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3D cellular reconstruction of cortical glia and parenchymal morphometric analysis from Serial Block-Face Electron Microscopy of juvenile rat. Prog Neurobiol 2019; 183:101696. [PMID: 31550514 DOI: 10.1016/j.pneurobio.2019.101696] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 09/12/2019] [Accepted: 09/17/2019] [Indexed: 01/04/2023]
Abstract
With the rapid evolution in the automation of serial electron microscopy in life sciences, the acquisition of terabyte-sized datasets is becoming increasingly common. High resolution serial block-face imaging (SBEM) of biological tissues offers the opportunity to segment and reconstruct nanoscale structures to reveal spatial features previously inaccessible with simple, single section, two-dimensional images. In particular, we focussed here on glial cells, whose reconstruction efforts in literature are still limited, compared to neurons. We imaged a 750,000 cubic micron volume of the somatosensory cortex from a juvenile P14 rat, with 20 nm accuracy. We recognized a total of 186 cells using their nuclei, and classified them as neuronal or glial based on features of the soma and the processes. We reconstructed for the first time 4 almost complete astrocytes and neurons, 4 complete microglia and 4 complete pericytes, including their intracellular mitochondria, 186 nuclei and 213 myelinated axons. We then performed quantitative analysis on the three-dimensional models. Out of the data that we generated, we observed that neurons have larger nuclei, which correlated with their lesser density, and that astrocytes and pericytes have a higher surface to volume ratio, compared to other cell types. All reconstructed morphologies represent an important resource for computational neuroscientists, as morphological quantitative information can be inferred, to tune simulations that take into account the spatial compartmentalization of the different cell types.
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52
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Wang P, Liang Z, Kang BH. Electron tomography of plant organelles and the outlook for correlative microscopic approaches. THE NEW PHYTOLOGIST 2019; 223:1756-1761. [PMID: 31058325 DOI: 10.1111/nph.15882] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 04/11/2019] [Indexed: 05/17/2023]
Abstract
Structural analyses of organelles and localization of proteins in their confines are essential to investigate inner workings of eukaryotic cells. Electron tomography (ET) is a three-dimensional electron microscopy method with which we can extract sliced views of organelles from any direction and quantify their structural parameters at nanometer-level resolution. This advanced electron microscopy tool is suited for characterization of convoluted membrane compartments and of cellular constituents of dimensions smaller than 100 nm. ET studies of plant cells fixed by rapid freezing have expanded our understanding of the biogenesis and functions of plant organelles. Here we describe how the molecular imaging capacity of correlative light and electron microscopy can be integrated with ET in studies of plant organelles.
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Affiliation(s)
- Pengfei Wang
- Centre for Cell and Developmental Biology, State Key Laboratory for Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Zizhen Liang
- Centre for Cell and Developmental Biology, State Key Laboratory for Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Byung-Ho Kang
- Centre for Cell and Developmental Biology, State Key Laboratory for Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
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53
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Lippens S, Kremer A, Borghgraef P, Guérin CJ. Serial block face-scanning electron microscopy for volume electron microscopy. Methods Cell Biol 2019; 152:69-85. [PMID: 31326027 DOI: 10.1016/bs.mcb.2019.04.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
There are different technologies that can be used to obtain a 3D image at nanometer resolution. Over the past decade, there has been a growing interest in applying Serial Block Face Scanning Electron Microscopy (SBF-SEM) in different fields of life science research. This technology has the advantage that it can cover a range of volumes, going from monolayers to multiple tissue layers in all three dimensions. SBF-SEM was originally used in neuroscience and then expanded to other research domains. The whole process of sample preparation for SBF-SEM is very long and consists of many steps, which makes adjustment of a given workflow very challenging. Here we describe the SBF-SEM workflow and those steps in the process that can be tweaked for any sample.
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Affiliation(s)
- Saskia Lippens
- VIB BioImaging Core, VIB, Ghent, Belgium; VIB Inflammation Research Center, VIB, Ghent, Belgium; Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
| | - Anna Kremer
- VIB BioImaging Core, VIB, Ghent, Belgium; VIB Inflammation Research Center, VIB, Ghent, Belgium; Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Peter Borghgraef
- VIB BioImaging Core, VIB, Ghent, Belgium; VIB Inflammation Research Center, VIB, Ghent, Belgium; Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Christopher J Guérin
- VIB BioImaging Core, VIB, Ghent, Belgium; VIB Inflammation Research Center, VIB, Ghent, Belgium; Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
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54
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Abstract
Focused ion beam-scanning electron microscopy (FIB-SEM) has become a widely used technique in life sciences. To achieve the best data quality, sample preparation is important and has to be adapted to the specimen and the specific application. Here we illustrate three preparation procedures for mouse nervous tissue: First, the use of high-pressure freezing followed by direct imaging of vitrified tissue without any staining in the FIB-SEM under cryo-conditions as direct and fast procedure. Second, a slow procedure involving freeze substitution of frozen samples combined with additional staining for enhanced contrast and plastic embedding. Third, a fast preparation applying microwave-assisted chemical fixation and processing for resin embedding. All three methods of sample preparation are suitable for obtaining data stacks by FIB-SEM acquisition and 3D reconstruction.
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55
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Smith D, Starborg T. Serial block face scanning electron microscopy in cell biology: Applications and technology. Tissue Cell 2019; 57:111-122. [DOI: 10.1016/j.tice.2018.08.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/22/2018] [Accepted: 08/26/2018] [Indexed: 10/28/2022]
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56
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Song K, Gras C, Capin G, Gimber N, Lehmann M, Mohd S, Puchkov D, Rödiger M, Wilhelmi I, Daumke O, Schmoranzer J, Schürmann A, Krauss M. A SEPT1-based scaffold is required for Golgi integrity and function. J Cell Sci 2019; 132:132/3/jcs225557. [PMID: 30709970 PMCID: PMC6382012 DOI: 10.1242/jcs.225557] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/17/2018] [Indexed: 12/13/2022] Open
Abstract
Compartmentalization of membrane transport and signaling processes is of pivotal importance to eukaryotic cell function. While plasma membrane compartmentalization and dynamics are well known to depend on the scaffolding function of septin GTPases, the roles of septins at intracellular membranes have remained largely elusive. Here, we show that the structural and functional integrity of the Golgi depends on its association with a septin 1 (SEPT1)-based scaffold, which promotes local microtubule nucleation and positioning of the Golgi. SEPT1 function depends on the Golgi matrix protein GM130 (also known as GOLGA2) and on centrosomal proteins, including CEP170 and components of γ-tubulin ring complex (γ-Turc), to facilitate the perinuclear concentration of Golgi membranes. Accordingly, SEPT1 depletion triggers a massive fragmentation of the Golgi ribbon, thereby compromising anterograde membrane traffic at the level of the Golgi.
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Affiliation(s)
- Kyungyeun Song
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Molecular Pharmacology and Cell Biology, 13125 Berlin, Germany
| | - Claudia Gras
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Molecular Pharmacology and Cell Biology, 13125 Berlin, Germany
| | - Gabrielle Capin
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Molecular Pharmacology and Cell Biology, 13125 Berlin, Germany
| | - Niclas Gimber
- Charité Universitätsmedizin Berlin, Advanced Medical Bioimaging Core Facility - AMBIO, 10117 Berlin, Germany
| | - Martin Lehmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Cellular Imaging Facility, 13125 Berlin, Germany
| | - Saif Mohd
- Max-Delmbrück-Centrum für Molekulare Medizin, 13125 Berlin, Germany
| | - Dmytro Puchkov
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Cellular Imaging Facility, 13125 Berlin, Germany
| | - Maria Rödiger
- Deutsches Institut für Ernährungsforschung, Potsdam Rehbrücke, and German Center for Diabetes Research (DZD), München-Neuherberg, 14558 Potsdam-Rehbrücke, Germany
| | - Ilka Wilhelmi
- Deutsches Institut für Ernährungsforschung, Potsdam Rehbrücke, and German Center for Diabetes Research (DZD), München-Neuherberg, 14558 Potsdam-Rehbrücke, Germany
| | - Oliver Daumke
- Max-Delmbrück-Centrum für Molekulare Medizin, 13125 Berlin, Germany
| | - Jan Schmoranzer
- Charité Universitätsmedizin Berlin, Advanced Medical Bioimaging Core Facility - AMBIO, 10117 Berlin, Germany
| | - Annette Schürmann
- Deutsches Institut für Ernährungsforschung, Potsdam Rehbrücke, and German Center for Diabetes Research (DZD), München-Neuherberg, 14558 Potsdam-Rehbrücke, Germany
| | - Michael Krauss
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) Berlin, Molecular Pharmacology and Cell Biology, 13125 Berlin, Germany
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57
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Nguyen HB, Thai TQ, Sui Y, Azuma M, Fujiwara K, Ohno N. Methodological Improvements With Conductive Materials for Volume Imaging of Neural Circuits by Electron Microscopy. Front Neural Circuits 2018; 12:108. [PMID: 30532696 PMCID: PMC6265348 DOI: 10.3389/fncir.2018.00108] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 11/13/2018] [Indexed: 12/29/2022] Open
Abstract
Recent advancements in electron microscope volume imaging, such as serial imaging using scanning electron microscopy (SEM), have facilitated the acquisition of three-dimensional ultrastructural information of biological samples. These advancements help build a comprehensive understanding of the functional structures in entire organelles, cells, organs and organisms, including large-scale wiring maps of neural circuitry in various species. Advanced volume imaging of biological specimens has often been limited by artifacts and insufficient contrast, which are partly caused by problems in staining, serial sectioning and electron beam irradiation. To address these issues, methods of sample preparation have been modified and improved in order to achieve better resolution and higher signal-to-noise ratios (SNRs) in large tissue volumes. These improvements include the development of new embedding media for electron microscope imaging that have desirable physical properties such as less deformation in the electron beam and higher stability for sectioning. The optimization of embedding media involves multiple resins and filler materials including biological tissues, metallic particles and conductive carbon black. These materials alter the physical properties of the embedding media, such as conductivity, which reduces specimen charge, ameliorates damage to sections, reduces image deformation and results in better ultrastructural data. These improvements and further studies to improve electron microscope volume imaging methods provide options for better scale, quality and throughput in the three-dimensional ultrastructural analyses of biological samples. These efforts will enable a deeper understanding of neuronal circuitry and the structural foundation of basic and higher brain functions.
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Affiliation(s)
- Huy Bang Nguyen
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences (NIPS), Okazaki, Japan
- Department of Anatomy and Structural Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Japan
- Department of Anatomy, Faculty of Medicine, University of Medicine and Pharmacy (UMP), Ho Chi Minh City, Vietnam
| | - Truc Quynh Thai
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences (NIPS), Okazaki, Japan
- Department of Anatomy and Structural Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Japan
| | - Yang Sui
- Department of Anatomy and Structural Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Japan
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
| | - Morio Azuma
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
| | - Ken Fujiwara
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
| | - Nobuhiko Ohno
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences (NIPS), Okazaki, Japan
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
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58
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Kubota Y, Sohn J, Kawaguchi Y. Large Volume Electron Microscopy and Neural Microcircuit Analysis. Front Neural Circuits 2018; 12:98. [PMID: 30483066 PMCID: PMC6240581 DOI: 10.3389/fncir.2018.00098] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 10/17/2018] [Indexed: 12/23/2022] Open
Abstract
One recent technical innovation in neuroscience is microcircuit analysis using three-dimensional reconstructions of neural elements with a large volume Electron microscopy (EM) data set. Large-scale data sets are acquired with newly-developed electron microscope systems such as automated tape-collecting ultramicrotomy (ATUM) with scanning EM (SEM), serial block-face EM (SBEM) and focused ion beam-SEM (FIB-SEM). Currently, projects are also underway to develop computer applications for the registration and segmentation of the serially-captured electron micrographs that are suitable for analyzing large volume EM data sets thoroughly and efficiently. The analysis of large volume data sets can bring innovative research results. These recently available techniques promote our understanding of the functional architecture of the brain.
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Affiliation(s)
- Yoshiyuki Kubota
- Division of Cerebral Circuitry, National Institute for Physiological Sciences (NIPS), Okazaki, Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Japan
| | - Jaerin Sohn
- Division of Cerebral Circuitry, National Institute for Physiological Sciences (NIPS), Okazaki, Japan
- Research Fellow of Japan Society for the Promotion of Science (JSPS), Tokyo, Japan
| | - Yasuo Kawaguchi
- Division of Cerebral Circuitry, National Institute for Physiological Sciences (NIPS), Okazaki, Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Japan
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59
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Wanner AA, Vishwanathan A. Methods for Mapping Neuronal Activity to Synaptic Connectivity: Lessons From Larval Zebrafish. Front Neural Circuits 2018; 12:89. [PMID: 30410437 PMCID: PMC6209671 DOI: 10.3389/fncir.2018.00089] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/28/2018] [Indexed: 12/29/2022] Open
Abstract
For a mechanistic understanding of neuronal circuits in the brain, a detailed description of information flow is necessary. Thereby it is crucial to link neuron function to the underlying circuit structure. Multiphoton calcium imaging is the standard technique to record the activity of hundreds of neurons simultaneously. Similarly, recent advances in high-throughput electron microscopy techniques allow for the reconstruction of synaptic resolution wiring diagrams. These two methods can be combined to study both function and structure in the same specimen. Due to its small size and optical transparency, the larval zebrafish brain is one of the very few vertebrate systems where both, activity and connectivity of all neurons from entire, anatomically defined brain regions, can be analyzed. Here, we describe different methods and the tools required for combining multiphoton microscopy with dense circuit reconstruction from electron microscopy stacks of entire brain regions in the larval zebrafish.
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Affiliation(s)
- Adrian A Wanner
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, United States
| | - Ashwin Vishwanathan
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, United States
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60
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Genoud C, Titze B, Graff-Meyer A, Friedrich RW. Fast Homogeneous En Bloc Staining of Large Tissue Samples for Volume Electron Microscopy. Front Neuroanat 2018; 12:76. [PMID: 30323746 PMCID: PMC6172304 DOI: 10.3389/fnana.2018.00076] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 08/29/2018] [Indexed: 11/15/2022] Open
Abstract
Fixation and staining of large tissue samples are critical for the acquisition of volumetric electron microscopic image datasets and the subsequent reconstruction of neuronal circuits. Efficient protocols exist for the staining of small samples, but uniform contrast is often difficult to achieve when the sample diameter exceeds a few hundred micrometers. Recently, a protocol (BROPA, brain-wide reduced-osmium staining with pyrogallol-mediated amplification) was developed that achieves homogeneous staining of the entire mouse brain but requires very long sample preparation times. By exploring modifications of this protocol we developed a substantially faster procedure, fBROPA, that allows for reliable high-quality staining of tissue blocks on the millimeter scale. Modifications of the original BROPA protocol include drastically reduced incubation times and a lead aspartate incubation to increase sample conductivity. Using this procedure, whole brains from adult zebrafish were stained within 4 days. Homogenous high-contrast staining was achieved throughout the brain. High-quality image stacks with voxel sizes of 10 × 10 × 25 nm3 were obtained by serial block-face imaging using an electron dose of ~15 e−/nm2. No obvious reduction in staining quality was observed in comparison to smaller samples stained by other state-of-the-art procedures. Furthermore, high-quality images with minimal charging artifacts were obtained from non-neural tissues with low membrane density. fBROPA is therefore likely to be a versatile and efficient sample preparation protocol for a wide range of applications in volume electron microscopy.
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Affiliation(s)
- Christel Genoud
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Benjamin Titze
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | | | - Rainer W Friedrich
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.,Faculty of Natural Sciences, University of Basel, Basel, Switzerland
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61
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Coggan JS, Calì C, Keller D, Agus M, Boges D, Abdellah M, Kare K, Lehväslaiho H, Eilemann S, Jolivet RB, Hadwiger M, Markram H, Schürmann F, Magistretti PJ. A Process for Digitizing and Simulating Biologically Realistic Oligocellular Networks Demonstrated for the Neuro-Glio-Vascular Ensemble. Front Neurosci 2018; 12:664. [PMID: 30319342 PMCID: PMC6171468 DOI: 10.3389/fnins.2018.00664] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/04/2018] [Indexed: 01/01/2023] Open
Abstract
One will not understand the brain without an integrated exploration of structure and function, these attributes being two sides of the same coin: together they form the currency of biological computation. Accordingly, biologically realistic models require the re-creation of the architecture of the cellular components in which biochemical reactions are contained. We describe here a process of reconstructing a functional oligocellular assembly that is responsible for energy supply management in the brain and creating a computational model of the associated biochemical and biophysical processes. The reactions that underwrite thought are both constrained by and take advantage of brain morphologies pertaining to neurons, astrocytes and the blood vessels that deliver oxygen, glucose and other nutrients. Each component of this neuro-glio-vasculature ensemble (NGV) carries-out delegated tasks, as the dynamics of this system provide for each cell-type its own energy requirements while including mechanisms that allow cooperative energy transfers. Our process for recreating the ultrastructure of cellular components and modeling the reactions that describe energy flow uses an amalgam of state-of the-art techniques, including digital reconstructions of electron micrographs, advanced data analysis tools, computational simulations and in silico visualization software. While we demonstrate this process with the NGV, it is equally well adapted to any cellular system for integrating multimodal cellular data in a coherent framework.
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Affiliation(s)
- Jay S Coggan
- Blue Brain Project, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
| | - Corrado Calì
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Daniel Keller
- Blue Brain Project, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
| | - Marco Agus
- Visual Computing Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.,CRS4, Center of Research and Advanced Studies in Sardinia, Visual Computing, Pula, Italy
| | - Daniya Boges
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Marwan Abdellah
- Blue Brain Project, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
| | - Kalpana Kare
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Heikki Lehväslaiho
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.,CSC - IT Center for Science, Espoo, Finland
| | - Stefan Eilemann
- Blue Brain Project, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
| | - Renaud Blaise Jolivet
- Département de Physique Nucléaire et Corpusculaire, University of Geneva, Geneva, Switzerland.,The European Organization for Nuclear Research, Geneva, Switzerland
| | - Markus Hadwiger
- Visual Computing Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Henry Markram
- Blue Brain Project, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
| | - Felix Schürmann
- Blue Brain Project, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
| | - Pierre J Magistretti
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
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62
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Biological serial block face scanning electron microscopy at improved z-resolution based on Monte Carlo model. Sci Rep 2018; 8:12985. [PMID: 30154532 PMCID: PMC6113311 DOI: 10.1038/s41598-018-31231-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 08/10/2018] [Indexed: 12/12/2022] Open
Abstract
Serial block-face electron microscopy (SBEM) provides nanoscale 3D ultrastructure of embedded and stained cells and tissues in volumes of up to 107 µm3. In SBEM, electrons with 1–3 keV energies are incident on a specimen block, from which backscattered electron (BSE) images are collected with x, y resolution of 5–10 nm in the block-face plane, and successive layers are removed by an in situ ultramicrotome. Spatial resolution along the z-direction, however, is limited to around 25 nm by the minimum cutting thickness. To improve the z-resolution, we have extracted depth information from BSE images acquired at dual primary beam energies, using Monte Carlo simulations of electron scattering. The relationship between depth of stain and ratio of dual-energy BSE intensities enables us to determine 3D structure with a ×2 improvement in z-resolution. We demonstrate the technique by sub-slice imaging of hepatocyte membranes in liver tissue.
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63
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Subgroup Characteristics of Marine Methane-Oxidizing ANME-2 Archaea and Their Syntrophic Partners as Revealed by Integrated Multimodal Analytical Microscopy. Appl Environ Microbiol 2018; 84:AEM.00399-18. [PMID: 29625978 DOI: 10.1128/aem.00399-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 03/31/2018] [Indexed: 02/06/2023] Open
Abstract
Phylogenetically diverse environmental ANME archaea and sulfate-reducing bacteria cooperatively catalyze the anaerobic oxidation of methane oxidation (AOM) in multicelled consortia within methane seep environments. To better understand these cells and their symbiotic associations, we applied a suite of electron microscopy approaches, including correlative fluorescence in situ hybridization-electron microscopy (FISH-EM), transmission electron microscopy (TEM), and serial block face scanning electron microscopy (SBEM) three-dimensional (3D) reconstructions. FISH-EM of methane seep-derived consortia revealed phylogenetic variability in terms of cell morphology, ultrastructure, and storage granules. Representatives of the ANME-2b clade, but not other ANME-2 groups, contained polyphosphate-like granules, while some bacteria associated with ANME-2a/2c contained two distinct phases of iron mineral chains resembling magnetosomes. 3D segmentation of two ANME-2 consortium types revealed cellular volumes of ANME and their symbiotic partners that were larger than previous estimates based on light microscopy. Polyphosphate-like granule-containing ANME (tentatively termed ANME-2b) were larger than both ANME with no granules and partner bacteria. This cell type was observed with up to 4 granules per cell, and the volume of the cell was larger in proportion to the number of granules inside it, but the percentage of the cell occupied by these granules did not vary with granule number. These results illuminate distinctions between ANME-2 archaeal lineages and partnering bacterial populations that are apparently unified in their ability to perform anaerobic methane oxidation.IMPORTANCE Methane oxidation in anaerobic environments can be accomplished by a number of archaeal groups, some of which live in syntrophic relationships with bacteria in structured consortia. Little is known of the distinguishing characteristics of these groups. Here, we applied imaging approaches to better understand the properties of these cells. We found unexpected morphological, structural, and volume variability of these uncultured groups by correlating fluorescence labeling of cells with electron microscopy observables.
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64
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Tsang TK, Bushong EA, Boassa D, Hu J, Romoli B, Phan S, Dulcis D, Su CY, Ellisman MH. High-quality ultrastructural preservation using cryofixation for 3D electron microscopy of genetically labeled tissues. eLife 2018; 7:35524. [PMID: 29749931 PMCID: PMC5988420 DOI: 10.7554/elife.35524] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 05/09/2018] [Indexed: 02/06/2023] Open
Abstract
Electron microscopy (EM) offers unparalleled power to study cell substructures at the nanoscale. Cryofixation by high-pressure freezing offers optimal morphological preservation, as it captures cellular structures instantaneously in their near-native state. However, the applicability of cryofixation is limited by its incompatibility with diaminobenzidine labeling using genetic EM tags and the high-contrast en bloc staining required for serial block-face scanning electron microscopy (SBEM). In addition, it is challenging to perform correlated light and electron microscopy (CLEM) with cryofixed samples. Consequently, these powerful methods cannot be applied to address questions requiring optimal morphological preservation. Here, we developed an approach that overcomes these limitations; it enables genetically labeled, cryofixed samples to be characterized with SBEM and 3D CLEM. Our approach is broadly applicable, as demonstrated in cultured cells, Drosophila olfactory organ and mouse brain. This optimization exploits the potential of cryofixation, allowing for quality ultrastructural preservation for diverse EM applications.
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Affiliation(s)
- Tin Ki Tsang
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Eric A Bushong
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California, San Diego, La Jolla, United States
| | - Daniela Boassa
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California, San Diego, La Jolla, United States
| | - Junru Hu
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California, San Diego, La Jolla, United States
| | - Benedetto Romoli
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, United States
| | - Sebastien Phan
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California, San Diego, La Jolla, United States
| | - Davide Dulcis
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, United States
| | - Chih-Ying Su
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Mark H Ellisman
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California, San Diego, La Jolla, United States.,Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, United States
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Comparison of 3D cellular imaging techniques based on scanned electron probes: Serial block face SEM vs. Axial bright-field STEM tomography. J Struct Biol 2018; 202:216-228. [PMID: 29408702 DOI: 10.1016/j.jsb.2018.01.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 01/26/2018] [Accepted: 01/30/2018] [Indexed: 11/22/2022]
Abstract
Microscopies based on focused electron probes allow the cell biologist to image the 3D ultrastructure of eukaryotic cells and tissues extending over large volumes, thus providing new insight into the relationship between cellular architecture and function of organelles. Here we compare two such techniques: electron tomography in conjunction with axial bright-field scanning transmission electron microscopy (BF-STEM), and serial block face scanning electron microscopy (SBF-SEM). The advantages and limitations of each technique are illustrated by their application to determining the 3D ultrastructure of human blood platelets, by considering specimen geometry, specimen preparation, beam damage and image processing methods. Many features of the complex membranes composing the platelet organelles can be determined from both approaches, although STEM tomography offers a higher ∼3 nm isotropic pixel size, compared with ∼5 nm for SBF-SEM in the plane of the block face and ∼30 nm in the perpendicular direction. In this regard, we demonstrate that STEM tomography is advantageous for visualizing the platelet canalicular system, which consists of an interconnected network of narrow (∼50-100 nm) membranous cisternae. In contrast, SBF-SEM enables visualization of complete platelets, each of which extends ∼2 µm in minimum dimension, whereas BF-STEM tomography can typically only visualize approximately half of the platelet volume due to a rapid non-linear loss of signal in specimens of thickness greater than ∼1.5 µm. We also show that the limitations of each approach can be ameliorated by combining 3D and 2D measurements using a stereological approach.
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