scholarly journals The 3D Architecture and Molecular Foundations of De Novo Centriole Assembly Via Bicentrioles

2021 ◽  
Author(s):  
Sónia Gomes Pereira ◽  
Ana Laura Sousa ◽  
Catarina Nabais ◽  
Tiago Paixão ◽  
Alexander J. Holmes ◽  
...  
Keyword(s):  
De Novo ◽  
3D Architecture ◽  
Centriole Assembly

scholarly journals The 3D architecture and molecular foundations of de novo centriole assembly via bicentrioles

2020 ◽  
Author(s):  
Sónia Gomes Pereira ◽  
Ana Laura Sousa ◽  
Catarina Nabais ◽  
Tiago Paixão ◽  
Alexander. J. Holmes ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cell Division ◽  
De Novo ◽  
Cellular Functions ◽  
Spindle Poles ◽  
3D Architecture ◽  
Centriole Assembly ◽  
Work Supports ◽  
Wall Components

Abstract/SummaryCentrioles are structurally conserved organelles, composing both centrosomes and cilia. In animal cycling cells, centrioles often form through a highly characterized process termed canonical duplication. However, a large diversity of eukaryotes form centrioles de novo through uncharacterized pathways. This unexplored diversity is key to understanding centriole assembly mechanisms and how they evolved to assist specific cellular functions. Here, combining electron microscopy and tomography, we show that during spermatogenesis of the moss Physcomitrium patens, centrioles are born as a co-axially oriented centriole pair united by a cartwheel. We observe that microtubules emanate from those bicentrioles, which localize to the spindle poles during cell division. Thereafter, each bicentriole breaks apart, and the two resulting sister centrioles mature asymmetrically, elongating specific microtubule triplets and a naked cartwheel. Subsequently, two cilia are assembled which are capable of beating asynchronously. We further show that conserved cartwheel and centriole wall components, SAS6, BLD10 and POC1 are expressed during spermatogenesis and are required for this de novo biogenesis pathway. Our work supports a scenario where centriole biogenesis is more diverse than previously thought and that conserved molecular modules underlie diversification of this essential pathway.

scholarly journals The 3D architecture and molecular foundations of de novo centriole assembly via bicentrioles

2021 ◽  
Author(s):  
Sónia Gomes Pereira ◽  
Ana Laura Sousa ◽  
Catarina Nabais ◽  
Tiago Paixão ◽  
Alexander J. Holmes ◽  
...  
Keyword(s):  
De Novo ◽  
3D Architecture ◽  
Centriole Assembly

Rapid centriole assembly inNaegleriareveals conserved roles for both de novo and mentored assembly

Cytoskeleton ◽  
2016 ◽  
Vol 73 (3) ◽  
pp. 109-116 ◽  
Author(s):  
Lillian K. Fritz-Laylin ◽  
Yaron Y. Levy ◽  
Edward Levitan ◽  
Sean Chen ◽  
W. Zacheus Cande ◽  
...  
Keyword(s):  
De Novo ◽  
Centriole Assembly

scholarly journals Kinetics and regulation of de novo centriole assembly

2001 ◽  
Vol 11 (5) ◽  
pp. 308-317 ◽  
Author(s):  
Wallace F Marshall ◽  
Yvonne Vucica ◽  
Joel L Rosenbaum
Keyword(s):  
De Novo ◽  
Centriole Assembly

scholarly journals Plk4 triggers autonomous de novo centriole biogenesis and maturation

2021 ◽  
Vol 220 (5) ◽  
Author(s):  
Catarina Nabais ◽  
Delphine Pessoa ◽  
Jorge de-Carvalho ◽  
Thomas van Zanten ◽  
Paulo Duarte ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
De Novo ◽  
Cell Types ◽  
Proliferating Cells ◽  
Cycle Progression ◽  
Controlled System ◽  
Pericentriolar Material ◽  
Centriole Assembly ◽  
Critical Components

Centrioles form centrosomes and cilia. In most proliferating cells, centrioles assemble through canonical duplication, which is spatially, temporally, and numerically regulated by the cell cycle and the presence of mature centrioles. However, in certain cell types, centrioles assemble de novo, yet by poorly understood mechanisms. Herein, we established a controlled system to investigate de novo centriole biogenesis, using Drosophila melanogaster egg explants overexpressing Polo-like kinase 4 (Plk4), a trigger for centriole biogenesis. We show that at a high Plk4 concentration, centrioles form de novo, mature, and duplicate, independently of cell cycle progression and of the presence of other centrioles. Plk4 concentration determines the temporal onset of centriole assembly. Moreover, our results suggest that distinct biochemical kinetics regulate de novo and canonical biogenesis. Finally, we investigated which other factors modulate de novo centriole assembly and found that proteins of the pericentriolar material (PCM), and in particular γ-tubulin, promote biogenesis, likely by locally concentrating critical components.

scholarly journals Plk4 triggers autonomous de novo centriole biogenesis and maturation

2020 ◽  
Author(s):  
Catarina Nabais ◽  
Delphine Pessoa ◽  
Jorge de-Carvalho ◽  
Thomas van Zanten ◽  
Paulo Duarte ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
De Novo ◽  
Cell Types ◽  
Proliferating Cells ◽  
Cycle Progression ◽  
Controlled System ◽  
Centriole Assembly ◽  
Critical Components ◽  
Kinetics Of

AbstractCentrioles form centrosomes and cilia. In most proliferating cells, centrioles assemble through canonical duplication, which is spatially, temporally and numerically regulated by the cell cycle and the presence of mature centrioles. However, in certain cell-types, centrioles assemble de novo, yet by poorly understood mechanisms. Here, we established a controlled system to investigate de novo centriole biogenesis, using Drosophila melanogaster egg explants overexpressing Polo-like kinase 4 (Plk4), a trigger for centriole biogenesis. We show that at high Plk4 concentration, centrioles form de novo, mature and duplicate, independently of cell cycle progression and of the presence of other centrioles. Plk4 concentration determines the kinetics of centriole assembly. Moreover, our results suggest Plk4 operates in a switch-like manner to control the onset of de novo centriole formation, and that distinct biochemical kinetics regulate de novo and canonical biogenesis. Finally, we investigated which other factors modulate de novo centriole assembly and reveal that proteins of the pericentriolar matrix (PCM) promote biogenesis, likely by locally concentrating critical components.

scholarly journals The de novo centriole assembly pathway in HeLa cells

2005 ◽  
Vol 168 (5) ◽  
pp. 713-722 ◽  
Author(s):  
Sabrina La Terra ◽  
Christopher N. English ◽  
Polla Hergert ◽  
Bruce F. McEwen ◽  
Greenfield Sluder ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Hela Cells ◽  
Mammalian Cells ◽  
Cell Cycle Progression ◽  
De Novo ◽  
Variable Number ◽  
S Phase ◽  
Cycle Progression ◽  
Assembly Pathway ◽  
Centriole Assembly

It has been reported that nontransformed mammalian cells become arrested during G1 in the absence of centrioles (Hinchcliffe, E., F. Miller, M. Cham, A. Khodjakov, and G. Sluder. 2001. Science. 291:1547–1550). Here, we show that removal of resident centrioles (by laser ablation or needle microsurgery) does not impede cell cycle progression in HeLa cells. HeLa cells born without centrosomes, later, assemble a variable number of centrioles de novo. Centriole assembly begins with the formation of small centrin aggregates that appear during the S phase. These, initially amorphous “precentrioles” become morphologically recognizable centrioles before mitosis. De novo–assembled centrioles mature (i.e., gain abilities to organize microtubules and replicate) in the next cell cycle. This maturation is not simply a time-dependent phenomenon, because de novo–formed centrioles do not mature if they are assembled in S phase–arrested cells. By selectively ablating only one centriole at a time, we find that the presence of a single centriole inhibits the assembly of additional centrioles, indicating that centrioles have an activity that suppresses the de novo pathway.

The Morphology of the Rat Kidney Following Folic Acid Administration

1970 ◽  
Vol 28 ◽  
pp. 200-201
Author(s):  
Aline Byrnes ◽  
Elsa E. Ramos ◽  
Minoru Suzuki ◽  
E.D. Mayfield
Keyword(s):  
Folic Acid ◽  
De Novo ◽  
Specific Activity ◽  
Rat Kidney ◽  
Present Report ◽  
Intracellular Localization ◽  
Male Rats ◽  
Renal Hypertrophy ◽  
Electron Microscopic ◽  
Biochemical Alterations

Renal hypertrophy was induced in 100 g male rats by the injection of 250 mg folic acid (FA) dissolved in 0.3 M NaHCO3/kg body weight (i.v.). Preliminary studies of the biochemical alterations in ribonucleic acid (RNA) metabolism of the renal tissue have been reported recently (1). They are: RNA content and concentration, orotic acid-c14 incorporation into RNA and acid soluble nucleotide pool, intracellular localization of the newly synthesized RNA, and the specific activity of enzymes of the de novo pyrimidine biosynthesis pathway. The present report describes the light and electron microscopic observations in these animals. For light microscopy, kidney slices were fixed in formalin, embedded, sectioned, and stained with H & E and PAS.

Early ossicle growth in the regenerating disc of a brittle star

1994 ◽  
Vol 52 ◽  
pp. 364-365
Author(s):  
M. Shlepr ◽  
R. L. Turner
Keyword(s):  
Cell Membrane ◽  
Light Microscopy ◽  
De Novo ◽  
Current Model ◽  
Syncytium Formation ◽  
Brittle Star ◽  
Intracellular Location ◽  
Limited Volume ◽  
Tissue Calcification

Calcification in the echinoderms occurs within a limited-volume cavity enclosed by cytoplasmic extensions of the mineral depositing cells, the sclerocytes. The current model of this process maintains that the sheath formed from these cytoplasmic extensions is syncytial. Prior studies indicate that syncytium formation might be dependent on sclerocyte density and not required for calcification. This model further envisions that ossicles formed de novo nucleate and grow intracellularly until the ossicle effectively outgrows the vacuole. Continued ossicle growth occurs within the sheath but external to the cell membrane. The initial intracellular location has been confirmed only for elements of the echinoid tooth.The regenerating aboral disc integument of ophiophragmus filograneus was used to test the current echinoderm calcification model. This tissue is free of calcite fragments, thus avoiding questions of cellular engulfment, and ossicles are formed de novo. The tissue calcification pattern was followed by light microscopy in both living and fixed preparations.

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