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.

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 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.

scholarly journals Stereo electron microscopy of the 25-nm chromatin fibers in isolated nuclei.

1979 ◽  
Vol 81 (1) ◽  
pp. 260-265 ◽  
Author(s):  
A L Olins ◽  
D E Olins
Keyword(s):  
Electron Microscopy ◽  
Nuclear Envelope ◽  
Electron Micrographs ◽  
Chicken Erythrocyte ◽  
Thin Sections ◽  
Isolated Nuclei ◽  
Chromatin Fibers

Thin sections (0.1-0.25 micron) of isolated chicken erythrocyte nuclei were examined at various tilt angles. Stereo pairs of electron micrographs document the parallel alignment of 25-nm chromatin fibers adjacent to the nuclear envelope, and demonstrate a fiber substructure consistent with close-packed arrays of nucleosomes.

Karyotype analysis of the plant-parasitic nematode Heterodera glycines by electron microscopy. 1. The diploid

1979 ◽  
Vol 40 (1) ◽  
pp. 171-179
Author(s):  
P. Goldstein ◽  
A.C. Triantaphyllou
Keyword(s):  
Electron Microscopy ◽  
Parasitic Nematode ◽  
Heterodera Glycines ◽  
Karyotype Analysis ◽  
Serial Sections ◽  
Synaptonemal Complexes ◽  
3 Dimensional ◽  
Recombination Nodules ◽  
Dimensional Reconstruction ◽  
Plant Parasitic

Heterodera glycines is a diploid amphimictic nematode with n = 9 chromosomes. Nine normal synaptonemal complexes (SC) were detected following 3-dimensional reconstruction of pachytene nuclei from electron microscopy of serial sections. Regions of unique ‘modified synaptonemal complexes’ (MSC) were observed along 2 SCs. These consist of a heterochromatic knob within which the SC appears either disorganized or stacked in layers of lateral elements. Its function is not known. Recombination nodules and ‘cylindrical granular complexes’, were not observed in H. glycines.

The ultrastructure of mitosis in Plasmodiophora brassicae (Plasmodiophorales)

1979 ◽  
Vol 40 (1) ◽  
pp. 89-110
Author(s):  
R.C. Garber ◽  
J.R. Aist
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Plasmodiophora Brassicae ◽  
Light And Electron Microscopy ◽  
Chromosome Count ◽  
End To End ◽  
Mitotic Nucleus

Mitosis was examined in plasmodia of Plasmodiophora brassicae within artifically inoculated cabbage roots, using light- and electron microscopy. Mitotic nuclear divisions are characterized by a persistent nucleolus, bipolar centrioles paired end-to-end, densely staining chromatin, and a complex array of membranes that surround and ramify through the spindle. Chromatin begins to condense in prophase, and is aligned at metaphase in a reticulate plate on the nuclear equator. The chromatin is not resolvable into distinct chromosomes at metaphase, and a chromosome count is not possible. Large amounts of membrane cisternae within the spindle are most clearly visible at metaphase, and apparently represent the remains of the nuclear envelope. The nuclear envelope is disrupted during prometaphase and may become entangled in the spindle when centriolar microtubules enter the nucleus. Several concentric sheets of perinuclear endoplasmic reticulum surround the spindle and give the mitotic nucleus the superficial appearance of having an intact nuclear envelope. This interpretation of the identity of nucleus-associated membranes differs from those previously reported for other protists, including members of the Plasmodiophorales.

The ultrastructure of meiosis in Plasmodiophora brassicae (Plasmodiophorales)

1979 ◽  
Vol 57 (22) ◽  
pp. 2509-2518 ◽  
Author(s):  
Robert C. Garber ◽  
James R. Aist
Keyword(s):  
Electron Microscopy ◽  
Vegetative Growth ◽  
Plasmodiophora Brassicae ◽  
Light And Electron Microscopy ◽  
Synaptonemal Complexes ◽  
Prophase I ◽  
Meiosis I

Meiosis was examined in plasmodia of the protist Plasmodiophora brassicae within artificially inoculated cabbage roots, using light and electron microscopy. Meiotic nuclear divisions occur following the cessation of vegetative growth of the Plasmodium. Synaptonemal complexes develop in nuclei of the “akaryote stage,” which represents prophase I. Meiosis I and II take place concurrently with cleavage of the Plasmodium into resting sporangia. Previous reports of synaptonemal complexes and sporangiogenic meiosis in the Plasmodiophorales are thus corroborated. Centrioles are paired and bipolar until the end of meiosis I; then they separate and migrate to opposite poles, without replicating, between prophase II and metaphase II. Centrioles elongate considerably between prophase I and the end of meiosis II, then appear to disintegrate as uninucleate resting sporangia are formed and are absent from mature sporangia.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Lead aspartate: a new en bloc stain for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 34-35
Author(s):  
J.R. Walton
Keyword(s):  
Electron Microscopy ◽  
Calcium Ion ◽  
Enzyme Reaction ◽  
Lead Citrate ◽  
Reaction Products ◽  
En Bloc ◽  
Thin Sections ◽  
Lead Salts ◽  
Thin Sectioning ◽  
High Alkalinity

In electron microscopy, lead is the metal most widely used for enhancing specimen contrast. Lead citrate requires a pH of 12 to stain thin sections of epoxy-embedded material rapidly and intensively. However, this high alkalinity tends to leach out enzyme reaction products, making lead citrate unsuitable for many cytochemical studies. Substitution of the chelator aspartate for citrate allows staining to be carried out at pH 6 or 7 without apparent effect on cytochemical products. Moreover, due to the low, controlled level of free lead ions, contamination-free staining can be carried out en bloc, prior to dehydration and embedding. En bloc use of lead aspartate permits the grid-staining step to be bypassed, allowing samples to be examined immediately after thin-sectioning.Procedures. To prevent precipitation of lead salts, double- or glass-distilled H20 used in the stain and rinses should be boiled to drive off carbon dioxide and glassware should be carefully rinsed to remove any persisting traces of calcium ion.

Membranous alterations in the cytoplasm and nucleus in a primitive neuroectodermal tumor of the brain

1978 ◽  
Vol 36 (2) ◽  
pp. 628-629
Author(s):  
C. N. Sun ◽  
C. Araoz ◽  
H. J. White
Keyword(s):  
Nuclear Envelope ◽  
Tumor Cells ◽  
Osmium Tetroxide ◽  
Primitive Neuroectodermal Tumor ◽  
Uranyl Acetate ◽  
Neuroectodermal Tumor ◽  
Annulate Lamellae ◽  
Lead Citrate ◽  
Thin Sections ◽  
The Brain

The ultrastructure of a cerebral primitive neuroectodermal tumor has been reported previously. In the present case, we will present some unusual previously unreported membranous structures and alterations in the cytoplasm and nucleus of the tumor cells.Specimens were cut into small pieces about 1 mm3 and immediately fixed in 4% glutaraldehyde in phosphate buffer for two hours, then post-fixed in 1% buffered osmium tetroxide for one hour. After dehydration, tissues were embedded in Epon 812. Thin sections were stained with uranyl acetate and lead citrate.In the cytoplasm of the tumor cells, we found paired cisternae (Fig. 1) and annulate lamellae (Fig. 2) noting that the annulate lamellae were sometimes associated with the outer nuclear envelope (Fig. 3). These membranous structures have been reported in other tumor cells. In our case, mitochondrial to nuclear envelope fusions were often noted (Fig. 4). Although this phenomenon was reported in an oncocytoma, their frequency in the present study is quite striking.

Ectodesmata as Revealed By Freeze-Etch Preparations of Plant Epidermal Cell Walls

1973 ◽  
Vol 31 ◽  
pp. 468-469
Author(s):  
N.C. Lyon ◽  
W. C. Mueller
Keyword(s):  
Electron Microscopy ◽  
Acetic Acid ◽  
Nitric Acid ◽  
Oxalic Acid ◽  
Light Microscopy ◽  
Epidermal Cell ◽  
Cell Walls ◽  
Plant Viruses ◽  
Plant Leaves ◽  
Thin Sections

Schumacher and Halbsguth first demonstrated ectodesmata as pores or channels in the epidermal cell walls in haustoria of Cuscuta odorata L. by light microscopy in tissues fixed in a sublimate fixative (30% ethyl alcohol, 30 ml:glacial acetic acid, 10 ml: 65% nitric acid, 1 ml: 40% formaldehyde, 5 ml: oxalic acid, 2 g: mecuric chloride to saturation 2-3 g). Other workers have published electron micrographs of structures transversing the outer epidermal cell in thin sections of plant leaves that have been interpreted as ectodesmata. Such structures are evident following treatment with Hg++ or Ag+ salts and are only rarely observed by electron microscopy. If ectodesmata exist without such treatment, and are not artefacts, they would afford natural pathways of entry for applied foliar solutions and plant viruses.

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