scholarly journals Neurl4, a novel daughter centriole protein, prevents formation of ectopic microtubule organizing centres

EMBO Reports ◽  
2012 ◽  
Vol 13 (6) ◽  
pp. 547-553 ◽  
Author(s):  
Ji Li ◽  
Sehyun Kim ◽  
Tetsuo Kobayashi ◽  
Feng‐Xia Liang ◽  
Nina Korzeniewski ◽  
...  
Keyword(s):  
Microtubule Organizing Centres ◽  
Daughter Centriole

scholarly journals Function of Centrobin: a Novel Daughter Centriole-Associated Protein

2006 ◽  
Vol 12 (S02) ◽  
pp. 300-301
Author(s):  
C Zou ◽  
J Li ◽  
Y Bai ◽  
W Gunning ◽  
D Wazer ◽  
...  
Keyword(s):  
Daughter Centriole

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006

Cytasters induced within unfertilized sea-urchin eggs

1983 ◽  
Vol 61 (1) ◽  
pp. 175-189
Author(s):  
R. Kuriyama ◽  
G.G. Borisy
Keyword(s):  
Electron Microscopy ◽  
Sea Urchin ◽  
Sea Water ◽  
Light And Electron Microscopy ◽  
Sea Urchin Eggs ◽  
Microtubule Organizing Centres ◽  
Treatment Step

Conditions that induce the formation of asters in unfertilized sea-urchin eggs have been investigated. Monasters were formed by treatment of eggs with acidic or basic sea-water, or procaine- or thymol-containing sea-water. A second treatment step, incubation with D2O-containing, ethanol-containing or hypertonic sea-water induced multiple cytasters. The number and size of cytasters varied according to the concentration of agents and duration of the first and second treatments, and also upon the species of eggs and the season in which the eggs were obtained. Generally, a longer second treatment or a higher concentration of the second medium resulted in a higher number of cytasters per egg. Asters were isolated and then examined by light and electron microscopy. Isolated monasters apparently lacked centrioles, whereas cytasters obtained from eggs undergoing the two-step treatment contained one or more centrioles. Up to eight centrioles were seen in a single aster; the centrioles appeared to have been produced during the second incubation. Centrospheres prepared from isolated asters retained the capacity to nucleate the formation of microtubules in vitro as assayed by light and electron microscopy. Many microtubules radiated from the centre of isolated asters, whether they contained centrioles or not. This observation is consistent with many other reports that microtubule-organizing centres need not contain centrioles.

Ultrastructure of multiple microtubule initiation sites in mouse neuroblastoma cells

1981 ◽  
Vol 47 (1) ◽  
pp. 1-24
Author(s):  
G.A. Sharp ◽  
M. Osborn ◽  
K. Weber
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Immunofluorescence Microscopy ◽  
Neuroblastoma Cells ◽  
Biological Significance ◽  
Optimal Conditions ◽  
Serial Sectioning ◽  
Mouse Neuroblastoma ◽  
Microtubule Organizing Centres ◽  
Perinuclear Area

Morphologically undifferentiated and differentiated mouse neuroblastoma N115 and N18 cells were examined after serial sectioning by electron microscopy. A sizeable percentage of the cells revealed multiple centrioles, usually clustered together in the perinuclear area with 2 preferential locations, i.e. above and below the largest nuclear diameter. These results indicate that the multiple microtubule-organizing centres previously visualized by immunofluorescence microscopy with tubulin antibody in neuroblastoma cells recovering from Colcemid poisoning are most likely in majority related to multiple centrioles. This interpretation is further strengthened by experiments in which cells are first recorded in the fluorescence microscope and then after serial sectioning in the electron microscope. The results show that under optimal conditions immunofluorescence microscopy is able to visualize single centrioles. The possible biological significance of the combined electron and immunofluorescence microscopical results is discussed.

scholarly journals A homeostatic clock sets daughter centriole size in flies

2018 ◽  
Vol 217 (4) ◽  
pp. 1233-1248 ◽  
Author(s):  
Mustafa G. Aydogan ◽  
Alan Wainman ◽  
Saroj Saurya ◽  
Thomas L. Steinacker ◽  
Anna Caballe ◽  
...  
Keyword(s):  
Growth Rate ◽  
Drosophila Melanogaster ◽  
Inverse Relationship ◽  
S Phase ◽  
Cell Type ◽  
Linear Rate ◽  
Mother Centriole ◽  
Daughter Centriole ◽  
Correct Size

Centrioles are highly structured organelles whose size is remarkably consistent within any given cell type. New centrioles are born when Polo-like kinase 4 (Plk4) recruits Ana2/STIL and Sas-6 to the side of an existing “mother” centriole. These two proteins then assemble into a cartwheel, which grows outwards to form the structural core of a new daughter. Here, we show that in early Drosophila melanogaster embryos, daughter centrioles grow at a linear rate during early S-phase and abruptly stop growing when they reach their correct size in mid- to late S-phase. Unexpectedly, the cartwheel grows from its proximal end, and Plk4 determines both the rate and period of centriole growth: the more active the centriolar Plk4, the faster centrioles grow, but the faster centriolar Plk4 is inactivated and growth ceases. Thus, Plk4 functions as a homeostatic clock, establishing an inverse relationship between growth rate and period to ensure that daughter centrioles grow to the correct size.

Microtubule-organizing centres and assembly of the double-spiral microtubule pattern in certain heliozoan axonemes

1981 ◽  
Vol 50 (1) ◽  
pp. 259-280
Author(s):  
J.C. Jones ◽  
J.B. Tucker
Keyword(s):  
Nuclear Envelope ◽  
Surface Membrane ◽  
Cold Treatment ◽  
Dense Material ◽  
Microtubule Assembly ◽  
Central Nucleus ◽  
Spiral Pattern ◽  
Microtubule Organizing Centres ◽  
Double Spiral ◽  
Actinophrys Sol

The double-spiral microtubule pattern is established by a self-linkage procedure when axopodial axonemes reassemble after cold treatment in multinucleate Echinosphaerium nucleofilum and mononucleate Actinophrys sol. Nuclei are related spatially to axoneme morphogenesis in both organisms but in rather different ways. Microtubules grow out in all directions from discrete clumps of dense material situated close to nuclei in E. nucleofilum as axonemal assembly begins. Each clump acts as a microtubule-organizing centre (MTOC) in so far as it is associated spatially with the assembly of microtubules for a single axoneme. The dense material spreads along the sides of a developing axoneme for several micrometers, where it probably promotes further microtubule assembly as the double-spiral pattern is established. Pattern is generated as microtubules that are randomly oriented to begin with become more closely juxtaposed and aligned with each other. There are indications that juxtaposition is brought about by the contractile action of a filamentous meshwork that interconnects the microtubules. Final positioning and alignment appears to be accomplished by a ‘zippering’ together of adjacent portions of microtubules that proceeds in both directions along the lengths of developing axonemes as self-linkage is effected. Considerable numbers of more or less radially oriented microtubules remain and project from the surface membrane of the single central nucleus during cold treatment of A. sol. Additional tubules assemble and become associated similarly with the nuclear envelope immediately after cold treatment. Initially these microtubules are not arranged in a double-spiral pattern, which is subsequently generated by procedures similar to those outlined above for E. nucleofilum. It is suggested that the surface of the nuclear envelope may act as an MTOC.

Evidence for microtubule nucleation at plasma membrane-associated sites in Drosophila

1987 ◽  
Vol 88 (1) ◽  
pp. 95-107 ◽  
Author(s):  
M.M. Mogensen ◽  
J.B. Tucker
Keyword(s):  
Plasma Membrane ◽  
Cell Differentiation ◽  
Cross Section ◽  
Plasma Membranes ◽  
Early Stage ◽  
Apical Cell ◽  
Apical Plasma Membrane ◽  
Cell Surfaces ◽  
Microtubule Organizing Centres ◽  
Oriented Parallel

This report is concerned with the nucleation and organization of microtubule bundles that assemble after ‘conventional’ centrosomal microtubule-organizing centres have been lost. The microtubule bundles in question span the lengths of wing epidermal cells. Bundles extend between hemidesmosomes at the apical cuticle-secreting surfaces of cells and basal attachment desmosomes that unite the dorsal and ventral epidermal layers of developing wing blades. Furthermore, each bundle includes up to 1500 microtubules and most of the microtubules are composed of 15 protofilaments. Individual cells were serially cross-sectioned at an early stage of bundle assembly. The number of microtubule profiles/cell cross-section decreased progressively by up to 59% of the most apical values in section sequences cut from fairly apical to more basal levels in the cells. The apical ends of microtubules were associated with numerous small dense plaque-like sites (diameter 0.1-0.2 micron), which were specialized regions of plasma membranes at the apical surfaces of cells. Many of the microtubules near apical plaques were not well aligned with each other; they ‘radiated away’ from cell apices. This was in contrast to the situation at more basal levels where most microtubules were oriented parallel to the longitudinal axes of cells. These findings indicate that the relatively dispersed arrays of apical plasma membrane-associated plaques act as microtubule-nucleating sites to initiate basally directed elongation of bundle microtubules. Apical cell surfaces and their plaques seem to operate as microtubule-nucleating and -organizing regions that functionally replace the centrosomal microtubule-organizing centres lost earlier in cell differentiation.

Microtubule-organizing centres in binucleate cells and homosynkaryons

1980 ◽  
Vol 44 (1) ◽  
pp. 123-133
Author(s):  
F.M. Watt ◽  
E. Sidebottom ◽  
H. Harris
Keyword(s):  
Vero Cells ◽  
Binucleate Cells ◽  
Microtubule Organizing Centres ◽  
Immunofluorescence Studies

Immunofluorescence studies showed that most binucleate Vero cells formed by virus-induced fusion or by inhibition of cytokinesis had a single microtubule-organizing centre (MTOC) when examined during the reassembly of microtubules after chilling, but two or more organizing centres when examined after exposure to colcemid. These findings suggest that although binucleate cells initially contain more MTOC than mononucleate cells, the extra MTOC are normally aggregated, so that the number of MTOC in binucleate cells tends to be reduced very quickly to that in mononucleate cells.

Phosphorylation of keratin 18 serine 52 regulates mother–daughter centriole engagement and microtubule nucleation by cell cycle-dependent accumulation at the centriole

2020 ◽  
Vol 153 (5) ◽  
pp. 307-321 ◽  
Author(s):  
Huiping Yu ◽  
Xinjie Yang ◽  
Hui Wu ◽  
Chunmei Li ◽  
Jingwen Shi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Microtubule Nucleation ◽  
Keratin 18 ◽  
Cycle Dependent ◽  
Daughter Centriole

On Centrioles, Microtubules, and Cellular Electromagnetism

2014 ◽  
Vol 5 (3) ◽  
Author(s):  
Ronald L. Huston
Keyword(s):  
Cell Division ◽  
Cancer Cells ◽  
Daughter Centriole

This paper describes the inner workings of centrioles (a pair of small organelles adjacent to the nucleus) as they create cell electropolarity, engage in cell division (mitosis), but in going awry, also promote the development of cancers. The electropolarity arises from vibrations of microtubules composing the centrioles. Mitosis begins as each centrioles duplicates itself by growing a daughter centriole on its side. If during duplication more than one daughter is grown, cancer can occur and the cells divide uncontrollably. Cancer cells with supernumerary centrioles have high electropolarity which can serve as an attractor for charged therapeutic nanoparticles.

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