1
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Le BT, Auer KM, Lopez DA, Shum JP, Suarsana B, Suh GYK, Hedde PN, Ahrar S. Orthogonal-view microscope for the biomechanics investigations of aquatic organisms. HARDWAREX 2024; 18:e00533. [PMID: 38711599 PMCID: PMC11070628 DOI: 10.1016/j.ohx.2024.e00533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 04/07/2024] [Accepted: 04/13/2024] [Indexed: 05/08/2024]
Abstract
Microscopes are essential for the biomechanical and hydrodynamical investigation of small aquatic organisms. We report a prototype of a do-it-yourself microscope that enables the visualization of organisms from two orthogonal imaging planes - top and side views. Compared to conventional imaging systems, this approach provides a comprehensive visualization strategy of organisms, which could have complex shapes and morphologies. The microscope was constructed by combining custom 3D-printed parts and off-the-shelf components. The system is designed for modularity and reconfigurability. Open-source design files and build instructions are provided in this report. Additionally, proof-of-use experiments (particularly with Hydra) and other organisms that combine the imaging with an analysis pipeline were demonstrated to highlight the system's utility. Beyond the applications demonstrated, the system can be used or modified for various imaging applications.
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Affiliation(s)
- Brian T. Le
- Department of Biomedical Engineering, California State University Long Beach, 1250 Bellflower Blvd. Long Beach, CA 90840, USA
| | - Katherine M. Auer
- Department of Biomedical Engineering, California State University Long Beach, 1250 Bellflower Blvd. Long Beach, CA 90840, USA
| | - David A. Lopez
- Department of Biomedical Engineering, California State University Long Beach, 1250 Bellflower Blvd. Long Beach, CA 90840, USA
| | - Justin P. Shum
- Department of Biomedical Engineering, California State University Long Beach, 1250 Bellflower Blvd. Long Beach, CA 90840, USA
| | - Brian Suarsana
- Department of Biomedical Engineering, California State University Long Beach, 1250 Bellflower Blvd. Long Beach, CA 90840, USA
| | - Ga-Young Kelly Suh
- Department of Biomedical Engineering, California State University Long Beach, 1250 Bellflower Blvd. Long Beach, CA 90840, USA
| | - Per Niklas Hedde
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, CA 92612, USA
| | - Siavash Ahrar
- Department of Biomedical Engineering, California State University Long Beach, 1250 Bellflower Blvd. Long Beach, CA 90840, USA
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2
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Goel T, Adams EM, Bialas AL, Tran CM, Rowe T, Martin S, Chandler M, Schubert J, Diamond PH, Collins EMS. Nonlinear elasticity and short-range mechanical coupling govern the rate and symmetry of mouth opening in Hydra. Proc Biol Sci 2024; 291:20232123. [PMID: 38378148 PMCID: PMC10878823 DOI: 10.1098/rspb.2023.2123] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 01/18/2024] [Indexed: 02/22/2024] Open
Abstract
Hydra has a tubular bilayered epithelial body column with a dome-shaped head on one end and a foot on the other. Hydra lacks a permanent mouth: its head epithelium is sealed. Upon neuronal activation, a mouth opens at the apex of the head which can exceed the body column diameter in seconds, allowing Hydra to ingest prey larger than itself. While the kinematics of mouth opening are well characterized, the underlying mechanism is unknown. We show that Hydra mouth opening is generated by independent local contractions that require tissue-level coordination. We model the head epithelium as an active viscoelastic nonlinear spring network. The model reproduces the size, timescale and symmetry of mouth opening. It shows that radial contractions, travelling inwards from the outer boundary of the head, pull the mouth open. Nonlinear elasticity makes mouth opening larger and faster, contrary to expectations. The model correctly predicts changes in mouth shape in response to external forces. By generating innervated : nerve-free chimera in experiments and simulations, we show that nearest-neighbour mechanical signalling suffices to coordinate mouth opening. Hydra mouth opening shows that in the absence of long-range chemical or neuronal signals, short-range mechanical coupling is sufficient to produce long-range order in tissue deformations.
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Affiliation(s)
- Tapan Goel
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Ellen M. Adams
- Department of Biology, Swarthmore College, Swarthmore, PA 19081, USA
| | - April L. Bialas
- Department of Biology, Swarthmore College, Swarthmore, PA 19081, USA
| | - Cassidy M. Tran
- Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Trevor Rowe
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Sara Martin
- Department of Biology, Swarthmore College, Swarthmore, PA 19081, USA
| | - Maia Chandler
- Department of Biology, Swarthmore College, Swarthmore, PA 19081, USA
| | - Johanna Schubert
- Department of Biology, Swarthmore College, Swarthmore, PA 19081, USA
| | - Patrick H. Diamond
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Eva-Maria S. Collins
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
- Department of Biology, Swarthmore College, Swarthmore, PA 19081, USA
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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3
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Gooshvar S, Madhu G, Ruszczyk M, Prakash VN. Non-Bilaterians as Model Systems for Tissue Mechanics. Integr Comp Biol 2023; 63:1442-1454. [PMID: 37355780 DOI: 10.1093/icb/icad074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 06/26/2023] Open
Abstract
In animals, epithelial tissues are barriers against the external environment, providing protection against biological, chemical, and physical damage. Depending on the organism's physiology and behavior, these tissues encounter different types of mechanical forces and need to provide a suitable adaptive response to ensure success. Therefore, understanding tissue mechanics in different contexts is an important research area. Here, we review recent tissue mechanics discoveries in three early divergent non-bilaterian systems-Trichoplax adhaerens, Hydra vulgaris, and Aurelia aurita. We highlight each animal's simple body plan and biology and unique, rapid tissue remodeling phenomena that play a crucial role in its physiology. We also discuss the emergent large-scale mechanics in these systems that arise from small-scale phenomena. Finally, we emphasize the potential of these non-bilaterian animals to be model systems in a bottom-up approach for further investigation in tissue mechanics.
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Affiliation(s)
- Setareh Gooshvar
- Department of Physics, College of Arts and Sciences, University of Miami, 33146 FL, USA
| | - Gopika Madhu
- Department of Physics, College of Arts and Sciences, University of Miami, 33146 FL, USA
| | - Melissa Ruszczyk
- Department of Physics, College of Arts and Sciences, University of Miami, 33146 FL, USA
| | - Vivek N Prakash
- Department of Physics, College of Arts and Sciences, University of Miami, 33146 FL, USA
- Department of Biology, College of Arts and Sciences, University of Miami, 33146 FL, USA
- Department of Marine Biology and Ecology, Rosenstiel School of Marine, Atmospheric and Earth Science, University of Miami, 33149 FL, USA
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4
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Giez C, Pinkle D, Giencke Y, Wittlieb J, Herbst E, Spratte T, Lachnit T, Klimovich A, Selhuber-Unkel C, Bosch TCG. Multiple neuronal populations control the eating behavior in Hydra and are responsive to microbial signals. Curr Biol 2023; 33:5288-5303.e6. [PMID: 37995697 DOI: 10.1016/j.cub.2023.10.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 09/05/2023] [Accepted: 10/20/2023] [Indexed: 11/25/2023]
Abstract
Although recent studies indicate the impact of microbes on the central nervous systems and behavior, it remains unclear how the relationship between the functionality of the nervous system, behavior, and the microbiota evolved. In this work, we analyzed the eating behavior of Hydra, a host that has a simple nervous system and a low-complexity microbiota. To identify the neuronal subpopulations involved, we used a subpopulation-specific cell ablation system and calcium imaging. The role of the microbiota was uncovered by manipulating the diversity of the natural microbiota. We show that different neuronal subpopulations are functioning together to control eating behavior. Animals with a drastically reduced microbiome had severe difficulties in mouth opening due to a significantly increased level of glutamate. This could be reversed by adding a full complement of the microbiota. In summary, we provide a mechanistic explanation of how Hydra's nervous system controls eating behavior and what role microbes play in this.
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Affiliation(s)
- Christoph Giez
- Zoological Institute, University of Kiel, Christian-Albrechts-Platz 4, 24118 Kiel, Germany.
| | - Denis Pinkle
- Zoological Institute, University of Kiel, Christian-Albrechts-Platz 4, 24118 Kiel, Germany
| | - Yan Giencke
- Zoological Institute, University of Kiel, Christian-Albrechts-Platz 4, 24118 Kiel, Germany
| | - Jörg Wittlieb
- Zoological Institute, University of Kiel, Christian-Albrechts-Platz 4, 24118 Kiel, Germany
| | - Eva Herbst
- Zoological Institute, University of Kiel, Christian-Albrechts-Platz 4, 24118 Kiel, Germany
| | - Tobias Spratte
- Institute for Molecular Systems Engineering and Advanced Materials (INSEAM), University Heidelberg, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Tim Lachnit
- Zoological Institute, University of Kiel, Christian-Albrechts-Platz 4, 24118 Kiel, Germany
| | - Alexander Klimovich
- Zoological Institute, University of Kiel, Christian-Albrechts-Platz 4, 24118 Kiel, Germany
| | - Christine Selhuber-Unkel
- Institute for Molecular Systems Engineering and Advanced Materials (INSEAM), University Heidelberg, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
| | - Thomas C G Bosch
- Zoological Institute, University of Kiel, Christian-Albrechts-Platz 4, 24118 Kiel, Germany.
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5
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Tommasini G, De Simone M, Santillo S, Dufil G, Iencharelli M, Mantione D, Stavrinidou E, Tino A, Tortiglione C. In vivo neuromodulation of animal behavior with organic semiconducting oligomers. SCIENCE ADVANCES 2023; 9:eadi5488. [PMID: 37851802 PMCID: PMC10584338 DOI: 10.1126/sciadv.adi5488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 09/08/2023] [Indexed: 10/20/2023]
Abstract
Modulating neural activity with electrical or chemical stimulus can be used for fundamental and applied research. Typically, neuronal stimulation is performed with intracellular and extracellular electrodes that deliver brief electrical pulses to neurons. However, alternative wireless methodologies based on functional materials may allow clinical translation of technologies to modulate neuronal function. Here, we show that the organic semiconducting oligomer 4-[2-{2,5-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)thiophen-3-yl}ethoxy]butane-1-sulfonate (ETE-S) induces precise behaviors in the small invertebrate Hydra, which were dissected through pharmacological and electrophysiological approaches. ETE-S-induced behavioral response relies on the presence of head neurons and calcium ions and is prevented by drugs targeting ionotropic channels and muscle contraction. Moreover, ETE-S affects Hydra's electrical activity enhancing the contraction burst frequency. The unexpected neuromodulatory function played by this conjugated oligomer on a simple nerve net opens intriguing research possibilities on fundamental chemical and physical phenomena behind organic bioelectronic interfaces for neuromodulation and on alternative methods that could catalyze a wide expansion of this rising technology for clinical applications.
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Affiliation(s)
- Giuseppina Tommasini
- Istituto di Scienze Applicate e Sistemi Intelligenti “E. Caianiello”, Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078 Pozzuoli, Italy
| | - Mariarosaria De Simone
- Istituto di Scienze Applicate e Sistemi Intelligenti “E. Caianiello”, Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078 Pozzuoli, Italy
| | - Silvia Santillo
- Istituto di Scienze Applicate e Sistemi Intelligenti “E. Caianiello”, Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078 Pozzuoli, Italy
| | - Gwennaël Dufil
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, SE-60174 Norrkoping, Sweden
| | - Marika Iencharelli
- Istituto di Scienze Applicate e Sistemi Intelligenti “E. Caianiello”, Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078 Pozzuoli, Italy
| | - Daniele Mantione
- POLYMAT University of the Basque Country UPV/EHU, 20018 Donostia-San Sebastián, Spain; IKERBASQUE, Basque Foundation for Science, 48009, Bilbao, Spain
| | - Eleni Stavrinidou
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, SE-60174 Norrkoping, Sweden
| | - Angela Tino
- Istituto di Scienze Applicate e Sistemi Intelligenti “E. Caianiello”, Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078 Pozzuoli, Italy
| | - Claudia Tortiglione
- Istituto di Scienze Applicate e Sistemi Intelligenti “E. Caianiello”, Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078 Pozzuoli, Italy
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6
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Le BT, Auer KM, Lopez DA, Shum JP, Suarsana B, Suh GYK, Hedde PN, Ahrar S. Orthogonal-view Microscope for the Biomechanics Investigations of Aquatic Organisms. ARXIV 2023:arXiv:2307.13079v1. [PMID: 37547659 PMCID: PMC10402206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Microscopes are essential for the biomechanical and hydrodynamical investigation of small aquatic organisms. We report a do-it-yourself microscope (GLUBscope) that enables the visualization of organisms from two orthogonal imaging planes - top and side views. Compared to conventional imaging systems, this approach provides a comprehensive visualization strategy of organisms, which could have complex shapes and morphologies. The microscope was constructed by combining custom 3D-printed parts and off-the-shelf components. The system is designed for modularity and reconfigurability. Open-source design files and build instructions are provided in this report. Additionally, proof-of-use experiments (particularly with Hydra) and other organisms that combine the GLUBscope with an analysis pipeline were demonstrated to highlight the system's utility. Beyond the applications demonstrated, the system can be used or modified for various imaging applications.
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Affiliation(s)
- Brian T. Le
- Department of Biomedical Engineering, California State University Long Beach 1250 Bellflower Blvd. Long Beach, CA 90840, USA
| | - Katherine M. Auer
- Department of Biomedical Engineering, California State University Long Beach 1250 Bellflower Blvd. Long Beach, CA 90840, USA
| | - David A. Lopez
- Department of Biomedical Engineering, California State University Long Beach 1250 Bellflower Blvd. Long Beach, CA 90840, USA
| | - Justin P. Shum
- Department of Biomedical Engineering, California State University Long Beach 1250 Bellflower Blvd. Long Beach, CA 90840, USA
| | - Brian Suarsana
- Department of Biomedical Engineering, California State University Long Beach 1250 Bellflower Blvd. Long Beach, CA 90840, USA
| | - Ga-Young Kelly Suh
- Department of Biomedical Engineering, California State University Long Beach 1250 Bellflower Blvd. Long Beach, CA 90840, USA
| | - Per Niklas Hedde
- Beckman Laser Institute and Medical Clinic, University of California Irvine Irvine, CA 92612, USA
| | - Siavash Ahrar
- Department of Biomedical Engineering, California State University Long Beach 1250 Bellflower Blvd. Long Beach, CA 90840, USA
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7
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Wang H, Swore J, Sharma S, Szymanski JR, Yuste R, Daniel TL, Regnier M, Bosma MM, Fairhall AL. A complete biomechanical model of Hydra contractile behaviors, from neural drive to muscle to movement. Proc Natl Acad Sci U S A 2023; 120:e2210439120. [PMID: 36897982 PMCID: PMC10089167 DOI: 10.1073/pnas.2210439120] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 01/03/2023] [Indexed: 03/12/2023] Open
Abstract
How does neural activity drive muscles to produce behavior? The recent development of genetic lines in Hydra that allow complete calcium imaging of both neuronal and muscle activity, as well as systematic machine learning quantification of behaviors, makes this small cnidarian an ideal model system to understand and model the complete transformation from neural firing to body movements. To achieve this, we have built a neuromechanical model of Hydra's fluid-filled hydrostatic skeleton, showing how drive by neuronal activity activates distinct patterns of muscle activity and body column biomechanics. Our model is based on experimental measurements of neuronal and muscle activity and assumes gap junctional coupling among muscle cells and calcium-dependent force generation by muscles. With these assumptions, we can robustly reproduce a basic set of Hydra's behaviors. We can further explain puzzling experimental observations, including the dual timescale kinetics observed in muscle activation and the engagement of ectodermal and endodermal muscles in different behaviors. This work delineates the spatiotemporal control space of Hydra movement and can serve as a template for future efforts to systematically decipher the transformations in the neural basis of behavior.
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Affiliation(s)
- Hengji Wang
- Department of Physics, University of Washington, Seattle, WA98195
- Computational Neuroscience Center, University of Washington, Seattle, WA98195
| | - Joshua Swore
- Department of Biology, University of Washington, Seattle, WA98195
| | - Shashank Sharma
- Department of Physiology and Biophysics, University of Washington, Seattle, WA98195
| | - John R. Szymanski
- NeuroTechnology Center, Department of Biological Sciences, Columbia University, New York, NY10027
- Marine Biological Laboratory, Woods Hole, MA02543
| | - Rafael Yuste
- NeuroTechnology Center, Department of Biological Sciences, Columbia University, New York, NY10027
- Marine Biological Laboratory, Woods Hole, MA02543
| | - Thomas L. Daniel
- Department of Biology, University of Washington, Seattle, WA98195
| | - Michael Regnier
- Department of Bioengineering, University of Washington, Seattle, WA98195
| | - Martha M. Bosma
- Department of Biology, University of Washington, Seattle, WA98195
| | - Adrienne L. Fairhall
- Department of Physics, University of Washington, Seattle, WA98195
- Computational Neuroscience Center, University of Washington, Seattle, WA98195
- Department of Physiology and Biophysics, University of Washington, Seattle, WA98195
- Marine Biological Laboratory, Woods Hole, MA02543
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8
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Hedde PN, Le BT, Gomez EL, Duong L, Steele RE, Ahrar S. SPIM-Flow: An Integrated Light Sheet and Microfluidics Platform for Hydrodynamic Studies of Hydra. BIOLOGY 2023; 12:biology12010116. [PMID: 36671808 PMCID: PMC9856110 DOI: 10.3390/biology12010116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 01/13/2023]
Abstract
Selective plane illumination microscopy (SPIM), or light sheet microscopy, is a powerful imaging approach. However, access to and interfacing microscopes with microfluidics have remained challenging. Complex interfacing with microfluidics has limited the SPIM's utility for studying the hydrodynamics of freely moving multicellular organisms. We developed SPIM-Flow, an inexpensive light sheet platform that enables easy integration with microfluidics. We used SPIM-Flow to investigate the hydrodynamics of a freely moving Hydra polyp via particle tracking in millimeter-sized chambers. Initial experiments across multiple animals, feeding on a chip (Artemia franciscana nauplii used as food), and baseline behaviors (tentacle swaying, elongation, and bending) indicated the organisms' health inside the system. Fluidics were used to investigate Hydra's response to flow. The results suggested that the animals responded to an established flow by bending and swaying their tentacles in the flow direction. Finally, using SPIM-Flow in a proof-of-concept experiment, the shear stress required to detach an animal from a surface was demonstrated. Our results demonstrated SPIM-Flow's utility for investigating the hydrodynamics of freely moving animals.
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Affiliation(s)
- Per Niklas Hedde
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, CA 92612, USA
- Correspondence: (P.N.H.); (S.A.)
| | - Brian T. Le
- Department of Biomedical Engineering, CSU Long Beach, Long Beach, CA 90840, USA
| | - Erika L. Gomez
- Department of Biomedical Engineering, CSU Long Beach, Long Beach, CA 90840, USA
| | - Leora Duong
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, CA 92697, USA
| | - Robert E. Steele
- Department of Biological Chemistry, University of California Irvine, Irvine, CA 92697, USA
| | - Siavash Ahrar
- Department of Biomedical Engineering, CSU Long Beach, Long Beach, CA 90840, USA
- Department of Physics and Astronomy, University of California Irvine, Irvine, CA 92697, USA
- Correspondence: (P.N.H.); (S.A.)
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9
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Sonam S, Balasubramaniam L, Lin SZ, Ivan YMY, Jaumà IP, Jebane C, Karnat M, Toyama Y, Marcq P, Prost J, Mège RM, Rupprecht JF, Ladoux B. Mechanical stress driven by rigidity sensing governs epithelial stability. NATURE PHYSICS 2023; 19:132-141. [PMID: 36686215 PMCID: PMC7614076 DOI: 10.1038/s41567-022-01826-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Epithelia act as a barrier against environmental stress and abrasion and in vivo they are continuously exposed to environments of various mechanical properties. The impact of this environment on epithelial integrity remains elusive. By culturing epithelial cells on 2D hydrogels, we observe a loss of epithelial monolayer integrity through spontaneous hole formation when grown on soft substrates. Substrate stiffness triggers an unanticipated mechanical switch of epithelial monolayers from tensile on soft to compressive on stiff substrates. Through active nematic modelling, we find that spontaneous half-integer defect formation underpinning large isotropic stress fluctuations initiate hole opening events. Our data show that monolayer rupture due to high tensile stress is promoted by the weakening of cell-cell junctions that could be induced by cell division events or local cellular stretching. Our results show that substrate stiffness provides feedback on monolayer mechanical state and that topological defects can trigger stochastic mechanical failure, with potential application towards a mechanistic understanding of compromised epithelial integrity during immune response and morphogenesis.
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Affiliation(s)
- Surabhi Sonam
- Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France
| | | | - Shao-Zhen Lin
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, Turing Center for Living Systems, Marseille, France
| | | | - Irina Pi Jaumà
- Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France
| | - Cecile Jebane
- Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France
| | - Marc Karnat
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, Turing Center for Living Systems, Marseille, France
| | - Yusuke Toyama
- Mechanobiology Institute, National University of Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Philippe Marcq
- Physique et Mécanique des Milieux Hétérogènes, CNRS, ESPCI Paris, PSL University, Sorbonne Université, Université de Paris, 75005, Paris, France
| | - Jacques Prost
- Mechanobiology Institute, National University of Singapore, Singapore
- Physico-Chimie Curie, Institut Curie, CNRS UMR 168, Paris, France
| | - René-Marc Mège
- Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France
| | - Jean-François Rupprecht
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, Turing Center for Living Systems, Marseille, France
- Corresponding authors Dr. Benoit Ladoux, , Dr. Jean-François Rupprecht,
| | - Benoît Ladoux
- Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France
- Corresponding authors Dr. Benoit Ladoux, , Dr. Jean-François Rupprecht,
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10
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Bosch TCG. Beyond Lynn Margulis’ green hydra. Symbiosis 2022. [DOI: 10.1007/s13199-022-00849-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AbstractLynn Margulis has made it clear that in nature partnerships are the predominant form of life; that life processes can only be understood in terms of the interactions of such partnerships; and that their inherent complexity can only be understood by taking a holistic approach. Here I attempt to relate Lynn Margulis´ observations on the freshwater polyp hydra to the perceptions and problems of today’s Hydra research. To accomplish this, I will synthesize our current understanding of how symbionts influence the phenotype and fitness of hydra. Based on this new findings, a fundamental paradigm shift and a new era is emerging in the way that we consider organisms such as hydra as multi-organismic metaorganisms, just as Lynn Margulis may have thought about it.
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11
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Traffic light Hydra allows for simultaneous in vivo imaging of all three cell lineages. Dev Biol 2022; 488:74-80. [DOI: 10.1016/j.ydbio.2022.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 05/06/2022] [Accepted: 05/10/2022] [Indexed: 11/19/2022]
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12
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Alzugaray ME, Gavazzi MV, Ronderos JR. G protein-coupled receptor signal transduction and Ca 2+ signaling pathways of the allatotropin/orexin system in Hydra. Gen Comp Endocrinol 2021; 300:113637. [PMID: 33017583 DOI: 10.1016/j.ygcen.2020.113637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 09/16/2020] [Accepted: 09/28/2020] [Indexed: 11/24/2022]
Abstract
Allatotropin is a pleiotropic peptide originally characterized in insects. The existence of AT neuropeptide signaling was proposed in other invertebrates. In fact, we previously proposed the presence of an AT-like system regulating feeding behavior in Hydra sp. Even in insects, the information about the AT signaling pathway is incomplete. The aim of this study is to analyze the signaling cascade activated by AT in Hydra plagiodesmica using a pharmacological approach. The results show the involvement of Ca2+ and IP3 signaling in the transduction pathway of the peptide. Furthermore, we confirm the existence of a GPCR system involved in this pathway, that would be coupled to a Gq subfamily of Gα protein, which activates a PLC, inducing an increase in IP3 and cytosolic Ca2+. To the best of our knowledge, this work represents the first in vivo approach to study the overall signaling pathway and intracellular events involved in the myoregulatory effect of AT in Hydra sp.
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Affiliation(s)
- María Eugenia Alzugaray
- Cátedra de Histología y Embriología Animal. Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata (FCNyM-UNLP), Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - María Victoria Gavazzi
- Cátedra de Histología y Embriología Animal. Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata (FCNyM-UNLP), Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Jorge Rafael Ronderos
- Cátedra de Histología y Embriología Animal. Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata (FCNyM-UNLP), Argentina.
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13
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Naik S, Unni M, Sinha D, Rajput SS, Reddy PC, Kartvelishvily E, Solomonov I, Sagi I, Chatterji A, Patil S, Galande S. Differential tissue stiffness of body column facilitates locomotion of Hydra on solid substrates. J Exp Biol 2020; 223:jeb232702. [PMID: 32958523 PMCID: PMC7116704 DOI: 10.1242/jeb.232702] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/03/2020] [Indexed: 11/20/2022]
Abstract
The bell-shaped members of the Cnidaria typically move around by swimming, whereas the Hydra polyp can perform locomotion on solid substrates in an aquatic environment. To address the biomechanics of locomotion on rigid substrates, we studied the 'somersaulting' locomotion in Hydra We applied atomic force microscopy to measure the local mechanical properties of Hydra's body column and identified the existence of differential Young's modulus between the shoulder region versus rest of the body column at 3:1 ratio. We show that somersaulting primarily depends on differential tissue stiffness of the body column and is explained by computational models that accurately recapitulate the mechanics involved in this process. We demonstrate that perturbation of the observed stiffness variation in the body column by modulating the extracellular matrix polymerization impairs the 'somersault' movement. These results provide a mechanistic basis for the evolutionary significance of differential extracellular matrix properties and tissue stiffness.
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Affiliation(s)
- Suyash Naik
- Department of Biology, Indian Institute of Science Education and Research, Pune 411008, India
- Department of Physics, Indian Institute of Science Education and Research, Pune 411008, India
| | - Manu Unni
- Department of Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Devanshu Sinha
- Department of Physics, Indian Institute of Science Education and Research, Pune 411008, India
| | - Shatruhan Singh Rajput
- Department of Physics, Indian Institute of Science Education and Research, Pune 411008, India
| | - Puli Chandramouli Reddy
- Department of Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Elena Kartvelishvily
- Electron Microscopy Unit, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Inna Solomonov
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Irit Sagi
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Apratim Chatterji
- Department of Physics, Indian Institute of Science Education and Research, Pune 411008, India
| | - Shivprasad Patil
- Department of Physics, Indian Institute of Science Education and Research, Pune 411008, India
| | - Sanjeev Galande
- Department of Biology, Indian Institute of Science Education and Research, Pune 411008, India
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14
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Abstract
The freshwater polyp Hydra provides a potent model system for investigating the conditions that promote wound healing, reactivation of a developmental process and, ultimately, regeneration of an amputated body part. Hydra polyps can also be dissociated to the single cell level and can regenerate a complete body axis from aggregates, behaving as natural organoids. In recent years, the ability to exploit Hydra has been expanded with the advent of new live-imaging approaches, genetic manipulations that include stable transgenesis, gene silencing and genome editing, and the accumulation of high-throughput omics data. In this Primer, we provide an overview of Hydra as a model system for studying regeneration, highlighting recent results that question the classical self-enhancement and long-range inhibition model supposed to drive Hydra regeneration. We underscore the need for integrative explanations incorporating biochemical as well as mechanical signalling.
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Affiliation(s)
- Matthias C Vogg
- Department of Genetics and Evolution, Institute of Genetics and Genomics in Geneva (iGE3), Faculty of Sciences, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Brigitte Galliot
- Department of Genetics and Evolution, Institute of Genetics and Genomics in Geneva (iGE3), Faculty of Sciences, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Charisios D Tsiairis
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
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15
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Goel T, Wang R, Martin S, Lanphear E, Collins EMS. Linalool acts as a fast and reversible anesthetic in Hydra. PLoS One 2019; 14:e0224221. [PMID: 31648269 PMCID: PMC6812832 DOI: 10.1371/journal.pone.0224221] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 10/08/2019] [Indexed: 01/23/2023] Open
Abstract
The ability to make transgenic Hydra lines has allowed for quantitative in vivo studies of Hydra regeneration and physiology. These studies commonly include excision, grafting and transplantation experiments along with high-resolution imaging of live animals, which can be challenging due to the animal’s response to touch and light stimuli. While various anesthetics have been used in Hydra studies, they tend to be toxic over the course of a few hours or their long-term effects on animal health are unknown. Here, we show that the monoterpenoid alcohol linalool is a useful anesthetic for Hydra. Linalool is easy to use, non-toxic, fast acting, and reversible. It has no detectable long-term effects on cell viability or cell proliferation. We demonstrate that the same animal can be immobilized in linalool multiple times at intervals of several hours for repeated imaging over 2–3 days. This uniquely allows for in vivo imaging of dynamic processes such as head regeneration. We directly compare linalool to currently used anesthetics and show its superior performance. Linalool will be a useful tool for tissue manipulation and imaging in Hydra research in both research and teaching contexts.
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Affiliation(s)
- Tapan Goel
- Department of Physics, University of California San Diego, La Jolla, CA, United States of America
- Department of Biology, Swarthmore College, Swarthmore, PA, United States of America
| | - Rui Wang
- Department of Biology, Swarthmore College, Swarthmore, PA, United States of America
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States of America
| | - Sara Martin
- Department of Biology, Swarthmore College, Swarthmore, PA, United States of America
| | - Elizabeth Lanphear
- Department of Biology, Swarthmore College, Swarthmore, PA, United States of America
| | - Eva-Maria S. Collins
- Department of Physics, University of California San Diego, La Jolla, CA, United States of America
- Department of Biology, Swarthmore College, Swarthmore, PA, United States of America
- * E-mail:
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16
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He S, Grasis JA, Nicotra ML, Juliano CE, Schnitzler CE. Cnidofest 2018: the future is bright for cnidarian research. EvoDevo 2019; 10:20. [PMID: 31508195 PMCID: PMC6724248 DOI: 10.1186/s13227-019-0134-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 08/21/2019] [Indexed: 12/02/2022] Open
Abstract
The 2018 Cnidarian Model Systems Meeting (Cnidofest) was held September 6-9th at the University of Florida Whitney Laboratory for Marine Bioscience in St. Augustine, FL. Cnidofest 2018, which built upon the momentum of Hydroidfest 2016, brought together research communities working on a broad spectrum of cnidarian organisms from North America and around the world. Meeting talks covered diverse aspects of cnidarian biology, with sessions focused on genomics, development, neurobiology, immunology, symbiosis, ecology, and evolution. In addition to interesting biology, Cnidofest also emphasized the advancement of modern research techniques. Invited technology speakers showcased the power of microfluidics and single-cell transcriptomics and demonstrated their application in cnidarian models. In this report, we provide an overview of the exciting research that was presented at the meeting and discuss opportunities for future research.
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Affiliation(s)
- Shuonan He
- Stowers Institute for Medical Research, Kansas City, MO 64110 USA
| | - Juris A. Grasis
- School of Natural Sciences, University of California, Merced, CA 95343 USA
| | - Matthew L. Nicotra
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA 15261 USA
- Pittsburgh Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA USA
- Department of Immunology, University of Pittsburgh, Pittsburgh, PA USA
| | - Celina E. Juliano
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616 USA
| | - Christine E. Schnitzler
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080 USA
- Department of Biology, University of Florida, Gainesville, FL 32611 USA
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17
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Wang R, Goel T, Khazoyan K, Sabry Z, Quan HJ, Diamond PH, Collins EMS. Mouth Function Determines the Shape Oscillation Pattern in Regenerating Hydra Tissue Spheres. Biophys J 2019; 117:1145-1155. [PMID: 31443907 DOI: 10.1016/j.bpj.2019.07.051] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 06/25/2019] [Accepted: 07/30/2019] [Indexed: 12/12/2022] Open
Abstract
Hydra is a small freshwater polyp capable of regeneration from small tissue pieces and from aggregates of cells. During regeneration, a hollow bilayered sphere is formed that undergoes osmotically driven shape oscillations of inflation and rupture. These oscillations are necessary for successful regeneration. Eventually, the oscillating sphere breaks rotational symmetry along the future head-foot axis of the animal. Notably, the shape oscillations show an abrupt shift from large-amplitude, long-period oscillations to small-amplitude, short-period oscillations. It has been widely accepted that this shift in oscillation pattern is linked to symmetry breaking and axis formation, and current theoretical models of Hydra symmetry breaking use this assumption as a model constraint. However, a mechanistic explanation for the shift in oscillation pattern is lacking. Using in vivo manipulation and imaging, we quantified the shape oscillation dynamics and dissected the timing and triggers of the pattern shift. Our experiments demonstrate that the shift in the shape oscillation pattern in regenerating Hydra tissue pieces is caused by the formation of a functional mouth and not by shape symmetry breaking as previously assumed. Thus, model assumptions must be revised in light of these new experimental data, which can be used to constrain and validate improved theoretical models of pattern formation in Hydra.
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Affiliation(s)
- Rui Wang
- Department of Bioengineering, University of California San Diego, La Jolla, California; Biology Department, Swarthmore College, Swarthmore, Pennsylvania
| | - Tapan Goel
- Department of Physics, University of California San Diego, La Jolla, California; Biology Department, Swarthmore College, Swarthmore, Pennsylvania
| | - Kate Khazoyan
- Department of Bioengineering, University of California San Diego, La Jolla, California
| | - Ziad Sabry
- Biology Department, Swarthmore College, Swarthmore, Pennsylvania
| | - Heng J Quan
- Department of Physics, University of California San Diego, La Jolla, California; Department of Mathematics, University of California San Diego, La Jolla, California
| | - Patrick H Diamond
- Department of Physics, University of California San Diego, La Jolla, California
| | - Eva-Maria S Collins
- Department of Physics, University of California San Diego, La Jolla, California; Biology Department, Swarthmore College, Swarthmore, Pennsylvania.
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18
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Live imaging of Aiptasia larvae, a model system for coral and anemone bleaching, using a simple microfluidic device. Sci Rep 2019; 9:9275. [PMID: 31239506 PMCID: PMC6592900 DOI: 10.1038/s41598-019-45167-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 05/22/2019] [Indexed: 11/13/2022] Open
Abstract
Coral reefs, and their associated diverse ecosystems, are of enormous ecological importance. In recent years, coral health has been severely impacted by environmental stressors brought on by human activity and climate change, threatening the extinction of several major reef ecosystems. Reef damage is mediated by a process called ‘coral bleaching’ where corals, sea anemones, and other cnidarians lose their photosynthetic algal symbionts (family Symbiodiniaceae) upon stress induction, resulting in drastically decreased host energy harvest and, ultimately, coral death. The mechanism by which this critical cnidarian-algal symbiosis is lost remains poorly understood. The larvae of the sea anemone, Exaiptasia pallida (commonly referred to as ‘Aiptasia’) are an attractive model organism to study this process, but they are large (∼100 mm in length, ∼75 mm in diameter), deformable, and highly motile, complicating long-term imaging and limiting study of this critical endosymbiotic relationship in live organisms. Here, we report ‘Traptasia’, a simple microfluidic device with multiple traps designed to isolate and image individual, live larvae of Aiptasia and their algal symbionts over extended time courses. Using a trap design parameterized via fluid flow simulations and polymer bead loading tests, we trapped Aiptasia larvae containing algal symbionts and demonstrated stable imaging for >10 hours. We visualized algae within Aiptasia larvae and observed algal expulsion under an environmental stressor. To our knowledge, this device is the first to enable time-lapsed, high-throughput live imaging of cnidarian larvae and their algal symbionts and, in further implementation, could provide important insights into the cellular mechanisms of cnidarian bleaching under different environmental stressors. The ‘Traptasia’ device is simple to use, requires minimal external equipment and no specialized training to operate, and can easily be adapted using the trap optimization data presented here to study a variety of large, motile organisms.
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19
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Shoemark DK, Ziegler B, Watanabe H, Strompen J, Tucker RP, Özbek S, Adams JC. Emergence of a Thrombospondin Superfamily at the Origin of Metazoans. Mol Biol Evol 2019; 36:1220-1238. [PMID: 30863851 PMCID: PMC6526912 DOI: 10.1093/molbev/msz060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Extracellular matrix (ECM) is considered central to the evolution of metazoan multicellularity; however, the repertoire of ECM proteins in nonbilaterians remains unclear. Thrombospondins (TSPs) are known to be well conserved from cnidarians to vertebrates, yet to date have been considered a unique family, principally studied for matricellular functions in vertebrates. Through searches utilizing the highly conserved C-terminal region of TSPs, we identify undisclosed new families of TSP-related proteins in metazoans, designated mega-TSP, sushi-TSP, and poriferan-TSP, each with a distinctive phylogenetic distribution. These proteins share the TSP C-terminal region domain architecture, as determined by domain composition and analysis of molecular models against known structures. Mega-TSPs, the only form identified in ctenophores, are typically >2,700 aa and are also characterized by N-terminal leucine-rich repeats and central cadherin/immunoglobulin domains. In cnidarians, which have a well-defined ECM, Mega-TSP was expressed throughout embryogenesis in Nematostella vectensis, with dynamic endodermal expression in larvae and primary polyps and widespread ectodermal expression in adult Nematostella vectensis and Hydra magnipapillata polyps. Hydra Mega-TSP was also expressed during regeneration and siRNA-silencing of Mega-TSP in Hydra caused specific blockade of head regeneration. Molecular phylogenetic analyses based on the conserved TSP C-terminal region identified each of the TSP-related groups to form clades distinct from the canonical TSPs. We discuss models for the evolution of the newly defined TSP superfamily by gene duplications, radiation, and gene losses from a debut in the last metazoan common ancestor. Together, the data provide new insight into the evolution of ECM and tissue organization in metazoans.
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Affiliation(s)
| | - Berenice Ziegler
- Centre for Organismal Studies, Department of Molecular Evolution and Genomics, University of Heidelberg, Heidelberg, Germany
| | - Hiroshi Watanabe
- Evolutionary Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Jennifer Strompen
- Centre for Organismal Studies, Department of Molecular Evolution and Genomics, University of Heidelberg, Heidelberg, Germany
| | - Richard P Tucker
- Department of Cell Biology and Human Anatomy, University of California at Davis, Davis, CA
| | - Suat Özbek
- Centre for Organismal Studies, Department of Molecular Evolution and Genomics, University of Heidelberg, Heidelberg, Germany
| | - Josephine C Adams
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
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20
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Szymanski JR, Yuste R. Mapping the Whole-Body Muscle Activity of Hydra vulgaris. Curr Biol 2019; 29:1807-1817.e3. [PMID: 31130460 DOI: 10.1016/j.cub.2019.05.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 03/12/2019] [Accepted: 05/01/2019] [Indexed: 10/26/2022]
Abstract
Hydra is a cnidarian polyp with an anatomically simple neuromuscular system that can offer evolutionary insights on the functional design of animal body plans. Using calcium imaging to map the activity of the entire epitheliomuscular system of behaving Hydra, we find seven basic spatiotemporal patterns of muscle activity. Patterns include global and local activation events with widely varying kinetics of initiation and wave-like propagation. The orthogonally oriented endodermal and ectodermal muscle fibers are jointly activated during longitudinal contractions. Individual epitheliomuscular cells can participate in multiple patterns, even with very different kinetics. This cellular multifunctionality could enable the structurally simple epitheliomuscular tissue of basal metazoans to implement a diverse behavioral output.
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Affiliation(s)
- John R Szymanski
- Neurotechnology Center, Department Biological Sciences, Columbia University, New York, NY 10027, USA; Marine Biological Laboratory, Woods Hole, MA 02543, USA.
| | - Rafael Yuste
- Neurotechnology Center, Department Biological Sciences, Columbia University, New York, NY 10027, USA; Marine Biological Laboratory, Woods Hole, MA 02543, USA
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21
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Rojas Pérez Y, Etchenique R. Optical manipulation of animal behavior using a ruthenium-based phototrigger. Photochem Photobiol Sci 2019; 18:208-212. [PMID: 30421767 DOI: 10.1039/c8pp00467f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A visible-light activatable caged compound based on a ruthenium-polypyridine complex was used to elicit the feeding response of the freshwater cnidarian Hydra vulgaris. The phototrigger delivers l-arginine in a clean reaction under irradiation with blue or green light. The synthesis, characterization and application mode of this caged arginine are described. A combination of fiber-optics setup and a high absorbance medium allows the precise control of uncaging in the submillimetric range, needed to address the zone where activation takes place.
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Affiliation(s)
- Yeraldith Rojas Pérez
- Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CONICET, Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón 2, Buenos Aires (C1428EGA), Argentina.
| | - Roberto Etchenique
- Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CONICET, Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón 2, Buenos Aires (C1428EGA), Argentina.
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22
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Armon S, Bull MS, Aranda-Diaz A, Prakash M. Ultrafast epithelial contractions provide insights into contraction speed limits and tissue integrity. Proc Natl Acad Sci U S A 2018; 115:E10333-E10341. [PMID: 30309963 PMCID: PMC6217427 DOI: 10.1073/pnas.1802934115] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
By definition of multicellularity, all animals need to keep their cells attached and intact, despite internal and external forces. Cohesion between epithelial cells provides this key feature. To better understand fundamental limits of this cohesion, we study the epithelium mechanics of an ultrathin (∼25 μm) primitive marine animal Trichoplax adhaerens, composed essentially of two flat epithelial layers. With no known extracellular matrix and no nerves or muscles, T. adhaerens has been claimed to be the "simplest known living animal," yet is still capable of coordinated locomotion and behavior. Here we report the discovery of the fastest epithelial cellular contractions known in any metazoan, to be found in T. adhaerens dorsal epithelium (50% shrinkage of apical cell area within one second, at least an order of magnitude faster than other known examples). Live imaging reveals emergent contractile patterns that are mostly sporadic single-cell events, but also include propagating contraction waves across the tissue. We show that cell contraction speed can be explained by current models of nonmuscle actin-myosin bundles without load, while the tissue architecture and unique mechanical properties are softening the tissue, minimizing the load on a contracting cell. We propose a hypothesis, in which the physiological role of the contraction dynamics is to resist external stresses while avoiding tissue rupture ("active cohesion"), a concept that can be further applied to engineering of active materials.
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Affiliation(s)
- Shahaf Armon
- Department of Bioengineering, Stanford University, Stanford, CA 94305
| | | | | | - Manu Prakash
- Department of Bioengineering, Stanford University, Stanford, CA 94305;
- Chan Zuckerberg Biohub, San Francisco, CA 94158
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23
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Sanders SM, Ma Z, Hughes JM, Riscoe BM, Gibson GA, Watson AM, Flici H, Frank U, Schnitzler CE, Baxevanis AD, Nicotra ML. CRISPR/Cas9-mediated gene knockin in the hydroid Hydractinia symbiolongicarpus. BMC Genomics 2018; 19:649. [PMID: 30176818 PMCID: PMC6122657 DOI: 10.1186/s12864-018-5032-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/22/2018] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Hydractinia symbiolongicarpus, a colonial cnidarian, is a tractable model system for many cnidarian-specific and general biological questions. Until recently, tests of gene function in Hydractinia have relied on laborious forward genetic approaches, randomly integrated transgenes, or transient knockdown of mRNAs. RESULTS Here, we report the use of CRISPR/Cas9 genome editing to generate targeted genomic insertions in H. symbiolonigcarpus. We used CRISPR/Cas9 to promote homologous recombination of two fluorescent reporters, eGFP and tdTomato, into the Eukaryotic elongation factor 1 alpha (Eef1a) locus. We demonstrate that the transgenes are expressed ubiquitously and are stable over two generations of breeding. We further demonstrate that CRISPR/Cas9 genome editing can be used to mark endogenous proteins with FLAG or StrepII-FLAG affinity tags to enable in vivo and ex vivo protein studies. CONCLUSIONS This is the first account of CRISPR/Cas9 mediated knockins in Hydractinia and the first example of the germline transmission of a CRISPR/Cas9 inserted transgene in a cnidarian. The ability to precisely insert exogenous DNA into the Hydractinia genome will enable sophisticated genetic studies and further development of functional genomics tools in this understudied cnidarian model.
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Affiliation(s)
- Steven M. Sanders
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA USA
- Pittsburgh Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA USA
| | - Zhiwei Ma
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA USA
- Pittsburgh Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA USA
| | - Julia M. Hughes
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA USA
- Pittsburgh Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA USA
| | - Brooke M. Riscoe
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA USA
- Pittsburgh Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA USA
| | - Gregory A. Gibson
- Center for Biological Imaging and Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA USA
| | - Alan M. Watson
- Center for Biological Imaging and Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA USA
| | - Hakima Flici
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Uri Frank
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Christine E. Schnitzler
- Whitney Laboratory for Marine Bioscience, and Department of Biology, University of Florida, St. Augustine, FL USA
| | - Andreas D. Baxevanis
- Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD USA
| | - Matthew L. Nicotra
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA USA
- Pittsburgh Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA USA
- Department of Immunology, University of Pittsburgh, Pittsburgh, PA USA
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24
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Badhiwala KN, Gonzales DL, Vercosa DG, Avants BW, Robinson JT. Microfluidics for electrophysiology, imaging, and behavioral analysis of Hydra. LAB ON A CHIP 2018; 18:2523-2539. [PMID: 29987278 DOI: 10.1039/c8lc00475g] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The nervous system of the cnidarian Hydra vulgaris exhibits remarkable regenerative abilities. When cut in two, the bisected tissue reorganizes into fully behaving animals in approximately 48 hours. Furthermore, new animals can reform from aggregates of dissociated cells. Understanding how behaviors are coordinated by this highly plastic nervous system could reveal basic principles of neural circuit dynamics underlying behaviors. However, Hydra's deformable and contractile body makes it difficult to manipulate the local environment while recording neural activity. Here, we present the first microfluidic technologies capable of simultaneous electrical, chemical, and optical interrogation of these soft, deformable organisms. Specifically, we demonstrate devices that can immobilize Hydra for hours-long simultaneous electrical and optical recording, and chemical stimulation of behaviors revealing neural activity during muscle contraction. We further demonstrate quantitative locomotive and behavioral tracking made possible by confining the animal to quasi-two-dimensional micro-arenas. Together, these proof-of-concept devices show that microfluidics provide a platform for scalable, quantitative cnidarian neurobiology. The experiments enabled by this technology may help reveal how highly plastic networks of neurons provide robust control of animal behavior.
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Affiliation(s)
- Krishna N Badhiwala
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
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25
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Lommel M, Strompen J, Hellewell AL, Balasubramanian GP, Christofidou ED, Thomson AR, Boyle AL, Woolfson DN, Puglisi K, Hartl M, Holstein TW, Adams JC, Özbek S. Hydra Mesoglea Proteome Identifies Thrombospondin as a Conserved Component Active in Head Organizer Restriction. Sci Rep 2018; 8:11753. [PMID: 30082916 PMCID: PMC6079037 DOI: 10.1038/s41598-018-30035-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 07/23/2018] [Indexed: 02/06/2023] Open
Abstract
Thrombospondins (TSPs) are multidomain glycoproteins with complex matricellular functions in tissue homeostasis and remodeling. We describe a novel role of TSP as a Wnt signaling target in the basal eumetazoan Hydra. Proteome analysis identified Hydra magnipapillata TSP (HmTSP) as a major component of the cnidarian mesoglea. In general, the domain organization of cnidarian TSPs is related to the pentameric TSPs of bilaterians, and in phylogenetic analyses cnidarian TSPs formed a separate clade of high sequence diversity. HmTSP expression in polyps was restricted to the hypostomal tip and tentacle bases that harbor Wnt-regulated organizer tissues. In the hypostome, HmTSP- and Wnt3-expressing cells were identical or in close vicinity to each other, and regions of ectopic tentacle formation induced by pharmacological β-Catenin activation (Alsterpaullone) corresponded to foci of HmTSP expression. Chromatin immunoprecipitation (ChIP) confirmed binding of Hydra TCF to conserved elements in the HmTSP promotor region. Accordingly, β-Catenin knockdown by siRNAs reduced normal HmTSP expression at the head organizer. In contrast, knockdown of HmTSP expression led to increased numbers of ectopic organizers in Alsterpaullone-treated animals, indicating a negative regulatory function. Our data suggest an unexpected role for HmTSP as a feedback inhibitor of Wnt signaling during Hydra body axis patterning and maintenance.
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Affiliation(s)
- Mark Lommel
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120, Heidelberg, Germany
| | - Jennifer Strompen
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120, Heidelberg, Germany
| | - Andrew L Hellewell
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Gnana Prakash Balasubramanian
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120, Heidelberg, Germany.,G200 Division of Applied Bioinformatics, German Cancer Research Institute (DKFZ) and National Center for Tumor Diseases (NCT) Heidelberg, Im Neuenheimer Feld 580, D-69120, Heidelberg, Germany
| | - Elena D Christofidou
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Andrew R Thomson
- School of Chemistry, Cantock's Close, University of Bristol, Bristol, BS8 1TS, UK.,School of Chemistry, University of Glasgow, Joseph Black Building, University Avenue, Glasgow, G12 8QQ, Scotland
| | - Aimee L Boyle
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK.,School of Chemistry, Cantock's Close, University of Bristol, Bristol, BS8 1TS, UK.,Leiden Institute of Chemistry, Leiden University, POB 9502, NL-2300, RA Leiden, Netherlands
| | - Derek N Woolfson
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK.,School of Chemistry, Cantock's Close, University of Bristol, Bristol, BS8 1TS, UK
| | - Kane Puglisi
- Institute of Biochemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, A-6020, Innsbruck, Austria
| | - Markus Hartl
- Institute of Biochemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, A-6020, Innsbruck, Austria
| | - Thomas W Holstein
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120, Heidelberg, Germany
| | - Josephine C Adams
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK.
| | - Suat Özbek
- University of Heidelberg, Centre for Organismal Studies, Department of Molecular Evolution and Genomics, Im Neuenheimer Feld 230, 69120, Heidelberg, Germany.
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26
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Lauro BM, Kass-Simon G. Hydra's feeding response: Effect of GABA B ligands on GSH-induced electrical activity in the hypostome of H. vulgaris. Comp Biochem Physiol A Mol Integr Physiol 2018; 225:83-93. [PMID: 30036674 DOI: 10.1016/j.cbpa.2018.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 07/10/2018] [Accepted: 07/11/2018] [Indexed: 11/17/2022]
Abstract
The feeding response in the Cnidarian, hydra, consists of mouth opening, tentacle writhing, and the cessation of pacemaker-controlled tentacle and body contractions. The behavior can be induced by reduced glutathione (GSH), contained in body fluids that leak from prey impaled by hydra's cnidocysts. Mouth, tentacle, and body-contraction behavior is carried out by hydra's ectodermal and endodermal epitheliomuscular cells. Here, we present the first evidence of GSH-induced electrical activity in the hypostome and its modification by GABA and GABAB ligands. The 'heads' of hydra were ablated and the tentacles removed. Suction electrodes, positioned on the mouth, recorded electrical activity produced by GSH, contained either within the electrode, or in the surrounding bath, the mouth being shielded. Recorded impulses were characterized, according to size and temporal pattern, as small, medium and (large) pacemaker impulses. GSH applied in the bath caused a frequency increase of small and medium impulses and a decrease in pacemaker bursts. The changes in frequencies of medium and pacemaker bursts, though not obviously affected by GABA, were counteracted by blocking GABAB inhibition with phaclofen. Only the highest concentration of GSH applied at the mouth potentially decreased pacemaker frequency and potentially increased medium impulses, without affecting small impulses. GABA caused a significant increase in small and medium impulses relative to GSH which was counteracted by baclofen and/or baclofen plus phaclofen. The results indicate that considerable GSH-receptor circuitry is located in hypostomal tissue proximal to hydra's mouth, and substantiate GABA and GABAB inhibition within the neuroeffector network of the feeding response.
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Affiliation(s)
- B M Lauro
- University of Rhode Island, Interdisciplinary Neuroscience Program, USA
| | - G Kass-Simon
- University of Rhode Island, Interdisciplinary Neuroscience Program, USA; University of Rhode Island, Department of Biological Sciences, USA.
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27
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Physical Mechanisms Driving Cell Sorting in Hydra. Biophys J 2018; 113:2827-2841. [PMID: 29262375 DOI: 10.1016/j.bpj.2017.10.045] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 10/10/2017] [Accepted: 10/30/2017] [Indexed: 12/19/2022] Open
Abstract
Cell sorting, whereby a heterogeneous cell mixture organizes into distinct tissues, is a fundamental patterning process in development. Hydra is a powerful model system for carrying out studies of cell sorting in three dimensions, because of its unique ability to regenerate after complete dissociation into individual cells. The physicists Alfred Gierer and Hans Meinhardt recognized Hydra's self-organizing properties more than 40 years ago. However, what drives cell sorting during regeneration of Hydra from cell aggregates is still debated. Differential motility and differential adhesion have been proposed as driving mechanisms, but the available experimental data are insufficient to distinguish between these two. Here, we answer this longstanding question by using transgenic Hydra expressing fluorescent proteins and a multiscale experimental and numerical approach. By quantifying the kinematics of single cell and whole aggregate behaviors, we show that no differences in cell motility exist among cell types and that sorting dynamics follow a power law with an exponent of ∼0.5. Additionally, we measure the physical properties of separated tissues and quantify their viscosities and surface tensions. Based on our experimental results and numerical simulations, we conclude that tissue interfacial tensions are sufficient to explain cell sorting in aggregates of Hydra cells. Furthermore, we demonstrate that the aggregate's geometry during sorting is key to understanding the sorting dynamics and explains the exponent of the power law behavior. Our results answer the long standing question of the physical mechanisms driving cell sorting in Hydra cell aggregates. In addition, they demonstrate how powerful this organism is for biophysical studies of self-organization and pattern formation.
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28
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Chiou K, Collins EMS. Why we need mechanics to understand animal regeneration. Dev Biol 2017; 433:155-165. [PMID: 29179947 DOI: 10.1016/j.ydbio.2017.09.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 08/31/2017] [Accepted: 09/17/2017] [Indexed: 12/19/2022]
Abstract
Mechanical forces are an important contributor to cell fate specification and cell migration during embryonic development in animals. Similarities between embryogenesis and regeneration, particularly with regards to pattern formation and large-scale tissue movements, suggest similarly important roles for physical forces during regeneration. While the influence of the mechanical environment on stem cell differentiation in vitro is being actively exploited in the fields of tissue engineering and regenerative medicine, comparatively little is known about the role of stresses and strains acting during animal regeneration. In this review, we summarize published work on the role of physical principles and mechanical forces in animal regeneration. Novel experimental techniques aimed at addressing the role of mechanics in embryogenesis have greatly enhanced our understanding at scales from the subcellular to the macroscopic - we believe the time is ripe for the field of regeneration to similarly leverage the tools of the mechanobiological research community.
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Affiliation(s)
- Kevin Chiou
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eva-Maria S Collins
- Physics Department, UC San Diego, La Jolla, CA 92093, USA; Section of Cell&Developmental Biology, UC San Diego, La Jolla, CA 92093, USA.
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29
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Leclère L, Röttinger E. Diversity of Cnidarian Muscles: Function, Anatomy, Development and Regeneration. Front Cell Dev Biol 2017; 4:157. [PMID: 28168188 PMCID: PMC5253434 DOI: 10.3389/fcell.2016.00157] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 12/30/2016] [Indexed: 12/12/2022] Open
Abstract
The ability to perform muscle contractions is one of the most important and distinctive features of eumetazoans. As the sister group to bilaterians, cnidarians (sea anemones, corals, jellyfish, and hydroids) hold an informative phylogenetic position for understanding muscle evolution. Here, we review current knowledge on muscle function, diversity, development, regeneration and evolution in cnidarians. Cnidarian muscles are involved in various activities, such as feeding, escape, locomotion and defense, in close association with the nervous system. This variety is reflected in the large diversity of muscle organizations found in Cnidaria. Smooth epithelial muscle is thought to be the most common type, and is inferred to be the ancestral muscle type for Cnidaria, while striated muscle fibers and non-epithelial myocytes would have been convergently acquired within Cnidaria. Current knowledge of cnidarian muscle development and its regeneration is limited. While orthologs of myogenic regulatory factors such as MyoD have yet to be found in cnidarian genomes, striated muscle formation potentially involves well-conserved myogenic genes, such as twist and mef2. Although satellite cells have yet to be identified in cnidarians, muscle plasticity (e.g., de- and re-differentiation, fiber repolarization) in a regenerative context and its potential role during regeneration has started to be addressed in a few cnidarian systems. The development of novel tools to study those organisms has created new opportunities to investigate in depth the development and regeneration of cnidarian muscle cells and how they contribute to the regenerative process.
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Affiliation(s)
- Lucas Leclère
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV) Villefranche-sur-mer, France
| | - Eric Röttinger
- Université Côte d'Azur, CNRS, INSERM, Institute for Research on Cancer and Aging (IRCAN) Nice, France
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30
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Seeing the invisible in differential interference contrast microscopy images. Med Image Anal 2016; 34:65-81. [DOI: 10.1016/j.media.2016.04.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/14/2016] [Accepted: 04/23/2016] [Indexed: 11/18/2022]
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31
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Hufnagel LA, Kass-Simon G. The two nerve rings of the hypostomal nervous system of Hydra vulgaris-an immunohistochemical analysis. Cell Tissue Res 2016; 366:255-269. [PMID: 27344671 DOI: 10.1007/s00441-016-2447-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 06/02/2016] [Indexed: 01/08/2023]
Abstract
In Hydra vulgaris, physiological and pharmacological evidence exists for a hypostomal circumferential neuro-effector pathway that initiates ectodermal pacemaker activity at tentacular-hypostomal loci coordinating body and tentacle contractions. Here, we describe an ectodermal nerve ring that runs below and between the tentacles, and an anti-GABAB receptor antibody-labeled ring coincident with it. The location of this ring is consistent with the physiology of the hypostomal pacemaker systems of hydra. We also describe a distally located, ectodermal ring of nerve fibers that is not associated with anti-GABAB receptor antibody labeling. The neurites and cell bodies of sensory cells contribute to both rings. The location of the distal ring and its sensory cell neurites suggests an involvement in the behavior of the mouth. Between the two rings is a network of anastomosing sensory and ganglion cell bodies and their neurites. Phase contrast, darkfield, and antibody-labeled images reveal that the mouth of hydra comprises five or six epithelial folds whose endoderm extensively labels with anti-GABAB receptor antibody, suggesting that endodermal metabotrobic GABA receptors are also involved in regulating mouth behavior.
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Affiliation(s)
- L A Hufnagel
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI 02881, USA.,Interdisciplinary Neurosciences Program, University of Rhode Island, Kingston, RI 02881, USA
| | - G Kass-Simon
- Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA. .,Interdisciplinary Neurosciences Program, University of Rhode Island, Kingston, RI 02881, USA.
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32
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Dunn A. How Hydra Eats. Biophys J 2016; 110:1467-1468. [DOI: 10.1016/j.bpj.2016.01.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 01/29/2016] [Indexed: 11/17/2022] Open
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