1
|
Flaum E, Prakash M. Curved crease origami and topological singularities enable hyperextensibility of L. olor. Science 2024; 384:eadk5511. [PMID: 38843314 DOI: 10.1126/science.adk5511] [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: 08/28/2023] [Accepted: 04/12/2024] [Indexed: 06/15/2024]
Abstract
Fundamental limits of cellular deformations, such as hyperextension of a living cell, remain poorly understood. Here, we describe how the single-celled protist Lacrymaria olor, a 40-micrometer cell, is capable of reversibly and repeatably extending its necklike protrusion up to 1200 micrometers in 30 seconds. We discovered a layered cortical cytoskeleton and membrane architecture that enables hyperextensions through the folding and unfolding of cellular-scale origami. Physical models of this curved crease origami display topological singularities, including traveling developable cones and cytoskeletal twisted domain walls, which provide geometric control of hyperextension. Our work unravels how cell geometry encodes behavior in single cells and provides inspiration for geometric control in microrobotics and deployable architectures.
Collapse
Affiliation(s)
- Eliott Flaum
- Graduate Program in Biophysics, Stanford University, Stanford, CA, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Manu Prakash
- Graduate Program in Biophysics, Stanford University, Stanford, CA, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Biology (courtesy), Stanford University, Stanford, CA, USA
- Department of Oceans (courtesy), Stanford University, Stanford, CA, USA
- Woods Institute for the Environment, Stanford University, Stanford, CA, USA
| |
Collapse
|
2
|
Gordillo L, Cerda E. A tiny, long-distance hunter. Science 2024; 384:1064-1065. [PMID: 38843349 DOI: 10.1126/science.adn9351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2024]
Abstract
Lacrymaria olor cytoskeleton and membrane "origami" enables rapid cell hyperextension.
Collapse
Affiliation(s)
- Leonardo Gordillo
- Departamento de Física, Facultad de Ciencia, Universidad de Santiago de Chile (USACH), Santiago, Chile
| | - Enrique Cerda
- Departamento de Física, Facultad de Ciencia, Universidad de Santiago de Chile (USACH), Santiago, Chile
| |
Collapse
|
3
|
Durden S, Hunter WB, Cruz A, Debboun M, Duguma D. Cross-infectivity of Vorticella sp. across genera of mosquitoes for development of biological mosquito control strategies. J Invertebr Pathol 2024; 203:108064. [PMID: 38311230 DOI: 10.1016/j.jip.2024.108064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/16/2023] [Accepted: 01/18/2024] [Indexed: 02/10/2024]
Abstract
Protists in general comprise about one-third of the parasitic species infecting arthropod vectors, the role of free-living and epibiotic ciliates on mosquitoes have been insufficiently studied either due to their low pathogenicity or facultative parasites. Studies have shown that exposure of Paramecium ciliate protists, like Vorticella species, to first instar Culex nigripalpus Theobald, larvae delayed larval development and reduced biomass of emerged adults due to competition for food sources like bacteria and other microbes essential to mosquito growth and survival. Thus, we report on the capacity of a Vorticella sp. protist's ability to cross-infect host species and parasitize multiple mosquito larvae. The unique adapted behavior with the ability to remain on the exuviae in tree hole habitats provide a novel delivery system to develop products for target species-specific mosquitocides, larvicides, or viricides to be applied and sustained in aquatic systems.
Collapse
Affiliation(s)
- Shelby Durden
- University of Florida/IFAS, Florida Medical Entomology Laboratory, Vero Beach, FL, USA; United States Department of Agriculture, Agricultural Research Service, U.S. Horticultural Research Laboratory, Fort Pierce, FL, USA
| | - Wayne B Hunter
- United States Department of Agriculture, Agricultural Research Service, U.S. Horticultural Research Laboratory, Fort Pierce, FL, USA.
| | - Anthony Cruz
- University of Florida/IFAS, Florida Medical Entomology Laboratory, Vero Beach, FL, USA
| | | | - Dagne Duguma
- University of Florida/IFAS, Florida Medical Entomology Laboratory, Vero Beach, FL, USA; Broward County Mosquito Control, Pembroke Pines, FL, USA
| |
Collapse
|
4
|
Samsami K, Sanchez Arias L, Redd H, Stoll R, Pepper RE, Fu HC. Incorporating recirculation effects into metrics of feeding performance for current-feeding zooplankton. J R Soc Interface 2024; 21:20230706. [PMID: 38471535 PMCID: PMC10932701 DOI: 10.1098/rsif.2023.0706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 02/05/2024] [Indexed: 03/14/2024] Open
Abstract
The feeding performance of zooplankton influences their evolution and can explain their behaviour. A commonly used metric for feeding performance is the volume of fluid that flows through a filtering surface and is scanned for food. Here, we show that such a metric may give incorrect results for organisms that produce recirculatory flows, so that fluid flowing through the filter may have been already filtered of food. In a numerical model, we construct a feeding metric that correctly accounts for recirculation in a sessile model organism inspired by our experimental observations of Vorticella and its flow field. Our metric tracks the history of current-borne particles to determine if they have already been filtered by the filtering surface. Examining the pathlines of food particles reveals that the capture of fresh particles preferentially involves the tips of cilia, which we corroborate in observations of feeding Vorticella. We compare the amount of fresh nutrient particles carried to the organism with other metrics of feeding, and show that metrics that do not take into account the history of particles cannot correctly compute the volume of freshly scanned fluid.
Collapse
Affiliation(s)
| | | | - Haven Redd
- University of Utah, Salt Lake City, UT, USA
| | - Rob Stoll
- University of Utah, Salt Lake City, UT, USA
| | | | | |
Collapse
|
5
|
Zhang Z, Shi Z, Ahmed D. SonoTransformers: Transformable acoustically activated wireless microscale machines. Proc Natl Acad Sci U S A 2024; 121:e2314661121. [PMID: 38289954 PMCID: PMC10861920 DOI: 10.1073/pnas.2314661121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 12/22/2023] [Indexed: 02/01/2024] Open
Abstract
Shape transformation, a key mechanism for organismal survival and adaptation, has gained importance in developing synthetic shape-shifting systems with diverse applications ranging from robotics to bioengineering. However, designing and controlling microscale shape-shifting materials remains a fundamental challenge in various actuation modalities. As materials and structures are scaled down to the microscale, they often exhibit size-dependent characteristics, and the underlying physical mechanisms can be significantly affected or rendered ineffective. Additionally, surface forces such as van der Waals forces and electrostatic forces become dominant at the microscale, resulting in stiction and adhesion between small structures, making them fracture and more difficult to deform. Furthermore, despite various actuation approaches, acoustics have received limited attention despite their potential advantages. Here, we introduce "SonoTransformer," the acoustically activated micromachine that delivers shape transformability using preprogrammed soft hinges with different stiffnesses. When exposed to an acoustic field, these hinges concentrate sound energy through intensified oscillation and provide the necessary force and torque for the transformation of the entire micromachine within milliseconds. We have created machine designs to predetermine the folding state, enabling precise programming and customization of the acoustic transformation. Additionally, we have shown selective shape transformable microrobots by adjusting acoustic power, realizing high degrees of control and functional versatility. Our findings open new research avenues in acoustics, physics, and soft matter, offering new design paradigms and development opportunities in robotics, metamaterials, adaptive optics, flexible electronics, and microtechnology.
Collapse
Affiliation(s)
- Zhiyuan Zhang
- Acoustic Robotics Systems Lab, Institute of Robotics and Intelligent Systems, Department of Mechanical and Process Engineering, ETH Zurich, ZurichCH-8803, Switzerland
| | - Zhan Shi
- Acoustic Robotics Systems Lab, Institute of Robotics and Intelligent Systems, Department of Mechanical and Process Engineering, ETH Zurich, ZurichCH-8803, Switzerland
| | - Daniel Ahmed
- Acoustic Robotics Systems Lab, Institute of Robotics and Intelligent Systems, Department of Mechanical and Process Engineering, ETH Zurich, ZurichCH-8803, Switzerland
| |
Collapse
|
6
|
Pandey A, Chen ZY, Yuk J, Sun Y, Roh C, Takagi D, Lee S, Jung S. Optimal free-surface pumping by an undulating carpet. Nat Commun 2023; 14:7735. [PMID: 38007556 PMCID: PMC10676362 DOI: 10.1038/s41467-023-43059-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 10/30/2023] [Indexed: 11/27/2023] Open
Abstract
Examples of fluid flows driven by undulating boundaries are found in nature across many different length scales. Even though different driving mechanisms have evolved in distinct environments, they perform essentially the same function: directional transport of liquid. Nature-inspired strategies have been adopted in engineered devices to manipulate and direct flow. Here, we demonstrate how an undulating boundary generates large-scale pumping of a thin liquid near the liquid-air interface. Two dimensional traveling waves on the undulator, a canonical strategy to transport fluid at low Reynolds numbers, surprisingly lead to flow rates that depend non-monotonically on the wave speed. Through an asymptotic analysis of the thin-film equations that account for gravity and surface tension, we predict the observed optimal speed that maximizes pumping. Our findings reveal how proximity to free surfaces, which ensure lower energy dissipation, can be leveraged to achieve directional transport of liquids.
Collapse
Affiliation(s)
- Anupam Pandey
- Mechanical & Aerospace Engineering Department and BioInspired Syracuse, Syracuse University, Syracuse, NY, 13244, USA.
| | - Zih-Yin Chen
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Jisoo Yuk
- Department of Biological & Environmental Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Yuming Sun
- Sibley School of Mechanical & Aerospace Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Chris Roh
- Department of Biological & Environmental Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Daisuke Takagi
- Department of Mathematics, University of Hawaii at Manoa, Honolulu, HI, 96822, USA
| | - Sungyon Lee
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Sunghwan Jung
- Department of Biological & Environmental Engineering, Cornell University, Ithaca, NY, 14853, USA.
| |
Collapse
|
7
|
Lupatelli CA, Attard A, Kuhn ML, Cohen C, Thomen P, Noblin X, Galiana E. Automated high-content image-based characterization of microorganism behavioral diversity and distribution. Comput Struct Biotechnol J 2023; 21:5640-5649. [PMID: 38047236 PMCID: PMC10692603 DOI: 10.1016/j.csbj.2023.10.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/30/2023] [Accepted: 10/30/2023] [Indexed: 12/05/2023] Open
Abstract
Microorganisms have evolved complex systems to respond to environmental signals. Gradients of particular molecules and elemental ions alter the behavior of microbes and their distribution within their environment. Microdevices coupled with automated image-based methods are now employed to analyze the instantaneous distribution and motion behaviors of microbial species in controlled environments at small temporal scales, mimicking, to some extent, macro conditions. Such technologies have so far been adopted for investigations mainly on individual species. Similar versatile approaches must now be developed for the characterization of multiple and complex interactions between a microbial community and its environment. Here, we provide a comprehensive step-by-step method for the characterization of species-specific behavior in a synthetic mixed microbial suspension in response to an environmental driver. By coupling accessible microfluidic devices with automated image analysis approaches, we evaluated the behavioral response of three morphologically different telluric species (Phytophthora parasitica, Vorticella microstoma, Enterobacter aerogenes) to a potassium gradient driver. Using the TrackMate plug-in algorithm, we performed morphometric and then motion analyses to characterize the response of each microbial species to the driver. Such an approach enabled to confirm the different morphological features of the three species and simultaneously characterize their specific motion in reaction to the driver and their co-interaction dynamics. By increasing the complexity of suspensions, this approach could be integrated in a framework for phenotypic analysis in microbial ecology research, helping to characterize how key drivers influence microbiota assembly at microbiota host-environment interfaces.
Collapse
Affiliation(s)
- Carlotta Aurora Lupatelli
- Université Côte d’Azur, INRAE, CNRS, ISA, Sophia Antipolis, 06903, France
- Université Côte d’Azur, CNRS, UMR 7010, INPHYNI, Nice 06200, France
| | - Agnes Attard
- Université Côte d’Azur, INRAE, CNRS, ISA, Sophia Antipolis, 06903, France
| | - Marie-Line Kuhn
- Université Côte d’Azur, INRAE, CNRS, ISA, Sophia Antipolis, 06903, France
| | - Celine Cohen
- Université Côte d’Azur, CNRS, UMR 7010, INPHYNI, Nice 06200, France
| | - Philippe Thomen
- Université Côte d’Azur, CNRS, UMR 7010, INPHYNI, Nice 06200, France
| | - Xavier Noblin
- Université Côte d’Azur, CNRS, UMR 7010, INPHYNI, Nice 06200, France
| | - Eric Galiana
- Université Côte d’Azur, INRAE, CNRS, ISA, Sophia Antipolis, 06903, France
| |
Collapse
|
8
|
Flaum E, Prakash M. Curved crease origami and topological singularities at a cellular scale enable hyper-extensibility of Lacrymaria olor. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.04.551915. [PMID: 37577489 PMCID: PMC10418517 DOI: 10.1101/2023.08.04.551915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Eukaryotic cells undergo dramatic morphological changes during cell division, phagocytosis and motility. Fundamental limits of cellular morphodynamics such as how fast or how much cellular shapes can change without harm to a living cell remain poorly understood. Here we describe hyper-extensibility in the single-celled protist Lacrymaria olor, a 40 μm cell which is capable of reversible and repeatable extensions (neck-like protrusions) up to 1500 μm in 30 seconds. We discover that a unique and intricate organization of cortical cytoskeleton and membrane enables these hyper-extensions that can be described as the first cellular scale curved crease origami. Furthermore, we show how these topological singularities including d-cones and twisted domain walls provide a geometrical control mechanism for the deployment of membrane and microtubule sheets as they repeatably spool thousands of time from the cell body. We lastly build physical origami models to understand how these topological singularities provide a mechanism for the cell to control the hyper-extensile deployable structure. This new geometrical motif where a cell employs curved crease origami to perform a physiological function has wide ranging implications in understanding cellular morphodynamics and direct applications in deployable micro-robotics.
Collapse
Affiliation(s)
- Eliott Flaum
- Graduate Program in Biophysics
- Department of Bioengineering
- Stanford University
| | - Manu Prakash
- Graduate Program in Biophysics
- Department of Bioengineering
- Department of Biology (courtesy)
- Department of Oceans (courtesy)
- Stanford University
| |
Collapse
|
9
|
Zhang J, Qin W, Hu C, Gu S, Chai X, Yang M, Zhou F, Wang X, Chen K, Yan G, Wang G, Jiang C, Warren A, Xiong J, Miao W. Giant proteins in a giant cell: Molecular basis of ultrafast Ca 2+-dependent cell contraction. SCIENCE ADVANCES 2023; 9:eadd6550. [PMID: 36812318 PMCID: PMC9946354 DOI: 10.1126/sciadv.add6550] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 01/20/2023] [Indexed: 06/18/2023]
Abstract
The giant single-celled eukaryote, Spirostomum, exhibits one of the fastest movements in the biological world. This ultrafast contraction is dependent on Ca2+ rather than ATP and therefore differs to the actin-myosin system in muscle. We obtained the high-quality genome of Spirostomum minus from which we identified the key molecular components of its contractile apparatus, including two major Ca2+ binding proteins (Spasmin 1 and 2) and two giant proteins (GSBP1 and GSBP2), which act as the backbone and allow for the binding of hundreds of spasmins. The evidence suggests that the GSBP-spasmin protein complex is the functional unit of the mesh-like contractile fibrillar system, which, coupled with various other subcellular structures, provides the mechanism for repetitive ultrafast cell contraction and extension. These findings improve our understanding of the Ca2+-dependent ultrafast movement and provide a blueprint for future biomimicry, design, and construction of this kind of micromachine.
Collapse
Affiliation(s)
- Jing Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Weiwei Qin
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Che Hu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- Harbin Normal University, Harbin 150025, China
| | - Siyu Gu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaocui Chai
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Mingkun Yang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Fang Zhou
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Xueyan Wang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kai Chen
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Guanxiong Yan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Guangying Wang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Chuanqi Jiang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Alan Warren
- Department of Life Sciences, Natural History Museum, London SW7 5BD, UK
| | - Jie Xiong
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Wei Miao
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- State Key Laboratory of Freshwater Ecology and Biotechnology of China, Wuhan 430072, China
- CAS Center for Excellence in Animal Evolution and Genetics, Kunming 650223, China
| |
Collapse
|
10
|
Comparative study on the larvicidal effect of some ciliated protists on Culex gelidus, Culex tritaeniorhynchus, and Aedes aegypti in Sri Lanka. Parasitol Res 2023; 122:497-507. [PMID: 36478208 DOI: 10.1007/s00436-022-07750-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022]
Abstract
Rice fields in Sri Lanka create suitable breeding places for vector mosquitoes. Such sites provide habitats for diversified naturally occurring microbiota. Ciliated protists, Zoothamnium sp., Chilodonella sp., and Vorticella microstoma are among such microbiota found in vector mosquito habitats especially in rice field habitats in Sri Lanka. The present study was carried out to determine the comparative larvicidal effect of these ciliated protists collected from naturally infested mosquito larvae in some rice-field habitats in Kurunegala, Sri Lanka, against vector mosquito larvae. Vector mosquito larvae, Culex tritaeniorhynchus, and Culex gelidus were reared in the laboratory from field-collected water samples while Aedes aegypti mosquito larvae were reared using egg sheets, for the laboratory bioassays. V. microstoma showed the potential for infection and mortality of Cx. tritaeniorhynchus larvae (71.33% ± 5.23). Results revealed a minimum of 1000 V. microstoma is required to kill a single third instar larva of Cx. tritaeniorhynchus at 69.60 ± 2.40 h of exposure. Cx. gelidus larvae showed 41.33% ± 3.43 mortality due to V. microstoma infestation. However, none of the ciliates were effective against Ae. aegypti larvae. Chilodonella sp. was very occasionally reported during this study hence was not possible to the mass rear for experimentations. This study concludes that V. microstoma is an effective ciliated parasite of Cx. tritaeniorhynchus larvae. Due to their effectiveness and eco-friendly nature, this species can be developed as an effective bio-controlling agent against Cx. tritaeniorhynchus mosquito species.
Collapse
|
11
|
Krishnamurthy D, Pepper R, Prakash M. Active sinking particles: sessile suspension feeders significantly alter the flow and transport to sinking aggregates. J R Soc Interface 2023; 20:20220537. [PMID: 36751929 PMCID: PMC9905981 DOI: 10.1098/rsif.2022.0537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 01/04/2023] [Indexed: 02/09/2023] Open
Abstract
Sinking or sedimentation of biological aggregates plays a critical role in carbon sequestration in the ocean and in vertical material fluxes in wastewater treatment plants. In both these contexts, the sinking aggregates are 'active', since they are biological hot-spots and are densely colonized by microorganisms including bacteria and sessile protists, some of which generate feeding currents. However, the effect of these feeding currents on the sinking rates, trajectories and mass transfer to these 'active sinking particles' has not previously been studied. Here, we use a novel scale-free vertical tracking microscope (a.k.a. gravity machine; Krishnamurthy et al. 2020 Nat. Methods 17, 1040-1051 (doi:10.1038/s41592-020-0924-7)) to follow model sinking aggregates (agar spheres) with attached protists (Vorticella convallaria), sinking over long distances while simultaneously measuring local flows. We find that activity due to attached V. convallaria causes significant changes to the flow around aggregates in a dynamic manner and reshapes mass transport boundary layers. Further, we find that activity-mediated local flows along with sinking modify the encounter and plume cross-sections of the aggregate and induce sustained aggregate rotations. Overall, our work shows the important role of biological activity in shaping the near-field flows around aggregates with potentially important effects on aggregate fate and material fluxes.
Collapse
Affiliation(s)
- Deepak Krishnamurthy
- Department of Bioengineering, University of California, Berkeley, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Rachel Pepper
- Department of Physics, University of Puget Sound, Tacoma, WA, USA
| | - Manu Prakash
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| |
Collapse
|
12
|
Biocontrol Potential of the Vorticella sp. Isolated from Vermicompost Against Meloidogyne javanica. Curr Microbiol 2022; 79:333. [DOI: 10.1007/s00284-022-03030-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 09/07/2022] [Indexed: 11/03/2022]
|
13
|
Schenone L, Balseiro E, Modenutti B. Light dependence in the phototrophy-phagotrophy balance of constitutive and non-constitutive mixotrophic protists. Oecologia 2022; 200:295-306. [PMID: 35962828 DOI: 10.1007/s00442-022-05226-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 07/20/2022] [Indexed: 11/28/2022]
Abstract
Mixotrophic protists display contrasting nutritional strategies and are key groups connecting planktonic food webs. They comprise constitutive mixotrophs (CMs) that have an innate photosynthetic ability and non-constitutive mixotrophs (NCMs) that acquire it from their prey. We modelled phototrophy and phagotrophy of two mixotrophic protists as a function of irradiance and prey abundance. We hypothesised that differences in their physiology (constitutive versus non-constitutive mixotrophy) can result in different responses to light gradients. We fitted the models with primary production and bacterivory data from laboratory and field experiments with the nanoflagellate Chrysochromulina parva (CM) and the ciliate Ophrydium naumanni (NCM) from north Andean Patagonian lakes. We found a non-monotonic response of phototrophy and phagotrophy to irradiance in both mixotrophs, which was successfully represented by our models. Maximum values for phototrophy and phagotrophy were found at intermediate irradiance coinciding with the light at the deep chlorophyll maxima in these lakes. At lower and higher irradiances, we found a decoupling between phototrophy and phagotrophy in the NCM while these functions were more coupled in the CM. Our modelling approach revealed the difference between both mixotrophic functional types on the balance between their nutritional strategies under different light scenarios. Thus, our proposed models can be applied to account how changing environmental conditions affect both primary and secondary production within the planktonic microbial food web.
Collapse
Affiliation(s)
- Luca Schenone
- Laboratorio de Limnología, INIBIOMA-CONICET, Universidad Nacional del Comahue. Quintral 1250, 8400, San Carlos de Bariloche, Río Negro, Argentina.
| | - Esteban Balseiro
- Laboratorio de Limnología, INIBIOMA-CONICET, Universidad Nacional del Comahue. Quintral 1250, 8400, San Carlos de Bariloche, Río Negro, Argentina
| | - Beatriz Modenutti
- Laboratorio de Limnología, INIBIOMA-CONICET, Universidad Nacional del Comahue. Quintral 1250, 8400, San Carlos de Bariloche, Río Negro, Argentina
| |
Collapse
|
14
|
Mondal D, Prabhune AG, Ramaswamy S, Sharma P. Strong confinement of active microalgae leads to inversion of vortex flow and enhanced mixing. eLife 2021; 10:e67663. [PMID: 34806977 PMCID: PMC8758135 DOI: 10.7554/elife.67663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 11/16/2021] [Indexed: 11/13/2022] Open
Abstract
Microorganisms swimming through viscous fluids imprint their propulsion mechanisms in the flow fields they generate. Extreme confinement of these swimmers between rigid boundaries often arises in natural and technological contexts, yet measurements of their mechanics in this regime are absent. Here, we show that strongly confining the microalga Chlamydomonas between two parallel plates not only inhibits its motility through contact friction with the walls but also leads, for purely mechanical reasons, to inversion of the surrounding vortex flows. Insights from the experiment lead to a simplified theoretical description of flow fields based on a quasi-2D Brinkman approximation to the Stokes equation rather than the usual method of images. We argue that this vortex flow inversion provides the advantage of enhanced fluid mixing despite higher friction. Overall, our results offer a comprehensive framework for analyzing the collective flows of strongly confined swimmers.
Collapse
Affiliation(s)
- Debasmita Mondal
- Department of Physics, Indian Institute of ScienceBangaloreIndia
| | - Ameya G Prabhune
- Department of Physics, Indian Institute of ScienceBangaloreIndia
| | - Sriram Ramaswamy
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of ScienceBangaloreIndia
| | - Prerna Sharma
- Department of Physics, Indian Institute of ScienceBangaloreIndia
| |
Collapse
|
15
|
The bank of swimming organisms at the micron scale (BOSO-Micro). PLoS One 2021; 16:e0252291. [PMID: 34111118 PMCID: PMC8191957 DOI: 10.1371/journal.pone.0252291] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 05/13/2021] [Indexed: 12/24/2022] Open
Abstract
Unicellular microscopic organisms living in aqueous environments outnumber all other creatures on Earth. A large proportion of them are able to self-propel in fluids with a vast diversity of swimming gaits and motility patterns. In this paper we present a biophysical survey of the available experimental data produced to date on the characteristics of motile behaviour in unicellular microswimmers. We assemble from the available literature empirical data on the motility of four broad categories of organisms: bacteria (and archaea), flagellated eukaryotes, spermatozoa and ciliates. Whenever possible, we gather the following biological, morphological, kinematic and dynamical parameters: species, geometry and size of the organisms, swimming speeds, actuation frequencies, actuation amplitudes, number of flagella and properties of the surrounding fluid. We then organise the data using the established fluid mechanics principles for propulsion at low Reynolds number. Specifically, we use theoretical biophysical models for the locomotion of cells within the same taxonomic groups of organisms as a means of rationalising the raw material we have assembled, while demonstrating the variability for organisms of different species within the same group. The material gathered in our work is an attempt to summarise the available experimental data in the field, providing a convenient and practical reference point for future studies.
Collapse
|
16
|
Hamilton E, Cicuta P. Changes in geometrical aspects of a simple model of cilia synchronization control the dynamical state, a possible mechanism for switching of swimming gaits in microswimmers. PLoS One 2021; 16:e0249060. [PMID: 33831025 PMCID: PMC8031381 DOI: 10.1371/journal.pone.0249060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Accepted: 03/10/2021] [Indexed: 12/23/2022] Open
Abstract
Active oscillators, with purely hydrodynamic coupling, are useful simple models to understand various aspects of motile cilia synchronization. Motile cilia are used by microorganisms to swim and to control the flow fields in their surroundings; the patterns observed in cilia carpets can be remarkably complex, and can be changed over time by the organism. It is often not known to what extent the coupling between cilia is due to just hydrodynamic forces, and neither is it known if it is biological or physical triggers that can change the dynamical collective state. Here we treat this question from a very simplified point of view. We describe three possible mechanisms that enable a switch in the dynamical state, in a simple scenario of a chain of oscillators. We find that shape-change provides the most consistent strategy to control collective dynamics, but also imposing small changes in frequency produces some unique stable states. Demonstrating these effects in the abstract minimal model proves that these could be possible explanations for gait switching seen in ciliated micro organisms like Paramecium and others. Microorganisms with many cilia could in principle be taking advantage of hydrodynamic coupling, to switch their swimming gait through either a shape change that manifests in decreased coupling between groups of cilia, or alterations to the beat style of a small subset of the cilia.
Collapse
Affiliation(s)
- Evelyn Hamilton
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Pietro Cicuta
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
| |
Collapse
|
17
|
Soto F, Karshalev E, Zhang F, Esteban Fernandez de Avila B, Nourhani A, Wang J. Smart Materials for Microrobots. Chem Rev 2021; 122:5365-5403. [DOI: 10.1021/acs.chemrev.0c00999] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Fernando Soto
- Department of Nanoengineering, Chemical Engineering Program and Contextual Robotics Institute, University of California San Diego, La Jolla, California 92093, United States
| | - Emil Karshalev
- Department of Nanoengineering, Chemical Engineering Program and Contextual Robotics Institute, University of California San Diego, La Jolla, California 92093, United States
| | - Fangyu Zhang
- Department of Nanoengineering, Chemical Engineering Program and Contextual Robotics Institute, University of California San Diego, La Jolla, California 92093, United States
| | - Berta Esteban Fernandez de Avila
- Department of Nanoengineering, Chemical Engineering Program and Contextual Robotics Institute, University of California San Diego, La Jolla, California 92093, United States
| | - Amir Nourhani
- Department of Mechanical Engineering, Department of Mathematics, Biology, Biomimicry Research and Innovation Center, University of Akron, Akron, Ohio 44325, United States
| | - Joseph Wang
- Department of Nanoengineering, Chemical Engineering Program and Contextual Robotics Institute, University of California San Diego, La Jolla, California 92093, United States
| |
Collapse
|
18
|
Soto F, Wang J, Ahmed R, Demirci U. Medical Micro/Nanorobots in Precision Medicine. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2002203. [PMID: 33173743 PMCID: PMC7610261 DOI: 10.1002/advs.202002203] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/09/2020] [Indexed: 05/15/2023]
Abstract
Advances in medical robots promise to improve modern medicine and the quality of life. Miniaturization of these robotic platforms has led to numerous applications that leverages precision medicine. In this review, the current trends of medical micro and nanorobotics for therapy, surgery, diagnosis, and medical imaging are discussed. The use of micro and nanorobots in precision medicine still faces technical, regulatory, and market challenges for their widespread use in clinical settings. Nevertheless, recent translations from proof of concept to in vivo studies demonstrate their potential toward precision medicine.
Collapse
Affiliation(s)
- Fernando Soto
- Bio‐Acoustic MEMS in Medicine (BAMM) LaboratoryCanary Center at Stanford for Cancer Early DetectionDepartment of RadiologySchool of Medicine Stanford UniversityPalo AltoCA94304‐5427USA
- Canary Center at Stanford for Cancer Early DetectionDepartment of RadiologySchool of MedicineStanford UniversityPalo AltoCA94304‐5427USA
| | - Jie Wang
- Bio‐Acoustic MEMS in Medicine (BAMM) LaboratoryCanary Center at Stanford for Cancer Early DetectionDepartment of RadiologySchool of Medicine Stanford UniversityPalo AltoCA94304‐5427USA
- Canary Center at Stanford for Cancer Early DetectionDepartment of RadiologySchool of MedicineStanford UniversityPalo AltoCA94304‐5427USA
| | - Rajib Ahmed
- Bio‐Acoustic MEMS in Medicine (BAMM) LaboratoryCanary Center at Stanford for Cancer Early DetectionDepartment of RadiologySchool of Medicine Stanford UniversityPalo AltoCA94304‐5427USA
- Canary Center at Stanford for Cancer Early DetectionDepartment of RadiologySchool of MedicineStanford UniversityPalo AltoCA94304‐5427USA
| | - Utkan Demirci
- Bio‐Acoustic MEMS in Medicine (BAMM) LaboratoryCanary Center at Stanford for Cancer Early DetectionDepartment of RadiologySchool of Medicine Stanford UniversityPalo AltoCA94304‐5427USA
- Canary Center at Stanford for Cancer Early DetectionDepartment of RadiologySchool of MedicineStanford UniversityPalo AltoCA94304‐5427USA
| |
Collapse
|
19
|
Liu Y, Peters WS, Froelich DR, Howell AH, Mooney S, Evans JE, Hellmann HA, Knoblauch M. Aspartate Residues in a Forisome-Forming SEO Protein Are Critical for Protein Body Assembly and Ca2+ Responsiveness. PLANT & CELL PHYSIOLOGY 2020; 61:1699-1710. [PMID: 33035344 DOI: 10.1093/pcp/pcaa093] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 07/07/2020] [Indexed: 06/11/2023]
Abstract
Forisomes are protein bodies known exclusively from sieve elements of legumes. Forisomes contribute to the regulation of phloem transport due to their unique Ca2+-controlled, reversible swelling. The assembly of forisomes from sieve element occlusion (SEO) protein monomers in developing sieve elements and the mechanism(s) of Ca2+-dependent forisome contractility are poorly understood because the amino acid sequences of SEO proteins lack conventional protein-protein interaction and Ca2+-binding motifs. We selected amino acids potentially responsible for forisome-specific functions by analyzing SEO protein sequences in comparison to those of the widely distributed SEO-related (SEOR), or SEOR proteins. SEOR proteins resemble SEO proteins closely but lack any Ca2+ responsiveness. We exchanged identified candidate residues by directed mutagenesis of the Medicago truncatula SEO1 gene, expressed the mutated genes in yeast (Saccharomyces cerevisiae) and studied the structural and functional phenotypes of the forisome-like bodies that formed in the transgenic cells. We identified three aspartate residues critical for Ca2+ responsiveness and two more that were required for forisome-like bodies to assemble. The phenotypes observed further suggested that Ca2+-controlled and pH-inducible swelling effects in forisome-like bodies proceeded by different yet interacting mechanisms. Finally, we observed a previously unknown surface striation in native forisomes and in recombinant forisome-like bodies that could serve as an indicator of successful forisome assembly. To conclude, this study defines a promising path to the elucidation of the so-far elusive molecular mechanisms of forisome assembly and Ca2+-dependent contractility.
Collapse
Affiliation(s)
- Yan Liu
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164, USA
| | - Winfried S Peters
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164, USA
| | | | - Alexander H Howell
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164, USA
| | - Sutton Mooney
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164, USA
| | - James E Evans
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164, USA
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 3335 Innovation Blvd, Richland, WA 99354, USA
| | - Hanjo A Hellmann
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164, USA
| | - Michael Knoblauch
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, WA 99164, USA
| |
Collapse
|
20
|
Butler TC, Zhang J, Zhang H, Ryu S, Greene AS. Magnetic Patterning of Vorticella convallaria in a Microfluidic Device. J Eukaryot Microbiol 2020; 67:687-690. [PMID: 32702141 DOI: 10.1111/jeu.12819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 06/23/2020] [Accepted: 07/10/2020] [Indexed: 11/30/2022]
Abstract
We describe an inexpensive magnetic cell patterning method as a tool for protozoologists. The ciliate Vorticella convallaria is useful for various biofluidics applications. Here, we show that V. convallaria will ingest metal beads and that permanent magnets can be used to pattern cells in Petri dishes or a microfluidic device. Patterning is reversibly achieved by placing magnets at the point of desired cell attachment. Analogous magnetic manipulation could be performed using other phagocytic cells.
Collapse
Affiliation(s)
- Trevor C Butler
- Science and Math Department, Judson University, Elgin, 60123, Illinois, USA
| | - Jieyu Zhang
- Chemistry and Biochemistry Department, Albright College, Reading, 19604, Pennsylvania, USA
| | - Haipeng Zhang
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, 68588, Nebraska, USA
| | - Sangjin Ryu
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, 68588, Nebraska, USA.,Nebraska Center for Materials and Nanoscience, Lincoln, 68588, Nebraska, USA
| | - Amy Styer Greene
- Chemistry and Biochemistry Department, Albright College, Reading, 19604, Pennsylvania, USA
| |
Collapse
|
21
|
Nakamura F, Nakayama T, Kageyama I, Kato R, Nagai M, Shibata T, Sawada K, Hattori T. Characterization of Calcium Ion Release from a Polymer-Coated Electrode with a Plasticized PVC Membrane Containing Calcium Salts, and Its Contraction Examination of Vorticella Convallaria. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2020. [DOI: 10.1246/bcsj.20200015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Fumiya Nakamura
- Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tenpaku, Toyohashi, Aichi 441-8580, Japan
| | - Taisei Nakayama
- Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tenpaku, Toyohashi, Aichi 441-8580, Japan
| | - Itsuki Kageyama
- Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tenpaku, Toyohashi, Aichi 441-8580, Japan
| | - Ryo Kato
- Cooperative Research Facility Center, Toyohashi University of Technology, 1-1 Hibarigaoka, Tenpaku, Toyohashi, Aichi 441-8580, Japan
| | - Moeto Nagai
- Department of Mechanical Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tenpaku, Toyohashi, Aichi 441-8580, Japan
| | - Takayuki Shibata
- Department of Mechanical Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tenpaku, Toyohashi, Aichi 441-8580, Japan
| | - Kazuaki Sawada
- Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tenpaku, Toyohashi, Aichi 441-8580, Japan
| | - Toshiaki Hattori
- Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tenpaku, Toyohashi, Aichi 441-8580, Japan
| |
Collapse
|
22
|
Collective intercellular communication through ultra-fast hydrodynamic trigger waves. Nature 2019; 571:560-564. [DOI: 10.1038/s41586-019-1387-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 06/18/2019] [Indexed: 11/08/2022]
|
23
|
Neagu AN. Proteome Imaging: From Classic to Modern Mass Spectrometry-Based Molecular Histology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1140:55-98. [PMID: 31347042 DOI: 10.1007/978-3-030-15950-4_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In order to overcome the limitations of classic imaging in Histology during the actually era of multiomics, the multi-color "molecular microscope" by its emerging "molecular pictures" offers quantitative and spatial information about thousands of molecular profiles without labeling of potential targets. Healthy and diseased human tissues, as well as those of diverse invertebrate and vertebrate animal models, including genetically engineered species and cultured cells, can be easily analyzed by histology-directed MALDI imaging mass spectrometry. The aims of this review are to discuss a range of proteomic information emerging from MALDI mass spectrometry imaging comparative to classic histology, histochemistry and immunohistochemistry, with applications in biology and medicine, concerning the detection and distribution of structural proteins and biological active molecules, such as antimicrobial peptides and proteins, allergens, neurotransmitters and hormones, enzymes, growth factors, toxins and others. The molecular imaging is very well suited for discovery and validation of candidate protein biomarkers in neuroproteomics, oncoproteomics, aging and age-related diseases, parasitoproteomics, forensic, and ecotoxicology. Additionally, in situ proteome imaging may help to elucidate the physiological and pathological mechanisms involved in developmental biology, reproductive research, amyloidogenesis, tumorigenesis, wound healing, neural network regeneration, matrix mineralization, apoptosis and oxidative stress, pain tolerance, cell cycle and transformation under oncogenic stress, tumor heterogeneity, behavior and aggressiveness, drugs bioaccumulation and biotransformation, organism's reaction against environmental penetrating xenobiotics, immune signaling, assessment of integrity and functionality of tissue barriers, behavioral biology, and molecular origins of diseases. MALDI MSI is certainly a valuable tool for personalized medicine and "Eco-Evo-Devo" integrative biology in the current context of global environmental challenges.
Collapse
Affiliation(s)
- Anca-Narcisa Neagu
- Laboratory of Animal Histology, Faculty of Biology, "Alexandru Ioan Cuza" University of Iasi, Iasi, Romania.
| |
Collapse
|
24
|
Chung EG, Ryu S. Stalk-length-dependence of the contractility ofVorticella convallaria. Phys Biol 2017; 14:066002. [DOI: 10.1088/1478-3975/aa89b8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
25
|
Zhou J, Ryu S, Admiraal D. Flow and transport effect caused by the stalk contraction cycle of Vorticella convallaria. BIOMICROFLUIDICS 2017; 11:034119. [PMID: 28670352 PMCID: PMC5472479 DOI: 10.1063/1.4985654] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 05/31/2017] [Indexed: 06/07/2023]
Abstract
Vorticella convallaria is a protozoan attached to a substrate by a stalk which can contract in less than 10 ms, translating the zooid toward the substrate with a maximum Reynolds number of ∼1. Following contraction, the stalk slowly relaxes, moving the zooid away from the substrate, which results in creeping flow. Although Vorticella has long been believed to contract to evade danger, it has been suggested that its stalk may contract to enhance food transport near the substrate. To elucidate how Vorticella utilizes its contraction-relaxation cycle, we investigated water flow caused by the cycle, using a computational fluid dynamics model validated with an experimental scale model and particle tracking velocimetry. The simulated flow was visualized and analyzed by tracing virtual particles around the Vorticella. It is observed that one cycle can displace particles up to ∼190 μm with the maximum net vertical displacement of 3-4 μm and that the net transport effect becomes more evident over repeated cycles. This transport effect appears to be due to asymmetry of the contraction and relaxation phases of the flow field, and it can be more effective on motile food particles than non-motile ones. Therefore, our Vorticella model enabled investigating the fluid dynamics principle and ecological role of the transport effects of Vorticella's stalk contraction.
Collapse
Affiliation(s)
- Jiazhong Zhou
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 98588, USA
| | | | - David Admiraal
- Department of Civil Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 98588, USA
| |
Collapse
|
26
|
France D, Tejada J, Matsudaira P. Direct measurement of Vorticella contraction force by micropipette deflection. FEBS Lett 2017; 591:581-589. [PMID: 28130786 DOI: 10.1002/1873-3468.12577] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/22/2017] [Accepted: 01/23/2017] [Indexed: 11/08/2022]
Abstract
The ciliated protozoan Vorticella convallaria is noted for its exceptionally fast adenosine triphosphate-independent cellular contraction, but direct measurements of contractile force have proven difficult given the length scale, speed, and forces involved. We used high-speed video microscopy to image live Vorticella stalled in midcontraction by deflection of an attached micropipette. Stall forces correlate with both distance contracted and the resting stalk length. Estimated isometric forces range from 95 to 177 nanonewtons (nN), or 1.12 nN·μm-1 of the stalk. Maximum velocity and work are also proportional to distance contracted. These parameters constrain proposed biochemical/physical models of the contractile mechanism.
Collapse
Affiliation(s)
- Danielle France
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jonathan Tejada
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Paul Matsudaira
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| |
Collapse
|