scholarly journals Electron cryo-tomography of vestibular hair-cell stereocilia

2018 ◽  
Author(s):  
Zoltan Metlagel ◽  
Jocelyn F Krey ◽  
Junha Song ◽  
Mark F Swift ◽  
William J Tivol ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Hair Cell ◽  
3D Imaging ◽  
Three Dimensional ◽  
Vestibular Function ◽  
Structural Features ◽  
High Resolution Imaging ◽  
Native State ◽  
Resolution Imaging

High-resolution imaging of hair-cell stereocilia of the inner ear has contributed substantially to our understanding of auditory and vestibular function. To provide three-dimensional views of the structure of stereocilia cytoskeleton and membranes, we developed a method for rapidly freezing unfixed stereocilia on electron microscopy grids, which allowed subsequent 3D imaging by electron cryo-tomography. Structures of stereocilia tips, shafts, and tapers were revealed, demonstrating that the actin paracrystal was not perfectly ordered. This sample-preparation and imaging procedure will allow for examination of structural features of stereocilia in a near-native state.

scholarly journals Genome-Wide Mutagenesis of Dengue Virus Reveals Plasticity of the NS1 Protein and Enables Generation of Infectious Tagged Reporter Viruses

2017 ◽  
Vol 91 (23) ◽  
Author(s):  
Nicholas S. Eyre ◽  
Stephen M. Johnson ◽  
Auda A. Eltahla ◽  
Maria Aloi ◽  
Amanda L. Aloia ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Insertional Mutagenesis ◽  
High Resolution Imaging ◽  
Ns1 Protein ◽  
Reporter Virus ◽  
Genome Wide ◽  
Infected Cells ◽  
Resolution Imaging ◽  
Virus Replication Cycle

ABSTRACT Dengue virus (DENV) is a major global pathogen that causes significant morbidity and mortality in tropical and subtropical areas worldwide. An improved understanding of the regions within the DENV genome and its encoded proteins that are required for the virus replication cycle will expedite the development of urgently required therapeutics and vaccines. We subjected an infectious DENV genome to unbiased insertional mutagenesis and used next-generation sequencing to identify sites that tolerate 15-nucleotide insertions during the virus replication cycle in hepatic cell culture. This revealed that the regions within capsid, NS1, and the 3′ untranslated region were the most tolerant of insertions. In contrast, prM- and NS2A-encoding regions were largely intolerant of insertions. Notably, the multifunctional NS1 protein readily tolerated insertions in regions within the Wing, connector, and β-ladder domains with minimal effects on viral RNA replication and infectious virus production. Using this information, we generated infectious reporter viruses, including a variant encoding the APEX2 electron microscopy tag in NS1 that uniquely enabled high-resolution imaging of its localization to the surface and interior of viral replication vesicles. In addition, we generated a tagged virus bearing an mScarlet fluorescent protein insertion in NS1 that, despite an impact on fitness, enabled live cell imaging of NS1 localization and traffic in infected cells. Overall, this genome-wide profile of DENV genome flexibility may be further dissected and exploited in reporter virus generation and antiviral strategies. IMPORTANCE Regions of genetic flexibility in viral genomes can be exploited in the generation of reporter virus tools and should arguably be avoided in antiviral drug and vaccine design. Here, we subjected the DENV genome to high-throughput insertional mutagenesis to identify regions of genetic flexibility and enable tagged reporter virus generation. In particular, the viral NS1 protein displayed remarkable tolerance of small insertions. This genetic flexibility enabled generation of several novel NS1-tagged reporter viruses, including an APEX2-tagged virus that we used in high-resolution imaging of NS1 localization in infected cells by electron microscopy. For the first time, this analysis revealed the localization of NS1 within viral replication factories known as “vesicle packets” (VPs), in addition to its acknowledged localization to the luminal surface of these VPs. Together, this genetic profile of DENV may be further refined and exploited in the identification of antiviral targets and the generation of reporter virus tools.

High Resolution Imaging of As-Grown Sapphire Surfaces

1985 ◽  
Vol 62 ◽  
Author(s):  
Tung Hsu ◽  
S. R. Nutt
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Features ◽  
High Resolution Imaging ◽  
Sapphire Surface ◽  
Surface Steps ◽  
Transmission Electron ◽  
Reflection Electron Microscopy ◽  
Resolution Imaging ◽  
Surface Facets

ABSTRACTSurfaces of commercially grown edge-defined film-fed growth sapphire (EFG α-Al2O3) were studied in the electron microscope using both reflection electron microscopy (REM) and conventional transmission electron microscopy (TEM). The as-grown sapphire surface, ostensibly {1120}, was characterized by “rooftop” structures which were often locally periodic. These rooftop structures consisted of alternating {1120} facets and additional facets inclined a few degrees. The crystallography of the surface facets was analyzed using REM imaging of bulk specimens, and trace analysis of back-thinned plan section TEM specimens. Surface roughness was measured by stylus profilometry. and these measurements were compared to the electron microscopy observations. Fine structural features parallel to <0110> directions were also observed in both REM and TEM experiments, and these were attributed to surface steps of atomic scales.

scholarly journals Plastic embedding immunolabeled large-volume samples for three-dimensional high-resolution imaging

2017 ◽  
Vol 8 (8) ◽  
pp. 3583 ◽  
Author(s):  
Yadong Gang ◽  
Xiuli Liu ◽  
Xiaojun Wang ◽  
Qi Zhang ◽  
Hongfu Zhou ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Volume ◽  
Three Dimensional ◽  
High Resolution Imaging ◽  
Plastic Embedding ◽  
Resolution Imaging

Atomic Structure of Interfaces in Epitaxial NiSi2 on (001) Silicon

1992 ◽  
Vol 263 ◽  
Author(s):  
W.J. Chen ◽  
F.R. Chen ◽  
L.J. Chen
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Atomic Structure ◽  
Imaging Technique ◽  
Interface Structure ◽  
High Resolution Imaging ◽  
Image Simulation ◽  
Transmission Electron ◽  
Resolution Imaging ◽  
Boundary Core

ABSTRACTHigh resolution transmission electron microscopy (HRTEM) has been applied to study the atomic structure of NiSi2 /(001)Si interface. Previous HRTEM result suggested that Ni atoms in the boundary core are six-fold coordinated and Si atoms are everywhere tetrahedrally coordinated. In this work, high resolution imaging technique and computer image simulation were used to study the atomic structure of NiSi2 /(001)Si interfaces and a new interface structure was found. For the new interface structure, Ni and Si atoms are also six-fold and tetrahedrally coordinated, respectively, with an extra layer of fourfold planar bonded Si atoms present at the interface.

scholarly journals Three-Dimensional High-Resolution Imaging of Gold Nanorods Uptake in Sentinel Lymph Nodes

Nano Letters ◽  
2011 ◽  
Vol 11 (7) ◽  
pp. 2938-2943 ◽  
Author(s):  
Yeongri Jung ◽  
Roberto Reif ◽  
Yaguang Zeng ◽  
Ruikang K. Wang
Keyword(s):  
High Resolution ◽  
Lymph Nodes ◽  
Gold Nanorods ◽  
Three Dimensional ◽  
Sentinel Lymph Nodes ◽  
High Resolution Imaging ◽  
Resolution Imaging
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