Centrosome and microtubule dynamics during meiotic progression in the mouse oocyte

1991 ◽  
Vol 100 (2) ◽  
pp. 289-298 ◽  
Author(s):  
S.M. Messinger ◽  
D.F. Albertini
Keyword(s):  
Mouse Oocyte ◽  
Meiotic Maturation ◽  
Microtubule Nucleation ◽  
Microtubule Organization ◽  
Double Labeling ◽  
Meiotic Progression ◽  
Tubulin Antibodies ◽  
Discrete Populations ◽  
Meiosis I

The disposition, function and fate of centrosomes were analysed in mouse oocytes undergoing in vitro meiotic maturation, using multiple-label fluorescence microscopy. Oocytes fixed at various points during meiotic progression were double labeled with either human centrosome-specific antibody, 5051, and anti-tubulin antibodies or 5051 and MPM-2 antibodies in order to evaluate the microtubule nucleation capacity and phosphorylation status of centrosomes during this process. Double labeling with anti-tubulin antibodies revealed two populations of centrosomes that undergo stage-specific changes in number, location and microtubule nucleation capacity in relation to spindle assembly and cytoplasmic events. Specifically, one population was consistently associated with chromatin throughout meiotic maturation whereas a second population of cytoplasmic centrosomes exhibited maximal numbers and nucleation capacity at prometaphase and anaphase of meiosis-I. Quantitative evaluation of cytoplasmic centrosomes indicated increased numbers during the transition from diakinesis to prometaphase and metaphase to anaphase and total disappearance during telophase. Colocalization studies with MPM-2 revealed that centrosomes were always phosphorylated. However, at metaphase of meiosis I and II the microtubule nucleation capacity of centrosomes was diminished. These results suggest the existence of two discrete populations of centrosomes in the mouse oocyte that are coordinately regulated to subserve aspects of microtubule organization relative to both nuclear and cytoplasmic events.

Diethylstilbestrol exposure disrupts mouse oocyte meiotic maturation in vitro through affecting spindle assembly and chromosome alignment

Chemosphere ◽  
2020 ◽  
Vol 249 ◽  
pp. 126182 ◽  
Author(s):  
Zhi-Ming Ding ◽  
Li-Ping Hua ◽  
Muhammad Jamil Ahmad ◽  
Muhammad Safdar ◽  
Fan Chen ◽  
...  
Keyword(s):  
Spindle Assembly ◽  
Mouse Oocyte ◽  
Meiotic Maturation ◽  
Maturation In Vitro ◽  
Chromosome Alignment ◽  
Oocyte Meiotic Maturation

scholarly journals Interaction of Aurora-A and centrosomin at the microtubule-nucleating site in Drosophila and mammalian cells

2003 ◽  
Vol 162 (5) ◽  
pp. 757-764 ◽  
Author(s):  
Yasuhiko Terada ◽  
Yumi Uetake ◽  
Ryoko Kuriyama
Keyword(s):  
Mammalian Cells ◽  
Aurora A Kinase ◽  
Aurora A ◽  
Mitotic Spindles ◽  
Microtubule Nucleation ◽  
Microtubule Organization ◽  
Centrosomal Protein ◽  
Spindle Poles

A mitosis-specific Aurora-A kinase has been implicated in microtubule organization and spindle assembly in diverse organisms. However, exactly how Aurora-A controls the microtubule nucleation onto centrosomes is unknown. Here, we show that Aurora-A specifically binds to the COOH-terminal domain of a Drosophila centrosomal protein, centrosomin (CNN), which has been shown to be important for assembly of mitotic spindles and spindle poles. Aurora-A and CNN are mutually dependent for localization at spindle poles, which is required for proper targeting of γ-tubulin and other centrosomal components to the centrosome. The NH2-terminal half of CNN interacts with γ-tubulin, and induces cytoplasmic foci that can initiate microtubule nucleation in vivo and in vitro in both Drosophila and mammalian cells. These results suggest that Aurora-A regulates centrosome assembly by controlling the CNN's ability to targeting and/or anchoring γ-tubulin to the centrosome and organizing microtubule-nucleating sites via its interaction with the COOH-terminal sequence of CNN.

scholarly journals XGef Mediates Early CPEB Phosphorylation duringXenopusOocyte Meiotic Maturation

2005 ◽  
Vol 16 (3) ◽  
pp. 1152-1164 ◽  
Author(s):  
Susana E. Martínez ◽  
Lei Yuan ◽  
Charlemagne Lacza ◽  
Heather Ransom ◽  
Gwendolyn M. Mahon ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Regulatory Mechanism ◽  
Meiotic Maturation ◽  
Protein Accumulation ◽  
Interacting Protein ◽  
Meiotic Progression ◽  
Messenger Ribonucleoprotein ◽  
Guanine Exchange Factor ◽  
Exchange Activity

Polyadenylation-induced translation is an important regulatory mechanism during metazoan development. During Xenopus oocyte meiotic progression, polyadenylation-induced translation is regulated by CPEB, which is activated by phosphorylation. XGef, a guanine exchange factor, is a CPEB-interacting protein involved in the early steps of progesterone-stimulated oocyte maturation. We find that XGef influences early oocyte maturation by directly influencing CPEB function. XGef and CPEB interact during oogenesis and oocyte maturation and are present in a c-mos messenger ribonucleoprotein (mRNP). Both proteins also interact directly in vitro. XGef overexpression increases the level of CPEB phosphorylated early during oocyte maturation, and this directly correlates with increased Mos protein accumulation and acceleration of meiotic resumption. To exert this effect, XGef must retain guanine exchange activity and the interaction with CPEB. Overexpression of a guanine exchange deficient version of XGef, which interacts with CPEB, does not enhance early CPEB phosphorylation. Overexpression of a version of XGef that has significantly reduced interaction with CPEB, but retains guanine exchange activity, decreases early CPEB phosphorylation and delays oocyte maturation. Injection of XGef antibodies into oocytes blocks progesterone-induced oocyte maturation and early CPEB phosphorylation. These findings indicate that XGef is involved in early CPEB activation and implicate GTPase signaling in this process.

Energy substrates and the completion of spontaneous meiotic maturation

Zygote ◽  
2000 ◽  
Vol 8 (4) ◽  
pp. 339-351 ◽  
Author(s):  
Stephen M. Downs ◽  
Elliott D. Hudson
Keyword(s):  
Cumulus Cell ◽  
Suppressive Effect ◽  
Meiotic Maturation ◽  
Culture Volume ◽  
Energy Substrate ◽  
Meiotic Progression ◽  
Culture Viability ◽  
Effect Of Glucose ◽  
Positive Effect

This study was carried out to examine how different combinations of pyruvate and glucose affect spontaneous meiotic maturation of cumulus-cell-enclosed mouse oocytes (CEO) to metaphase II (MII). Most experiments used an open system in which oocytes were cultured in 1 ml medium in plastic tubes. Initial experiments examined the dose response effects of pyruvate or glucose alone in the presence or absence of 2 mM glutamine. When medium lacked both pyruvate and glucose, more than 91% of the oocytes died in glutamine-free medium during 15 h of culture; viability was restored with the addition of glutamine, but only 11% of the CEO reached MII. In the absence of glutamine, 62–68% of oocytes completed maturation in 0.23–2.3 mM pyruvate, while 44–60% MII was observed in 0.55–27.8 mM glucose. The addition of glutamine to these cultures had a general suppressive effect on the completion of maturation. When glucose was added to pyruvate-containing cultures, the combination of 1 mM pyruvate/5.5 mM glucose was most effective in supporting maturation (about 90% MII), with little effect of glutamine. No further increase in maturation was observed when glucose was increased five-fold (to 27.8 mM). The positive effect of glucose was in part attributed to stimulation of glycolysis and increased production of pyruvate, since a reduced culture volume (8 μl), which allows the accumulation of secreted pyruvate, improved maturation in glucose-containing, but not pyruvate-containing, medium, and FSH, which stimulates glycolysis, increased progression to MII in glucose-containing, but not pyruvate-containing, medium. Yet these results also suggest that glucose has a beneficial effect on maturation apart from simple provision of pyruvate. The pyruvate effect was directly on the oocyte, because denuded oocytes responded more effectively than CEO to this energy substrate. The highest percentage of MII oocytes (96–97%) occurred in microdrop cultures containing glucose but lacking glutamine. These results indicate that glutamine supports oocyte viability but is not an adequate energy source for the completion of spontaneous meiotic maturation and may be detrimental. In addition, while pyruvate and glucose alone can each support meiotic progression of CEO to MII, optimal maturation requires the provision of both substrates to the culture medium when a large volume (1 ml) is used. It is concluded that careful attention to specific energy substrate supplementation and culture volume is important to optimise spontaneous meiotic maturation in vitro.

scholarly journals Fission Yeast mto2p Regulates Microtubule Nucleation by the Centrosomin-related Protein mto1p

2005 ◽  
Vol 16 (6) ◽  
pp. 3040-3051 ◽  
Author(s):  
Itaru Samejima ◽  
Paula C. C. Lourenço ◽  
Hilary A. Snaith ◽  
Kenneth E. Sawin
Keyword(s):  
Fission Yeast ◽  
Insertional Mutagenesis ◽  
Spindle Pole ◽  
Related Protein ◽  
Microtubule Nucleation ◽  
Microtubule Organization ◽  
Cytoplasmic Microtubule ◽  
Division Site ◽  
Cell Extracts

From an insertional mutagenesis screen, we isolated a novel gene, mto2+, involved in microtubule organization in fission yeast. mto2Δ strains are viable but exhibit defects in interphase microtubule nucleation and in formation of the postanaphase microtubule array at the end of mitosis. The mto2Δ defects represent a subset of the defects displayed by cells deleted for mto1+ (also known as mod20+ and mbo1+), a centrosomin-related protein required to recruit the γ-tubulin complex to cytoplasmic microtubule-organizing centers (MTOCs). We show that mto2p colocalizes with mto1p at MTOCs throughout the cell cycle and that mto1p and mto2p coimmunoprecipitate from cytoplasmic extracts. In vitro studies suggest that mto2p binds directly to mto1p. In mto2Δ mutants, although some aspects of mto1p localization are perturbed, mto1p can still localize to spindle pole bodies and the cell division site and to “satellite” particles on interphase microtubules. In mto1Δ mutants, localization of mto2p to all of these MTOCs is strongly reduced or absent. We also find that in mto2Δ mutants, cytoplasmic forms of the γ-tubulin complex are mislocalized, and the γ-tubulin complex no longer coimmunoprecipitates with mto1p from cell extracts. These experiments establish mto2p as a major regulator of mto1p-mediated microtubule nucleation by the γ-tubulin complex.

Meiotic maturation of mouse oocytes in vitro: association of newly synthesized proteins with condensing chromosomes

1976 ◽  
Vol 20 (3) ◽  
pp. 549-568 ◽  
Author(s):  
P.M. Wassarman ◽  
G.E. Letourneau
Keyword(s):  
Protein Synthesis ◽  
Mammalian Species ◽  
Germinal Vesicle ◽  
Chromosome Condensation ◽  
Intracellular Distribution ◽  
Meiotic Maturation ◽  
Meiotic Progression ◽  
Mouse Oocytes

The nature, intracellular distribution, and role of proteins synthesized during meiotic maturation of mouse oocytes in vitro have been examined. Proteins synthesized during the initial stages of maturation are concentrated within the nucleus (germinal vesicle) and become intimately associated with the condensing chromosomes. Inhibition of protein synthesis during this period does not prevent germinal vesicle dissolution or chromosome condensation, but meiotic progression is blocked reversibly at the circular bivalent stage. A protein is synthesized during meiotic maturation of the mouse oocyte which exhibits several of the characteristics of the very lysine-rich histone, FI; this and other histones are phosphorylated during the initial stages of maturation. These results are discussed in relation to studies of meiotic maturation of oocytes from non-mammalian species and chromosome condensation in both oocytes and mitotic cells.

scholarly journals MEK1/2 Regulates Microtubule Organization, Spindle Pole Tethering and Asymmetric Division During Mouse Oocyte Meiotic Maturation

Cell Cycle ◽  
2007 ◽  
Vol 6 (3) ◽  
pp. 330-338 ◽  
Author(s):  
Ling-Zhu Yu ◽  
Bo Xiong ◽  
Wen-Xue Gao ◽  
Chun-Min Wang ◽  
Zhi-Sheng Zhong ◽  
...  
Keyword(s):  
Asymmetric Division ◽  
Spindle Pole ◽  
Mouse Oocyte ◽  
Meiotic Maturation ◽  
Microtubule Organization ◽  
Oocyte Meiotic Maturation

scholarly journals Bisphenol B Exposure Disrupts Mouse Oocyte Meiotic Maturation in vitro Through Affecting Spindle Assembly and Chromosome Alignment

2020 ◽  
Vol 8 ◽  
Author(s):  
Shou-Xin Zhang ◽  
Zhi-Ming Ding ◽  
Muhammad Jamil Ahmad ◽  
Yong-Sheng Wang ◽  
Ze-Qun Duan ◽  
...  
Keyword(s):  
Dna Damage ◽  
Spindle Assembly ◽  
Epigenetic Modifications ◽  
Mouse Oocyte ◽  
Meiotic Maturation ◽  
Meiotic Arrest ◽  
First Polar Body ◽  
Chromosome Alignment ◽  
Oocyte Meiotic Maturation

Bisphenol B (BPB), a substitute of bisphenol A (BPA), is widely used in the polycarbonate plastic and resins production. However, BPB proved to be not a safe alternative to BPA, and as an endocrine disruptor, it can harm the health of humans and animals. In the present study, we explored the effects of BPB on mouse oocyte meiotic maturation in vitro. We found that 150 μM of BPB significantly compromised the first polar body extrusion (PBE) and disrupted the cell cycle progression with meiotic arrest. The spindle assembly and chromosome alignment were disordered after BPB exposure, which was further demonstrated by the aberrant localization of p-MAPK. Also, BPB exposure increased the acetylation levels of α-tubulin. As a result, the spindle assemble checkpoint (SAC) was continuously provoked, contributing to meiotic arrest. We further demonstrated that BPB severely induced DNA damage, but the ROS and ATP production were not altered. Furthermore, the epigenetic modifications were changed after BPB exposure, as indicated by increased K3K9me3 and H3K27me3 levels. Besides, the pattern of estrogen receptor α (ERα) dynamics was disrupted with a mass gathering on the spindle in BPB-exposed oocytes. Our collective results indicated that exposure to BPB compromised meiotic maturation and damaged oocyte quality by affecting spindle assembly and chromosome alignment, acetylation of α-tubulin, DNA damage, epigenetic modifications, and ERα dynamics in mouse oocytes.

scholarly journals γ-Tubulin Complexes and Fibrillar Arrays: Two Conserved High Molecular Forms with Many Cellular Functions

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 776
Author(s):  
Jana Chumová ◽  
Hana Kourová ◽  
Lucie Trögelová ◽  
Geoffrey Daniel ◽  
Pavla Binarová
Keyword(s):  
Higher Plants ◽  
Molecular Forms ◽  
Cellular Functions ◽  
Animal Cells ◽  
Microtubule Nucleation ◽  
Microtubule Organization ◽  
Independent Manner ◽  
Spontaneous Nucleation ◽  
Plant Microtubules

Higher plants represent a large group of eukaryotes where centrosomes are absent. The functions of γ-tubulin small complexes (γ-TuSCs) and γ-tubulin ring complexes (γ-TuRCs) in metazoans and fungi in microtubule nucleation are well established and the majority of components found in the complexes are present in plants. However, plant microtubules are also nucleated in a γ-tubulin-dependent but γ-TuRC-independent manner. There is growing evidence that γ-tubulin is a microtubule nucleator without being complexed in γ-TuRC. Fibrillar arrays of γ-tubulin were demonstrated in plant and animal cells and the ability of γ-tubulin to assemble into linear oligomers/polymers was confirmed in vitro for both native and recombinant γ-tubulin. The functions of γ-tubulin as a template for microtubule nucleation or in promoting spontaneous nucleation is outlined. Higher plants represent an excellent model for studies on the role of γ-tubulin in nucleation due to their acentrosomal nature and high abundancy and conservation of γ-tubulin including its intrinsic ability to assemble filaments. The defining scaffolding or sequestration functions of plant γ-tubulin in microtubule organization or in nuclear processes will help our understanding of its cellular roles in eukaryotes.

Sign in / Sign up

Export Citation Format

Share Document