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Durand M, Paillard J, Ménard MP, Suranyi T, Grondin P, Blarquez O. Pollen identification through convolutional neural networks: First application on a full fossil pollen sequence. PLoS One 2024; 19:e0302424. [PMID: 38687746 PMCID: PMC11060525 DOI: 10.1371/journal.pone.0302424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 04/03/2024] [Indexed: 05/02/2024] Open
Abstract
The automation of pollen identification has seen vast improvements in the past years, with Convolutional Neural Networks coming out as the preferred tool to train models. Still, only a small portion of works published on the matter address the identification of fossil pollen. Fossil pollen is commonly extracted from organic sediment cores and are used by paleoecologists to reconstruct past environments, flora, vegetation, and their evolution through time. The automation of fossil pollen identification would allow paleoecologists to save both time and money while reducing bias and uncertainty. However, Convolutional Neural Networks require a large amount of data for training and databases of fossilized pollen are rare and often incomplete. Since machine learning models are usually trained using labelled fresh pollen associated with many different species, there exists a gap between the training data and target data. We propose a method for a large-scale fossil pollen identification workflow. Our proposed method employs an accelerated fossil pollen extraction protocol and Convolutional Neural Networks trained on the labelled fresh pollen of the species most commonly found in Northeastern American organic sediments. We first test our model on fresh pollen and then on a full fossil pollen sequence totalling 196,526 images. Our model achieved an average per class accuracy of 91.2% when tested against fresh pollen. However, we find that our model does not perform as well when tested on fossil data. While our model is overconfident in its predictions, the general abundance patterns remain consistent with the traditional palynologist IDs. Although not yet capable of accurately classifying a whole fossil pollen sequence, our model serves as a proof of concept towards creating a full large-scale identification workflow.
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Affiliation(s)
- Médéric Durand
- Département de Géographie, Université de Montréal, Montréal, Québec, Canada
| | - Jordan Paillard
- Département de Géographie, Université de Montréal, Montréal, Québec, Canada
| | - Marie-Pier Ménard
- Département de Géographie, Université de Montréal, Montréal, Québec, Canada
| | - Thomas Suranyi
- Département de Géographie, Université de Montréal, Montréal, Québec, Canada
- Laboratoire Chrono-Environnement, UMR 6249 CNRS, Université de Franche-Comté, Besançon, France
| | - Pierre Grondin
- Direction de la recherche forestière, Ministère des Ressources naturelles et des Forêts, Québec City, Québec, Canada
| | - Olivier Blarquez
- Département de Géographie, Université de Montréal, Montréal, Québec, Canada
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2
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Snedeker J, Davis BEM, Ranjan R, Wooten M, Blundon J, Chen X. Reduced Levels of Lagging Strand Polymerases Shape Stem Cell Chromatin. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.26.591383. [PMID: 38746451 PMCID: PMC11092439 DOI: 10.1101/2024.04.26.591383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Stem cells display asymmetric histone inheritance while non-stem progenitor cells exhibit symmetric patterns in the Drosophila male germline lineage. Here, we report that components involved in lagging strand synthesis, such as DNA polymerase α and δ (Polα and Polδ), have significantly reduced levels in stem cells compared to progenitor cells. Compromising Polα genetically induces the replication-coupled histone incorporation pattern in progenitor cells to be indistinguishable from that in stem cells, which can be recapitulated using a Polα inhibitor in a concentration-dependent manner. Furthermore, stem cell-derived chromatin fibers display a higher degree of old histone recycling by the leading strand compared to progenitor cell-derived chromatin fibers. However, upon reducing Polα levels in progenitor cells, the chromatin fibers now display asymmetric old histone recycling just like GSC-derived fibers. The old versus new histone asymmetry is comparable between stem cells and progenitor cells at both S-phase and M-phase. Together, these results indicate that developmentally programmed expression of key DNA replication components is important to shape stem cell chromatin. Furthermore, manipulating one crucial DNA replication component can induce replication-coupled histone dynamics in non-stem cells in a manner similar to that in stem cells.
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Affiliation(s)
- Jonathan Snedeker
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Brendon E. M. Davis
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Rajesh Ranjan
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
- Howard Hughes Medical Institute, Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Baltimore, MD 21218, USA
| | - Matthew Wooten
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
- Current address: Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA
| | - Joshua Blundon
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
- Howard Hughes Medical Institute, Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Baltimore, MD 21218, USA
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3
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Broderson M, Niyogi KK, Iwai M. Macroscale structural changes of thylakoid architecture during high light acclimation in Chlamydomonas reinhardtii. PHOTOSYNTHESIS RESEARCH 2024:10.1007/s11120-023-01067-1. [PMID: 38180578 DOI: 10.1007/s11120-023-01067-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 12/04/2023] [Indexed: 01/06/2024]
Abstract
Photoprotection mechanisms are ubiquitous among photosynthetic organisms. The photoprotection capacity of the green alga Chlamydomonas reinhardtii is correlated with protein levels of stress-related light-harvesting complex (LHCSR) proteins, which are strongly induced by high light (HL). However, the dynamic response of overall thylakoid structure during acclimation to growth in HL has not been fully understood. Here, we combined live-cell super-resolution microscopy and analytical membrane subfractionation to investigate macroscale structural changes of thylakoid membranes during HL acclimation in Chlamydomonas. Subdiffraction-resolution live-cell imaging revealed that the overall thylakoid structures became thinned and shrunken during HL acclimation. The stromal space around the pyrenoid also became enlarged. Analytical density-dependent membrane fractionation indicated that the structural changes were partly a consequence of membrane unstacking. The analysis of both an LHCSR loss-of-function mutant, npq4 lhcsr1, and a regulatory mutant that over-expresses LHCSR, spa1-1, showed that structural changes occurred independently of LHCSR protein levels, demonstrating that LHCSR was neither necessary nor sufficient to induce the thylakoid structural changes associated with HL acclimation. In contrast, stt7-9, a mutant lacking a kinase of major light-harvesting antenna proteins, had a slower thylakoid structural response to HL relative to all other lines tested but still showed membrane unstacking. These results indicate that neither LHCSR- nor antenna-phosphorylation-dependent HL acclimation are required for the observed macroscale structural changes of thylakoid membranes in HL conditions.
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Affiliation(s)
- Mimi Broderson
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA
| | - Krishna K Niyogi
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Masakazu Iwai
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA.
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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4
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Gleason RJ, Guo Y, Semancik CS, Ow C, Lakshminarayanan G, Chen X. Developmentally programmed histone H3 expression regulates cellular plasticity at the parental-to-early embryo transition. SCIENCE ADVANCES 2023; 9:eadh0411. [PMID: 37027463 PMCID: PMC10081851 DOI: 10.1126/sciadv.adh0411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 03/08/2023] [Indexed: 06/19/2023]
Abstract
During metazoan development, the marked change in developmental potential from the parental germline to the embryo raises an important question regarding how the next life cycle is reset. As the basic unit of chromatin, histones are essential for regulating chromatin structure and function and, accordingly, transcription. However, the genome-wide dynamics of the canonical, replication-coupled (RC) histones during gametogenesis and embryogenesis remain unknown. In this study, we use CRISPR-Cas9-mediated gene editing in Caenorhabditis elegans to investigate the expression pattern and role of individual RC histone H3 genes and compare them to the histone variant, H3.3. We report a tightly regulated epigenome landscape change from the germline to embryos that are regulated through differential expression of distinct histone gene clusters. Together, this study reveals that a change from a H3.3- to H3-enriched epigenome during embryogenesis restricts developmental plasticity and uncovers distinct roles for individual H3 genes in regulating germline chromatin.
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Affiliation(s)
- Ryan J. Gleason
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Yanrui Guo
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | | | - Cindy Ow
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
- University of California, San Francisco, San Francisco, CA 94143, USA
| | - Gitanjali Lakshminarayanan
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
- Dana-Farber Cancer Institute, Boston, MA 02215 USA
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
- Howard Hughes Medical Institute, Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
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5
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Ranjan R, Snedeker J, Wooten M, Chu C, Bracero S, Mouton T, Chen X. Differential condensation of sister chromatids acts with Cdc6 to ensure asynchronous S-phase entry in Drosophila male germline stem cell lineage. Dev Cell 2022; 57:1102-1118.e7. [PMID: 35483360 PMCID: PMC9134767 DOI: 10.1016/j.devcel.2022.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 01/16/2022] [Accepted: 04/05/2022] [Indexed: 01/06/2023]
Abstract
During Drosophila melanogaster male germline stem cell (GSC) asymmetric division, preexisting old versus newly synthesized histones H3 and H4 are asymmetrically inherited. However, the biological outcomes of this phenomenon have remained unclear. Here, we tracked old and new histones throughout the GSC cell cycle through the use of high spatial and temporal resolution microscopy. We found unique features that differ between old and new histone-enriched sister chromatids, including differences in nucleosome density, chromosomal condensation, and H3 Ser10 phosphorylation. These distinct chromosomal features lead to their differential association with Cdc6, a pre-replication complex component, and subsequent asynchronous DNA replication initiation in the resulting daughter cells. Disruption of asymmetric histone inheritance abolishes differential Cdc6 association and asynchronous S-phase entry, demonstrating that histone asymmetry acts upstream of these critical cell-cycle progression events. Furthermore, disruption of these GSC-specific chromatin features leads to GSC defects, indicating a connection between histone inheritance, cell-cycle progression, and cell fate determination.
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Affiliation(s)
- Rajesh Ranjan
- Howard Hughes Medical Institute, Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA.
| | - Jonathan Snedeker
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Matthew Wooten
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Carolina Chu
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Sabrina Bracero
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Taylar Mouton
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Xin Chen
- Howard Hughes Medical Institute, Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA.
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6
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Attique R, Zafar M, Ahmad M, Zafar S, Ghufran MA, Mustafa MRU, Yaseen G, Ahmad L, Sultana S, Nabila, Zafar A, Majeed S. Pollen morphology of selected melliferous plants and its taxonomic implications using microscopy. Microsc Res Tech 2022; 85:2361-2380. [PMID: 35247018 DOI: 10.1002/jemt.24091] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/17/2022] [Accepted: 02/16/2022] [Indexed: 01/09/2023]
Abstract
This research aimed to explore the melliferous bee flora pollen from arid zones of District Attock, Islamabad Capital and Rawalpindi. Morpho-palynological features has provided key information for the classification and help to explain the taxonomy of several genera and species. Therefore, in this work, we examined the morphological characters of pollen potentially to be used for the species delimitation of bee flora. A total of 18 bee floral species, classified into 12 different families were collected, pressed, identified and then acetolyized to observe the grains under microscopy. Bee pollen can be described by small, medium to large sized morphotypes presenting five types of shapes, prolate spheroidal in (seven species), sub-prolate (six species), oblate spheroidal (three species), oblate and prolate (one species each) was examined. The observed polar and equatorial diameter were found maximum in Zea mays 73.5 μm and Pelargonium inquinans 66.75 μm respectively. Pollen of six different types was found namely: tricolporate, 3-zonocolporate, monoportae, tetracolporate, tetraporate and mononsulcate. Whereas highest value of colpi length was measured in Grewia tenax (24.55 μm). Exine surface nature of pollen was examined echinate psilate and scabrate. Exine thickness noted to be maximum in Verbena tenuisecta (8.40 μm) and minimum in Citrus macrocarpa (0.4 μm). Bee floral species considered difficult to identify based on other morphological traits were successfully distinguished using pollen quantitative and qualitative traits, confirming the importance of pollen morphology to diagnose characters to correctly identify honeybee flora.
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Affiliation(s)
- Rafia Attique
- Department of Plant Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Muhammad Zafar
- Department of Plant Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Mushtaq Ahmad
- Department of Plant Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Sadia Zafar
- Department of Botany, Division of Science and Technology, University of Education, Faisalabad, Pakistan
| | - Muhammad Asad Ghufran
- Department of Environmental Sciences, International Islamic University, Islamabad, Pakistan
| | - Muhammad Raza Ul Mustafa
- Department of Civil and Environmental Engineering, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia.,Resource Sustainability, Institute of Self Sustainable Building, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia
| | - Ghulam Yaseen
- Department of Botany, Division of Science and Technology, University of Education, Lahore, Pakistan
| | - Latif Ahmad
- Department of Botany, Shaheed Benazir Bhutto University Sheringal, Upper Dir, Pakistan
| | - Shazia Sultana
- Department of Plant Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Nabila
- Department of Plant Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Aqeela Zafar
- Department of Plant Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Salman Majeed
- Department of Plant Sciences, Quaid-i-Azam University, Islamabad, Pakistan
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7
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The Development of Microscopy for Super-Resolution: Confocal Microscopy, and Image Scanning Microscopy. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11198981] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Optical methods of super-resolution microscopy, such as confocal microscopy, structured illumination, nonlinear microscopy, and image scanning microscopy are reviewed. These methods avoid strong invasive interaction with a sample, allowing the observation of delicate biological samples. The meaning of resolution and the basic principles and different approaches to superresolution are discussed.
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8
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Sivaguru M, Saw JJ, Wilson EM, Lieske JC, Krambeck AE, Williams JC, Romero MF, Fouke KW, Curtis MW, Kear-Scott JL, Chia N, Fouke BW. Human kidney stones: a natural record of universal biomineralization. Nat Rev Urol 2021; 18:404-432. [PMID: 34031587 DOI: 10.1038/s41585-021-00469-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2021] [Indexed: 02/04/2023]
Abstract
GeoBioMed - a new transdisciplinary approach that integrates the fields of geology, biology and medicine - reveals that kidney stones composed of calcium-rich minerals precipitate from a continuum of repeated events of crystallization, dissolution and recrystallization that result from the same fundamental natural processes that have governed billions of years of biomineralization on Earth. This contextual change in our understanding of renal stone formation opens fundamentally new avenues of human kidney stone investigation that include analyses of crystalline structure and stratigraphy, diagenetic phase transitions, and paragenetic sequences across broad length scales from hundreds of nanometres to centimetres (five Powers of 10). This paradigm shift has also enabled the development of a new kidney stone classification scheme according to thermodynamic energetics and crystalline architecture. Evidence suggests that ≥50% of the total volume of individual stones have undergone repeated in vivo dissolution and recrystallization. Amorphous calcium phosphate and hydroxyapatite spherules coalesce to form planar concentric zoning and sector zones that indicate disequilibrium precipitation. In addition, calcium oxalate dihydrate and calcium oxalate monohydrate crystal aggregates exhibit high-frequency organic-matter-rich and mineral-rich nanolayering that is orders of magnitude higher than layering observed in analogous coral reef, Roman aqueduct, cave, deep subsurface and hot-spring deposits. This higher frequency nanolayering represents the unique microenvironment of the kidney in which potent crystallization promoters and inhibitors are working in opposition. These GeoBioMed insights identify previously unexplored strategies for development and testing of new clinical therapies for the prevention and treatment of kidney stones.
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Affiliation(s)
- Mayandi Sivaguru
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA. .,Carl Zeiss Labs@Location Partner, Carl R. Woese Institute for Genomic Biology University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| | - Jessica J Saw
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Mayo Clinic School of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Elena M Wilson
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - John C Lieske
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Amy E Krambeck
- Department of Urology, Mayo Clinic, Rochester, MN, USA.,Department of Urology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - James C Williams
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Michael F Romero
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.,Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Kyle W Fouke
- Jackson School of Geosciences, University of Texas at Austin, Austin, TX, USA
| | - Matthew W Curtis
- Carl Zeiss Microscopy LLC, One North Broadway, White Plains, NY, USA
| | | | - Nicholas Chia
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Individualized Medicine, Mayo Clinic, Rochester, MN, USA
| | - Bruce W Fouke
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA. .,Carl Zeiss Labs@Location Partner, Carl R. Woese Institute for Genomic Biology University of Illinois at Urbana-Champaign, Urbana, IL, USA. .,School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA. .,Department of Geology, University of Illinois at Urbana-Champaign, Urbana, IL, USA. .,Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA. .,Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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9
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Kahney EW, Zion EH, Sohn L, Viets-Layng K, Johnston R, Chen X. Characterization of histone inheritance patterns in the Drosophila female germline. EMBO Rep 2021; 22:e51530. [PMID: 34031963 PMCID: PMC8406404 DOI: 10.15252/embr.202051530] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 04/02/2021] [Accepted: 04/16/2021] [Indexed: 11/30/2022] Open
Abstract
Stem cells have the unique ability to undergo asymmetric division which produces two daughter cells that are genetically identical, but commit to different cell fates. The loss of this balanced asymmetric outcome can lead to many diseases, including cancer and tissue dystrophy. Understanding this tightly regulated process is crucial in developing methods to treat these abnormalities. Here, we report that during a Drosophila female germline stem cell asymmetric division, the two daughter cells differentially inherit histones at key genes related to either maintaining the stem cell state or promoting differentiation, but not at constitutively active or silenced genes. We combine histone labeling with DNA Oligopaints to distinguish old versus new histones and visualize their inheritance patterns at a single‐gene resolution in asymmetrically dividing cells in vivo. This strategy can be applied to other biological systems involving cell fate change during development or tissue homeostasis in multicellular organisms.
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Affiliation(s)
| | - Emily H Zion
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Lydia Sohn
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Kayla Viets-Layng
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Robert Johnston
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
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10
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Mangeat T, Labouesse S, Allain M, Negash A, Martin E, Guénolé A, Poincloux R, Estibal C, Bouissou A, Cantaloube S, Vega E, Li T, Rouvière C, Allart S, Keller D, Debarnot V, Wang XB, Michaux G, Pinot M, Le Borgne R, Tournier S, Suzanne M, Idier J, Sentenac A. Super-resolved live-cell imaging using random illumination microscopy. CELL REPORTS METHODS 2021; 1:100009. [PMID: 35474693 PMCID: PMC9017237 DOI: 10.1016/j.crmeth.2021.100009] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/12/2021] [Accepted: 04/08/2021] [Indexed: 12/11/2022]
Abstract
Current super-resolution microscopy (SRM) methods suffer from an intrinsic complexity that might curtail their routine use in cell biology. We describe here random illumination microscopy (RIM) for live-cell imaging at super-resolutions matching that of 3D structured illumination microscopy, in a robust fashion. Based on speckled illumination and statistical image reconstruction, easy to implement and user-friendly, RIM is unaffected by optical aberrations on the excitation side, linear to brightness, and compatible with multicolor live-cell imaging over extended periods of time. We illustrate the potential of RIM on diverse biological applications, from the mobility of proliferating cell nuclear antigen (PCNA) in U2OS cells and kinetochore dynamics in mitotic S. pombe cells to the 3D motion of myosin minifilaments deep inside Drosophila tissues. RIM's inherent simplicity and extended biological applicability, particularly for imaging at increased depths, could help make SRM accessible to biology laboratories.
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Affiliation(s)
- Thomas Mangeat
- LITC Core Facility, Centre de Biologie Integrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Simon Labouesse
- Institut Fresnel, Aix Marseille Université, CNRS, Centrale Marseille, Marseille, France
| | - Marc Allain
- Institut Fresnel, Aix Marseille Université, CNRS, Centrale Marseille, Marseille, France
| | - Awoke Negash
- Institut Fresnel, Aix Marseille Université, CNRS, Centrale Marseille, Marseille, France
| | - Emmanuel Martin
- Molecular, Cellular & Developmental Biology (MCD), Center of Integrative Biology (CBI), Toulouse University, CNRS, UPS, Toulouse, France
| | - Aude Guénolé
- Molecular, Cellular & Developmental Biology (MCD), Center of Integrative Biology (CBI), Toulouse University, CNRS, UPS, Toulouse, France
| | - Renaud Poincloux
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Claire Estibal
- LITC Core Facility, Centre de Biologie Integrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Anaïs Bouissou
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Sylvain Cantaloube
- LITC Core Facility, Centre de Biologie Integrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Elodie Vega
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Tong Li
- Molecular, Cellular & Developmental Biology (MCD), Center of Integrative Biology (CBI), Toulouse University, CNRS, UPS, Toulouse, France
| | - Christian Rouvière
- LITC Core Facility, Centre de Biologie Integrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Sophie Allart
- INSERM Université de Toulouse, UPS, CNRS, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France
| | - Debora Keller
- Molecular, Cellular & Developmental Biology (MCD), Center of Integrative Biology (CBI), Toulouse University, CNRS, UPS, Toulouse, France
| | - Valentin Debarnot
- LITC Core Facility, Centre de Biologie Integrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Xia Bo Wang
- Molecular, Cellular & Developmental Biology (MCD), Center of Integrative Biology (CBI), Toulouse University, CNRS, UPS, Toulouse, France
| | - Grégoire Michaux
- Univ Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) - UMR 6290, 35000 Rennes, France
| | - Mathieu Pinot
- Univ Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) - UMR 6290, 35000 Rennes, France
| | - Roland Le Borgne
- Univ Rennes, CNRS, Institut de Génétique et Développement de Rennes (IGDR) - UMR 6290, 35000 Rennes, France
| | - Sylvie Tournier
- Molecular, Cellular & Developmental Biology (MCD), Center of Integrative Biology (CBI), Toulouse University, CNRS, UPS, Toulouse, France
| | - Magali Suzanne
- Molecular, Cellular & Developmental Biology (MCD), Center of Integrative Biology (CBI), Toulouse University, CNRS, UPS, Toulouse, France
| | - Jérome Idier
- LS2N, CNRS UMR 6004, 1 rue de la Noë, F44321 Nantes Cedex 3, France
| | - Anne Sentenac
- Institut Fresnel, Aix Marseille Université, CNRS, Centrale Marseille, Marseille, France
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11
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Olevsko I, Szederkenyi K, Corridon J, Au A, Delhomme B, Bastien T, Fernandes J, Yip C, Oheim M, Salomon A. A simple, inexpensive and multi-scale 3-D fluorescent test sample for optical sectioning microscopies. Microsc Res Tech 2021; 84:2625-2635. [PMID: 34008289 DOI: 10.1002/jemt.23813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 04/05/2021] [Accepted: 04/27/2021] [Indexed: 11/11/2022]
Abstract
Fluorescence standards allow for quality control and for the comparison of data sets across instruments and laboratories in applications of quantitative fluorescence. For example, users of microscopy core facilities can expect a homogenous and time-invariant illumination and an uniform detection sensitivity, which are prerequisites for imaging analysis, tracking or fluorimetric pH or Ca2+ -concentration measurements. Similarly, confirming the three-dimensional (3-D) resolution of optical sectioning microscopes calls for a regular calibration with a standardized point source. The test samples required for such measurements are typically different ones, they are often expensive and they depend much on the very microscope technique used. Similarly, the ever-increasing choice among microscope techniques and geometries increases the demand for comparison across instruments. Here, we advocate and demonstrate the multiple uses of a surprisingly versatile and simple 3-D test sample that can complement existing and much more expensive calibration samples: commercial tissue paper labeled with a fluorescent highlighter pen. We provide relevant sample characteristics and show examples ranging from the sub-μm to cm scale, acquired on epifluorescence, confocal, image scanning, two-photon (2P) and light-sheet microscopes.
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Affiliation(s)
- Ilya Olevsko
- Department of Chemistry, Bar-Ilan University, Institute of Nanotechnology and Advanced Materials (BINA), Ramat-Gan, Israel
| | - Kaitlin Szederkenyi
- Université de Paris, CNRS, SPPIN - Saints-Pères Paris Institute for the Neurosciences, Paris, France.,University of Toronto, Donnelly Centre for Cellular & Biomolecular Research, Toronto, Ontario, Canada
| | - Jennifer Corridon
- Université de Paris, CNRS UMS 2009, INSERM US 36, BioMedTech Facilities, Paris, France.,Université de Paris, Service Commun de Microscopie (SCM), Paris, France
| | - Aaron Au
- University of Toronto, Donnelly Centre for Cellular & Biomolecular Research, Toronto, Ontario, Canada
| | - Brigitte Delhomme
- Université de Paris, CNRS, SPPIN - Saints-Pères Paris Institute for the Neurosciences, Paris, France
| | - Thierry Bastien
- Université de Paris, CNRS UMS 2009, INSERM US 36, BioMedTech Facilities, Paris, France.,Université de Paris, Plateforme de Prototypage, Paris, France
| | - Julien Fernandes
- UTechS Photonic BioImaging, C2RT, Institut Pasteur, Paris, France
| | - Christopher Yip
- University of Toronto, Donnelly Centre for Cellular & Biomolecular Research, Toronto, Ontario, Canada
| | - Martin Oheim
- Université de Paris, CNRS, SPPIN - Saints-Pères Paris Institute for the Neurosciences, Paris, France.,Université de Paris, CNRS UMS 2009, INSERM US 36, BioMedTech Facilities, Paris, France.,Université de Paris, Service Commun de Microscopie (SCM), Paris, France
| | - Adi Salomon
- Department of Chemistry, Bar-Ilan University, Institute of Nanotechnology and Advanced Materials (BINA), Ramat-Gan, Israel.,Université de Paris, CNRS, SPPIN - Saints-Pères Paris Institute for the Neurosciences, Paris, France
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12
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Sims J, Schlögelhofer P, Kurzbauer MT. From Microscopy to Nanoscopy: Defining an Arabidopsis thaliana Meiotic Atlas at the Nanometer Scale. FRONTIERS IN PLANT SCIENCE 2021; 12:672914. [PMID: 34084178 PMCID: PMC8167036 DOI: 10.3389/fpls.2021.672914] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/27/2021] [Indexed: 06/12/2023]
Abstract
Visualization of meiotic chromosomes and the proteins involved in meiotic recombination have become essential to study meiosis in many systems including the model plant Arabidopsis thaliana. Recent advances in super-resolution technologies changed how microscopic images are acquired and analyzed. New technologies enable observation of cells and nuclei at a nanometer scale and hold great promise to the field since they allow observing complex meiotic molecular processes with unprecedented detail. Here, we provide an overview of classical and advanced sample preparation and microscopy techniques with an updated Arabidopsis meiotic atlas based on super-resolution microscopy. We review different techniques, focusing on stimulated emission depletion (STED) nanoscopy, to offer researchers guidance for selecting the optimal protocol and equipment to address their scientific question.
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13
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Qiao Y, Luo Y, Long N, Xing Y, Tu J. Single-Molecular Förster Resonance Energy Transfer Measurement on Structures and Interactions of Biomolecules. MICROMACHINES 2021; 12:492. [PMID: 33925350 PMCID: PMC8145425 DOI: 10.3390/mi12050492] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/21/2021] [Accepted: 04/23/2021] [Indexed: 12/15/2022]
Abstract
Single-molecule Förster resonance energy transfer (smFRET) inherits the strategy of measurement from the effective "spectroscopic ruler" FRET and can be utilized to observe molecular behaviors with relatively high throughput at nanometer scale. The simplicity in principle and configuration of smFRET make it easy to apply and couple with other technologies to comprehensively understand single-molecule dynamics in various application scenarios. Despite its widespread application, smFRET is continuously developing and novel studies based on the advanced platforms have been done. Here, we summarize some representative examples of smFRET research of recent years to exhibit the versatility and note typical strategies to further improve the performance of smFRET measurement on different biomolecules.
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Affiliation(s)
- Yi Qiao
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China; (Y.Q.); (Y.L.); (N.L.)
| | - Yuhan Luo
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China; (Y.Q.); (Y.L.); (N.L.)
| | - Naiyun Long
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China; (Y.Q.); (Y.L.); (N.L.)
| | - Yi Xing
- Institute of Child and Adolescent Health, School of Public Health, Peking University, Beijing 100191, China;
| | - Jing Tu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China; (Y.Q.); (Y.L.); (N.L.)
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14
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DeVree BT, Steiner LM, Głazowska S, Ruhnow F, Herburger K, Persson S, Mravec J. Current and future advances in fluorescence-based visualization of plant cell wall components and cell wall biosynthetic machineries. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:78. [PMID: 33781321 PMCID: PMC8008654 DOI: 10.1186/s13068-021-01922-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 03/05/2021] [Indexed: 05/18/2023]
Abstract
Plant cell wall-derived biomass serves as a renewable source of energy and materials with increasing importance. The cell walls are biomacromolecular assemblies defined by a fine arrangement of different classes of polysaccharides, proteoglycans, and aromatic polymers and are one of the most complex structures in Nature. One of the most challenging tasks of cell biology and biomass biotechnology research is to image the structure and organization of this complex matrix, as well as to visualize the compartmentalized, multiplayer biosynthetic machineries that build the elaborate cell wall architecture. Better knowledge of the plant cells, cell walls, and whole tissue is essential for bioengineering efforts and for designing efficient strategies of industrial deconstruction of the cell wall-derived biomass and its saccharification. Cell wall-directed molecular probes and analysis by light microscopy, which is capable of imaging with a high level of specificity, little sample processing, and often in real time, are important tools to understand cell wall assemblies. This review provides a comprehensive overview about the possibilities for fluorescence label-based imaging techniques and a variety of probing methods, discussing both well-established and emerging tools. Examples of applications of these tools are provided. We also list and discuss the advantages and limitations of the methods. Specifically, we elaborate on what are the most important considerations when applying a particular technique for plants, the potential for future development, and how the plant cell wall field might be inspired by advances in the biomedical and general cell biology fields.
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Affiliation(s)
- Brian T DeVree
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
| | - Lisa M Steiner
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
| | - Sylwia Głazowska
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
| | - Felix Ruhnow
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
| | - Klaus Herburger
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
| | - Staffan Persson
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
- Joint International Research Laboratory of Metabolic and Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Jozef Mravec
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
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15
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Wang N, Wang C, Zhao H, He Y, Lan B, Sun L, Gao Y. The MAMs Structure and Its Role in Cell Death. Cells 2021; 10:cells10030657. [PMID: 33809551 PMCID: PMC7999768 DOI: 10.3390/cells10030657] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 02/06/2023] Open
Abstract
The maintenance of cellular homeostasis involves the participation of multiple organelles. These organelles are associated in space and time, and either cooperate or antagonize each other with regards to cell function. Crosstalk between organelles has become a significant topic in research over recent decades. We believe that signal transduction between organelles, especially the endoplasmic reticulum (ER) and mitochondria, is a factor that can influence the cell fate. As the cellular center for protein folding and modification, the endoplasmic reticulum can influence a range of physiological processes by regulating the quantity and quality of proteins. Mitochondria, as the cellular "energy factory," are also involved in cell death processes. Some researchers regard the ER as the sensor of cellular stress and the mitochondria as an important actuator of the stress response. The scientific community now believe that bidirectional communication between the ER and the mitochondria can influence cell death. Recent studies revealed that the death signals can shuttle between the two organelles. Mitochondria-associated membranes (MAMs) play a vital role in the complex crosstalk between the ER and mitochondria. MAMs are known to play an important role in lipid synthesis, the regulation of Ca2+ homeostasis, the coordination of ER-mitochondrial function, and the transduction of death signals between the ER and the mitochondria. Clarifying the structure and function of MAMs will provide new concepts for studying the pathological mechanisms associated with neurodegenerative diseases, aging, and cancers. Here, we review the recent studies of the structure and function of MAMs and its roles involved in cell death, especially in apoptosis.
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Affiliation(s)
- Nan Wang
- China Japan Union Hospital, Jilin University, Changchun 130031, China; (N.W.); (C.W.); (H.Z.); (Y.H.); (B.L.)
| | - Chong Wang
- China Japan Union Hospital, Jilin University, Changchun 130031, China; (N.W.); (C.W.); (H.Z.); (Y.H.); (B.L.)
| | - Hongyang Zhao
- China Japan Union Hospital, Jilin University, Changchun 130031, China; (N.W.); (C.W.); (H.Z.); (Y.H.); (B.L.)
| | - Yichun He
- China Japan Union Hospital, Jilin University, Changchun 130031, China; (N.W.); (C.W.); (H.Z.); (Y.H.); (B.L.)
| | - Beiwu Lan
- China Japan Union Hospital, Jilin University, Changchun 130031, China; (N.W.); (C.W.); (H.Z.); (Y.H.); (B.L.)
| | - Liankun Sun
- Key Laboratory of Pathobiology, Ministry of Education, Department of Pathophysiology, College of Basic Medical Sciences, Jilin University, Changchun 130012, China
- Correspondence: (L.S.); (Y.G.)
| | - Yufei Gao
- China Japan Union Hospital, Jilin University, Changchun 130031, China; (N.W.); (C.W.); (H.Z.); (Y.H.); (B.L.)
- Correspondence: (L.S.); (Y.G.)
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16
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Kubalová I, Němečková A, Weisshart K, Hřibová E, Schubert V. Comparing Super-Resolution Microscopy Techniques to Analyze Chromosomes. Int J Mol Sci 2021; 22:ijms22041903. [PMID: 33672992 PMCID: PMC7917581 DOI: 10.3390/ijms22041903] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/04/2021] [Accepted: 02/10/2021] [Indexed: 12/21/2022] Open
Abstract
The importance of fluorescence light microscopy for understanding cellular and sub-cellular structures and functions is undeniable. However, the resolution is limited by light diffraction (~200–250 nm laterally, ~500–700 nm axially). Meanwhile, super-resolution microscopy, such as structured illumination microscopy (SIM), is being applied more and more to overcome this restriction. Instead, super-resolution by stimulated emission depletion (STED) microscopy achieving a resolution of ~50 nm laterally and ~130 nm axially has not yet frequently been applied in plant cell research due to the required specific sample preparation and stable dye staining. Single-molecule localization microscopy (SMLM) including photoactivated localization microscopy (PALM) has not yet been widely used, although this nanoscopic technique allows even the detection of single molecules. In this study, we compared protein imaging within metaphase chromosomes of barley via conventional wide-field and confocal microscopy, and the sub-diffraction methods SIM, STED, and SMLM. The chromosomes were labeled by DAPI (4′,6-diamidino-2-phenylindol), a DNA-specific dye, and with antibodies against topoisomerase IIα (Topo II), a protein important for correct chromatin condensation. Compared to the diffraction-limited methods, the combination of the three different super-resolution imaging techniques delivered tremendous additional insights into the plant chromosome architecture through the achieved increased resolution.
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Affiliation(s)
- Ivona Kubalová
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, D-06466 Seeland, Germany;
| | - Alžběta Němečková
- Centre of the Region Hana for Biotechnological and Agricultural Research, Institute of Experimental Botany of the Czech Academy of Sciences, 77900 Olomouc, Czech Republic; (A.N.); (E.H.)
| | | | - Eva Hřibová
- Centre of the Region Hana for Biotechnological and Agricultural Research, Institute of Experimental Botany of the Czech Academy of Sciences, 77900 Olomouc, Czech Republic; (A.N.); (E.H.)
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, D-06466 Seeland, Germany;
- Correspondence: ; Tel.: +49-394-825-212
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17
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Abstract
There has long been a crucial tradeoff between spatial and temporal resolution in imaging. Imaging beyond the diffraction limit of light has traditionally been restricted to be used only on fixed samples or live cells outside of tissue labeled with strong fluorescent signal. Current super-resolution live cell imaging techniques require the use of special fluorescence probes, high illumination, multiple image acquisitions with post-acquisition processing, or often a combination of these processes. These prerequisites significantly limit the biological samples and contexts that this technique can be applied to. Here we describe a method to perform super-resolution (~140 nm XY-resolution) time-lapse fluorescence live cell imaging in situ. This technique is also compatible with low fluorescent intensity, for example, EGFP or mCherry endogenously tagged at lowly expressed genes. As a proof-of-principle, we have used this method to visualize multiple subcellular structures in the Drosophila testis. During tissue preparation, both the cellular structure and tissue morphology are maintained within the dissected testis. Here, we use this technique to image microtubule dynamics, the interactions between microtubules and the nuclear membrane, as well as the attachment of microtubules to centromeres. This technique requires special procedures in sample preparation, sample mounting and immobilizing of specimens. Additionally, the specimens must be maintained for several hours after dissection without compromising cellular function and activity. While we have optimized the conditions for live super-resolution imaging specifically in Drosophila male germline stem cells (GSCs) and progenitor germ cells in dissected testis tissue, this technique is broadly applicable to a variety of different cell types. The ability to observe cells under their physiological conditions without sacrificing either spatial or temporal resolution will serve as an invaluable tool to researchers seeking to address crucial questions in cell biology.
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Affiliation(s)
- Rajesh Ranjan
- Department of Biology, The Johns Hopkins University;
| | - Xin Chen
- Department of Biology, The Johns Hopkins University;
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18
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Dunker S, Motivans E, Rakosy D, Boho D, Mäder P, Hornick T, Knight TM. Pollen analysis using multispectral imaging flow cytometry and deep learning. THE NEW PHYTOLOGIST 2021; 229:593-606. [PMID: 32803754 DOI: 10.1111/nph.16882] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 07/28/2020] [Indexed: 05/24/2023]
Abstract
Pollen identification and quantification are crucial but challenging tasks in addressing a variety of evolutionary and ecological questions (pollination, paleobotany), but also for other fields of research (e.g. allergology, honey analysis or forensics). Researchers are exploring alternative methods to automate these tasks but, for several reasons, manual microscopy is still the gold standard. In this study, we present a new method for pollen analysis using multispectral imaging flow cytometry in combination with deep learning. We demonstrate that our method allows fast measurement while delivering high accuracy pollen identification. A dataset of 426 876 images depicting pollen from 35 plant species was used to train a convolutional neural network classifier. We found the best-performing classifier to yield a species-averaged accuracy of 96%. Even species that are difficult to differentiate using microscopy could be clearly separated. Our approach also allows a detailed determination of morphological pollen traits, such as size, symmetry or structure. Our phylogenetic analyses suggest phylogenetic conservatism in some of these traits. Given a comprehensive pollen reference database, we provide a powerful tool to be used in any pollen study with a need for rapid and accurate species identification, pollen grain quantification and trait extraction of recent pollen.
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Affiliation(s)
- Susanne Dunker
- Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, Leipzig, 04318, Germany
- German Centre for Integrative Biodiversity Research - iDiv, Deutscher Platz 5a, Leipzig, 04103, Germany
| | - Elena Motivans
- German Centre for Integrative Biodiversity Research - iDiv, Deutscher Platz 5a, Leipzig, 04103, Germany
- Helmholtz-Centre for Environmental Research - UFZ, Am Kirchtor 1, Halle (Saale), 06120, Germany
- Martin Luther University Halle-Wittenberg, Am Kirchtor 1, Halle (Saale), 06108, Germany
| | - Demetra Rakosy
- Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, Leipzig, 04318, Germany
- German Centre for Integrative Biodiversity Research - iDiv, Deutscher Platz 5a, Leipzig, 04103, Germany
| | - David Boho
- Software Engineering for Safety-Critical Systems Group, Technische Universität Ilmenau, Ilmenau, 98693, Germany
| | - Patrick Mäder
- Software Engineering for Safety-Critical Systems Group, Technische Universität Ilmenau, Ilmenau, 98693, Germany
| | - Thomas Hornick
- Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, Leipzig, 04318, Germany
- German Centre for Integrative Biodiversity Research - iDiv, Deutscher Platz 5a, Leipzig, 04103, Germany
| | - Tiffany M Knight
- German Centre for Integrative Biodiversity Research - iDiv, Deutscher Platz 5a, Leipzig, 04103, Germany
- Helmholtz-Centre for Environmental Research - UFZ, Am Kirchtor 1, Halle (Saale), 06120, Germany
- Martin Luther University Halle-Wittenberg, Am Kirchtor 1, Halle (Saale), 06108, Germany
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19
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Romero IC, Kong S, Fowlkes CC, Jaramillo C, Urban MA, Oboh-Ikuenobe F, D'Apolito C, Punyasena SW. Improving the taxonomy of fossil pollen using convolutional neural networks and superresolution microscopy. Proc Natl Acad Sci U S A 2020; 117:28496-28505. [PMID: 33097671 PMCID: PMC7668113 DOI: 10.1073/pnas.2007324117] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Taxonomic resolution is a major challenge in palynology, largely limiting the ecological and evolutionary interpretations possible with deep-time fossil pollen data. We present an approach for fossil pollen analysis that uses optical superresolution microscopy and machine learning to create a quantitative and higher throughput workflow for producing palynological identifications and hypotheses of biological affinity. We developed three convolutional neural network (CNN) classification models: maximum projection (MPM), multislice (MSM), and fused (FM). We trained the models on the pollen of 16 genera of the legume tribe Amherstieae, and then used these models to constrain the biological classifications of 48 fossil Striatopollis specimens from the Paleocene, Eocene, and Miocene of western Africa and northern South America. All models achieved average accuracies of 83 to 90% in the classification of the extant genera, and the majority of fossil identifications (86%) showed consensus among at least two of the three models. Our fossil identifications support the paleobiogeographic hypothesis that Amherstieae originated in Paleocene Africa and dispersed to South America during the Paleocene-Eocene Thermal Maximum (56 Ma). They also raise the possibility that at least three Amherstieae genera (Crudia, Berlinia, and Anthonotha) may have diverged earlier in the Cenozoic than predicted by molecular phylogenies.
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Affiliation(s)
- Ingrid C Romero
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801;
| | - Shu Kong
- Robotics Institute, Carnegie Mellon University, Pittsburgh, PA 15213
- Department of Computer Science, University of California, Irvine, CA 92697
| | - Charless C Fowlkes
- Department of Computer Science, University of California, Irvine, CA 92697
| | - Carlos Jaramillo
- Center for Tropical Paleoecology and Archaeology, Smithsonian Tropical Research Institute, Ancon, 0843-03092, Panama
- Institut des Sciences de l'Évolution de Montpellier, Université de Montpellier, CNRS, Ecole Pratique des Hautes Études, Institut de Recherche pour le Développement, Montpellier, 34095, France
- Department of Geology, Faculty of Sciences, University of Salamanca, Salamanca, 37008, Spain
| | - Michael A Urban
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
- Department of Biology, University of New Brunswick, Fredericton, NB, E3B 5A3, Canada
| | - Francisca Oboh-Ikuenobe
- Department of Geosciences and Geological and Petroleum Engineering, Missouri University of Science and Technology, Rolla, MO 65409
| | - Carlos D'Apolito
- Faculdade de Geociencias, Universidade Federal de Mato Grosso, Cuiaba, 78000, Brazil
| | - Surangi W Punyasena
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801;
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20
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Radja A. Pollen wall patterns as a model for biological self-assembly. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2020; 336:629-641. [PMID: 32991047 PMCID: PMC9292386 DOI: 10.1002/jez.b.23005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 08/26/2020] [Accepted: 08/28/2020] [Indexed: 12/21/2022]
Abstract
We are still far from being able to predict organisms' shapes purely from their genetic codes. While it is imperative to identify which encoded macromolecules contribute to a phenotype, determining how macromolecules self-assemble independently of the genetic code may be equally crucial for understanding shape development. Pollen grains are typically single-celled microgametophytes that have decorated walls of various shapes and patterns. The accumulation of morphological data and a comprehensive understanding of the wall development makes this system ripe for mathematical and physical modeling. Therefore, pollen walls are an excellent system for identifying both the genetic products and the physical processes that result in a huge diversity of extracellular morphologies. In this piece, I highlight the current understanding of pollen wall biology relevant for quantification studies and enumerate the modellable aspects of pollen wall patterning and specific approaches that one may take to elucidate how pollen grains build their beautifully patterned walls.
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Affiliation(s)
- Asja Radja
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
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21
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Ma B, Trieu TJ, Cheng J, Zhou S, Tang Q, Xie J, Liu JL, Zhao K, Habib SJ, Chen X. Differential Histone Distribution Patterns in Induced Asymmetrically Dividing Mouse Embryonic Stem Cells. Cell Rep 2020; 32:108003. [PMID: 32783931 PMCID: PMC7962874 DOI: 10.1016/j.celrep.2020.108003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 11/03/2019] [Accepted: 07/15/2020] [Indexed: 12/14/2022] Open
Abstract
Wnt3a-coated beads can induce asymmetric divisions of mouse embryonic stem cells (mESCs), resulting in one self-renewed mESC and one differentiating epiblast stem cell. This provides an opportunity for studying histone inheritance pattern at a single-cell resolution in cell culture. Here, we report that mESCs with Wnt3a-bead induction display nonoverlapping preexisting (old) versus newly synthesized (new) histone H3 patterns, but mESCs without Wnt3a beads have largely overlapping patterns. Furthermore, H4K20me2/3, an old histone-enriched modification, displays a higher instance of asymmetric distribution on chromatin fibers from Wnt3a-induced mESCs than those from non-induced mESCs. These locally distinct distributions between old and new histones have both cellular specificity in Wnt3a-induced mESCs and molecular specificity for histones H3 and H4. Given that post-translational modifications at H3 and H4 carry the major histone modifications, our findings provide a mammalian cell culture system to study histone inheritance for maintaining stem cell fate and for resetting it during differentiation.
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Affiliation(s)
- Binbin Ma
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA; Research Center for Regenerative Medicine, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200120, China; Key Laboratory for the Genetics of Developmental & Neuropsychiatric Disorders (Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tung-Jui Trieu
- Centre for Stem Cells and Regenerative Medicine, King's College London, London SE1 9RT, UK
| | - Ji Cheng
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
| | - Shuang Zhou
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Qingsong Tang
- Systems Biology Center, Division of Intramural Research, NHLBI, NIH, Bethesda, MD, USA
| | - Jing Xie
- Research Center for Regenerative Medicine, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200120, China
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Keji Zhao
- Systems Biology Center, Division of Intramural Research, NHLBI, NIH, Bethesda, MD, USA
| | - Shukry J Habib
- Centre for Stem Cells and Regenerative Medicine, King's College London, London SE1 9RT, UK
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA.
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22
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Barlow AM, Mostaço-Guidolin LB, Osei ET, Booth S, Hackett TL. Super resolution measurement of collagen fibers in biological samples: Validation of a commercial solution for multiphoton microscopy. PLoS One 2020; 15:e0229278. [PMID: 32059025 PMCID: PMC7021303 DOI: 10.1371/journal.pone.0229278] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 02/03/2020] [Indexed: 01/06/2023] Open
Abstract
Multiphoton microscopy is a powerful, non-invasive technique to image biological specimens. One current limitation of multiphoton microscopy is resolution as many of the biological molecules and structures investigated by research groups are similar in size or smaller than the diffraction limit. To date, the combination of multiphoton and super-resolution imaging has proved technically challenging for biology focused laboratories to implement. Here we validate that the commercial super-resolution Airyscan detector from ZEISS, which is based on image scanning microscopy, can be integrated under warranty with a pulsed multi-photon laser to enable multiphoton microscopy with super-resolution. We demonstrate its biological application in two different imaging modalities, second harmonic generation (SHG) and two-photon excited fluorescence (TPEF), to measure the fibre thicknesses of collagen and elastin molecules surpassing the diffraction limit by a factor of 1.7±0.3x and 1.4±0.3x respectively, in human heart and lung tissues, and 3-dimensional in vitro models. We show that enhanced resolution and signal-to-noise of SHG using the Airyscan compared to traditional GaAs detectors allows for automated and precise measurement of collagen fibres using texture analysis in biological tissues.
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Affiliation(s)
- Aaron M. Barlow
- Centre for Heart Lung Innovation, St. Paul’s Hospital, Vancouver, BC, Canada
| | - Leila B. Mostaço-Guidolin
- Centre for Heart Lung Innovation, St. Paul’s Hospital, Vancouver, BC, Canada
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada
- Department of Systems and Computer Engineering, Carleton University, Ottawa, ON, Canada
| | - Emmanuel T. Osei
- Centre for Heart Lung Innovation, St. Paul’s Hospital, Vancouver, BC, Canada
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Steven Booth
- Centre for Heart Lung Innovation, St. Paul’s Hospital, Vancouver, BC, Canada
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Tillie-Louise Hackett
- Centre for Heart Lung Innovation, St. Paul’s Hospital, Vancouver, BC, Canada
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada
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23
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Superresolution imaging of chromatin fibers to visualize epigenetic information on replicative DNA. Nat Protoc 2020; 15:1188-1208. [PMID: 32051613 DOI: 10.1038/s41596-019-0283-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 12/13/2019] [Indexed: 12/12/2022]
Abstract
During DNA replication, the genetic information of a cell is copied. Subsequently, identical genetic information is segregated reliably to the two daughter cells through cell division. Meanwhile, DNA replication is intrinsically linked to the process of chromatin duplication, which is required for regulating gene expression and establishing cell identities. Understanding how chromatin is established, maintained or changed during DNA replication represents a fundamental question in biology. Recently, we developed a method to directly visualize chromatin components at individual replication forks undergoing DNA replication. This method builds upon the existing chromatin fiber technique and combines it with cell type-specific chromatin labeling and superresolution microscopy. In this method, a short pulse of nucleoside analog labels replicative regions in the cells of interest. Chromatin fibers are subsequently isolated and attached to a glass slide, after which a laminar flow of lysis buffer extends the lysed chromatin fibers parallel with the direction of the flow. Fibers are then immunostained for different chromatin-associated proteins and mounted for visualization using superresolution microscopy. Replication foci, or 'bubbles,' are identified by the presence of the incorporated nucleoside analog. For researchers experienced in molecular biology and superresolution microscopy, this protocol typically takes 2-3 d from sample preparation to data acquisition, with an additional day for data processing and quantification.
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24
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Deroubaix A, Moahla B, Penny C. Monitoring of intracellular localization of Hepatitis B virus P22 protein using Laser Scanning Confocal Microscopy and Airyscan. Microsc Res Tech 2020; 83:499-506. [PMID: 31926041 DOI: 10.1002/jemt.23438] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 12/03/2019] [Accepted: 12/27/2019] [Indexed: 11/09/2022]
Abstract
The aim of this study was to assess nucleo-cytoplasmic protein localization to better understand the exact intracellular localization of viral proteins involved with infections. Having determined the general protein localization of hepatitis B virus P22 precore protein, the aim was to more specifically resolve its intracellular organization. This was done using both laser scanning microscopy and Airyscan techniques. Using a 63× objective, the resolution obtained with Airyscan was increased by 1.5-fold as compared to confocal microscopy (p value <.00001).
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Affiliation(s)
- Aurélie Deroubaix
- Life Sciences Imaging Facility, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,HVDRU, School of Clinical Medicine, Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Bongani Moahla
- HVDRU, School of Clinical Medicine, Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Clement Penny
- Life Sciences Imaging Facility, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Oncology Division, School of Clinical Medicine, Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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25
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Jansz N, Nesterova T, Keniry A, Iminitoff M, Hickey PF, Pintacuda G, Masui O, Kobelke S, Geoghegan N, Breslin KA, Willson TA, Rogers K, Kay GF, Fox AH, Koseki H, Brockdorff N, Murphy JM, Blewitt ME. Smchd1 Targeting to the Inactive X Is Dependent on the Xist-HnrnpK-PRC1 Pathway. Cell Rep 2019; 25:1912-1923.e9. [PMID: 30428357 DOI: 10.1016/j.celrep.2018.10.044] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/06/2018] [Accepted: 10/11/2018] [Indexed: 01/08/2023] Open
Abstract
We and others have recently reported that the SMC protein Smchd1 is a regulator of chromosome conformation. Smchd1 is critical for the structure of the inactive X chromosome and at autosomal targets such as the Hox genes. However, it is unknown how Smchd1 is recruited to these sites. Here, we report that Smchd1 localizes to the inactive X via the Xist-HnrnpK-PRC1 (polycomb repressive complex 1) pathway. Contrary to previous reports, Smchd1 does not bind Xist or other RNA molecules with any specificity. Rather, the localization of Smchd1 to the inactive X is H2AK119ub dependent. Following perturbation of this interaction, Smchd1 is destabilized, which has consequences for gene silencing genome-wide. Our work adds Smchd1 to the PRC1 silencing pathway for X chromosome inactivation.
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Affiliation(s)
- Natasha Jansz
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Tatyana Nesterova
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Andrew Keniry
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Megan Iminitoff
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia
| | - Peter F Hickey
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Greta Pintacuda
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Osamu Masui
- Centre for Integrative Medical Sciences, RIKEN Yokohama Institute, 1-7-22, Suehiro-cho, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| | - Simon Kobelke
- School of Human Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Niall Geoghegan
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Kelsey A Breslin
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia
| | - Tracy A Willson
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia
| | - Kelly Rogers
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Graham F Kay
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Archa H Fox
- School of Human Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Haruhiko Koseki
- Centre for Integrative Medical Sciences, RIKEN Yokohama Institute, 1-7-22, Suehiro-cho, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| | - Neil Brockdorff
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - James M Murphy
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Marnie E Blewitt
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia; Department of Genetics, University of Melbourne, Melbourne, VIC 3010, Australia.
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26
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Tasan I, Sustackova G, Zhang L, Kim J, Sivaguru M, HamediRad M, Wang Y, Genova J, Ma J, Belmont AS, Zhao H. CRISPR/Cas9-mediated knock-in of an optimized TetO repeat for live cell imaging of endogenous loci. Nucleic Acids Res 2019; 46:e100. [PMID: 29912475 PMCID: PMC6158506 DOI: 10.1093/nar/gky501] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Accepted: 06/13/2018] [Indexed: 12/30/2022] Open
Abstract
Nuclear organization has an important role in determining genome function; however, it is not clear how spatiotemporal organization of the genome relates to functionality. To elucidate this relationship, a method for tracking any locus of interest is desirable. Recently clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) or transcription activator-like effectors were adapted for imaging endogenous loci; however, they are mostly limited to visualization of repetitive regions. Here, we report an efficient and scalable method named SHACKTeR (Short Homology and CRISPR/Cas9-mediated Knock-in of a TetO Repeat) for live cell imaging of specific chromosomal regions without the need for a pre-existing repetitive sequence. SHACKTeR requires only two modifications to the genome: CRISPR/Cas9-mediated knock-in of an optimized TetO repeat and its visualization by TetR-EGFP expression. Our simplified knock-in protocol, utilizing short homology arms integrated by polymerase chain reaction, was successful at labeling 10 different loci in HCT116 cells. We also showed the feasibility of knock-in into lamina-associated, heterochromatin regions, demonstrating that these regions prefer non-homologous end joining for knock-in. Using SHACKTeR, we were able to observe DNA replication at a specific locus by long-term live cell imaging. We anticipate the general applicability and scalability of our method will enhance causative analyses between gene function and compartmentalization in a high-throughput manner.
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Affiliation(s)
- Ipek Tasan
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Gabriela Sustackova
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Liguo Zhang
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Jiah Kim
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Mayandi Sivaguru
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Mohammad HamediRad
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yuchuan Wang
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Justin Genova
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Jian Ma
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Andrew S Belmont
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Huimin Zhao
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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27
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Wooten M, Snedeker J, Nizami ZF, Yang X, Ranjan R, Urban E, Kim JM, Gall J, Xiao J, Chen X. Asymmetric histone inheritance via strand-specific incorporation and biased replication fork movement. Nat Struct Mol Biol 2019; 26:732-743. [PMID: 31358945 PMCID: PMC6684448 DOI: 10.1038/s41594-019-0269-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 06/17/2019] [Indexed: 02/01/2023]
Abstract
Many stem cells undergo asymmetric division to produce a self-renewing stem cell and a differentiating daughter cell. Here we show that, similarly to H3, histone H4 is inherited asymmetrically in Drosophila melanogaster male germline stem cells undergoing asymmetric division. In contrast, both H2A and H2B are inherited symmetrically. By combining super-resolution microscopy and chromatin fiber analyses with proximity ligation assays on intact nuclei, we find that old H3 is preferentially incorporated by the leading strand, whereas newly synthesized H3 is enriched on the lagging strand. Using a sequential nucleoside analog incorporation assay, we detect a high incidence of unidirectional replication fork movement in testes-derived chromatin and DNA fibers. Biased fork movement coupled with a strand preference in histone incorporation would explain how asymmetric old and new H3 and H4 are established during replication. These results suggest a role for DNA replication in patterning epigenetic information in asymmetrically dividing cells in multicellular organisms.
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Affiliation(s)
- Matthew Wooten
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Jonathan Snedeker
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Zehra F Nizami
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD, USA
| | - Xinxing Yang
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Rajesh Ranjan
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Elizabeth Urban
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Jee Min Kim
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA
| | - Joseph Gall
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD, USA
| | - Jie Xiao
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, Baltimore, MD, USA.
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28
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Image scanning microscopy. Curr Opin Chem Biol 2019; 51:74-83. [DOI: 10.1016/j.cbpa.2019.05.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/01/2019] [Accepted: 05/13/2019] [Indexed: 12/27/2022]
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29
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Sivaguru M, Khaw YM, Inoue M. A Confocal Reflection Super-Resolution Technique to Image Golgi-Cox Stained Neurons. J Microsc 2019; 275:115-130. [PMID: 31237354 DOI: 10.1111/jmi.12821] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 06/20/2019] [Accepted: 06/23/2019] [Indexed: 11/26/2022]
Abstract
Metal-based Golgi-Cox (GC) staining is an established method used to visualise neurons with great morphological detail. Although GC stained samples are imaged routinely under transmitted light microscopy, this method is unable to yield information on the three-dimensional structure of dendrites and neurons and thus help reveal the connective properties of the central nervous system. Although a few studies have attempted simultaneous visualisation of GC staining and antigen-specific fluorescent labelling under a confocal reflection technique, the resolution of both confocal reflection and fluorescence modalities used to acquire GC reflection and fluorescently stained antibody signals are still limited by the diffraction limit of light at about 220 nm. Here, we report a confocal reflection super-resolution technique (CRSR) to break this diffraction barrier, which is achieved by minimising the pinhole size from 1 airy unit (AU) to 0.1 AU. This is achieved by minimising or closing the confocal pinhole size and is possible in this reflection modality, unlike fluorescence, because it is not a photon limited technique. Utilising the lowest wavelength of light available in the system (405 nm), the CRSR technique results in ∼30% lateral and axial resolution improvement. We also show that the CRSR technique can be used in conjunction to visualise both GC and immunofluorescence targets to create precise and improved three-dimensional visualisation and analysis. In addition, using these superresolution confocal reflection data sets from GC in CRSR mode significantly reduced the data overestimation, improving the accuracy of statistical analysis of dendritic spine density and average spine dimensions. Combining the 0.1 AU setting with deconvolution routines, the signal-to-noise ratio and resolution could further be improved an additional ∼20-25%, yielding CRSR images with resolutions up to 2-fold over the diffraction limit both laterally and axially. The improved precision of both visualisation and quantification of subdiffraction limited dendritic spines using the CRSR technique may prove to be critical in investigations that concern changes in detailed neuron morphology under central nervous system disease conditions such as multiple sclerosis and Alzheimer's disease. LAY DESCRIPTION: For over a century, Golgi-Cox (GC) has been a leading staining technique in the field of neuroscience, used to visualise neurons with great morphological detail. GC stained brain or spinal cord samples are conventionally visualised under transmitted light techniques. This limits the view of Golgi-staining to a two-dimensional image. A recent report showed that Golgi staining can be visualised in three-dimensions using the reflection modality of the confocal microscope. This visualisation also allows for the simultaneous acquisition of immunofluorescence signals. However, the reported resolution of Golgi staining confocal reflection is limited by the diffraction limit of light, which is around 220 nm. Here, we report a superresolution confocal reflection technique (CRSR) that achieves superresolution by minimising the pinhole size used in confocal microscopy. The CRSR technique results in ∼30% lateral and axial resolution improvement. Adding a deconvolution step in the final processing could improve the SNR and resolution even further up to 2-fold improvement in resolution over the diffraction limit both laterally and axially. We hope that this improved visualisation will help in investigations that concern changes in detailed neuron morphology under central nervous system disease conditions such as multiple sclerosis and Alzheimer's disease.
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Affiliation(s)
- Mayandi Sivaguru
- Microscopy and Imaging Core Facility, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, U.S.A.,Carl Zeiss Labs at Location Partner, Microscopy and Imaging Core Facility, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, U.S.A
| | - Yee Ming Khaw
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, U.S.A.,Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois, U.S.A
| | - Makoto Inoue
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, U.S.A.,Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois, U.S.A
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30
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Kennedy T, Broadie K. Newly Identified Electrically Coupled Neurons Support Development of the Drosophila Giant Fiber Model Circuit. eNeuro 2018; 5:ENEURO.0346-18.2018. [PMID: 30627638 PMCID: PMC6325540 DOI: 10.1523/eneuro.0346-18.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/29/2018] [Accepted: 11/12/2018] [Indexed: 12/31/2022] Open
Abstract
The Drosophila giant fiber (GF) escape circuit is an extensively studied model for neuron connectivity and function. Researchers have long taken advantage of the simple linear neuronal pathway, which begins at peripheral sensory modalities, travels through the central GF interneuron (GFI) to motor neurons, and terminates on wing/leg muscles. This circuit is more complex than it seems, however, as there exists a complex web of coupled neurons connected to the GFI that widely innervates the thoracic ganglion. Here, we define four new neuron clusters dye coupled to the central GFI, which we name GF coupled (GFC) 1-4. We identify new transgenic Gal4 drivers that express specifically in these neurons, and map both neuronal architecture and synaptic polarity. GFC1-4 share a central site of GFI connectivity, the inframedial bridge, where the neurons each form electrical synapses. Targeted apoptotic ablation of GFC1 reveals a key role for the proper development of the GF circuit, including the maintenance of GFI connectivity with upstream and downstream synaptic partners. GFC1 ablation frequently results in the loss of one GFI, which is always compensated for by contralateral innervation from a branch of the persisting GFI axon. Overall, this work reveals extensively coupled interconnectivity within the GF circuit, and the requirement of coupled neurons for circuit development. Identification of this large population of electrically coupled neurons in this classic model, and the ability to genetically manipulate these electrically synapsed neurons, expands the GF system capabilities for the nuanced, sophisticated circuit dissection necessary for deeper investigations into brain formation.
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Affiliation(s)
- Tyler Kennedy
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, Tennessee 37235
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, Tennessee 37235
- Department of Cell and Developmental Biology, Vanderbilt University and Medical Center, Nashville, Tennessee 37235
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, Tennessee 37235
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31
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Sivaguru M, Saw JJ, Williams JC, Lieske JC, Krambeck AE, Romero MF, Chia N, Schwaderer AL, Alcalde RE, Bruce WJ, Wildman DE, Fried GA, Werth CJ, Reeder RJ, Yau PM, Sanford RA, Fouke BW. Geobiology reveals how human kidney stones dissolve in vivo. Sci Rep 2018; 8:13731. [PMID: 30213974 PMCID: PMC6137216 DOI: 10.1038/s41598-018-31890-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 08/29/2018] [Indexed: 11/26/2022] Open
Abstract
More than 10% of the global human population is now afflicted with kidney stones, which are commonly associated with other significant health problems including diabetes, hypertension and obesity. Nearly 70% of these stones are primarily composed of calcium oxalate, a mineral previously assumed to be effectively insoluble within the kidney. This has limited currently available treatment options to painful passage and/or invasive surgical procedures. We analyze kidney stone thin sections with a combination of optical techniques, which include bright field, polarization, confocal and super-resolution nanometer-scale auto-fluorescence microscopy. Here we demonstrate using interdisciplinary geology and biology (geobiology) approaches that calcium oxalate stones undergo multiple events of dissolution as they crystallize and grow within the kidney. These observations open a fundamentally new paradigm for clinical approaches that include in vivo stone dissolution and identify high-frequency layering of organic matter and minerals as a template for biomineralization in natural and engineered settings.
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Affiliation(s)
- Mayandi Sivaguru
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- Carl Zeiss Labs@Location Partner, Carl R. Woese Institute for Genomic Biology University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| | - Jessica J Saw
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana- Champaign, Urbana, IL, USA.
- Mayo Clinic School of Medicine, Mayo Clinic, Rochester, MN, USA.
| | - James C Williams
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - John C Lieske
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Amy E Krambeck
- Department of Urology, Mayo Clinic, Rochester, MN, USA
- Department of Urology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Michael F Romero
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Nicholas Chia
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
- Department of Individualized Medicine, Mayo Clinic, Rochester, MN, USA
| | - Andrew L Schwaderer
- Department of Pediatric Nephrology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Reinaldo E Alcalde
- Civil, Architectural and Environmental Engineering, University of Texas at Austin, Austin, TX, USA
| | - William J Bruce
- Loyola University Chicago, Stritch School of Medicine, Maywood, IL, USA
| | - Derek E Wildman
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana- Champaign, Urbana, IL, USA
| | - Glenn A Fried
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Carl Zeiss Labs@Location Partner, Carl R. Woese Institute for Genomic Biology University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Charles J Werth
- Civil, Architectural and Environmental Engineering, University of Texas at Austin, Austin, TX, USA
| | - Richard J Reeder
- Department of Geosciences, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Peter M Yau
- Protein Sciences, Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Robert A Sanford
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Geology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Bruce W Fouke
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- Carl Zeiss Labs@Location Partner, Carl R. Woese Institute for Genomic Biology University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- Department of Geology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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McIntosh AL, Huang H, Landrock D, Martin GG, Li S, Kier AB, Schroeder F. Impact of Fabp1 Gene Ablation on Uptake and Degradation of Endocannabinoids in Mouse Hepatocytes. Lipids 2018; 53:561-580. [PMID: 30203570 DOI: 10.1002/lipd.12071] [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: 11/17/2017] [Revised: 06/11/2018] [Accepted: 06/15/2018] [Indexed: 12/30/2022]
Abstract
Liver fatty-acid-binding protein (FABP1, L-FABP) is the major cytosolic binding/chaperone protein for both precursor arachidonic acid (ARA) and the endocannabinoid (EC) products N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG). Although FABP1 regulates hepatic uptake and metabolism of ARA, almost nothing is known regarding FABP1's impact on AEA and 2-AG uptake, intracellular distribution, and targeting of AEA and 2-AG to degradative hepatic enzymes. In vitro assays revealed that FABP1 considerably enhanced monoacylglycerol lipase hydrolysis of 2-AG but only modestly enhanced AEA hydrolysis by fatty-acid amide hydrolase. Conversely, liquid chromatography-mass spectrometry of lipids from Fabp1 gene-ablated (LKO) hepatocytes confirmed that loss of FABP1 markedly diminished hydrolysis of 2-AG. Furthermore, the real-time imaging of novel fluorescent NBD-labeled probes (NBD-AEA, NBD-2-AG, and NBD-ARA) resolved FABP1's impact on uptake vs intracellular targeting/hydrolysis. FABP1 bound NBD-ARA with 2:1 stoichiometry analogous to ARA, but bound NBD-2-AG and NBD-AEA with 1:1 stoichiometry-apparently at different sites in FABP1's binding cavity. All three probes were taken up, but NBD-2-AG and NBD-AEA were targeted to lipid droplets. LKO reduced the uptake of NBD-ARA as expected, significantly enhanced that of NBD-AEA, but had little effect on NBD-2-AG. These data indicated that FABP1 impacts hepatocyte EC levels by binding EC and differentially impacts their intracellular hydrolysis (2-AG) and uptake (AEA).
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Affiliation(s)
- Avery L McIntosh
- Departments of Physiology and Pharmacology, Texas A&M University, 664 Raymond Stotzer Pkwy, 4466 TAMU, College Station, TX 77843-4466, USA
| | - Huan Huang
- Departments of Physiology and Pharmacology, Texas A&M University, 664 Raymond Stotzer Pkwy, 4466 TAMU, College Station, TX 77843-4466, USA
| | - Danilo Landrock
- Departments of Pathobiology, Texas A&M University, 664 Raymond Stotzer Pkwy, 4467 TAMU, College Station, TX 77843-4467, USA
| | - Gregory G Martin
- Departments of Physiology and Pharmacology, Texas A&M University, 664 Raymond Stotzer Pkwy, 4466 TAMU, College Station, TX 77843-4466, USA
| | - Shengrong Li
- Avanti Polar Lipids, 700 Industrial Park Drive, Alabaster, AL 35007-9105, USA
| | - Ann B Kier
- Departments of Pathobiology, Texas A&M University, 664 Raymond Stotzer Pkwy, 4467 TAMU, College Station, TX 77843-4467, USA
| | - Friedhelm Schroeder
- Departments of Physiology and Pharmacology, Texas A&M University, 664 Raymond Stotzer Pkwy, 4466 TAMU, College Station, TX 77843-4466, USA
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Chitnis A, Dalle Nogare D. Time-lapse imaging beyond the diffraction limit. Methods 2018; 150:32-41. [PMID: 30056120 DOI: 10.1016/j.ymeth.2018.07.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 06/12/2018] [Accepted: 07/16/2018] [Indexed: 01/31/2023] Open
Abstract
The zebrafish, with its rapid external development, optical transparency, and the relative ease with which transgenic lines can be created, is rapidly becoming the model of choice for examining developmental processes via time-lapse microscopy. The recent proliferation of techniques for super-resolution imaging now allows for an unprecedented view of embryonic development at high spatial and temporal resolution in live tissues. This review examines both the theoretical basis and practical application of a number of established and emerging super-resolution microscopy techniques, focusing on their application in time-lapse imaging of live zebrafish embryos.
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Affiliation(s)
- Ajay Chitnis
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, United States
| | - Damian Dalle Nogare
- National Institutes of Health, 6 Center Drive, Building 6B Rm 3B315, United States.
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Roy S, Luzwick JW, Schlacher K. SIRF: Quantitative in situ analysis of protein interactions at DNA replication forks. J Cell Biol 2018; 217:1521-1536. [PMID: 29475976 PMCID: PMC5881507 DOI: 10.1083/jcb.201709121] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 01/17/2018] [Accepted: 02/09/2018] [Indexed: 02/07/2023] Open
Abstract
DNA replication reactions are central to diverse cellular processes including development, cancer etiology, drug treatment, and resistance. Many proteins and pathways exist to ensure DNA replication fidelity and protection of stalled or damaged replication forks. Consistently, mutations in proteins involved in DNA replication are implicated in diverse diseases that include defects during embryonic development and immunity, accelerated aging, increased inflammation, blood disease, and cancer. Thus, tools for efficient quantitative analysis of protein interactions at active and stalled replication forks are key for advanced and accurate biological understanding. Here we describe a sensitive single-cell-level assay system for the quantitative analysis of protein interactions with nascent DNA. Specifically, we achieve robust in situ analysis of protein interactions at DNA replication forks (SIRF) using proximity ligation coupled with 5'-ethylene-2'-deoxyuridine click chemistry suitable for multiparameter analysis in heterogeneous cell populations. We provide validation data for sensitivity, accuracy, proximity, and quantitation. Using SIRF, we obtained new insight on the regulation of pathway choice by 53BP1 at transiently stalled replication forks.
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Affiliation(s)
- Sunetra Roy
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, TX
| | - Jessica W Luzwick
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, TX
| | - Katharina Schlacher
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, TX
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Csordás G, Weaver D, Hajnóczky G. Endoplasmic Reticulum-Mitochondrial Contactology: Structure and Signaling Functions. Trends Cell Biol 2018; 28:523-540. [PMID: 29588129 DOI: 10.1016/j.tcb.2018.02.009] [Citation(s) in RCA: 335] [Impact Index Per Article: 55.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 02/23/2018] [Accepted: 02/23/2018] [Indexed: 02/08/2023]
Abstract
Interorganellar contacts are increasingly recognized as central to the control of cellular behavior. These contacts, which typically involve a small fraction of the endomembrane surface, are local communication hubs that resemble synapses. We propose the term contactology to denote the analysis of interorganellar contacts. Endoplasmic reticulum (ER) contacts with mitochondria were recognized several decades ago; major roles in ion and lipid transfer, signaling, and membrane dynamics have been established, while others continue to emerge. The functional diversity of ER-mitochondrial (ER-mito) contacts is mirrored in their structural heterogeneity, with subspecialization likely supported by multiple, different linker-forming protein structures. The nanoscale size of the contacts has made studying their structure, function, and dynamics difficult. This review focuses on the structure of the ER-mito contacts, methods for studying them, and the roles of contacts in Ca2+ and reactive oxygen species (ROS) signaling.
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Affiliation(s)
- György Csordás
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
| | - David Weaver
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
| | - György Hajnóczky
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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A role for domain I of the hepatitis C virus NS5A protein in virus assembly. PLoS Pathog 2018; 14:e1006834. [PMID: 29352312 PMCID: PMC5792032 DOI: 10.1371/journal.ppat.1006834] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 01/31/2018] [Accepted: 12/19/2017] [Indexed: 12/12/2022] Open
Abstract
The NS5A protein of hepatitis C virus (HCV) plays roles in both virus genome replication and assembly. NS5A comprises three domains, of these domain I is believed to be involved exclusively in genome replication. In contrast, domains II and III are required for the production of infectious virus particles and are largely dispensable for genome replication. Domain I is highly conserved between HCV and related hepaciviruses, and is highly structured, exhibiting different dimeric conformations. To investigate the functions of domain I in more detail, we conducted a mutagenic study of 12 absolutely conserved and surface-exposed residues within the context of a JFH-1-derived sub-genomic replicon and infectious virus. Whilst most of these abrogated genome replication, three mutants (P35A, V67A and P145A) retained the ability to replicate but showed defects in virus assembly. P35A exhibited a modest reduction in infectivity, however V67A and P145A produced no infectious virus. Using a combination of density gradient fractionation, biochemical analysis and high resolution confocal microscopy we demonstrate that V67A and P145A disrupted the localisation of NS5A to lipid droplets. In addition, the localisation and size of lipid droplets in cells infected with these two mutants were perturbed compared to wildtype HCV. Biophysical analysis revealed that V67A and P145A abrogated the ability of purified domain I to dimerize and resulted in an increased affinity of binding to HCV 3’UTR RNA. Taken together, we propose that domain I of NS5A plays multiple roles in assembly, binding nascent genomic RNA and transporting it to lipid droplets where it is transferred to Core. Domain I also contributes to a change in lipid droplet morphology, increasing their size. This study reveals novel functions of NS5A domain I in assembly of infectious HCV and provides new perspectives on the virus lifecycle. Hepatitis C virus infects 170 million people worldwide, causing long term liver disease. Recently new therapies comprising direct-acting antivirals (DAAs), small molecule inhibitors of virus proteins, have revolutionised treatment for infected patients. Despite this, we have a limited understanding of how the virus replicates in infected liver cells. Here we identify a previously uncharacterised function of the NS5A protein–a target for one class of DAAs. NS5A is comprised of three domains–we show that the first of these (domain I) plays a role in the production of new, infectious virus particles. Previously it was thought that domain I was only involved in replicating the virus genome. Mutations in domain I perturb dimer formation, enhanced binding to the 3’ end of the virus RNA genome and prevented NS5A from interacting with lipid droplets, cellular lipid storage organelles that are required for assembly of new viruses. We propose that domain I of NS5A plays multiple roles in virus assembly. As domain I is the putative target for one class of DAAs, our observations may have implications for the as yet undefined mode of action of these compounds.
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Pretorius E, Page MJ, Engelbrecht L, Ellis GC, Kell DB. Substantial fibrin amyloidogenesis in type 2 diabetes assessed using amyloid-selective fluorescent stains. Cardiovasc Diabetol 2017; 16:141. [PMID: 29096623 PMCID: PMC5668975 DOI: 10.1186/s12933-017-0624-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 10/23/2017] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND We have previously shown that many chronic, inflammatory diseases are accompanied, and possibly partly caused or exacerbated, by various coagulopathies, manifested as anomalous clots in the form of 'dense matted deposits'. More recently, we have shown that these clots can be amyloid in nature, and that the plasma of healthy controls can be induced to form such clots by the addition of tiny amounts of bacterial lipopolysaccharide or lipoteichoic acid. Type 2 diabetes (T2D) is also accompanied by raised levels of LPS. METHODS We use superresolution and confocal microscopies to investigate the amyloid nature of clots from healthy and T2D individuals. RESULTS We show here, with the established stain thioflavin T and the novel stains Amytracker™ 480 and 680, that the clotting of plasma from type 2 diabetics is also amyloid in nature, and that this may be prevented by the addition of suitable concentrations of LPS-binding protein. CONCLUSION This implies strongly that there is indeed a microbial component to the development of type 2 diabetes, and suggests that LBP might be used as treatment for it and its sequelae.
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Affiliation(s)
- Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, Stellenbosh, 7602, South Africa.
| | - Martin J Page
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, Stellenbosh, 7602, South Africa
| | - Lize Engelbrecht
- Central Analytical Facility, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, Stellenbosh, 7602, South Africa
| | - Graham C Ellis
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, Stellenbosh, 7602, South Africa.,Synexus Helderberg Clinical Research Centre, Helderberg Synexus South Africa, 7G&H Arun Place, Somerset West, 7130, South Africa
| | - Douglas B Kell
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch Private Bag X1 Matieland, Stellenbosh, 7602, South Africa. .,School of Chemistry and Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester, M1 7DN, Lancs, UK.
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Shashkova S, Leake MC. Single-molecule fluorescence microscopy review: shedding new light on old problems. Biosci Rep 2017; 37:BSR20170031. [PMID: 28694303 PMCID: PMC5520217 DOI: 10.1042/bsr20170031] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/08/2017] [Accepted: 07/10/2017] [Indexed: 12/19/2022] Open
Abstract
Fluorescence microscopy is an invaluable tool in the biosciences, a genuine workhorse technique offering exceptional contrast in conjunction with high specificity of labelling with relatively minimal perturbation to biological samples compared with many competing biophysical techniques. Improvements in detector and dye technologies coupled to advances in image analysis methods have fuelled recent development towards single-molecule fluorescence microscopy, which can utilize light microscopy tools to enable the faithful detection and analysis of single fluorescent molecules used as reporter tags in biological samples. For example, the discovery of GFP, initiating the so-called 'green revolution', has pushed experimental tools in the biosciences to a completely new level of functional imaging of living samples, culminating in single fluorescent protein molecule detection. Today, fluorescence microscopy is an indispensable tool in single-molecule investigations, providing a high signal-to-noise ratio for visualization while still retaining the key features in the physiological context of native biological systems. In this review, we discuss some of the recent discoveries in the life sciences which have been enabled using single-molecule fluorescence microscopy, paying particular attention to the so-called 'super-resolution' fluorescence microscopy techniques in live cells, which are at the cutting-edge of these methods. In particular, how these tools can reveal new insights into long-standing puzzles in biology: old problems, which have been impossible to tackle using other more traditional tools until the emergence of new single-molecule fluorescence microscopy techniques.
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Affiliation(s)
- Sviatlana Shashkova
- Department of Physics, Biological Physical Sciences Institute (BPSI), University of York, York YO10 5DD, U.K
- Department of Biology, Biological Physical Sciences Institute (BPSI), University of York, York YO10 5DD, U.K
| | - Mark C Leake
- Department of Physics, Biological Physical Sciences Institute (BPSI), University of York, York YO10 5DD, U.K.
- Department of Biology, Biological Physical Sciences Institute (BPSI), University of York, York YO10 5DD, U.K
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40
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Lambert TJ, Waters JC. Navigating challenges in the application of superresolution microscopy. J Cell Biol 2017; 216:53-63. [PMID: 27920217 PMCID: PMC5223610 DOI: 10.1083/jcb.201610011] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 11/15/2016] [Accepted: 11/18/2016] [Indexed: 11/22/2022] Open
Abstract
In 2014, the Nobel Prize in Chemistry was awarded to three scientists who have made groundbreaking contributions to the field of superresolution (SR) microscopy (SRM). The first commercial SR microscope came to market a decade earlier, and many other commercial options have followed. As commercialization has lowered the barrier to using SRM and the awarding of the Nobel Prize has drawn attention to these methods, biologists have begun adopting SRM to address a wide range of questions in many types of specimens. There is no shortage of reviews on the fundamental principles of SRM and the remarkable achievements made with these methods. We approach SRM from another direction: we focus on the current practical limitations and compromises that must be made when designing an SRM experiment. We provide information and resources to help biologists navigate through common pitfalls in SRM specimen preparation and optimization of image acquisition as well as errors and artifacts that may compromise the reproducibility of SRM data.
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Affiliation(s)
- Talley J Lambert
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Jennifer C Waters
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
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Fumoto S, Nishida K. Methods for Evaluating the Stimuli-Responsive Delivery of Nucleic Acid and Gene Medicines. Chem Pharm Bull (Tokyo) 2017; 65:642-648. [DOI: 10.1248/cpb.c17-00096] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Koyo Nishida
- Graduate School of Biomedical Sciences, Nagasaki University
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