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Zimyanin V, Redemann S. Microtubule length correlates with spindle length in C. elegans meiosis. Cytoskeleton (Hoboken) 2024. [PMID: 38450962 DOI: 10.1002/cm.21849] [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: 11/23/2023] [Revised: 01/24/2024] [Accepted: 02/21/2024] [Indexed: 03/08/2024]
Abstract
The accurate segregation of chromosomes during female meiosis relies on the precise assembly and function of the meiotic spindle, a dynamic structure primarily composed of microtubules. Despite the crucial role of microtubule dynamics in this process, the relationship between microtubule length and spindle size remains elusive. Leveraging Caenorhabditis elegans as a model system, we combined electron tomography and live imaging to investigate this correlation. Our analysis revealed significant changes in spindle length throughout meiosis, coupled with alterations in microtubule length. Surprisingly, while spindle size decreases during the initial stages of anaphase, the size of antiparallel microtubule overlap decreased as well. Detailed electron tomography shows a positive correlation between microtubule length and spindle size, indicating a role of microtubule length in determining spindle dimensions. Notably, microtubule numbers displayed no significant association with spindle length, highlighting the dominance of microtubule length regulation in spindle size determination. Depletion of the microtubule depolymerase KLP-7 led to elongated metaphase spindles with increased microtubule length, supporting the link between microtubule length and spindle size. These findings underscore the pivotal role of regulating microtubule dynamics, and thus microtubule length, in governing spindle rearrangements during meiotic division, shedding light on fundamental mechanisms dictating spindle architecture.
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Affiliation(s)
- Vitaly Zimyanin
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
- Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Stefanie Redemann
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
- Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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Kiewisz R, Baum D, Müller-Reichert T, Fabig G. Serial-section Electron Tomography and Quantitative Analysis of Microtubule Organization in 3D-reconstructed Mitotic Spindles. Bio Protoc 2023; 13:e4849. [PMID: 37900106 PMCID: PMC10603263 DOI: 10.21769/bioprotoc.4849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/15/2023] [Accepted: 08/15/2023] [Indexed: 10/31/2023] Open
Abstract
For the analysis of cellular architecture during mitosis, nanometer resolution is needed to visualize the organization of microtubules in spindles. Here, we present a detailed protocol that can be used to produce 3D reconstructions of whole mitotic spindles in cells grown in culture. For this, we attach mammalian cells enriched in mitotic stages to sapphire discs. Our protocol further involves cryo-immobilization by high-pressure freezing, freeze-substitution, and resin embedding. We then use fluorescence light microscopy to stage select mitotic cells in the resin-embedded samples. This is followed by large-scale electron tomography to reconstruct the selected and staged mitotic spindles in 3D. The generated and stitched electron tomograms are then used to semi-automatically segment the microtubules for subsequent quantitative analysis of spindle organization. Thus, by providing a detailed correlative light and electron microscopy (CLEM) approach, we give cell biologists a toolset to streamline the 3D visualization and analysis of spindle microtubules (http://kiewisz.shinyapps.io/asga). In addition, we refer to a recently launched platform that allows for an interactive display of the 3D-reconstructed mitotic spindles (https://cfci.shinyapps.io/ASGA_3DViewer/). Key features • High-throughput screening of mitotic cells by correlative light and electron microscopy (CLEM). • Serial-section electron tomography of selected cells. • Visualization of mitotic spindles in 3D and quantitative analysis of microtubule organization.
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Affiliation(s)
- Robert Kiewisz
- Simons Machine Learning Center, New York Structural Biology Center, New York, NY, USA
- Experimental Center, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Biocomputing Unit, Centro Nacional de Biotechnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, Cantoblanco, Madrid, Spain
| | - Daniel Baum
- Department of Visual and Data-Centric Computing, Zuse Institute Berlin, Berlin, Germany
| | - Thomas Müller-Reichert
- Experimental Center, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Gunar Fabig
- Experimental Center, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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Chang S, Li L, Hong B, Liu J, Xu Y, Pang K, Zhang L, Han H, Chen X. An intelligent workflow for sub-nanoscale 3D reconstruction of intact synapses from serial section electron tomography. BMC Biol 2023; 21:198. [PMID: 37743470 PMCID: PMC10519085 DOI: 10.1186/s12915-023-01696-x] [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: 12/04/2022] [Accepted: 09/06/2023] [Indexed: 09/26/2023] Open
Abstract
BACKGROUND As an extension of electron tomography (ET), serial section electron tomography (serial section ET) aims to align the tomographic images of multiple thick tissue sections together, to break through the volume limitation of the single section and preserve the sub-nanoscale voxel size. It could be applied to reconstruct the intact synapse, which expands about one micrometer and contains nanoscale vesicles. However, there are several drawbacks of the existing serial section ET methods. First, locating and imaging regions of interest (ROIs) in serial sections during the shooting process is time-consuming. Second, the alignment of ET volumes is difficult due to the missing information caused by section cutting and imaging. Here we report a workflow to simplify the acquisition of ROIs in serial sections, automatically align the volume of serial section ET, and semi-automatically reconstruct the target synaptic structure. RESULTS We propose an intelligent workflow to reconstruct the intact synapse with sub-nanometer voxel size. Our workflow includes rapid localization of ROIs in serial sections, automatic alignment, restoration, assembly of serial ET volumes, and semi-automatic target structure segmentation. For the localization and acquisition of ROIs in serial sections, we use affine transformations to calculate their approximate position based on their relative location in orderly placed sections. For the alignment of consecutive ET volumes with significantly distinct appearances, we use multi-scale image feature matching and the elastic with belief propagation (BP-Elastic) algorithm to align them from coarse to fine. For the restoration of the missing information in ET, we first estimate the number of lost images based on the pixel changes of adjacent volumes after alignment. Then, we present a missing information generation network that is appropriate for small-sample of ET volume using pre-training interpolation network and distillation learning. And we use it to generate the missing information to achieve the whole volume reconstruction. For the reconstruction of synaptic ultrastructures, we use a 3D neural network to obtain them quickly. In summary, our workflow can quickly locate and acquire ROIs in serial sections, automatically align, restore, assemble serial sections, and obtain the complete segmentation result of the target structure with minimal manual manipulation. Multiple intact synapses in wild-type rat were reconstructed at a voxel size of 0.664 nm/voxel to demonstrate the effectiveness of our workflow. CONCLUSIONS Our workflow contributes to obtaining intact synaptic structures at the sub-nanometer scale through serial section ET, which contains rapid ROI locating, automatic alignment, volume reconstruction, and semi-automatic synapse reconstruction. We have open-sourced the relevant code in our workflow, so it is easy to apply it to other labs and obtain complete 3D ultrastructures which size is similar to intact synapses with sub-nanometer voxel size.
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Affiliation(s)
- Sheng Chang
- Institute of Automation, Chinese Academy of Sciences, 100190, Beijing, China
- School of Artificial Intelligence, University of Chinese Academy of Sciences, 100190, Beijing, China
- State Key Laboratory of Multimodal Artificial Intelligence Systems, Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China
| | - Linlin Li
- Institute of Automation, Chinese Academy of Sciences, 100190, Beijing, China
| | - Bei Hong
- Institute of Automation, Chinese Academy of Sciences, 100190, Beijing, China
- School of Artificial Intelligence, University of Chinese Academy of Sciences, 100190, Beijing, China
| | - Jing Liu
- Institute of Automation, Chinese Academy of Sciences, 100190, Beijing, China
| | - Yuxuan Xu
- School of Software and Microelectronics, Peking University, 100871, Beijing, China
| | - Keliang Pang
- School of Pharmaceutical Sciences, Tsinghua University, 100084, Beijing, China
| | - Lina Zhang
- Institute of Automation, Chinese Academy of Sciences, 100190, Beijing, China
| | - Hua Han
- Institute of Automation, Chinese Academy of Sciences, 100190, Beijing, China.
- State Key Laboratory of Multimodal Artificial Intelligence Systems, Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China.
- School of Future Technology, University of Chinese Academy of Sciences, Beijing, 101408, China.
| | - Xi Chen
- Institute of Automation, Chinese Academy of Sciences, 100190, Beijing, China.
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Köckert M, Okafornta CW, Hill C, Ryndyk A, Striese C, Müller-Reichert T, Paliulis L, Fabig G. Ultrastructure of the nebenkern during spermatogenesis in the praying mantid Hierodula membranacea. PLoS One 2023; 18:e0285073. [PMID: 37498864 PMCID: PMC10374135 DOI: 10.1371/journal.pone.0285073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/04/2023] [Indexed: 07/29/2023] Open
Abstract
Spermatogenesis leads to the formation of functional sperm cells. Here we have applied high-pressure freezing in combination with transmission electron microscopy (TEM) to study the ultrastructure of sperm development in subadult males of the praying mantid Hierodula membranacea, a species in which spermatogenesis had not previously been studied. We show the ultrastructure of different stages of sperm development in this species. Thorough examination of TEM data and electron tomographic reconstructions revealed interesting structural features of the nebenkern, an organelle composed of fused mitochondria that has been studied in spermatids of other insect species. We have applied serial-section electron tomography of the nebenkern to demonstrate in three dimensions (3D) that this organelle in H. membranacea is composed of two interwoven mitochondrial derivatives, and that the mitochondrial derivatives are connected by a zipper-like structure at opposing positions. Our approach will enable further ultrastructural analyses of the nebenkern in other organisms.
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Affiliation(s)
- Maria Köckert
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | | | - Charlice Hill
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Anne Ryndyk
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Cynthia Striese
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Thomas Müller-Reichert
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Leocadia Paliulis
- Biology Department, Bucknell University, Lewisburg, PA, United States of America
| | - Gunar Fabig
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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Maheshwari R, Rahman MM, Drey S, Onyundo M, Fabig G, Martinez MAQ, Matus DQ, Müller-Reichert T, Cohen-Fix O. A membrane reticulum, the centriculum, affects centrosome size and function in Caenorhabditis elegans. Curr Biol 2023; 33:791-806.e7. [PMID: 36693370 PMCID: PMC10023444 DOI: 10.1016/j.cub.2022.12.059] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 11/21/2022] [Accepted: 12/21/2022] [Indexed: 01/24/2023]
Abstract
Centrosomes are cellular structures that nucleate microtubules. At their core is a pair of centrioles that recruit pericentriolar material (PCM). Although centrosomes are considered membraneless organelles, in many cell types, including human cells, centrosomes are surrounded by endoplasmic reticulum (ER)-derived membranes of unknown structure and function. Using volume electron microscopy (vEM), we show that centrosomes in the Caenorhabditis elegans (C. elegans) early embryo are surrounded by a three-dimensional (3D), ER-derived membrane reticulum that we call the centriculum, for centrosome-associated membrane reticulum. The centriculum is adjacent to the nuclear envelope in interphase and early mitosis and fuses with the fenestrated nuclear membrane at metaphase. Centriculum formation is dependent on the presence of an underlying centrosome and on microtubules. Conversely, increasing centriculum size by genetic means led to the expansion of the PCM, increased microtubule nucleation capacity, and altered spindle width. The effect of the centriculum on centrosome function suggests that in the C. elegans early embryo, the centrosome is not membraneless. Rather, it is encased in a membrane meshwork that affects its properties. We provide evidence that the centriculum serves as a microtubule "filter," preventing the elongation of a subset of microtubules past the centriculum. Finally, we propose that the fusion between the centriculum and the nuclear membrane contributes to nuclear envelope breakdown by coupling spindle elongation to nuclear membrane fenestration.
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Affiliation(s)
- Richa Maheshwari
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mohammad M Rahman
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Seth Drey
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Megan Onyundo
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gunar Fabig
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Michael A Q Martinez
- Department of Biochemistry and Cell Biology, Stony Brook University, 450 Life Sciences Building, Stony Brook, NY 11794, USA
| | - David Q Matus
- Department of Biochemistry and Cell Biology, Stony Brook University, 450 Life Sciences Building, Stony Brook, NY 11794, USA
| | - Thomas Müller-Reichert
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Orna Cohen-Fix
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA.
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Laguillo-Diego A, Kiewisz R, Martí-Gómez C, Baum D, Müller-Reichert T, Vernos I. MCRS1 modulates the heterogeneity of microtubule minus-end morphologies in mitotic spindles. Mol Biol Cell 2022; 34:ar1. [PMID: 36350698 PMCID: PMC9816640 DOI: 10.1091/mbc.e22-08-0306-t] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Faithful chromosome segregation requires the assembly of a bipolar spindle, consisting of two antiparallel microtubule (MT) arrays having most of their minus ends focused at the spindle poles and their plus ends overlapping in the spindle midzone. Spindle assembly, chromosome alignment, and segregation require highly dynamic MTs. The plus ends of MTs have been extensively investigated but their minus-end structure remains poorly characterized. Here, we used large-scale electron tomography to study the morphology of the MT minus ends in three dimensionally reconstructed metaphase spindles in HeLa cells. In contrast to the homogeneous open morphology of the MT plus ends at the kinetochores, we found that MT minus ends are heterogeneous, showing either open or closed morphologies. Silencing the minus end-specific stabilizer, MCRS1 increased the proportion of open MT minus ends. Altogether, these data suggest a correlation between the morphology and the dynamic state of the MT ends. Taking this heterogeneity of the MT minus-end morphologies into account, our work indicates an unsynchronized behavior of MTs at the spindle poles, thus laying the groundwork for further studies on the complexity of MT dynamics regulation.
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Affiliation(s)
- Alejandra Laguillo-Diego
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona 08003, Spain
| | - Robert Kiewisz
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
| | - Carlos Martí-Gómez
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Daniel Baum
- Department of Visual and Data-Centric Computing, Zuse Institute Berlin, 14195 Berlin, Germany
| | - Thomas Müller-Reichert
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
| | - Isabelle Vernos
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona 08003, Spain,Universitat Pompeu Fabra, Barcelona 08003, Spain,ICREA, Barcelona 08010, Spain,*Address correspondence to: Isabelle Vernos ()
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He B, Zhang Y, Zhang F, Han R. Correction of image distortion in large-field ssEM stitching by an unsupervised intermediate-space solving network. Bioinformatics 2022; 38:4797-4805. [PMID: 35977377 DOI: 10.1093/bioinformatics/btac566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/25/2022] [Accepted: 08/16/2022] [Indexed: 11/13/2022] Open
Abstract
MOTIVATION Serial-section electron microscopy (ssEM) is a powerful technique for cellular visualization, especially for large-scale specimens. Limited by the field of view, a megapixel image of whole-specimen is regularly captured by stitching several overlapping images. However, suffering from distortion by manual operations, lens distortion or electron impact, simple rigid transformations are not adequate for perfect mosaic generation. Non-linear deformation usually causes 'ghosting' phenomenon, especially with high magnification. To date, existing microscope image processing tools provide mature rigid stitching methods but have no idea with local distortion correction. RESULTS In this article, following the development of unsupervised deep learning, we present a multi-scale network to predict the dense deformation fields of image pairs in ssEM and blend these images into a clear and seamless montage. The model is composed of two pyramidal backbones, sharing parameters and interacting with a set of registration modules, in which the pyramidal architecture could effectively capture large deformation according to multi-scale decomposition. A novel 'intermediate-space solving' paradigm is adopted in our model to treat inputted images equally and ensure nearly perfect stitching of the overlapping regions. Combining with the existing rigid transformation method, our model further improves the accuracy of sequential image stitching. Extensive experimental results well demonstrate the superiority of our method over the other traditional methods. AVAILABILITY AND IMPLEMENTATION The code is available at https://github.com/HeracleBT/ssEM_stitching. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Bintao He
- Research Center for Mathematics and Interdisciplinary Sciences, Frontiers Science Center for Nonlinear Expectations (Ministry of Education), Shandong University, Shandong 266000, China
- BioMap, Inc., Beijing 100086, China
| | - Yan Zhang
- The Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100190, China
| | - Fa Zhang
- High Performance Computer Research Center, Institute of Computing Technology, Chinese Academy of Sciences, Beijing 100190, China
| | - Renmin Han
- Research Center for Mathematics and Interdisciplinary Sciences, Frontiers Science Center for Nonlinear Expectations (Ministry of Education), Shandong University, Shandong 266000, China
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Kiewisz R, Fabig G, Conway W, Baum D, Needleman DJ, Müller-Reichert T. Three-dimensional structure of kinetochore-fibers in human mitotic spindles. eLife 2022; 11:75459. [PMID: 35894209 PMCID: PMC9365394 DOI: 10.7554/elife.75459] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 07/24/2022] [Indexed: 11/13/2022] Open
Abstract
During cell division, kinetochore microtubules (KMTs) provide a physical linkage between the chromosomes and the rest of the spindle. KMTs in mammalian cells are organized into bundles, so-called kinetochore-fibers (k-fibers), but the ultrastructure of these fibers is currently not well characterized. Here, we show by large-scale electron tomography that each k-fiber in HeLa cells in metaphase is composed of approximately nine KMTs, only half of which reach the spindle pole. Our comprehensive reconstructions allowed us to analyze the three-dimensional (3D) morphology of k-fibers and their surrounding MTs in detail. We found that k-fibers exhibit remarkable variation in circumference and KMT density along their length, with the pole-proximal side showing a broadening. Extending our structural analysis then to other MTs in the spindle, we further observed that the association of KMTs with non-KMTs predominantly occurs in the spindle pole regions. Our 3D reconstructions have implications for KMT growth and k-fiber self-organization models as covered in a parallel publication applying complementary live-cell imaging in combination with biophysical modeling (Conway et al., 2022). Finally, we also introduce a new visualization tool allowing an interactive display of our 3D spindle data that will serve as a resource for further structural studies on mitosis in human cells.
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Affiliation(s)
- Robert Kiewisz
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Gunar Fabig
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - William Conway
- Department of Physics, Harvard University, Cambridge, United States
| | - Daniel Baum
- Department of Visual and Data-Centric Computing, Zuse Institute Berlin, Berlin, Germany
| | - Daniel J Needleman
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
| | - Thomas Müller-Reichert
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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Three-dimensional SEM, TEM, and STEM for analysis of large-scale biological systems. Histochem Cell Biol 2022; 158:203-211. [PMID: 35829815 PMCID: PMC9399040 DOI: 10.1007/s00418-022-02117-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2022] [Indexed: 12/12/2022]
Abstract
A major aim in structural cell biology is to analyze intact cells in three dimensions, visualize subcellular structures, and even localize proteins at the best possible resolution in three dimensions. Though recently developed electron microscopy tools such as electron tomography, or three-dimensional (3D) scanning electron microscopy, offer great resolution in three dimensions, the challenge is that, the better the resolution, usually the smaller the volume under investigation. Several different approaches to overcome this challenge were presented at the Microscopy Conference in Vienna in 2021. These tools include array tomography, batch tomography, or scanning transmission electron tomography, all of which can nowadays be extended toward correlative light and electron tomography, with greatly increased 3D information. Here, we review these tools, describe the underlying procedures, and discuss their advantages and limits.
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