Cytoplasmic silicon in the centric diatom Thalassiosira pseudonana localized by electron spectroscopic imaging

1987 ◽  
Vol 33 (2) ◽  
pp. 128-131 ◽  
Author(s):  
A. Rogerson ◽  
A. S. W. DeFreitas ◽  
A. G. McInnes
Keyword(s):  
Imaging Techniques ◽  
Spectroscopic Imaging ◽  
Thalassiosira Pseudonana ◽  
Centric Diatom ◽  
Electron Spectroscopic Imaging ◽  
Silicon Accumulation ◽  
Lipid Inclusions ◽  
High Degree ◽  
Cytoplasmic Ribosomes

Silicon and phosphorus distributions in the cytoplasm of the diatom Thalassiosira pseudonana were mapped separately using electron spectroscopic imaging techniques. The phosphorus profile delineating cytoplasmic ribosomes overlapped the silicon profile with a high degree of coincidence suggesting a silicon–ribosomal association. Lipid inclusions were also sites of silicon accumulation. The possible significance of these results in wall biomineralization is discussed.

Electron spectroscopic imaging of the centrosome in cells of the Indian muntjac

1988 ◽  
Vol 91 (1) ◽  
pp. 5-11
Author(s):  
J.B. Rattner ◽  
D.P. Bazett-Jones
Keyword(s):  
Imaging Techniques ◽  
Spectroscopic Imaging ◽  
Electron Spectroscopic Imaging ◽  
Intact Cells ◽  
Thin Sections ◽  
Indian Muntjac ◽  
Phosphorylated Proteins ◽  
Linking Elements ◽  
The Matrix ◽  
Precise Distribution

Specific antibody labelling indicates that phosphoproteins are present at microtubule-organizing centres, including the centrosome. We have employed electron spectroscopic imaging techniques that permit high-resolution elemental analysis of thin sections of intact cells to investigate the precise distribution of phosphorus and therefore phosphoproteins at the centrosome of Indian muntjac cells. We report that these proteins are localized to both the pericentriolar matrix and the centriole. The matrix contains an abundance of phosphorus and is associated with microtubule elements. Within the mature centriole, major structures including the nine triplet blades and linking elements that connect adjacent blades are composed of phosphorylated proteins. In addition, phosphoproteins are abundant at the ends of the centriole, at the interface between the centriole lumen and the pericentriolar environment. From these observations we suggest that phosphoproteins may play both a structural and a functional role within the centrosome region.

Visualisation of E. coli ribosomal RNA in situ by electron spectroscopic imaging and image averaging

1992 ◽  
Vol 50 (1) ◽  
pp. 466-467
Author(s):  
Daniel Beniac ◽  
George Harauz
Keyword(s):  
Ribosomal Rna ◽  
Three Dimensional ◽  
Spectroscopic Imaging ◽  
Electron Spectroscopic Imaging ◽  
E Coli ◽  
Microscopical Technique ◽  
Quantitative Image ◽  
Dimensional Reconstruction ◽  
Image Averaging ◽  
Protein Components

The structures of E. coli ribosomes have been extensively probed by electron microscopy of negatively stained and frozen hydrated preparations. Coupled with quantitative image analysis and three dimensional reconstruction, such approaches are worthwhile in defining size, shape, and quaternary organisation. The important question of how the nucleic acid and protein components are arranged with respect to each other remains difficult to answer, however. A microscopical technique that has been proposed to answer this query is electron spectroscopic imaging (ESI), in which scattered electrons with energy losses characteristic of inner shell ionisations are used to form specific elemental maps. Here, we report the use of image sorting and averaging techniques to determine the extent to which a phosphorus map of isolated ribosomal subunits can define the ribosomal RNA (rRNA) distribution within them.

Transcription factor/DNA interactions visualized by electron spectroscopic imaging

1992 ◽  
Vol 50 (1) ◽  
pp. 450-451
Author(s):  
David P. Bazett-Jones ◽  
Mark L. Brown
Keyword(s):  
Transcription Factor ◽  
Dna Sequences ◽  
Transcription Initiation ◽  
Molecular Mechanisms ◽  
Phosphorus Content ◽  
Spectroscopic Imaging ◽  
Electron Spectroscopic Imaging ◽  
Dna Backbone ◽  
Two Parameters ◽  
High Level

A multisubunit RNA polymerase enzyme is ultimately responsible for transcription initiation and elongation of RNA, but recognition of the proper start site by the enzyme is regulated by general, temporal and gene-specific trans-factors interacting at promoter and enhancer DNA sequences. To understand the molecular mechanisms which precisely regulate the transcription initiation event, it is crucial to elucidate the structure of the transcription factor/DNA complexes involved. Electron spectroscopic imaging (ESI) provides the opportunity to visualize individual DNA molecules. Enhancement of DNA contrast with ESI is accomplished by imaging with electrons that have interacted with inner shell electrons of phosphorus in the DNA backbone. Phosphorus detection at this intermediately high level of resolution (≈lnm) permits selective imaging of the DNA, to determine whether the protein factors compact, bend or wrap the DNA. Simultaneously, mass analysis and phosphorus content can be measured quantitatively, using adjacent DNA or tobacco mosaic virus (TMV) as mass and phosphorus standards. These two parameters provide stoichiometric information relating the ratios of protein:DNA content.

Localization of DNA in chromatin using ESI and osmium ammine staining

1990 ◽  
Vol 48 (3) ◽  
pp. 116-117
Author(s):  
C.L. Woodcock ◽  
R.A. Horowitz ◽  
D. P. Bazett-Jones ◽  
A.L. Olins
Keyword(s):  
Spectroscopic Imaging ◽  
Energy Losses ◽  
Electron Spectroscopic Imaging ◽  
Feulgen Reaction ◽  
Specific Location ◽  
Eukaryotic Nucleus ◽  
Chromatin Fibers ◽  
Patiria Miniata ◽  
Model Structures

In the eukaryotic nucleus, DNA is packaged into nucleosomes, and the nucleosome chain folded into ‘30nm’ chromatin fibers. A number of different model structures, each with a specific location of nucleosomal and linker DNA have been proposed for the arrangment of nucleosomes within the fiber. We are exploring two strategies for testing the models by localizing DNA within chromatin: electron spectroscopic imaging (ESI) of phosphorus atoms, and osmium ammine (OSAM) staining, a method based on the DNA-specific Feulgen reaction.Sperm were obtained from Patiria miniata (starfish), fixed in 2% GA in 150mM NaCl, 15mM HEPES pH 8.0, and embedded In Lowiciyl K11M at -55C. For OSAM staining, sections 100nm to 150nm thick were treated as described, and stereo pairs recorded at 40,000x and 100KV using a Philips CM10 TEM. (The new osmium ammine-B stain is available from Polysciences Inc). Uranyl-lead (U-Pb) staining was as described. ESI was carried out on unstained, very thin (<30 nm) beveled sections at 80KV using a Zeiss EM902. Images were recorded at 20,000x and 30,000x with median energy losses of 110eV, 120eV and 160eV, and a window of 20eV.

scholarly journals A Bimodal Fluorescence-Raman Probe for Cellular Imaging

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1699
Author(s):  
Jiarun Lin ◽  
Marcus E. Graziotto ◽  
Peter A. Lay ◽  
Elizabeth J. New
Keyword(s):  
Chemical Composition ◽  
Fluorescent Probes ◽  
Lipid Droplets ◽  
Imaging Techniques ◽  
Spectroscopic Imaging ◽  
Fluorescent Sensors ◽  
Chemical Environment ◽  
Novel Approach ◽  
Health And Disease ◽  
Raman Probe

Biochemical changes in specific organelles underpin cellular function, and studying these changes is crucial to understand health and disease. Fluorescent probes have become important biosensing and imaging tools as they can be targeted to specific organelles and can detect changes in their chemical environment. However, the sensing capacity of fluorescent probes is highly specific and is often limited to a single analyte of interest. A novel approach to imaging organelles is to combine fluorescent sensors with vibrational spectroscopic imaging techniques; the latter provides a comprehensive map of the relative biochemical distributions throughout the cell to gain a more complete picture of the biochemistry of organelles. We have developed NpCN1, a bimodal fluorescence-Raman probe targeted to the lipid droplets, incorporating a nitrile as a Raman tag. NpCN1 was successfully used to image lipid droplets in 3T3-L1 cells in both fluorescence and Raman modalities, reporting on the chemical composition and distribution of the lipid droplets in the cells.

Sign in / Sign up

Export Citation Format

Share Document