Mitosis in the Fission Yeast Schizosaccharomyces Pombe: A Comparative Study with Light and Electron Microscopy

1971 ◽  
Vol 9 (2) ◽  
pp. 475-507 ◽  
Author(s):  
E. KATHLEEN McCULLY ◽  
C. F. ROBINOW
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Nuclear Envelope ◽  
Schizosaccharomyces Pombe ◽  
Light And Electron Microscopy ◽  
Metaphase Plate ◽  
Middle Part ◽  
Mitotic Chromosomes ◽  
Nucleolar Material ◽  
Differential Expansion

Mitosis in Schizosaccharomyces pombe has been followed in living cells by phase-contrast microscopy and studied in fixed and suitably stained preparations by light microscopy. Successful preservation of nuclear fine structure in this yeast, not previously achieved, has allowed us to confirm and extend the observations made with light microscopy. Without first arranging themselves on a metaphase plate, mitotic chromosomes become grouped in 2 clusters radiating, finger-like, from 2 points of attachment at opposite poles of an elongating nucleus. At these 2 sites electron microscopy reveals the presence of disk-shaped electron-dense organelles which we have called kinetochore equivalents (KCE). At mitosis the KCEs are connected across the nucleus by a narrow bundle of parallel microtubules which we refer to as the spindle. Integration of our observations has led us to propose that at mitosis the separation of the KCEs and their attached chromosomes is initiated by a differential expansion of the nuclear envelope restricted to the region between recently divided KCEs and that expansion of the nuclear envelope later becomes general, resulting in a marked elongation of the nucleus. Displacement of the nuclear contents to the ends of the elongated nucleus gives it the shape of a dumbbell. The elongation of the microtubule bundle keeps in step with the elongation of the nucleus but does not appear to be the cause of it. It may have the function of keeping the separated KCEs rigidly apart. During mitosis the nucleolus persists and stretches out within the unbroken envelope of the nucleus as it elongates. Towards the end of division equal amounts of nucleolar material are found in the rounded ends of the dumbbell-shaped nucleus. The break up of the dumbbell shape into daughter nuclei seems to involve the breaking of its tenuous middle part and a pivoting of its 2 ends in opposite directions. In the course of our work on mitosis we have become aware of features in the cytoplasm of growing S. pombe cells which are described here for the first time. The cells invariably contain several prominent vacuoles containing an extremely electron-dense material which stains metachromatically with toluidine blue and may be polyphosphate. The mitochondria are of special interest for 2 reasons. First, because they have unique mesosome-like membrane invaginations and secondly, because a mitochondrion is regularly associated with the single KCE by the side of the interphase nucleus, as well as with each one of the 2 KCEs that occupy opposite ends of the intranuclear spindle during mitosis.

Studies on nuclear division in basidia of Poria latemarginata

1974 ◽  
Vol 52 (11) ◽  
pp. 2323-2333 ◽  
Author(s):  
E. C. Setliff ◽  
H. C. Hoch ◽  
R. F. Patton
Keyword(s):  
Electron Microscopy ◽  
Nuclear Envelope ◽  
Nuclear Division ◽  
Light And Electron Microscopy ◽  
Metaphase Plate ◽  
Longitudinal Axis ◽  
Spindle Pole ◽  
Prophase Nucleus ◽  
Oriented Parallel ◽  
Two Envelopes

Nuclear division in basidia of Poria latemarginata was studied comparatively by light and electron microscopy. Premeiotic mitosis occurred in the lower half of the basidium and was oriented parallel to the longitudinal axis of the basidium. Mitosis was not observed with the light microscope and only late anaphase figures of mitosis were seen with the electron microscope. Mitosis was intranuclear with microtubules oriented between two spindle pole bodies (SPBs). The SPBs were spherical with a central core of material slightly more electron opaque than the surrounding SPB material. The nuclear envelope remained intact except at the SPBs.Divisions I and II of meiosis were chiastobasidial and occurred at the apices of basidia. The major features of meiosis observed by both light and electron microscopy were (1) karyogamy followed by the presence of one or two nucleoli in the prophase nucleus; (2) elongated chromosomes and synapsis at late zygotene – pachytene; (3) occurrence of a spindle at metaphase–anaphase composed of chromosomal and continuous microtubules associated with the SPBs; (4) absence of a metaphase plate with chromosomes arranged randomly around a zone of continuous microtubules; (5) condensation of chromosomes and asynchronous separation at anaphase; (6) kinetochores at anaphase; (7) the nuclear envelope remaining intact throughout meiosis except for discontinuities at the SPBs; (8) membrane-bound vesicles associated with chromosomes during division; and (9) separation of daughter nuclei at telophase. Stages of division II meiosis were observed less frequently and were similar to division I. The four postmeiotic nuclei then migrated back toward the central part of the basidium. Sterigmata developed at this time. Postmeiotic nuclei were surrounded by one or two envelopes of perinuclear endoplasmic reticulum before their migration into basidiospores. Electron-opaque inclusions occurred within the nuclei at this stage.

The Response of Testis Cells to Low Dose X-Irradiation

1981 ◽  
Vol 39 ◽  
pp. 542-543
Author(s):  
D. E. Philpott ◽  
W. Sapp ◽  
C. Williams ◽  
Joann Stevenson ◽  
S. Black
Keyword(s):  
Electron Microscopy ◽  
Stem Cell ◽  
Light Microscopy ◽  
Dose Level ◽  
Cross Sections ◽  
Low Dose ◽  
Light And Electron Microscopy ◽  
Cellular Responses ◽  
Post Irradiation ◽  
X Irradiation

The response of spermatogonial cells to X-irradiation is well documented. It has been shown that there is a radiation resistent stem cell (As) which, after irradiation, replenishes the seminiferous epithelium. Most investigations in this area have dealt with radiation dosages of 100R or more. This study was undertaken to observe cellular responses at doses less than 100R of X-irradiation utilizing a system in which the tissue can be used for light and electron microscopy.Brown B6D2F1 mice aged 16 weeks were exposed to X-irradiation (225KeV; 15mA; filter 0.35 Cu; 50-60 R/min). Four mice were irradiated at each dose level between 1 and 100 rads. Testes were removed 3 days post-irradiation, fixed, and embedded. Sections were cut at 2 microns for light microscopy. After staining, surviving spermatogonia were identified and counted in tubule cross sections. The surviving fraction of spermatogonia compared to control, S/S0, was plotted against dose to give the curve shown in Fig. 1.

Solving the mechanisms responsible for organelle behavior in vivo by same-cell correlative light and electron microscopy

1992 ◽  
Vol 50 (1) ◽  
pp. 14-15
Author(s):  
Conly L. Rieder
Keyword(s):  
Electron Microscopy ◽  
Quantitative Analysis ◽  
Light Microscopy ◽  
Living Cell ◽  
Light And Electron Microscopy ◽  
Time Behavior ◽  
Dynamic Interactions ◽  
Positive Identification ◽  
Cellular Components

The behavior of many cellular components, and their dynamic interactions, can be characterized in the living cell with considerable spatial and temporal resolution by video-enhanced light microscopy (video-LM). Indeed, under the appropriate conditions video-LM can be used to determine the real-time behavior of organelles ≤ 25-nm in diameter (e.g., individual microtubules—see). However, when pushed to its limit the structures and components observed within the cell by video-LM cannot be resolved nor necessarily even identified, only detected. Positive identification and a quantitative analysis often requires the corresponding electron microcopy (EM).

Development of an in vitro Model for the Study of the Response of Equine Tendon Fibroblasts to Injury and Medication

1997 ◽  
Vol 10 (01) ◽  
pp. 6-11 ◽  
Author(s):  
R. F. Rosenbusch ◽  
L. C. Booth ◽  
L. A. Dahlgren
Keyword(s):  
Electron Microscopy ◽  
Extracellular Matrix ◽  
Light Microscopy ◽  
Light And Electron Microscopy ◽  
Tendon Healing ◽  
Matrix Proteins ◽  
Isolated Cells ◽  
Superficial Digital Flexor Tendon ◽  
Vitro Model

SummaryEquine tendon fibroblasts were isolated from explants of superficial digital flexor tendon, subcultured and maintained in monolayers. The cells were characterized by light microscopy, electron microscopy and radiolabel studies for proteoglycan production. Two predominant cell morphologies were identified. The cells dedifferentiated toward a more spindle shape with repeated subcultures. Equine tendon fibroblasts were successfully cryopreserved and subsequently subcultured. The ability to produce proteoglycan was preserved.The isolated cells were identified as fibroblasts, based on their characteristic shape by light microscopy and ultrastructure and the active production of extracellular matrix proteins. Abundant rough endoplasmic reticulum and the production of extracellular matrix products demonstrated active protein production and export. Proteoglycans were measurable via liquid scintillation counting in both the cell-associated fraction and free in the supernatant. This model is currently being utilized to study the effects of polysulfated glycosaminoglycan on tendon healing. Future uses include studying the effects of other pharmaceuticals, such as hyaluronic acid, on tendon healing.A model was developed for in vitro investigations into tendon healing. Fibroblasts were isolated from equine superficial digital flexor tendons and maintained in monolayer culture. The tenocytes were characterized via light and electron microscopy. Proteoglycan production was measured, using radio-label techniques. The fibroblasts were cryopreserved and subsequently subcultured. The cells maintained their capacity for proteoglycan production, following repeated subculturing and cryopreservation.

Further observations on nucleolar tails in amphibian oocytes

1991 ◽  
Vol 99 (3) ◽  
pp. 515-521
Author(s):  
PEDRO LEÓN ◽  
JAMES KEZER ◽  
ERIC SCHABTACH
Keyword(s):  
Electron Microscopy ◽  
Nuclear Envelope ◽  
Nuclear Membrane ◽  
Outer Surface ◽  
Light And Electron Microscopy ◽  
Nuclear Pores ◽  
Core Component ◽  
Amphibian Species ◽  
Attachment Structures ◽  
Convoluted Tubules

Large oocytes from some amphibian species possess beaded or unbeaded intranuclear tails that penetrate the extrachromosomal nucleoli through a distinct pit in their surface and attach to the central core component Here we show, using light and electron microscopy, that tails anchor nucleoli to the nuclear envelope through intricate attachment structures. These structures are composed of interconnected spherical masses containing highly convoluted tubules and associated extratubular proteins, directly directly in contact with the inner nuclear membrane. Fibers emerging from the nuclear pores seemingly hold the attachment complex in place. Beads on the nucleolar tails are formed by the accumulation of proteins on the outer surface of smooth tubules. The function of these intranuclear tubules is unknown

scholarly journals An Easy Path for Correlative Electron and Super-Resolution Light Microscopy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dorothea Pinotsi ◽  
Simona Rodighiero ◽  
Silvia Campioni ◽  
Gabor Csucs
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Amyloid Fibrils ◽  
Light And Electron Microscopy ◽  
Super Resolution ◽  
Wide Field ◽  
Set Up ◽  
Bio Compatibility ◽  
Scanning Electron

Abstract A number of new Correlative Light and Electron Microscopy approaches have been developed over the past years, offering the opportunity to combine the specificity and bio-compatibility of light microscopy with the high resolution achieved in electron microscopy. More recently, these approaches have taken one step further and also super-resolution light microscopy was combined with transmission or scanning electron microscopy. This combination usually requires moving the specimen between different imaging systems, an expensive set-up and relatively complicated imaging workflows. Here we present a way to overcome these difficulties by exploiting a commercially available wide-field fluorescence microscope integrated in the specimen chamber of a Scanning Electron Microscope (SEM) to perform correlative LM/EM studies. Super-resolution light microscopy was achieved by using a recently developed algorithm - the Super-Resolution Radial Fluctuations (SRRF) - to improve the resolution of diffraction limited fluorescent images. With this combination of hardware/software it is possible to obtain correlative super-resolution light and scanning electron microscopy images in an easy and fast way. The imaging workflow is described and demonstrated on fluorescently labelled amyloid fibrils, fibrillar protein aggregates linked to the onset of multiple neurodegenerative diseases, revealing information about their polymorphism.

scholarly journals THE GLOMERULUS IN EXPERIMENTAL RENAL DISEASE IN RATS AS OBSERVED BY LIGHT AND ELECTRON MICROSCOPY

1955 ◽  
Vol 102 (5) ◽  
pp. 573-580 ◽  
Author(s):  
Carolyn F. Piel ◽  
Luther Dong ◽  
F.W.S. Modern ◽  
Joseph R. Goodman ◽  
Roger Moore
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cells ◽  
Basement Membrane ◽  
Light Microscopy ◽  
Light And Electron Microscopy ◽  
Electron Microscopic ◽  
Crescent Formation ◽  
Colloidal Iron ◽  
Narrow Channels ◽  
Glomerular Capillary

Nephrotoxic serum disease in rats has been studied by light and electron microscopy from 1 hour to 10 weeks after production of the disease. By light microscopy leucocytic infiltration of the glomerular capillary was observed between the 3rd and 6th hour. At 6 hours an increase in colloidal iron-positive material was observed coating the extraluminal surface of the capillaries. Also at this time swelling of the endothelial cells becomes prominent. By 72 hours, thickening of the basement membrane was observed. Glomerular capillary thrombi were observed in approximately half the tissue examined in the first 2 weeks of disease. 50 per cent of the animals showed severe chronic lesions, exudation into the capsular space, crescent formation, and obliteration of glomeruli. At 1 hour electron microscopic pictures showed that osmophilic material may line the foot processes of the epithelial cells and obliterate all but narrow channels of the space between the feet. By 6 hours thickening of the basement membrane was prominent. This change persisted throughout 10 weeks of observation. The tissue from animals which had severe chronic alterations by light microscopy revealed changes which could not be interpreted at this time.

scholarly journals A tribute to Shinya Inoue and innovation in light microscopy

2004 ◽  
Vol 165 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Karen R. Dell ◽  
Ronald D. Vale
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Light Microscope ◽  
Light And Electron Microscopy ◽  
Single Molecules ◽  
Living Cells ◽  
Dynamic Processes ◽  
New Techniques

The 2003 International Prize for Biology was awarded to Shinya Inoue for his pioneering work in visualizing dynamic processes within living cells using the light microscope. He and his scientific descendants are now pushing light microscopy even further by developing new techniques such as imaging single molecules, visualizing processes in living animals, and correlating results from light and electron microscopy.

Scale structure and taxonomy of some species of Raphidocystis, Raphidiophrys, and Pompholyxophrys (Heliozoea) including descriptions of six new taxa

1985 ◽  
Vol 63 (8) ◽  
pp. 1944-1961 ◽  
Author(s):  
K. H. Nicholls ◽  
M. Dürrschmidt
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
New Zealand ◽  
Light Microscopy ◽  
Light And Electron Microscopy ◽  
Scale Structure ◽  
Taxonomic Descriptions ◽  
Transmission Electron ◽  
New Information ◽  
Freshwater Habitats

Sixteen taxa of the genera Raphidocystis, Raphidiophrys, and Pompholyxophrys from freshwater habitats in Canada, Chile, and New Zealand were studied by light and electron microscopy. Six taxa are described as new: Raphidocystis glabra, Raphidiophrys minuta, Raphidiophrys orbicularis ssp. orbicularis, R. orbicularis ssp. ovalis, Pompholyxophrys stellata, and P. ossea. New information on scale structure and arrangement based on scanning and transmission electron microscopy amplifies the taxonomic descriptions of Raphidiophrys ambigua, R. pallida, R. elegans, R. intermedia, R. marginata, R. symmetrica, Pompholyxophrys punicea, P. exigua, and P. ovuligera, which were previously imperfectly known by light microscopy only.

scholarly journals ELECTRON MICROSCOPY OF MITOSIS IN AMEBAE

1967 ◽  
Vol 34 (1) ◽  
pp. 47-59 ◽  
Author(s):  
L. E. Roth
Keyword(s):  
Electron Microscopy ◽  
Nuclear Envelope ◽  
Metaphase Plate ◽  
Test Sequence ◽  
Partial Loss ◽  
Mitotic Apparatus ◽  
In Vivo Test ◽  
Characteristic Sequences ◽  
Inhibitor Compounds

The mitotic apparatus (MA) of the giant ameba, Chaos carolinensis, has characteristic sequences of microtubule arrays and deployment of nuclear envelope fragments. If mitotic organisms are subjected to 2°C for 5 min, the MA microtubules are completely degraded, and the envelope fragments are released from the chromosomes which remain condensed but lose their metaphase-plate orientation. On warming, microtubules reform but show partial loss of their parallel alignment; displacement of the envelope fragments persists or is increased by microtubule reformation. This study demonstrates that cooling causes destruction of microtubules and intermicrotubular cross-bonds and further shows that such controlled dissolution and reformation can provide an in vivo test sequence for studies on the effects of inhibitor-compounds on microtubule subunit aggregation. Urea, at the comparatively low concentration of 0.8 M, inhibited reformation following cooling and rewarming but was ineffective in altering microtubules that had formed before treatment.

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