.1016/j.semcdb.2022.03.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 01/12/2023]
Abstract
During morphogenesis, changes in the shapes of individual cells are harnessed to mold an entire tissue. These changes in cell shapes require the coupled remodeling of the plasma membrane and underlying actin cytoskeleton. In this review, we highlight cellularization of the Drosophila embryo as a model system to uncover principles of how membrane and actin dynamics are co-regulated in space and time to drive morphogenesis.
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Affiliation(s)
- Anna Marie Sokac
- Department of Cell and Developmental Biology, University of Illinois at Urbana Champaign, Urbana, IL 61801, USA; Graduate Program in Integrative and Molecular Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Natalie Biel
- Department of Cell and Developmental Biology, University of Illinois at Urbana Champaign, Urbana, IL 61801, USA; Graduate Program in Integrative and Molecular Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA
| | - Stefano De Renzis
- European Molecular Biology Laboratory Heidelberg, 69117 Heidelberg, Germany
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6
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Ye Y, Homer HA. Two‐step nuclear centring by competing microtubule‐ and actin‐based mechanisms in 2‐cell mouse embryos. EMBO Rep 2022; 23:e55251. [DOI: 10.15252/embr.202255251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 09/01/2022] [Accepted: 09/12/2022] [Indexed: 11/07/2022] Open
Affiliation(s)
- Yunan Ye
- The Christopher Chen Oocyte Biology Research Laboratory, Centre for Clinical Research The University of Queensland Herston QLD Australia
| | - Hayden A Homer
- The Christopher Chen Oocyte Biology Research Laboratory, Centre for Clinical Research The University of Queensland Herston QLD Australia
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7
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Dzementsei A, Barooji YF, Ober EA, Oddershede LB. Foregut organ progenitors and their niche display distinct viscoelastic properties in vivo during early morphogenesis stages. Commun Biol 2022; 5:402. [PMID: 35488088 PMCID: PMC9054744 DOI: 10.1038/s42003-022-03349-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 04/10/2022] [Indexed: 12/12/2022] Open
Abstract
Material properties of living matter play an important role for biological function and development. Yet, quantification of material properties of internal organs in vivo, without causing physiological damage, remains challenging. Here, we present a non-invasive approach based on modified optical tweezers for quantifying sub-cellular material properties deep inside living zebrafish embryos. Material properties of cells within the foregut region are quantified as deep as 150 µm into the biological tissue through measurements of the positions of an inert tracer. This yields an exponent, α, which characterizes the scaling behavior of the positional power spectra and the complex shear moduli. The measurements demonstrate differential mechanical properties: at the time when the developing organs undergo substantial displacements during morphogenesis, gut progenitors are more elastic (α = 0.57 ± 0.07) than the neighboring yolk (α = 0.73 ± 0.08), liver (α = 0.66 ± 0.06) and two mesodermal (α = 0.68 ± 0.06, α = 0.64 ± 0.06) progenitor cell populations. The higher elasticity of gut progenitors correlates with an increased cellular concentration of microtubules. The results infer a role of material properties during morphogenesis and the approach paves the way for quantitative material investigations in vivo of embryos, explants, or organoids. Here, the authors present a method based on optical tweezers to measure mechanical properties of cells inside living zebrafish embryos. The measurement reveals spatiotemporally distinct mechanical properties, linking cell mechanics and morphogenesis.
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Affiliation(s)
- Aliaksandr Dzementsei
- Novo Nordisk Foundation Center for Stem Cell Biology, University of Copenhagen, Blegdamsvej 3b, 2200, Copenhagen N, Denmark
| | - Younes F Barooji
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100, Copenhagen, Denmark
| | - Elke A Ober
- Novo Nordisk Foundation Center for Stem Cell Biology, University of Copenhagen, Blegdamsvej 3b, 2200, Copenhagen N, Denmark.
| | - Lene B Oddershede
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100, Copenhagen, Denmark.
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8
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Selvaggi L, Ackermann M, Pasakarnis L, Brunner D, Aegerter CM. Force measurements of Myosin II waves at the yolk surface during Drosophila dorsal closure. Biophys J 2022; 121:410-420. [PMID: 34971619 PMCID: PMC8822616 DOI: 10.1016/j.bpj.2021.12.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 11/19/2021] [Accepted: 12/23/2021] [Indexed: 02/03/2023] Open
Abstract
The mechanical properties and the forces involved during tissue morphogenesis have been the focus of much research in the last years. Absolute values of forces during tissue closure events have not yet been measured. This is also true for a common force-producing mechanism involving Myosin II waves that results in pulsed cell surface contractions. Our patented magnetic tweezer, CAARMA, integrated into a spinning disk confocal microscope, provides a powerful explorative tool for quantitatively measuring forces during tissue morphogenesis. Here, we used this tool to quantify the in vivo force production of Myosin II waves that we observed at the dorsal surface of the yolk cell in stage 13 Drosophila melanogaster embryos. In addition to providing for the first time to our knowledge quantitative values on an active Myosin-driven force, we elucidated the dynamics of the Myosin II waves by measuring their periodicity in both absence and presence of external perturbations, and we characterized the mechanical properties of the dorsal yolk cell surface.
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Affiliation(s)
- Lara Selvaggi
- Physik-Institut, Universität Zürich, Zürich, Switzerland,Department of Molecular Life Science, Universität Zürich, Zürich, Switzerland
| | | | - Laurynas Pasakarnis
- Department of Molecular Life Science, Universität Zürich, Zürich, Switzerland
| | - Damian Brunner
- Department of Molecular Life Science, Universität Zürich, Zürich, Switzerland
| | - Christof M. Aegerter
- Physik-Institut, Universität Zürich, Zürich, Switzerland,Department of Molecular Life Science, Universität Zürich, Zürich, Switzerland,Corresponding author
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9
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Sharma S, Rikhy R. Measurement of Contractile Ring Tension Using Two-photon Laser Ablation during Drosophila Cellularization. Bio Protoc 2022; 12:e4362. [DOI: 10.21769/bioprotoc.4362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 10/20/2021] [Accepted: 02/05/2022] [Indexed: 11/02/2022] Open
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10
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Barooji YF, Hvid KG, Petitjean II, Brickman JM, Oddershede LB, Bendix PM. Changes in Cell Morphology and Actin Organization in Embryonic Stem Cells Cultured under Different Conditions. Cells 2021; 10:cells10112859. [PMID: 34831083 PMCID: PMC8616278 DOI: 10.3390/cells10112859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/05/2021] [Accepted: 10/15/2021] [Indexed: 11/16/2022] Open
Abstract
The cellular cytoskeleton provides the cell with a mechanical rigidity that allows mechanical interaction between cells and the extracellular environment. The actin structure plays a key role in mechanical events such as motility or the establishment of cell polarity. From the earliest stages of development, as represented by the ex vivo expansion of naïve embryonic stem cells (ESCs), the critical mechanical role of the actin structure is becoming recognized as a vital cue for correct segregation and lineage control of cells and as a regulatory structure that controls several transcription factors. Naïve ESCs have a characteristic morphology, and the ultrastructure that underlies this condition remains to be further investigated. Here, we investigate the 3D actin cytoskeleton of naïve mouse ESCs using super-resolution optical reconstruction microscopy (STORM). We investigate the morphological, cytoskeletal, and mechanical changes in cells cultured in 2i or Serum/LIF media reflecting, respectively, a homogeneous preimplantation cell state and a state that is closer to embarking on differentiation. STORM imaging showed that the peripheral actin structure undergoes a dramatic change between the two culturing conditions. We also detected micro-rheological differences in the cell periphery between the cells cultured in these two media correlating well with the observed nano-architecture of the ESCs in the two different culture conditions. These results pave the way for linking physical properties and cytoskeletal architecture to cell morphology during early development.
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Affiliation(s)
- Younes F. Barooji
- Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark; (Y.F.B.); (K.G.H.); (I.I.P.)
| | - Kasper G. Hvid
- Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark; (Y.F.B.); (K.G.H.); (I.I.P.)
| | - Irene Istúriz Petitjean
- Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark; (Y.F.B.); (K.G.H.); (I.I.P.)
| | - Joshua M. Brickman
- The Novo Nordisk Foundation Center for Stem Cell Biology, 2200 Copenhagen, Denmark;
| | - Lene B. Oddershede
- Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark; (Y.F.B.); (K.G.H.); (I.I.P.)
- Correspondence: (L.B.O.); (P.M.B.)
| | - Poul M. Bendix
- Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark; (Y.F.B.); (K.G.H.); (I.I.P.)
- Correspondence: (L.B.O.); (P.M.B.)
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11
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Wang Z, Wang X, Zhang Y, Xu W, Han X. Principles and Applications of Single Particle Tracking in Cell Research. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2005133. [PMID: 33533163 DOI: 10.1002/smll.202005133] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/24/2020] [Indexed: 06/12/2023]
Abstract
It is a tough challenge for many decades to decipher the complex relationships between cell behaviors and cellular physical properties. Single particle tracking (SPT) with high spatial and temporal resolution has been applied extensively in cell research to understand physicochemical properties of cells and their bio-functions by tracking endogenous or exogenous probes. This review describes the fundamental principles of SPT as well as its applications in intracellular mechanics, membrane dynamics, organelles distribution, and processes of internalization and transport. Finally, challenges and future directions of SPT are also discussed.
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Affiliation(s)
- Zhao Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Xuejing Wang
- College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, 310058, China
| | - Ying Zhang
- School of Materials and Chemical Engineering, Heilongjiang Institute of Technology, Harbin, 150027, China
| | - Weili Xu
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Xiaojun Han
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China
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12
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Lv Z, de-Carvalho J, Telley IA, Großhans J. Cytoskeletal mechanics and dynamics in the Drosophila syncytial embryo. J Cell Sci 2021; 134:134/4/jcs246496. [PMID: 33597155 DOI: 10.1242/jcs.246496] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Cell and tissue functions rely on the genetic programmes and cascades of biochemical signals. It has become evident during the past decade that the physical properties of soft material that govern the mechanics of cells and tissues play an important role in cellular function and morphology. The biophysical properties of cells and tissues are determined by the cytoskeleton, consisting of dynamic networks of F-actin and microtubules, molecular motors, crosslinkers and other associated proteins, among other factors such as cell-cell interactions. The Drosophila syncytial embryo represents a simple pseudo-tissue, with its nuclei orderly embedded in a structured cytoskeletal matrix at the embryonic cortex with no physical separation by cellular membranes. Here, we review the stereotypic dynamics and regulation of the cytoskeleton in Drosophila syncytial embryos and how cytoskeletal dynamics underlies biophysical properties and the emergence of collective features. We highlight the specific features and processes of syncytial embryos and discuss the applicability of biophysical approaches.
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Affiliation(s)
- Zhiyi Lv
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003, China
| | - Jorge de-Carvalho
- Instituto Gulbenkian de Ciência, Fundação Calouste Gulbenkian, 2780-156 Oeiras, Portugal
| | - Ivo A Telley
- Instituto Gulbenkian de Ciência, Fundação Calouste Gulbenkian, 2780-156 Oeiras, Portugal
| | - Jörg Großhans
- Fachbereich Biologie, Philipps-Universität Marburg, 35043 Marburg, Germany
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13
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Lv Z, Rosenbaum J, Mohr S, Zhang X, Kong D, Preiß H, Kruss S, Alim K, Aspelmeier T, Großhans J. The Emergent Yo-yo Movement of Nuclei Driven by Cytoskeletal Remodeling in Pseudo-synchronous Mitotic Cycles. Curr Biol 2020; 30:2564-2573.e5. [DOI: 10.1016/j.cub.2020.04.078] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 03/25/2020] [Accepted: 04/27/2020] [Indexed: 11/15/2022]
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14
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Biel N, Figard L, Sokac AM. Imaging Intranuclear Actin Rods in Live Heat Stressed Drosophila Embryos. J Vis Exp 2020. [PMID: 32478727 DOI: 10.3791/61297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The purpose of this protocol is to visualize intranuclear actin rods that assemble in live Drosophila melanogaster embryos following heat stress. Actin rods are a hallmark of a conserved, inducible Actin Stress Response (ASR) that accompanies human pathologies, including neurodegenerative disease. Previously, we showed that the ASR contributes to morphogenesis failures and reduced viability of developing embryos. This protocol allows the continued study of mechanisms underlying actin rod assembly and the ASR in a model system that is highly amenable to imaging, genetics and biochemistry. Embryos are collected and mounted on a coverslip to prepare them for injection. Rhodamine-conjugated globular actin (G-actinRed) is diluted and loaded into a microneedle. A single injection is made into the center of each embryo. After injection, embryos are incubated at elevated temperature and intranuclear actin rods are then visualized by confocal microscopy. Fluorescence recovery after photobleaching (FRAP) experiments may be performed on the actin rods; and other actin-rich structures in the cytoplasm can also be imaged. We find that G-actinRed polymerizes like endogenous G-actin and does not, on its own, interfere with normal embryo development. One limitation of this protocol is that care must be taken during injection to avoid serious injury to the embryo. However, with practice, injecting G-actinRed into Drosophila embryos is a fast and reliable way to visualize actin rods and can easily be used with flies of any genotype or with the introduction of other cellular stresses, including hypoxia and oxidative stress.
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Affiliation(s)
- Natalie Biel
- Integrative Molecular and Biomedical Sciences, Baylor College of Medicine; Department of Cell and Molecular Biology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign
| | - Lauren Figard
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine
| | - Anna Marie Sokac
- Integrative Molecular and Biomedical Sciences, Baylor College of Medicine; Department of Cell and Molecular Biology, School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign; Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine;
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15
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Selvaggio G, Chizhik A, Nißler R, Kuhlemann L, Meyer D, Vuong L, Preiß H, Herrmann N, Mann FA, Lv Z, Oswald TA, Spreinat A, Erpenbeck L, Großhans J, Karius V, Janshoff A, Pablo Giraldo J, Kruss S. Exfoliated near infrared fluorescent silicate nanosheets for (bio)photonics. Nat Commun 2020; 11:1495. [PMID: 32198383 PMCID: PMC7083911 DOI: 10.1038/s41467-020-15299-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 02/28/2020] [Indexed: 12/31/2022] Open
Abstract
Imaging of complex (biological) samples in the near-infrared (NIR) is beneficial due to reduced light scattering, absorption, phototoxicity, and autofluorescence. However, there are few NIR fluorescent materials known and suitable for biomedical applications. Here we exfoliate the layered pigment CaCuSi4O10 (Egyptian Blue, EB) via ball milling and facile tip sonication into NIR fluorescent nanosheets (EB-NS). The size of EB-NS can be tailored to diameters <20 nm and heights down to 1 nm. EB-NS fluoresce at 910 nm and the fluorescence intensity correlates with the number of Cu2+ ions. Furthermore, EB-NS display no bleaching and high brightness compared with other NIR fluorophores. The versatility of EB-NS is demonstrated by in-vivo single-particle tracking and microrheology measurements in Drosophila melanogaster embryos. EB-NS can be uptaken by plants and remotely detected in a low-cost stand-off detection setup. In summary, EB-NS have the potential for a wide range of bioimaging applications.
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Affiliation(s)
- Gabriele Selvaggio
- Institute of Physical Chemistry, University of Göttingen, Göttingen, 37077, Germany
| | - Alexey Chizhik
- Third Institute of Physics, University of Göttingen, Göttingen, 37077, Germany
| | - Robert Nißler
- Institute of Physical Chemistry, University of Göttingen, Göttingen, 37077, Germany
| | - Llyas Kuhlemann
- Institute of Physical Chemistry, University of Göttingen, Göttingen, 37077, Germany
| | - Daniel Meyer
- Institute of Physical Chemistry, University of Göttingen, Göttingen, 37077, Germany
| | - Loan Vuong
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, 37077, Germany
| | - Helen Preiß
- Institute of Physical Chemistry, University of Göttingen, Göttingen, 37077, Germany
| | - Niklas Herrmann
- Institute of Physical Chemistry, University of Göttingen, Göttingen, 37077, Germany
| | - Florian A Mann
- Institute of Physical Chemistry, University of Göttingen, Göttingen, 37077, Germany
| | - Zhiyi Lv
- Institute of Developmental Biochemistry, Medical School, University of Göttingen, Göttingen, 37077, Germany
| | - Tabea A Oswald
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, 37077, Germany
| | - Alexander Spreinat
- Institute of Physical Chemistry, University of Göttingen, Göttingen, 37077, Germany
| | - Luise Erpenbeck
- Department of Dermatology, Venereology and Allergology, University Medical Center Göttingen, Göttingen, 37075, Germany
| | - Jörg Großhans
- Institute of Developmental Biochemistry, Medical School, University of Göttingen, Göttingen, 37077, Germany
| | - Volker Karius
- Department of Sedimentology and Environmental Geology, Geoscience Center, University of Göttingen, Göttingen, 37077, Germany
| | - Andreas Janshoff
- Institute of Physical Chemistry, University of Göttingen, Göttingen, 37077, Germany
| | - Juan Pablo Giraldo
- Department of Botany and Plant Sciences, University of California, Riverside, California, 92507, USA
| | - Sebastian Kruss
- Institute of Physical Chemistry, University of Göttingen, Göttingen, 37077, Germany.
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16
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Loerke D, Blankenship JT. Viscoelastic voyages - Biophysical perspectives on cell intercalation during Drosophila gastrulation. Semin Cell Dev Biol 2019; 100:212-222. [PMID: 31784092 DOI: 10.1016/j.semcdb.2019.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 09/11/2019] [Accepted: 11/11/2019] [Indexed: 12/18/2022]
Abstract
Developmental processes are driven by a combination of cytoplasmic, cortical, and surface-associated forces. However, teasing apart the contributions of these forces and how a viscoelastic cell responds has long been a key question in developmental biology. Recent advances in applying biophysical approaches to these questions is leading to a fundamentally new understanding of morphogenesis. In this review, we discuss how computational analysis of experimental findings and in silico modeling of Drosophila gastrulation processes has led to a deeper comprehension of the physical principles at work in the early embryo. We also summarize many of the emerging methodologies that permit biophysical analysis as well as those that provide direct and indirect measurements of force directions and magnitudes. Finally, we examine the multiple frameworks that have been used to model tissue and cellular behaviors.
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Affiliation(s)
- Dinah Loerke
- Department of Physics and Astronomy, University of Denver, Denver, CO 80208, USA.
| | - J Todd Blankenship
- Department of Biological Sciences, University of Denver, Denver, CO 80208, USA.
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17
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Abstract
During typical early-stage embryo development, single-cell-thick tissues of tightly bound epithelial cells autonomously generate profound changes in their shape, forming the basis of organism anatomy. We report on a (covariant) active-hydrodynamic theory of such monolayer morphogenesis that is closed under its shape-changing dynamics-i.e., the degrees of freedom that encode monolayer geometry appear properly as broken-symmetry variables. In our theory, the salient physics of tissue-scale deformations emerges from a balance between the displacement and/or shear of a low-Reynolds-number embedding fluid (the "yolk") and cell-autonomous stresses, themselves a result of combining apical contractile stresses with an elastic-like mechanical response under the constraint of constant cell volume. The leading-order hydrodynamic instabilities include both passive constrained-buckling and active deformation, which can be further categorized by cell shape changes that are either "squamous to columnar" or "regular-prism to truncated-pyramid." The deformations resulting from the latter qualitatively reproduce in vivo observations of the onset of both mesoderm and posterior midgut invaginations, which take place during gastrulation in the model organism Drosophila melanogaster.
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Affiliation(s)
- Richard G Morris
- EMBL-Australia node in Single Molecule Science, University of New South Wales, Sydney, Australia
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bangalore, India
| | - Madan Rao
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bangalore, India
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18
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Cong J, Fang B, Wang Q, Su Y, Gu T, Luo T. The mechanobiology of actin cytoskeletal proteins during cell-cell fusion. J R Soc Interface 2019; 16:20190022. [PMID: 31337301 DOI: 10.1098/rsif.2019.0022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Myosin II and spectrin β display mechanosensitive accumulations in invasive protrusions during cell-cell fusion of Drosophila myoblasts. The biochemical inhibition and deactivation of these proteins results in significant fusion defects. Yet, a quantitative understanding of how the protrusion geometry and fusion process are linked to these proteins is still lacking. Here we present a quantitative model to interpret the dependence of the protrusion size and the protrusive force on the mechanical properties and microstructures of the actin cytoskeleton and plasma membrane based on a mean-field theory. We build a quantitative linkage between mechanosensitive accumulation of myosin II and fusion pore formation at the tip of the invasive protrusion through local area dilation. The mechanical feedback loop between myosin II and local deformation suggests that myosin II accumulation possibly reduces the energy barrier and the critical radius of fusion pores. We also analyse the effect of spectrin β on maintaining the proper geometry of the protrusions required for the success of cell-cell fusion.
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Affiliation(s)
- Jing Cong
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, People's Republic of China
| | - Bing Fang
- College of Mechanical and Electronic Engineering, Fujian Agriculture and Forestry University, Fuzhou 350002, People's Republic of China
| | - Qian Wang
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, People's Republic of China
| | - Yan Su
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, People's Republic of China
| | - Tianqi Gu
- College of Mechanical Engineering and Automation, Fuzhou University, Fuzhou 350108, People's Republic of China
| | - Tianzhi Luo
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, People's Republic of China
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19
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Kinzer-Ursem T. Relieving the Pressure on Tissue Development. Biophys J 2019; 113:360-361. [PMID: 28746846 DOI: 10.1016/j.bpj.2017.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 06/06/2017] [Indexed: 11/19/2022] Open
Affiliation(s)
- Tamara Kinzer-Ursem
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana.
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20
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Mechanical Model of Nuclei Ordering in Drosophila Embryos Reveals Dilution of Stochastic Forces. Biophys J 2019; 114:1730-1740. [PMID: 29642041 DOI: 10.1016/j.bpj.2018.02.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 01/16/2018] [Accepted: 02/05/2018] [Indexed: 02/07/2023] Open
Abstract
During the initial development of syncytial embryos, nuclei go through cycles of nuclear division and spatial rearrangement. The arising spatial pattern of nuclei is important for subsequent cellularization and morphing of the embryo. Although nuclei are contained within a common cytoplasm, cytoskeletal proteins are nonuniformly packaged into regions around every nucleus. In fact, cytoskeletal elements like microtubules and their associated motor proteins exert stochastic forces between nuclei, actively driving their rearrangement. Yet, it is unknown how the stochastic forces are balanced to maintain nuclear order in light of increased nuclear density upon every round of divisions. Here, we investigate the nuclear arrangements in Drosophila melanogaster over the course of several nuclear divisions starting from interphase 11. We develop a theoretical model in which we distinguish long-ranged passive forces due to the nuclei as inclusions in the elastic matrix, namely the cytoplasm, and active, stochastic forces arising from the cytoskeletal dynamics mediated by motor proteins. We perform computer simulations and quantify the observed degree of orientational and spatial order of nuclei. Solely doubling the nuclear density upon nuclear division, the model predicts a decrease in nuclear order. Comparing results to experimental recordings of tracked nuclei, we make contradictory observations, finding an increase in nuclear order upon nuclear divisions. Our analysis of model parameters resulting from this comparison suggests that overall motor protein density as well as relative active-force amplitude has to decrease by a factor of about two upon nuclear division to match experimental observations. We therefore expect a dilution of cytoskeletal motors during the rapid nuclear division to account for the increase in nuclear order during syncytial embryo development. Experimental measurements of kinesin-5 cluster lifetimes support this theoretical finding.
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21
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Mura F, Gradziuk G, Broedersz CP. Nonequilibrium Scaling Behavior in Driven Soft Biological Assemblies. PHYSICAL REVIEW LETTERS 2018; 121:038002. [PMID: 30085773 DOI: 10.1103/physrevlett.121.038002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/13/2018] [Indexed: 06/08/2023]
Abstract
Measuring and quantifying nonequilibrium dynamics in active biological systems is a major challenge because of their intrinsic stochastic nature and the limited number of variables accessible in any real experiment. We investigate what nonequilibrium information can be extracted from noninvasive measurements using a stochastic model of soft elastic networks with a heterogeneous distribution of activities, representing enzymatic force generation. In particular, we use this model to study how the nonequilibrium activity, detected by tracking two probes in the network, scales as a function of the distance between the probes. We quantify the nonequilibrium dynamics through the cycling frequencies, a simple measure of circulating currents in the phase space of the probes. We find that these cycling frequencies exhibit power-law scaling behavior with the distance between probes. In addition, we show that this scaling behavior governs the entropy production rate that can be recovered from the two traced probes. Our results provide insight into how internal enzymatic driving generates nonequilibrium dynamics on different scales in soft biological assemblies.
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Affiliation(s)
- Federica Mura
- Arnold-Sommerfeld-Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-Universität München, D-80333 München, Germany
| | - Grzegorz Gradziuk
- Arnold-Sommerfeld-Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-Universität München, D-80333 München, Germany
| | - Chase P Broedersz
- Arnold-Sommerfeld-Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-Universität München, D-80333 München, Germany
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22
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Córdoba A. The Effects of the Interplay between Motor and Brownian Forces on the Rheology of Active Gels. J Phys Chem B 2018; 122:4267-4277. [PMID: 29578713 DOI: 10.1021/acs.jpcb.8b00238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Active gels perform key mechanical roles inside the cell, such as cell division, motion, and force sensing. The unique mechanical properties required to perform such functions arise from the interactions between molecular motors and semiflexible polymeric filaments. Molecular motors can convert the energy released in the hydrolysis of ATP into forces of up to piconewton magnitudes. Moreover, the polymeric filaments that form active gels are flexible enough to respond to Brownian forces but also stiff enough to support the large tensions induced by the motor-generated forces. Brownian forces are expected to have a significant effect especially at motor activities at which stable noncontractile in vitro active gels are prepared for rheological measurements. Here, a microscopic mean-field theory of active gels originally formulated in the limit of motor-dominated dynamics is extended to include Brownian forces. In the model presented here, Brownian forces are included accurately, at real room temperature, even in systems with high motor activity. It is shown that a subtle interplay, or competition, between motor-generated forces and Brownian forces has an important impact on the mass transport and rheological properties of active gels. The model predictions show that at low frequencies the dynamic modulus of active gels is determined mostly by motor protein dynamics. However, Brownian forces significantly increase the breadth of the relaxation spectrum and can affect the shape of the dynamic modulus over a wide frequency range even for ratios of motor to Brownian forces of more than a hundred. Since the ratio between motor and Brownian forces is sensitive to ATP concentration, the results presented here shed some light on how the transient mechanical response of active gels changes with varying ATP concentration.
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Affiliation(s)
- Andrés Córdoba
- Department of Chemical Engineering , Universidad de Concepción , Concepción , Chile
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23
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Selvaggi L, Pasakarnis L, Brunner D, Aegerter CM. Magnetic tweezers optimized to exert high forces over extended distances from the magnet in multicellular systems. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:045106. [PMID: 29716356 DOI: 10.1063/1.5010788] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Magnetic tweezers are mainly divided into two classes depending on the ability of applying torque or forces to the magnetic probe. We focused on the second category and designed a device composed by a single electromagnet equipped with a core having a special asymmetric profile to exert forces as large as 230 pN-2.8 μm Dynabeads at distances in excess of 100 μm from the magnetic tip. Compared to existing solutions our magnetic tweezers overcome important limitations, opening new experimental paths for the study of a wide range of materials in a variety of biophysical research settings. We discuss the benefits and drawbacks of different magnet core characteristics, which led us to design the current core profile. To demonstrate the usefulness of our magnetic tweezers, we determined the microrheological properties inside embryos of Drosophila melanogaster during the syncytial stage. Measurements in different locations along the dorsal-ventral axis of the embryos showed little variation, with a slight increase in cytoplasm viscosity at the periphery of the embryos. The mean cytoplasm viscosity we obtain by active force exertion inside the embryos is comparable to that determined passively using high-speed video microrheology.
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Affiliation(s)
- L Selvaggi
- Department of Physics, University of Zurich UZH, Zurich, Switzerland
| | - L Pasakarnis
- Institute of Molecular Life Science IMLS, Zurich, Switzerland
| | - D Brunner
- Institute of Molecular Life Science IMLS, Zurich, Switzerland
| | - C M Aegerter
- Department of Physics, University of Zurich UZH, Zurich, Switzerland
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24
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Loosemore VE, Forde NR. Effects of finite and discrete sampling and blur on microrheology experiments. OPTICS EXPRESS 2017; 25:31239-31252. [PMID: 29245801 DOI: 10.1364/oe.25.031239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 10/28/2017] [Indexed: 06/07/2023]
Abstract
The frequency-dependent viscous and elastic properties of fluids can be determined from measurements of the thermal fluctuations of a micron-sized particle trapped by optical tweezers. Finite bandwidth and other instrument limitations lead to systematic errors in measurement of the fluctuations. In this work, we numerically represented power spectra of bead position measurements as if collected by two different measurement devices: a quadrant photodiode, which measures the deflection of the trapping laser; and a high-speed camera, which images the trapped bead directly. We explored the effects of aliasing, camera blur, sampling frequency, and measurement time. By comparing the power spectrum, complex response function, and the complex shear modulus with the ideal values, we found that the viscous and elastic properties inferred from the data are affected by the instrument limitations of each device. We discuss how these systematic effects might affect experimental results from microrheology measurements and suggest approaches to reduce discrepancies.
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25
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Perez-Mockus G, Mazouni K, Roca V, Corradi G, Conte V, Schweisguth F. Spatial regulation of contractility by Neuralized and Bearded during furrow invagination in Drosophila. Nat Commun 2017; 8:1594. [PMID: 29150614 PMCID: PMC5693868 DOI: 10.1038/s41467-017-01482-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 09/21/2017] [Indexed: 12/22/2022] Open
Abstract
Embryo-scale morphogenesis arises from patterned mechanical forces. During Drosophila gastrulation, actomyosin contractility drives apical constriction in ventral cells, leading to furrow formation and mesoderm invagination. It remains unclear whether and how mechanical properties of the ectoderm influence this process. Here, we show that Neuralized (Neur), an E3 ubiquitin ligase active in the mesoderm, regulates collective apical constriction and furrow formation. Conversely, the Bearded (Brd) proteins antagonize maternal Neur and lower medial-apical contractility in the ectoderm: in Brd-mutant embryos, the ventral furrow invaginates properly but rapidly unfolds as medial MyoII levels increase in the ectoderm. Increasing contractility in the ectoderm via activated Rho similarly triggers furrow unfolding whereas decreasing contractility restores furrow invagination in Brd-mutant embryos. Thus, the inhibition of Neur by Brd in the ectoderm differentiates the mechanics of the ectoderm from that of the mesoderm and patterns the activity of MyoII along the dorsal-ventral axis.
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Affiliation(s)
- Gantas Perez-Mockus
- Department of Developmental and Stem Cell Biology, Institut Pasteur, F-75015, Paris, France.,CNRS, UMR3738, F-75015, Paris, France.,Univ. Pierre et Marie Curie, Cellule Pasteur UPMC, F-75015, Paris, France
| | - Khalil Mazouni
- Department of Developmental and Stem Cell Biology, Institut Pasteur, F-75015, Paris, France.,CNRS, UMR3738, F-75015, Paris, France
| | - Vanessa Roca
- Department of Developmental and Stem Cell Biology, Institut Pasteur, F-75015, Paris, France.,CNRS, UMR3738, F-75015, Paris, France
| | - Giulia Corradi
- Department of Developmental and Stem Cell Biology, Institut Pasteur, F-75015, Paris, France.,CNRS, UMR3738, F-75015, Paris, France
| | - Vito Conte
- Institute for Bioengineering of Catalonia, Barcelona Institute of Science and Technology, 08028, Barcelona, Spain.
| | - François Schweisguth
- Department of Developmental and Stem Cell Biology, Institut Pasteur, F-75015, Paris, France. .,CNRS, UMR3738, F-75015, Paris, France.
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26
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Hörner F, Meissner R, Polali S, Pfeiffer J, Betz T, Denz C, Raz E. Holographic optical tweezers-based in vivo manipulations in zebrafish embryos. JOURNAL OF BIOPHOTONICS 2017; 10:1492-1501. [PMID: 28164445 DOI: 10.1002/jbio.201600226] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 11/22/2016] [Accepted: 01/12/2017] [Indexed: 05/14/2023]
Abstract
Understanding embryonic development requires the characterization of the forces and the mechanical features that shape cells and tissues within the organism. In addition, experimental application of forces on cells and altering cell and organelle shape allows determining the role such forces play in morphogenesis. Here, we present a holographic optical tweezers-based new microscopic platform for in vivo applications in the context of a developing vertebrate embryo that unlike currently used setups allows simultaneous trapping of multiple objects and rapid comparisons of viscoelastic properties in different locations. This non-invasive technique facilitates a dynamic analysis of mechanical properties of cells and tissues without intervening with embryonic development. We demonstrate the application of this platform for manipulating organelle shape and for characterizing the mechanobiological properties of cells in live zebrafish embryos. The method of holographic optical tweezers as described here is of general interest and can be easily transferred to studying a range of developmental processes in zebrafish, thereby establishing a versatile platform for similar investigations in other organisms. Fluorescent beads injected into zebrafish embryos at 1-cell stage are maintained within the embryos and do not affect their development as observed in the presented 1-day old embryo.
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Affiliation(s)
- Florian Hörner
- Institute of Cell Biology, Center of Molecular Biology of Inflammation, University of Münster, Von-Esmarch-Straße 56, 48149, Münster, Germany
| | - Robert Meissner
- Institute of Applied Physics, University of Münster, Corrensstraße 2/4, 48149, Münster, Germany
| | - Sruthi Polali
- Institute of Applied Physics, University of Münster, Corrensstraße 2/4, 48149, Münster, Germany
| | - Jana Pfeiffer
- Institute of Cell Biology, Center of Molecular Biology of Inflammation, University of Münster, Von-Esmarch-Straße 56, 48149, Münster, Germany
| | - Timo Betz
- Institute of Cell Biology, Center of Molecular Biology of Inflammation, University of Münster, Von-Esmarch-Straße 56, 48149, Münster, Germany
| | - Cornelia Denz
- Institute of Applied Physics, University of Münster, Corrensstraße 2/4, 48149, Münster, Germany
| | - Erez Raz
- Institute of Cell Biology, Center of Molecular Biology of Inflammation, University of Münster, Von-Esmarch-Straße 56, 48149, Münster, Germany
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27
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Raghunathan R, Zhang J, Wu C, Rippy J, Singh M, Larin KV, Scarcelli G. Evaluating biomechanical properties of murine embryos using Brillouin microscopy and optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-6. [PMID: 28861955 PMCID: PMC5582619 DOI: 10.1117/1.jbo.22.8.086013] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 08/03/2017] [Indexed: 05/19/2023]
Abstract
Embryogenesis is regulated by numerous changes in mechanical properties of the cellular microenvironment. Thus, studying embryonic mechanophysiology can provide a more thorough perspective of embryonic development, potentially improving early detection of congenital abnormalities as well as evaluating and developing therapeutic interventions. A number of methods and techniques have been used to study cellular biomechanical properties during embryogenesis. While some of these techniques are invasive or involve the use of external agents, others are compromised in terms of spatial and temporal resolutions. We propose the use of Brillouin microscopy in combination with optical coherence tomography (OCT) to measure stiffness as well as structural changes in a developing embryo. While Brillouin microscopy assesses the changes in stiffness among different organs of the embryo, OCT provides the necessary structural guidance.
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Affiliation(s)
- Raksha Raghunathan
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Jitao Zhang
- University of Maryland, Fischell Department of Bioengineering, College Park, Maryland, United States
| | - Chen Wu
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Justin Rippy
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Manmohan Singh
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Kirill V. Larin
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
- Tomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russia
- Address all correspondence to: Kirill V. Larin, E-mail: ; Giuliano Scarcelli, E-mail:
| | - Giuliano Scarcelli
- University of Maryland, Fischell Department of Bioengineering, College Park, Maryland, United States
- Address all correspondence to: Kirill V. Larin, E-mail: ; Giuliano Scarcelli, E-mail:
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28
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Yanez LZ, Camarillo DB. Microfluidic analysis of oocyte and embryo biomechanical properties to improve outcomes in assisted reproductive technologies. Mol Hum Reprod 2017; 23:235-247. [PMID: 27932552 PMCID: PMC5909856 DOI: 10.1093/molehr/gaw071] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 07/28/2016] [Indexed: 01/03/2023] Open
Abstract
Measurement of oocyte and embryo biomechanical properties has recently emerged as an exciting new approach to obtain a quantitative, objective estimate of developmental potential. However, many traditional methods for probing cell mechanical properties are time consuming, labor intensive and require expensive equipment. Microfluidic technology is currently making its way into many aspects of assisted reproductive technologies (ART), and is particularly well suited to measure embryo biomechanics due to the potential for robust, automated single-cell analysis at a low cost. This review will highlight microfluidic approaches to measure oocyte and embryo mechanics along with their ability to predict developmental potential and find practical application in the clinic. Although these new devices must be extensively validated before they can be integrated into the existing clinical workflow, they could eventually be used to constantly monitor oocyte and embryo developmental progress and enable more optimal decision making in ART.
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Affiliation(s)
- Livia Z. Yanez
- Department of Bioengineering, Stanford University, 443 Via Ortega, Stanford, CA 94305, USA
| | - David B. Camarillo
- Department of Bioengineering, Stanford University, 443 Via Ortega, Stanford, CA 94305, USA
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29
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Koslover EF, Chan CK, Theriot JA. Disentangling Random Motion and Flow in a Complex Medium. Biophys J 2017; 110:700-709. [PMID: 26840734 PMCID: PMC4744162 DOI: 10.1016/j.bpj.2015.11.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 11/03/2015] [Accepted: 11/05/2015] [Indexed: 11/07/2022] Open
Abstract
We describe a technique for deconvolving the stochastic motion of particles from large-scale fluid flow in a dynamic environment such as that found in living cells. The method leverages the separation of timescales to subtract out the persistent component of motion from single-particle trajectories. The mean-squared displacement of the resulting trajectories is rescaled so as to enable robust extraction of the diffusion coefficient and subdiffusive scaling exponent of the stochastic motion. We demonstrate the applicability of the method for characterizing both diffusive and fractional Brownian motion overlaid by flow and analytically calculate the accuracy of the method in different parameter regimes. This technique is employed to analyze the motion of lysosomes in motile neutrophil-like cells, showing that the cytoplasm of these cells behaves as a viscous fluid at the timescales examined.
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Affiliation(s)
- Elena F Koslover
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California
| | - Caleb K Chan
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California
| | - Julie A Theriot
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California.
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30
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Campàs O. A toolbox to explore the mechanics of living embryonic tissues. Semin Cell Dev Biol 2016; 55:119-30. [PMID: 27061360 PMCID: PMC4903887 DOI: 10.1016/j.semcdb.2016.03.011] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 03/15/2016] [Indexed: 01/03/2023]
Abstract
The sculpting of embryonic tissues and organs into their functional morphologies involves the spatial and temporal regulation of mechanics at cell and tissue scales. Decades of in vitro work, complemented by some in vivo studies, have shown the relevance of mechanical cues in the control of cell behaviors that are central to developmental processes, but the lack of methodologies enabling precise, quantitative measurements of mechanical cues in vivo have hindered our understanding of the role of mechanics in embryonic development. Several methodologies are starting to enable quantitative studies of mechanics in vivo and in situ, opening new avenues to explore how mechanics contributes to shaping embryonic tissues and how it affects cell behavior within developing embryos. Here we review the present methodologies to study the role of mechanics in living embryonic tissues, considering their strengths and drawbacks as well as the conditions in which they are most suitable.
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Affiliation(s)
- Otger Campàs
- Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106, USA; Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, CA 93106, USA; California Nanosystems Institute, University of California, Santa Barbara, CA 93106, USA.
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31
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Winkler F, Gummalla M, Künneke L, Lv Z, Zippelius A, Aspelmeier T, Grosshans J. Fluctuation Analysis of Centrosomes Reveals a Cortical Function of Kinesin-1. Biophys J 2016; 109:856-68. [PMID: 26331244 PMCID: PMC4564942 DOI: 10.1016/j.bpj.2015.07.044] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 07/20/2015] [Accepted: 07/31/2015] [Indexed: 01/28/2023] Open
Abstract
The actin and microtubule networks form the dynamic cytoskeleton. Network dynamics is driven by molecular motors applying force onto the networks and the interactions between the networks. Here we assay the dynamics of centrosomes in the scale of seconds as a proxy for the movement of microtubule asters. With this assay we want to detect the role of specific motors and of network interaction. During interphase of syncytial embryos of Drosophila, cortical actin and the microtubule network depend on each other. Centrosomes induce cortical actin to form caps, whereas F-actin anchors microtubules to the cortex. In addition, lateral interactions between microtubule asters are assumed to be important for regular spatial organization of the syncytial embryo. The functional interaction between the microtubule asters and cortical actin has been largely analyzed in a static manner, so far. We recorded the movement of centrosomes at 1 Hz and analyzed their fluctuations for two processes—pair separation and individual movement. We found that F-actin is required for directional movements during initial centrosome pair separation, because separation proceeds in a diffusive manner in latrunculin-injected embryos. For assaying individual movement, we established a fluctuation parameter as the deviation from temporally and spatially slowly varying drift movements. By analysis of mutant and drug-injected embryos, we found that the fluctuations were suppressed by both cortical actin and microtubules. Surprisingly, the microtubule motor Kinesin-1 also suppressed fluctuations to a similar degree as F-actin. Kinesin-1 may mediate linkage of the microtubule (+)-ends to the actin cortex. Consistent with this model is our finding that Kinesin-1-GFP accumulates at the cortical actin caps.
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Affiliation(s)
- Franziska Winkler
- Institute for Developmental Biochemistry, Medical School, Georg-August-University Göttingen, Göttingen, Germany
| | - Maheshwar Gummalla
- Institute for Developmental Biochemistry, Medical School, Georg-August-University Göttingen, Göttingen, Germany
| | - Lutz Künneke
- Institute for Theoretical Physics, Georg-August-University Göttingen, Göttingen, Germany
| | - Zhiyi Lv
- Institute for Developmental Biochemistry, Medical School, Georg-August-University Göttingen, Göttingen, Germany
| | - Annette Zippelius
- Institute for Theoretical Physics, Georg-August-University Göttingen, Göttingen, Germany
| | - Timo Aspelmeier
- Institute for Mathematical Stochastics, Georg-August-University Göttingen, Göttingen, Germany; Felix Bernstein Institute for Statistics in the Biosciences, Georg-August-University Göttingen, Göttingen, Germany
| | - Jörg Grosshans
- Institute for Developmental Biochemistry, Medical School, Georg-August-University Göttingen, Göttingen, Germany.
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Xie J, Hu GH. Hydrodynamic modeling of Bicoid morphogen gradient formation in Drosophila embryo. Biomech Model Mechanobiol 2016; 15:1765-1773. [DOI: 10.1007/s10237-016-0796-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 05/04/2016] [Indexed: 12/13/2022]
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van Hoorn H, Kurniawan NA, Koenderink GH, Iannuzzi D. Local dynamic mechanical analysis for heterogeneous soft matter using ferrule-top indentation. SOFT MATTER 2016; 12:3066-73. [PMID: 26908197 PMCID: PMC4819682 DOI: 10.1039/c6sm00300a] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
There is a strong demand for nanoindentation methods to probe the heterogeneous viscoelastic properties of soft tissues. Important applications include diagnosis of early onset diseases such as arthritis and investigations into cellular mechanoresponse in tissue. Quantification of tissue mechanics at length and time scales relevant to biological processes, however, remains a technical challenge. Here, we present a new nanoindentation approach that is ideally suited to probe the viscoelastic properties of soft, hydrated tissues. We built a ferrule-top probe that uses wavelength modulation in a Fabry-Pérot cavity configuration to detect cantilever deflection and to drive a feedback-controlled piezoelectric actuator. This technique allows us to control the static load applied onto the sample using an all-optical mm-sized probe. We extract the local elastic and viscous moduli of the samples by superposing a small oscillatory load and recording the indentation depth at the frequency of oscillation. By using a set of silicone elastomers with a range of stiffnesses representative of biological tissues, we demonstrate that the technique can accurately determine moduli over a wide range (0.1-100 kPa) and over a frequency range of 0.01-10 Hz. Direct comparison with macroscopic rheology measurements yields excellent quantitative agreement, without any fitting parameters. Finally, we show how this method can provide a spatially-resolved map of large variations in mechanical properties (orders of magnitude) across the surface of soft samples thanks to high sensitivity over large (>μm) cantilever deflections. This approach paves the way to investigations into the local dynamic mechanical properties of biological soft matter.
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Affiliation(s)
- Hedde van Hoorn
- Department of Physics and Astronomy, VU University, De Boelelaan 1081, Amsterdam, The Netherlands. and Laserlab Amsterdam, VU University, De Boelelaan 1081, Amsterdam, The Netherlands
| | | | - Gijsje H Koenderink
- Department of Physics and Astronomy, VU University, De Boelelaan 1081, Amsterdam, The Netherlands. and FOM institute AMOLF, Science Park 104, Amsterdam, The Netherlands
| | - Davide Iannuzzi
- Department of Physics and Astronomy, VU University, De Boelelaan 1081, Amsterdam, The Netherlands. and Laserlab Amsterdam, VU University, De Boelelaan 1081, Amsterdam, The Netherlands
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Blehm BH, Devine A, Staunton JR, Tanner K. In vivo tissue has non-linear rheological behavior distinct from 3D biomimetic hydrogels, as determined by AMOTIV microscopy. Biomaterials 2015; 83:66-78. [PMID: 26773661 DOI: 10.1016/j.biomaterials.2015.12.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 12/11/2015] [Accepted: 12/14/2015] [Indexed: 12/21/2022]
Abstract
Variation in matrix elasticity has been shown to determine cell fate in both differentiation and development of malignant phenotype. The tissue microenvironment provides complex biochemical and biophysical signals in part due to the architectural heterogeneities found in extracellular matrices (ECMs). Three dimensional cell cultures can partially mimic in vivo tissue architecture, but to truly understand the role of viscoelasticity on cell fate, we must first determine in vivo tissue mechanical properties to improve in vitro models. We employed Active Microrheology by Optical Trapping InVivo (AMOTIV), using in situ calibration to measure in vivo zebrafish tissue mechanics. Previously used trap calibration methods overestimate complex moduli by ∼ 2-20 fold compared to AMOTIV. Applying differential microscale stresses and strains showed that hyaluronic acid (HA) gels display semi-flexible polymer behavior, while laminin-rich ECM hydrogels display flexible polymer behavior. In contrast, zebrafish tissues displayed different moduli at different stresses, with higher power law exponents at lower stresses, indicating that living tissue has greater stress dependence than the 3D hydrogels examined. To our knowledge, this work is the first vertebrate tissue rheological characterization performed in vivo. Our fundamental observations are important for the development and refinement of in vitro platforms.
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Affiliation(s)
- Benjamin H Blehm
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute (NIH), Bethesda, MD 20892, USA
| | - Alexus Devine
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute (NIH), Bethesda, MD 20892, USA
| | - Jack R Staunton
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute (NIH), Bethesda, MD 20892, USA
| | - Kandice Tanner
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute (NIH), Bethesda, MD 20892, USA.
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