Electron Microscopy of Spindle Pole Bodies in Pathogenic Fungi

2010 ◽  
Vol 51 (1) ◽  
pp. 1-5
Author(s):  
Masashi Yamaguchi
Keyword(s):  
Electron Microscopy ◽  
Pathogenic Fungi ◽  
Spindle Pole ◽  
Spindle Pole Bodies

Computer-Assisted Analysis and Display of Nuclear Structures

1978 ◽  
Vol 36 (3) ◽  
pp. 557-563
Author(s):  
P.B. Moens
Keyword(s):  
Electron Microscopy ◽  
Relevant Information ◽  
Quantitative Information ◽  
Spindle Pole ◽  
Computer Assisted ◽  
Spindle Pole Bodies ◽  
Transmission Electron ◽  
Complete Series ◽  
Nuclear Structures ◽  
Assisted Analysis

Quantitative electron microscopy of cells, organelles, or chromosomes gives information on the numbers, sizes, distribution and organization of the structures in question. In the case of the nucleus, quantitative information can be obtained on nuclear pores, spindle pole bodies, kinetochores, centromeres, microtubules, chromosomes, synaptonemal complexes, and nucleoli. Scanning electron microscopy of fractured specimens and transmission electron microscopy of spread preparations and high voltage TKM can give some of the information, but total information can best be obtained from a complete series of sections of the material. The analysis of photographic records, however, is cumbersome and the relevant information is often not readily visible. In this report some of the methods ia compiling quantitative information on the nucleus and its components are described.

scholarly journals Structural role of Sfi1p–centrin filaments in budding yeast spindle pole body duplication

2006 ◽  
Vol 173 (6) ◽  
pp. 867-877 ◽  
Author(s):  
Sam Li ◽  
Alan M. Sandercock ◽  
Paul Conduit ◽  
Carol V. Robinson ◽  
Roger L. Williams ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Saccharomyces Cerevisiae ◽  
Crystal Structures ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Pole Body ◽  
Spindle Pole Bodies ◽  
N Terminus ◽  
Α Helix

Centrins are calmodulin-like proteins present in centrosomes and yeast spindle pole bodies (SPBs) and have essential functions in their duplication. The Saccharomyces cerevisiae centrin, Cdc31p, binds Sfi1p on multiple conserved repeats; both proteins localize to the SPB half-bridge, where the new SPB is assembled. The crystal structures of Sfi1p–centrin complexes containing several repeats show Sfi1p as an α helix with centrins wrapped around each repeat and similar centrin–centrin contacts between each repeat. Electron microscopy (EM) shadowing of an Sfi1p–centrin complex with 15 Sfi1 repeats and 15 centrins bound showed filaments 60 nm long, compatible with all the Sfi1 repeats as a continuous α helix. Immuno-EM localization of the Sfi1p N and C termini showed Sfi1p–centrin filaments spanning the length of the half-bridge with the Sfi1p N terminus at the SPB. This suggests a model for SPB duplication where the half-bridge doubles in length by association of the Sfi1p C termini, thereby providing a new Sfi1p N terminus to initiate SPB assembly.

scholarly journals Meiosis in Coprinus. VIII. A time-course study of the fusion and division of the spindle pole body during meiosis.

1978 ◽  
Vol 76 (3) ◽  
pp. 761-766 ◽  
Author(s):  
B C Lu
Keyword(s):  
Electron Microscopy ◽  
Time Course ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Coprinus Cinereus ◽  
Synaptonemal Complexes ◽  
Pole Body ◽  
Spindle Pole Bodies ◽  
Time Course Study ◽  
Metaphase I

The time-course study of meiosis in the fungus Coprinus cinereus (C. lagopus) by electron microscopy reveals that two monoglobular spindle pole bodies (SPB's) of prekaryogamy nuclei come together during karyogamy and are fused. The fusion SPB of postkaryogamy nucleus persists through zygotene and pachytene as evidenced by the presence of axial components and synaptonemal complexes. At early diplotene, the SPB divides. The divided SPB takes on a diglobular form, which grows in size to form two daughter SPB's. These separate and move to opposite poles at metaphase I.

Light and electron microscopy of conjugation in the yeast, Schizosaccharomyces octosporus

1982 ◽  
Vol 28 (9) ◽  
pp. 1059-1077 ◽  
Author(s):  
M.-L. Ashton ◽  
P. B. Moens
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Microscope Level ◽  
Nuclear Movement ◽  
Light Microscope Level ◽  
Spindle Pole Bodies ◽  
Interference Contrast Microscopy ◽  
Fluorescent Spot

Conjugation in Schizosaccharomyces octosporus is described through the use of interference contrast microscopy, fluorescence microscopy, and electron microscopy of serial sections. At the light microscope level, mating was frequently observed to occur between cells of common ancestry. Fluorescent staining of the nuclei showed that nuclear migration occurs prior to karyogamy, and following diploidization the nucleus then migrates to the end of the cell. A brightly fluorescent spot was found at the apex of the migration nucleus. At the electron microscope level, the results showed that nuclear movement occurs in the presence of cytoplasmic microtubules that are associated with the spindle pole body, the conjugatory nuclei first fuse at or near the spindle pole bodies, and fusion of the spindle bodies occurs apparently by stacking one onto the other.

Ultrastructure of meiosis and the spindle pole body cycle in freeze-substituted basidia of the smut fungi Ustilago maydis and Ustilago avenae

1992 ◽  
Vol 70 (3) ◽  
pp. 629-638 ◽  
Author(s):  
Kerry O'Donnell
Keyword(s):  
Electron Microscopy ◽  
Spindle Pole Body ◽  
Ustilago Maydis ◽  
Spindle Pole ◽  
Meiotic Spindle ◽  
Smut Fungi ◽  
Late Prophase ◽  
Prophase I ◽  
Pole Body ◽  
Middle Piece

Meiosis in the smut fungi Ustilago maydis and Ustilago avenae (Basidiomycota, Ustilaginales) was studied by electron microscopy of serial-sectioned freeze substituted basidia. At prophase I, a spindle pole body composed of two globular elements connected by a middle piece was attached to the extranuclear surface of each nucleus. Astral and spindle microtubules were initiated at each globular element at late prophase I to prometaphase I. During spindle initiation, the middle piece disappeared and interdigitating half-spindles entered the nucleoplasm, which was surrounded by discontinuous nuclear envelope together with perinuclear endoplasmic reticulum. Kinetochore pairs at metaphase I were analyzed to obtain a karyotype for each species. The meiotic spindle pole body replicational cycle is described. Key words: electron microscopy, freeze-substitution, meiosis, Ustilago, spindle pole body.

scholarly journals The Spindle Pole Bodies Facilitate Nuclear Envelope Division during Closed Mitosis in Fission Yeast

PLoS Biology ◽  
2007 ◽  
Vol 5 (7) ◽  
pp. e170 ◽  
Author(s):  
Liling Zheng ◽  
Cindi Schwartz ◽  
Valentin Magidson ◽  
Alexey Khodjakov ◽  
Snezhana Oliferenko
Keyword(s):  
Nuclear Envelope ◽  
Fission Yeast ◽  
Spindle Pole ◽  
Spindle Pole Bodies

Asymmetry of the spindle pole bodies and spg1p GAP segregation during mitosis in fission yeast

1999 ◽  
Vol 112 (14) ◽  
pp. 2313-2321 ◽  
Author(s):  
L. Cerutti ◽  
V. Simanis
Keyword(s):  
Cell Cycle ◽  
Fission Yeast ◽  
Spindle Pole Body ◽  
Mitotic Cell ◽  
Spindle Pole ◽  
The Other ◽  
Septum Formation ◽  
Spindle Pole Bodies ◽  
Interphase Cells ◽  
Early Mitosis

In the fission yeast Schizosaccharomyces pombe, the onset of septum formation is induced by a signal transduction network involving several protein kinases and a GTPase switch. One of the roles of the spg1p GTPase is to localise the cdc7p protein kinase to the poles of the mitotic spindle, from where the onset of septation is thought to be signalled at the end of mitosis. Immunofluorescence studies have shown that cdc7p is located on both spindle pole bodies early in mitosis, but only on one during the later stages of anaphase. This is mediated by inactivation of spg1p on one pole before the other. The GAP for spg1p is a complex of two proteins, cdc16p and byr4p. Localisation of cdc16p and byr4p by indirect immunofluorescence during the mitotic cell cycle showed that both proteins are present on the spindle pole body in interphase cells. During mitosis, byr4p is seen first on both poles of the spindle, then on only one. This occurs prior to cdc7p becoming asymmetric. In contrast, the signal due to cdc16p decreases to a low level during early mitosis, before being seen strongly on the same pole as byr4p. Double staining indicates that this is the opposite pole to that which retains cdc7p in late anaphase. Examination of the effect of inactivating cdc16p at various stages of the cell cycle suggests that cdc16p, together with cdc2p plays a role in restraining septum formation during interphase. The asymmetric inactivation of spg1p is mediated by recruitment of the cdc16p-byr4p GAP to one of the poles of the spindle before the other, and the asymmetry of the spindle pole bodies may be established early during mitosis. Moreover, the spindle pole bodies appear to be non-equivalent even after division has been completed.

scholarly journals Centrosome signaling pathways consult on their decision

2017 ◽  
Vol 216 (9) ◽  
pp. 2599-2599
Author(s):  
Ben Short
Keyword(s):  
Signaling Pathways ◽  
Spindle Pole ◽  
Spindle Pole Bodies

Study reveals unexpected dialog between mitotic entrance and exit pathway proteins on yeast spindle pole bodies.

scholarly journals The Three Fungal Transmembrane Nuclear Pore Complex Proteins of Aspergillus nidulans Are Dispensable in the Presence of an Intact An-Nup84-120 Complex

2009 ◽  
Vol 20 (2) ◽  
pp. 616-630 ◽  
Author(s):  
Hui-Lin Liu ◽  
Colin P.C. De Souza ◽  
Aysha H. Osmani ◽  
Stephen A. Osmani
Keyword(s):  
High Temperature ◽  
Nuclear Envelope ◽  
Aspergillus Nidulans ◽  
Nuclear Pore Complex ◽  
Mitotic Spindle ◽  
Spindle Pole ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Spindle Pole Bodies ◽  
Pore Complexes

In Aspergillus nidulans nuclear pore complexes (NPCs) undergo partial mitotic disassembly such that 12 NPC proteins (Nups) form a core structure anchored across the nuclear envelope (NE). To investigate how the NPC core is maintained, we affinity purified the major core An-Nup84-120 complex and identified two new fungal Nups, An-Nup37 and An-ELYS, previously thought to be vertebrate specific. During mitosis the An-Nup84-120 complex locates to the NE and spindle pole bodies but, unlike vertebrate cells, does not concentrate at kinetochores. We find that mutants lacking individual An-Nup84-120 components are sensitive to the membrane destabilizer benzyl alcohol (BA) and high temperature. Although such mutants display no defects in mitotic spindle formation, they undergo mitotic specific disassembly of the NPC core and transient aggregation of the mitotic NE, suggesting the An-Nup84-120 complex might function with membrane. Supporting this, we show cells devoid of all known fungal transmembrane Nups (An-Ndc1, An-Pom152, and An-Pom34) are viable but that An-ndc1 deletion combined with deletion of individual An-Nup84-120 components is either lethal or causes sensitivity to treatments expected to destabilize membrane. Therefore, the An-Nup84-120 complex performs roles, perhaps at the NPC membrane as proposed previously, that become essential without the An-Ndc1 transmembrane Nup.

Sign in / Sign up

Export Citation Format

Share Document