scholarly journals Transcription Sites Are Not Correlated with Chromosome Territories in Wheat Nuclei

1998 ◽  
Vol 143 (1) ◽  
pp. 5-12 ◽  
Author(s):  
Rita Abranches ◽  
Alison F. Beven ◽  
Luis Aragón-Alcaide ◽  
Peter J. Shaw
Keyword(s):  
Confocal Microscopy ◽  
Three Dimensional ◽  
Nuclear Architecture ◽  
Chromosome Territories ◽  
Addition Lines ◽  
Wheat Roots ◽  
Tissue Sections ◽  
Genomic Probe ◽  
Transcription Sites ◽  
The Relationship

We have determined the relationship between overall nuclear architecture, chromosome territories, and transcription sites within the nucleus, using three-dimensional confocal microscopy of well preserved tissue sections of wheat roots. Chromosome territories were visualized by GISH using rye genomic probe in wheat/rye translocation and addition lines. The chromosomes appeared as elongated regions and showed a clear centromere–telomere polarization, with the two visualized chromosomes lying approximately parallel to one another across the nucleus. Labeling with probes to telomeres and centromeres confirmed a striking Rabl configuration in all cells, with a clear clustering of the centromeres, and cell files often maintained a common polarity through several division cycles. Transcription sites were detected by BrUTP incorporation in unfixed tissue sections and revealed a pattern of numerous foci uniformly distributed throughout the nucleoplasm, as well as more intensely labeled foci in the nucleoli. It has been suggested that the gene-rich regions in wheat chromosomes are clustered towards the telomeres. However, we found no indication of a difference in concentration of transcription sites between telomere and centromere poles of the nucleus. Neither could we detect any evidence that the transcription sites were preferentially localized with respect to the chromosome territorial boundaries.

Replication and transcription sites are colocalized in human cells

1994 ◽  
Vol 107 (2) ◽  
pp. 425-434 ◽  
Author(s):  
A.B. Hassan ◽  
R.J. Errington ◽  
N.S. White ◽  
D.A. Jackson ◽  
P.R. Cook
Keyword(s):  
Cell Cycle ◽  
Confocal Microscopy ◽  
Dna Synthesis ◽  
Fluorescent Probes ◽  
Hela Cells ◽  
Nuclear Architecture ◽  
Human Cells ◽  
Dynamic Nature ◽  
Nucleotide Triphosphates ◽  
Transcription Sites

HeLa cells synchronized at different stages of the cell cycle were permeabilized and incubated with analogues of nucleotide triphosphates; then sites of incorporation were immunolabeled with the appropriate fluorescent probes. Confocal microscopy showed that sites of replication and transcription were not diffusely spread throughout nuclei, reflecting the distribution of euchromatin; rather, they were concentrated in ‘foci’ where many polymerases act together. Transcription foci aggregated as cells progressed towards the G1/S boundary; later they dispersed and became more diffuse. Replication was initiated only at transcription sites; later, when heterochromatin was replicated in enlarged foci, these remained sites of transcription. This illustrates the dynamic nature of nuclear architecture and suggests that transcription may be required for the initiation of DNA synthesis.

scholarly journals Targeting of the SUN protein Mps3 to the inner nuclear membrane by the histone variant H2A.Z

2011 ◽  
Vol 193 (3) ◽  
pp. 489-507 ◽  
Author(s):  
Jennifer M. Gardner ◽  
Christine J. Smoyer ◽  
Elizabeth S. Stensrud ◽  
Richard Alexander ◽  
Madelaine Gogol ◽  
...  
Keyword(s):  
Nuclear Membrane ◽  
Nuclear Periphery ◽  
Three Dimensional ◽  
Nuclear Architecture ◽  
Histone Variant ◽  
Inner Nuclear Membrane ◽  
Histone Fold ◽  
Acidic Domain ◽  
Histone Fold Domain ◽  
The Relationship

Understanding the relationship between chromatin and proteins at the nuclear periphery, such as the conserved SUN family of inner nuclear membrane (INM) proteins, is necessary to elucidate how three-dimensional nuclear architecture is established and maintained. We found that the budding yeast SUN protein Mps3 directly binds to the histone variant H2A.Z but not other histones. Biochemical and genetic data indicate that the interaction between Mps3 and H2A.Z requires the Mps3 N-terminal acidic domain and unique sequences in the H2A.Z N terminus and histone-fold domain. Analysis of binding-defective mutants showed that the Mps3–H2A.Z interaction is not essential for any previously described role for either protein in nuclear organization, and multiple lines of evidence suggest that Mps3–H2A.Z binding occurs independently of H2A.Z incorporation into chromatin. We demonstrate that H2A.Z is required to target a soluble Mps3 fragment to the nucleus and to localize full-length Mps3 in the INM, indicating that H2A.Z has a novel chromatin-independent function in INM targeting of SUN proteins.

Characterizing the Influence of Drying on Ink Absorption Using Reconstructed Images by Laser Scanning Confocal Microscopy

2014 ◽  
Vol 904 ◽  
pp. 59-62 ◽  
Author(s):  
Jian Guo Li ◽  
Ying Li
Keyword(s):  
Confocal Microscopy ◽  
Penetration Depth ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Confocal Microscopy ◽  
Coated Paper ◽  
Drying Temperature ◽  
Scanning Confocal Microscopy ◽  
Distribution Uniformity ◽  
The Relationship

The objective of this experiment was to investigate the relationship between drying and ink absorption using laser scanning confocal microscopy (LSCM). Fluorescent ink was used to observe and characterize ink penetration and distribution by LSCM. Three-dimensional images of ink penetration were obtained by reconstructing all XY plane images. Reconstructed images were used to describe ink absorption in coated paper by LSCM. The results implied that it was reliable and effective using LSCM to characterize the ink penetration depth and distribution uniformity. This method could not damage the specimen and did not need fluorescent dye to stain the specimen, which decreased the errors by hand operation. The results indicated that drying temperature affected ink penetration depth and distribution evenness. Higher and lower drying temperature could not contribute to ink absorption uniformity. With the drying temperature increasing, ink penetration depth in coated paper increased.

Laser Scanning Confocal Microscopy and Three-Dimesnsional Reconstruction of the Mitotic Spindles of Unequally Dividing Embryonic Cells

1990 ◽  
Vol 48 (3) ◽  
pp. 166-167
Author(s):  
J. Holy ◽  
G. Schatten
Keyword(s):  
Confocal Microscopy ◽  
Mitotic Spindle ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Confocal Microscopy ◽  
Two Dimensions ◽  
Embryonic Cells ◽  
Mitotic Spindles ◽  
Cleavage Division ◽  
Scanning Confocal Microscopy

One of the classic limitations of light microscopy has been the fact that three dimensional biological events could only be visualized in two dimensions. Recently, this shortcoming has been overcome by combining the technologies of laser scanning confocal microscopy (LSCM) and computer processing of microscopical data by volume rendering methods. We have employed these techniques to examine morphogenetic events characterizing early development of sea urchin embryos. Specifically, the fourth cleavage division was examined because it is at this point that the first morphological signs of cell differentiation appear, manifested in the production of macromeres and micromeres by unequally dividing vegetal blastomeres.The mitotic spindle within vegetal blastomeres undergoing unequal cleavage are highly polarized and develop specialized, flattened asters toward the micromere pole. In order to reconstruct the three-dimensional features of these spindles, both isolated spindles and intact, extracted embryos were fluorescently labeled with antibodies directed against either centrosomes or tubulin.

Automated 3-D cell population analysis in thick tissue sections using laser-scanning confocal-microscopy data

1993 ◽  
Vol 51 ◽  
pp. 562-563
Author(s):  
Hakan Ancin
Keyword(s):  
Laser Scanning ◽  
Population Analysis ◽  
Three Dimensional ◽  
Large Data ◽  
Laser Scanning Confocal Microscopy ◽  
Tissue Slices ◽  
Scanning Confocal Microscopy ◽  
Tissue Sections ◽  
Spatially Adaptive ◽  
Microscopy Data

This paper presents methods for performing detailed quantitative automated three dimensional (3-D) analysis of cell populations in thick tissue sections while preserving the relative 3-D locations of cells. Specifically, the method disambiguates overlapping clusters of cells, and accurately measures the volume, 3-D location, and shape parameters for each cell. Finally, the entire population of cells is analyzed to detect patterns and groupings with respect to various combinations of cell properties. All of the above is accomplished with zero subjective bias.In this method, a laser-scanning confocal light microscope (LSCM) is used to collect optical sections through the entire thickness (100 - 500μm) of fluorescently-labelled tissue slices. The acquired stack of optical slices is first subjected to axial deblurring using the expectation maximization (EM) algorithm. The resulting isotropic 3-D image is segmented using a spatially-adaptive Poisson based image segmentation algorithm with region-dependent smoothing parameters. Extracting the voxels that were labelled as "foreground" into an active voxel data structure results in a large data reduction.

scholarly journals Dynamics of Single Droplet Splashing on Liquid Film by Coupling FVM with VOF

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 841
Author(s):  
Yuzhen Jin ◽  
Huang Zhou ◽  
Linhang Zhu ◽  
Zeqing Li
Keyword(s):  
Liquid Film ◽  
Weber Number ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Single Droplet ◽  
Navier Stokes Equations ◽  
Volume Method ◽  
The Relationship

A three-dimensional numerical study of a single droplet splashing vertically on a liquid film is presented. The numerical method is based on the finite volume method (FVM) of Navier–Stokes equations coupled with the volume of fluid (VOF) method, and the adaptive local mesh refinement technology is adopted. It enables the liquid–gas interface to be tracked more accurately, and to be less computationally expensive. The relationship between the diameter of the free rim, the height of the crown with different numbers of collision Weber, and the thickness of the liquid film is explored. The results indicate that the crown height increases as the Weber number increases, and the diameter of the crown rim is inversely proportional to the collision Weber number. It can also be concluded that the dimensionless height of the crown decreases with the increase in the thickness of the dimensionless liquid film, which has little effect on the diameter of the crown rim during its growth.

Two-Photon Excitation Imaging of Glucose Metabolism in Living Tissue

1997 ◽  
Vol 3 (S2) ◽  
pp. 305-306
Author(s):  
David W. Piston
Keyword(s):  
Confocal Microscopy ◽  
Collection Efficiency ◽  
Three Dimensional ◽  
Spatial Filter ◽  
Input Power ◽  
Photon Absorption ◽  
Focal Volume ◽  
Two Photon ◽  
Photon Excitation ◽  
Two Photon Excitation

Two-photon excitation microscopy (TPEM) provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging and photochemistry. It provides three-dimensional resolution and eliminates background equivalent to an ideal confocal microscope without requiring a confocal spatial filter, whose absence enhances fluorescence collection efficiency. This results in inherent submicron optical sectioning by excitation alone. In practice, TPEM is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10−5 limits the average input power to less than 10 mW, only slightly greater than the power normally used in confocal microscopy. Because of the intensity-squared dependence of the two-photon absorption, the excitation is limited to the focal volume.

scholarly journals A Field Measurement Based Wind Characteristics Analysis of a Typhoon in Near-Ground Boundary Layer

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 873
Author(s):  
Dandan Xia ◽  
Liming Dai ◽  
Li Lin ◽  
Huaifeng Wang ◽  
Haitao Hu
Keyword(s):  
Turbulence Intensity ◽  
Field Measurement ◽  
Three Dimensional ◽  
Wind Data ◽  
Statistical Characteristics ◽  
Gust Factor ◽  
Characteristics Analysis ◽  
Wind Characteristics ◽  
The Mean ◽  
The Relationship

The field measurement was conducted to observe the wind field data of West Pacific typhoon “Maria” in this research. With the application of ultrasonic anemometers installed in different heights (10 m, 80 m, 100 m) of the tower, the three dimensional wind speed data of typhoon “Maria” was acquired. In addition, vane-type anemometers were installed to validate the accuracy of the wind data from ultrasonic anemometers. Wind characteristics such as the mean wind profile, turbulence intensity, integral length scale, and wind spectrum are studied in detail using the collected wind data. The relationship between the gust factor and turbulence intensity was also studied and compared with the existing literature to demonstrate the characteristics of Maria. The statistical characteristics of the turbulence intensity and gust factor are presented. The corresponding conclusion remarks are expected to provide a useful reference for designing wind-resistant buildings and structures.

scholarly journals Three-dimensional relationships between tumor cells and microcirculation with double cyanine immunolabeling, laser scanning confocal microscopy, and computer-assisted reconstruction: an alternative to cast corrosion preparations.

1994 ◽  
Vol 42 (5) ◽  
pp. 681-686 ◽  
Author(s):  
V Rummelt ◽  
L M Gardner ◽  
R Folberg ◽  
S Beck ◽  
B Knosp ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Blood Vessels ◽  
Tumor Cells ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Melanoma Cells ◽  
Tumor Blood Vessels ◽  
The Relationship ◽  
Scanning Electron

The morphology of the microcirculation of uveal melanomas is a reliable market of tumor progression. Scanning electron microscopy of cast corrosion preparations can generate three-dimensional views of these vascular patterns, but this technique sacrifices the tumor parenchyma. Formalin-fixed wet tissue sections 100-150 microns thick from uveal melanomas were stained with the lectin Ulex europaeus agglutinin I (UEAI) and proliferating cell nuclear antigen (PCNA) to demonstrate simultaneously the tumor blood vessels and proliferating tumor cells. Indocarbocyanine (Cy3) was used as a fluorophore for UEAI and indodicarbocyanine (Cy5) was used for PCNA. Double labeled sections were examined with a laser scanning confocal microscope. Images of both stains were digitized at the same 5-microns intervals and each of the two images per interval was combined digitally to form one image. These combined images were visualized through voxel processing to study the relationship between melanoma cells expressing PCNA and various microcirculatory patterns. This technique produces images comparable to scanning electron microscopy of cast corrosion preparations while permitting simultaneous localization of melanoma cells expressing PCNA. The microcirculatory tree can be viewed from any perspective and the relationship between tumor cells and the tumor blood vessels can be studied concurrently in three dimensions. This technique is an alternative to cast corrosion preparations.

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