Replicating DNA does not block germinal vesicle breakdown in mouse oocytes

1995 ◽  
Vol 272 (3) ◽  
pp. 245-248 ◽  
Author(s):  
J. Fulka ◽  
R. M. Moor ◽  
J. Fulka
Keyword(s):  
Germinal Vesicle ◽  
Germinal Vesicle Breakdown ◽  
Mouse Oocytes

Pleiotropic effect of okadaic acid on maturing mouse oocytes

Development ◽  
1991 ◽  
Vol 112 (4) ◽  
pp. 971-980 ◽  
Author(s):  
H. Alexandre ◽  
A. Van Cauwenberge ◽  
Y. Tsukitani ◽  
J. Mulnard
Keyword(s):  
Protein Kinase ◽  
Okadaic Acid ◽  
Protein Phosphatases ◽  
Chromatin Condensation ◽  
Polar Body ◽  
Germinal Vesicle ◽  
Inhibitory Effect ◽  
Negative Control ◽  
Germinal Vesicle Breakdown ◽  
Mouse Oocytes

Okadaic acid (OA), a potent inhibitor of types 1 and 2A protein phosphatases, was shown recently to induce chromatin condensation and germinal vesicle breakdown (GVBD) in mouse oocytes arrested at the dictyate stage by dibutyryl cAMP (dbcAMP), isobutyl methylxanthine (IBMX) and 12,13-phorbol dibutyrate (PDBu). We confirm these results using IBMX and another phorbol diester, 12-O-tetradecanoylphorbol-13-acetate (TPA) and show that OA also bypasses the inhibitory effect of 6-dimethylaminopurine (6-DMAP). It has been concluded that protein phosphatases 1 and/or 2A (PP1, 2A), involved in the negative control of MPF activation, are thus operating downstream from both the protein kinase A and protein kinase C catalysed phosphorylation steps that prevent the breakdown of GV. Similar enzymatic activities are also able to counteract the general inhibition of protein phosphorylation. However, PP1 and/or PP2A are positively involved in the activation of pericentriolar material (PCM) into microtubule organizing centres (MTOCs). This explains the inhibitory effect of OA on spindle assembly. Finally, OA interferes with the integrity and/or function of actomyosin filaments. This results in a dramatic ruffling of the plasma membrane leading to the internalization of large vacuoles, the inhibition of chromosome centrifugal displacement and, consequently, the prevention of polar body extrusion.

The Role of Tissue Transglutaminase in the Germinal Vesicle Breakdown of Mouse Oocytes

2001 ◽  
Vol 286 (2) ◽  
pp. 229-234 ◽  
Author(s):  
Sung Woo Kim ◽  
Zee-Won Lee ◽  
ChangKyu Lee ◽  
Kyung Soon Im ◽  
Kwon-Soo Ha
Keyword(s):  
Tissue Transglutaminase ◽  
Germinal Vesicle ◽  
Germinal Vesicle Breakdown ◽  
Mouse Oocytes

scholarly journals The dynamics of cyclin B1 distribution during meiosis I in mouse oocytes

Reproduction ◽  
2004 ◽  
Vol 128 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Petros Marangos ◽  
John Carroll
Keyword(s):  
Fluorescent Protein ◽  
Germinal Vesicle ◽  
Cyclin B1 ◽  
Nuclear Accumulation ◽  
Leptomycin B ◽  
Germinal Vesicle Breakdown ◽  
Mouse Oocytes ◽  
Living Mouse ◽  
Green Fluorescent ◽  
Meiosis I

Cdk1-cyclin B1 kinase activity drives oocytes through meiotic maturation. It is regulated by the phosphorylation status of cdk1 and by its spatial organisation. Here we used a cyclin B1-green fluorescent protein (GFP) fusion protein to examine the dynamics of cdk1-cyclin B1 distribution during meiosis I (MI) in living mouse oocytes. Microinjection of cyclin B1-GFP accelerated germinal vesicle breakdown (GVBD) and, as previously described, overrides cAMP-mediated meiotic arrest. GVBD was pre-empted by a translocation of cyclin B1-GFP from the cytoplasm to the germinal vesicle (GV). After nuclear accumulation, cyclin B1-GFP localised to the chromatin. The localisation of cyclin B1-GFP is governed by nuclear import and export. In GV intact oocytes, cyclin export was demonstrated by showing that cyclin B1-GFP injected into the GV is exported to the cytoplasm while a similar size dextran is retained. Import was revealed by the finding that cyclin B1-GFP accumulated in the GV when export was inhibited using leptomycin B. These studies show that GVBD in mouse oocytes is sensitive to cyclin B1 abundance and that the changes in distribution of cyclin B1 contribute to progression through MI.

The effect of PD98059 on MAPK regulation in cumulus-enclosed and cumulus-free mouse oocytes

Zygote ◽  
2003 ◽  
Vol 11 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Jaroslav Kalous ◽  
Michal Kubelka ◽  
Jan Motlík
Keyword(s):  
Germinal Vesicle ◽  
Cumulus Cells ◽  
Experimental Conditions ◽  
Germinal Vesicle Breakdown ◽  
Mapk Activation ◽  
Mapk Phosphorylation ◽  
Kinase Activation ◽  
Mouse Oocytes ◽  
Significant Difference ◽  
Epidermal Growth

The effect of the p42/44 mitogen-activated kinase (MAPK) inhibitor, PD98059, on MAPK activation and meiosis resumption in mouse oocytes was studied. When germinal vesicle (GV)-stage denuded oocytes (DOs) were cultured continuously in 50 μM PD98059, germinal vesicle breakdown (GVBD) was postponed for 2-3 h. MAPK phosphorylation and activation was delayed as well. However, PD98059 did not impair histone H1 kinase activation. After 14 h of culture there was no significant difference in the rate of DOs reaching metaphase II (MII) arrest in either control or experimental conditions. The effect of PD98059 on MAPK inhibition was further tested in epidermal growth factor (EGF)-treated oocyte–cumulus complexes (OCCs). Exposure of GV-stage OCCs for 5 min to EGF (10 ng/ml) induced a considerable increase in MAPK phosphorylation. After OCCs were further cultured in 50 μM PD98059 a rapid dephosphorylation of MAPK was induced. Already after 1 min of treatment the non-phosphorylated form of MAPK dominated, indicating the high effectivity of PD98059. This result indicates that short EGF/PD98059 treatment of OCCs induced MAPK phosphorylation/dephosphorylation in cumulus cells only. As only a transient delay in MAPK phosphorylation and activation was observed in PD98059-treated DOs we conclude that there is also another PD98059-nonsensitive pathway(s) leading to MAPK activation in mouse oocytes. The data obtained suggest that meiosis resumption in mouse oocytes is somehow influenced by the MEK/MAPK activation pathway.

Effects of protein kinase C activators on germinal vesicle breakdown and polar body emission of mouse oocytes

1986 ◽  
Vol 165 (2) ◽  
pp. 507-517 ◽  
Author(s):  
Elayne A. Bornslaeger ◽  
William T. Poueymirou ◽  
Peter Mattei ◽  
Richard M. Schultz
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Polar Body ◽  
Germinal Vesicle ◽  
Germinal Vesicle Breakdown ◽  
Mouse Oocytes ◽  
Kinase C ◽  
Protein Kinase C Activators

Dynamic alterations in H4K12 acetylation during meiotic maturation and after parthenogenetic activation of mouse oocytes

Zygote ◽  
2020 ◽  
Vol 28 (5) ◽  
pp. 367-370
Author(s):  
Ze Zhang ◽  
Baobao Chen ◽  
Haoliang Cui ◽  
Haixu Gao ◽  
Ming Gao ◽  
...  
Keyword(s):  
Germinal Vesicle ◽  
Histone Acetyltransferases ◽  
Meiotic Maturation ◽  
Histone H4 ◽  
Germinal Vesicle Breakdown ◽  
Parthenogenetic Activation ◽  
Expression Levels ◽  
Mouse Oocytes

SummaryThe aim of the study was to investigate the continuous changing pattern of H4K12 acetylation, and the expression levels of histone acetyltransferases (HATs) and histone deacetyltransferases (HDACs) in mouse oocytes during meiosis and after parthenogenetic activation (PA). The immunofluorescence results showed hyperacetylation of lysine-12 on histone H4 (H4K12) in the germinal vesicle (GV) oocytes that then decreased during germinal vesicle breakdown (GVBD), and disappeared in metaphase II (MII). However, it reappeared in the early 1-cell embryos derived after 4 h of PA. The expression levels of some selected HATs and HDACs also validated the changing pattern of H4K12 acetylation during meiosis and PA. In conclusion, H4K12 is deacetylated in GVBD and MII, and re-hyperacetylated after PA.

scholarly journals Condensins I and II are essential for construction of bivalent chromosomes in mouse oocytes

2011 ◽  
Vol 22 (18) ◽  
pp. 3465-3477 ◽  
Author(s):  
Jibak Lee ◽  
Sugako Ogushi ◽  
Mitinori Saitou ◽  
Tatsuya Hirano
Keyword(s):  
Sister Chromatid ◽  
Meiotic Chromosome ◽  
Germinal Vesicle ◽  
Primary Role ◽  
Germinal Vesicle Breakdown ◽  
Chromosome Dynamics ◽  
Mouse Oocytes ◽  
First Time ◽  
Striking Contrast ◽  
Metaphase I

In many eukaryotes, condensins I and II associate with chromosomes in an ordered fashion during mitosis and play nonoverlapping functions in their assembly and segregation. Here we report for the first time the spatiotemporal dynamics and functions of the two condensin complexes during meiotic divisions in mouse oocytes. At the germinal vesicle stage (prophase I), condensin I is present in the cytoplasm, whereas condensin II is localized within the nucleus. After germinal vesicle breakdown, condensin II starts to associate with chromosomes and becomes concentrated onto chromatid axes of bivalent chromosomes by metaphase I. REC8 “glues” chromosome arms along their lengths. In striking contrast to condensin II, condensin I localizes primarily around centromeric regions at metaphase I and starts to associate stably with chromosome arms only after anaphase I. Antibody injection experiments show that condensin functions are required for many aspects of meiotic chromosome dynamics, including chromosome individualization, resolution, and segregation. We propose that the two condensin complexes play distinctive roles in constructing bivalent chromosomes: condensin II might play a primary role in resolving sister chromatid axes, whereas condensin I might contribute to monopolar attachment of sister kinetochores, possibly by assembling a unique centromeric structure underneath.

scholarly journals Active maturation-promoting factor is present in mature mouse oocytes.

1985 ◽  
Vol 100 (5) ◽  
pp. 1637-1640 ◽  
Author(s):  
R A Sorensen ◽  
M S Cyert ◽  
R A Pedersen
Keyword(s):  
Xenopus Oocytes ◽  
Germinal Vesicle ◽  
Xenopus Laevis Oocytes ◽  
Factor Activity ◽  
Dibutyryl Cyclic Amp ◽  
Germinal Vesicle Breakdown ◽  
Mouse Oocytes ◽  
Immature Mouse ◽  
Mature Mouse ◽  
Maturation Promoting Factor

Cytoplasmic extracts of meiotically mature mouse oocytes were injected into immature Xenopus laevis oocytes, which underwent germinal vesicle breakdown within 2 h. Germinal vesicle breakdown was not inhibited by incubation of the Xenopus oocytes in cycloheximide (20 micrograms/ml). Identically prepared extracts of meiotically immature mouse oocytes, arrested at the germinal vesicle stage by dibutyryl cyclic AMP (100 micrograms/ml), did not induce germinal vesicle breakdown in Xenopus oocytes. The results show that maturation-promoting factor activity appears during the course of oocyte maturation in the mouse.

scholarly journals Mitochondrial Ca2+ Overload Leads to Mitochondrial Oxidative Stress and Delayed Meiotic Resumption in Mouse Oocytes

2020 ◽  
Vol 8 ◽  
Author(s):  
Luyao Zhang ◽  
Zichuan Wang ◽  
Tengfei Lu ◽  
Lin Meng ◽  
Yan Luo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Function ◽  
Maternal Obesity ◽  
Polar Body ◽  
Germinal Vesicle ◽  
Oocyte Quality ◽  
Obese Women ◽  
Germinal Vesicle Breakdown ◽  
Mouse Oocytes ◽  
First Polar Body

Overweight or obese women seeking pregnancy is becoming increasingly common. Human maternal obesity gives rise to detrimental effects during reproduction. Emerging evidence has shown that these abnormities are likely attributed to oocyte quality. Oxidative stress induces poor oocyte conditions, but whether mitochondrial calcium homeostasis plays a key role in oocyte status remains unresolved. Here, we established a mitochondrial Ca2+ overload model in mouse oocytes. Knockdown gatekeepers of the mitochondrial Ca2+ uniporters Micu1 and Micu2 as well as the mitochondrial sodium calcium exchanger NCLX in oocytes both increased oocytes mitochondrial Ca2+ concentration. The overload of mitochondria Ca2+ in oocytes impaired mitochondrial function, leaded to oxidative stress, and changed protein kinase A (PKA) signaling associated gene expression as well as delayed meiotic resumption. Using this model, we aimed to determine the mechanism of delayed meiosis caused by mitochondrial Ca2+ overload, and whether oocyte-specific inhibition of mitochondrial Ca2+ influx could improve the reproductive abnormalities seen within obesity. Germinal vesicle breakdown stage (GVBD) and extrusion of first polar body (PB1) are two indicators of meiosis maturation. As expected, the percentage of oocytes that successfully progress to the germinal vesicle breakdown stage and extrude the first polar body during in vitro culture was increased significantly, and the expression of PKA signaling genes and mitochondrial function recovered after appropriate mitochondrial Ca2+ regulation. Additionally, some indicators of mitochondrial performance—such as adenosine triphosphate (ATP) and reactive oxygen species (ROS) levels and mitochondrial membrane potential—recovered to normal. These results suggest that the regulation of mitochondrial Ca2+ uptake in mouse oocytes has a significant role during oocyte maturation as well as PKA signaling and that proper mitochondrial Ca2+ reductions in obese oocytes can recover mitochondrial performance and improve obesity-associated oocyte quality.

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