Karyotypic analysis of Polymyxa graminis (Plasmodiophoromycetes) based on serial sections of synaptonemal complexes

1984 ◽  
Vol 62 (11) ◽  
pp. 2414-2416 ◽  
Author(s):  
James P. Braselton
Keyword(s):  
Polymyxa Betae ◽  
Serial Sections ◽  
Haploid Number ◽  
Karyotypic Analysis ◽  
Thin Sections ◽  
Polymyxa Graminis ◽  
Synaptonemal Complexes

Three pachytene nuclei of Polymyxa graminis Ledingham were reconstructed from serial thin sections. Thirty synaptonemal complexes (SCs) were counted, indicating the identical haploid number (30) that was reported for Polymyxa betae. SCs of P. graminis and P. betae were similar in structure, and nuclear volumes and total lengths of SCs per nucleus were not significantly different for the two species.

Karyotypic analysis of Polymyxa betae (Plasmodiophoromycetes) based on serial thin sections of pachytene nuclei

1983 ◽  
Vol 61 (12) ◽  
pp. 3202-3206 ◽  
Author(s):  
James P. Braselton
Keyword(s):  
Chromosome Number ◽  
Plasmodiophora Brassicae ◽  
Polymyxa Betae ◽  
Karyotypic Analysis ◽  
Thin Sections ◽  
Haploid Chromosome Number ◽  
Synaptonemal Complexes

Three pachytene nuclei of Polymyxa betae Keskin were reconstructed from serial thin sections. Thirty synaptonemal complexes (SCs) were counted, indicating a haploid chromosome number of 30. SCs of Polymyxa were similar to those of Sorosphaera veronicae Schroeter and Membranosorus heterantherae Ostenfeld and Peterson but differed from SCs of Plasmodiophora brassicae Woron. and Woronina pythii Goldie-Smith.

Karyotypic analysis of Plasmodiophora brassicae based on serial thin sections of pachytene nuclei

1982 ◽  
Vol 60 (4) ◽  
pp. 403-408 ◽  
Author(s):  
James P. Braselton
Keyword(s):  
Electron Microscopy ◽  
Nuclear Envelope ◽  
Plasmodiophora Brassicae ◽  
Karyotypic Analysis ◽  
Thin Sections ◽  
Synaptonemal Complexes ◽  
Chromosomal Number ◽  
Recombination Nodules

Reconstructions based on electron microscopy of serial thin sections of three pachytene nuclei of Plasmodiophora brassicae Woron. showed 20 synaptonemal complexes (SCs) and thus indicated a haploid chromosomal number of 20. No recombination nodules were observed, but modified regions with lateral elements more electron opaque than the rest of the SCs were reported. Ends of SCs attached to the nuclear envelope and clustered near the two centriole pairs.

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

Probing the ultrastructure of the mitotic and meiotic spindle in eggs: An expeditious approach based on semi-thin (0.25 μm) serial sections

1983 ◽  
Vol 41 ◽  
pp. 552-555
Author(s):  
Conly L. Rieder ◽  
S. Bowser ◽  
R. Nowogrodzki ◽  
K. Ross ◽  
G. Sluder
Keyword(s):  
Small Sample Size ◽  
Small Sample ◽  
Meiotic Spindle ◽  
Serial Sections ◽  
Mitotic Apparatus ◽  
Thin Sections ◽  
Cell Cycles ◽  
Ultrastructural Studies

Eggs have long been a favorite material for studying the mechanism of karyokinesis in-vivo and in-vitro. They can be obtained in great numbers and, when fertilized, divide synchronously over many cell cycles. However, they are not considered to be a practical system for ultrastructural studies on the mitotic apparatus (MA) for several reasons, the most obvious of which is that sectioning them is a formidable task: over 1000 ultra-thin sections need to be cut from a single 80-100 μm diameter egg and of these sections only a small percentage will contain the area or structure of interest. Thus it is difficult and time consuming to obtain reliable ultrastructural data concerning the MA of eggs; and when it is obtained it is necessarily based on a small sample size.We have recently developed a procedure which will facilitate many studies concerned with the ultrastructure of the MA in eggs. It is based on the availability of biological HVEM's and on the observation that 0.25 μm thick serial sections can be screened at high resolution for content (after mounting on slot grids and staining with uranyl and lead) by phase contrast light microscopy (LM; Figs 1-2).

The ultrastructure of the double membrane-bound bodies and endoplasmic reticulum in serial sections of wheat spot mosaic-affected wheat plants

1990 ◽  
Vol 48 (3) ◽  
pp. 694-695
Author(s):  
M. H. Chen ◽  
C. Hiruki
Keyword(s):  
Endoplasmic Reticulum ◽  
High Resolution ◽  
Membrane Structure ◽  
Mosaic Disease ◽  
Serial Sections ◽  
Thin Sections ◽  
Double Membrane ◽  
Southern Alberta ◽  
Membrane Bound ◽  
Scanning Em

Wheat spot mosaic disease was first discovered in southern Alberta, Canada, in 1956. A hitherto unidentified disease-causing agent, transmitted by the eriophyid mite, caused chlorosis, stunting and finally severe necrosis resulting in the death of the affected plants. Double membrane-bound bodies (DMBB), 0.1-0.2 μm in diameter were found to be associated with the disease.Young tissues of leaf and root from 4-wk-old infected wheat plants were fixed, dehydrated, and embedded in Spurr’s resin. Serial sections were collected on slot copper grids and stained. The thin sections were then examined with a Hitachi H-7000 TEM at 75 kV. The membrane structure of the DMBBs was studied by numbering them individually and tracing along the sections to see any physical connection with endoplasmic reticulum (ER) membranes. For high resolution scanning EM, a modification of Tanaka’s method was used. The specimens were examined with a Hitachi Model S-570 SEM in its high resolution mode at 20 kV.

Histo-grade diamond knives may be an appropriate tool for high-voltage electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 296-297
Author(s):  
M.E. Rock ◽  
J.A. Anderson ◽  
P.S. Binder
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Stereo Pair ◽  
Specimen Thickness ◽  
Serial Sections ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Diamond Knife

High voltage electron microscopy (HVEM) has been employed in various ways (whole mounts of cells stereo pair imaging, axial tomography, and serial sections for reconstruction) to elucidate three dimensional (3-D) ultrastructural data. The increased specimen thickness allows further data analysis unobtainable from ultra-thin sections. HVEM can reduce the number of sections needed in 3-D reconstructiortby approximately ten times over conventional transmission electron microscopy (CTEM). But increasing section thickness also increases wear on the diamond knife used to section. We have compared the serial sections obtained from a histo-grade diamond knife with those from an E.M. grade ultra-knife. Both sets of sections were cut 0.5 μm thick from the same block, and evaluated under the one million volt beam of the HVEM.

Fine structure of Classopollis exines

1986 ◽  
Vol 64 (12) ◽  
pp. 3059-3074 ◽  
Author(s):  
John R. Rowley ◽  
Satish K. Srivastava
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Upper Jurassic ◽  
Thin Sheets ◽  
Serial Sections ◽  
Thin Sections ◽  
Band Area ◽  
Transmission Electron ◽  
Oxidative Etching

Serial sections for light microscopy or transmission electron microscopy of two Classopollis pollen tetrads show that the exine structure, except for the nexine, has radially arranged rodlike units interwoven with transverse subunits. The nexine consists of strands or thin sheets except in the equatorial infratectal striate band area, where it is up to ca. 1 μm thick. Nexine is absent in the areas of the distal cryptopore and the subequatorial circumpolar infratectal canal. It is very thin or absent in the tetrad scar. Native contrast and reactivity to stain disappeared on immersion of thin sections in 1 M NaOH or HCl or in water. Reactivity to stains was regained after oxidizing the sections in KMnO4. Reactivity to stains appears to be dependent upon non-sporopollenin molecules embedded within exines. The above immersions remove stain reactive sites. Oxidative etching of sporopollenin exposes new sites. The specimens of Classopollis classoides Pflug studied and illustrated were picked from an Upper Jurassic sample (CRC 31519-2) collected at Osmington Mills locality, Dorset, England.

Karyotypic analysis of Membranosorus heterantherae (Plasmodiophoromycetes)

1989 ◽  
Vol 67 (4) ◽  
pp. 1219-1220 ◽  
Author(s):  
James P. Braselton
Keyword(s):  
Chromosome Number ◽  
Serial Section ◽  
Karyotypic Analysis ◽  
Haploid Chromosome Number ◽  
Synaptonemal Complexes ◽  
Section Analysis

Synaptonemal complexes in nuclei of transitional plasmodia of Membranosorus heterantherae were counted through serial section analysis. The haploid chromosome number was determined to be 35, which distinguishes Membranosorus from other plasmodiophorid genera.

scholarly journals Thin Sections

1958 ◽  
Vol 4 (3) ◽  
pp. 233-242 ◽  
Author(s):  
Lee D. Peachey
Keyword(s):  
Electron Micrographs ◽  
Room Temperature ◽  
Butyl Methacrylate ◽  
Published Data ◽  
Serial Sections ◽  
Thin Sections ◽  
Apparent Lack ◽  
Reflected Light ◽  
The Face ◽  
Temperature Heating

Knowledge of the thickness of sections is important for proper interpretation of electron micrographs. Therefore, the thicknesses of sections of n-butyl methacrylate polymer were determined by ellipsometry, and correlated with the color shown in reflected light. The results are: gray, thinner than 60 mµ; silver, 60 to 90 mµ; gold, 90 to 150 mµ; purple, 150 to 190 mµ; blue, 190 to 240 mµ; green, 240 to 280 mµ; and yellow, 280 to 320 mµ. These results agree well with optical theory and with previous published data for thin films. Sections, after cutting, are 30 to 40 per cent shorter than the face of the block from which they were cut. Only a small improvement results from allowing the sections to remain in the collecting trough at room temperature. Heating above room temperature, however, reduces this shortening, with a corresponding improvement in dimensions and spatial relationships in the sections. When the thickness of the section is considered in interpreting electron micrographs instead of considering the section to be two-dimensional, a more accurate interpretation is possible. The consideration of electron micrographs as arising from projections of many profiles from throughout the whole thickness of the section explains the apparent lack of continuity often observed in serial sections. It is believed that serial sections are actually continuous, but that the change in size of structure through the thickness of one section and the consideration of only the largest profile shown in the micrograph can account for the lack of continuity previously observed.

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