Distribution of the Germinal Vesicle Material during Progesterone-Induced Oocyte Maturation in Xenopus and in Cynops. (germinal vesicle material/oocyte maturation/Xenopus laevis/Cynops pyrrhogaster)

We have measured the levels of cyclin mRNAs and polypeptides during oogenesis, progesterone-induced oocyte maturation, and immediately after egg activation in the frog, Xenopus laevis. The mRNA for each cyclin is present at a constant level of approximately 5 x 10(7) molecules per oocyte from the earliest stages of oogenesis until after fertilization. The levels of polypeptides show more complex patterns of accumulation. The B-type cyclins are first detectable in stage IV and V oocytes. Cyclin B2 polypeptide is present at approximately 2 x 10(9) molecules (150 pg) per oocyte by stage VI. The amount increases after progesterone treatment, but returns to its previous level after GVBD and undergoes no further change until it is destroyed at fertilization. Cyclin B1 is present at 4 x 10(8) molecules per oocyte in stage VI oocytes, and rises steadily during maturation, ultimately reaching similar levels to cyclin B2 in unfertilized eggs. Unlike the B-type cyclins, cyclin A is barely detectable in stage VI oocytes, and only starts to be made in significant amounts after oocytes are exposed to progesterone. A portion of all the cyclins are destroyed after germinal vesicle breakdown (GVBD), and cyclins B1 and B2 also experience posttranslational modifications during oocyte maturation. Progesterone strongly stimulates both cyclin and p34cdc2 synthesis in these oocytes, but whereas cyclin synthesis continues in eggs and after fertilization, synthesis of p34cdc2 declines strongly after GVBD. The significance of these results is discussed in terms of the activation and inactivation of maturation-promoting factor.

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PLCz-induced Ca2+ oscillations are enhanced after germinal vesicle breakdown during mouse oocyte maturation

Reproduction Abstracts ◽

10.1530/repabs.3.o003 ◽

2016 ◽

Author(s):

Jessica Sanders ◽

Ethan Bateson ◽

Yuansong Yu ◽

Michail Nomikos ◽

Antony Lai ◽

...

Keyword(s):

Oocyte Maturation ◽

Germinal Vesicle ◽

Mouse Oocyte ◽

Germinal Vesicle Breakdown

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Requirement of mosXe protein kinase for meiotic maturation of Xenopus oocytes induced by a cdc2 mutant lacking regulatory phosphorylation sites.

Molecular and Cellular Biology ◽

10.1128/mcb.12.7.3192 ◽

1992 ◽

Vol 12 (7) ◽

pp. 3192-3203 ◽

Cited By ~ 22

Author(s):

K M Pickham ◽

A N Meyer ◽

J Li ◽

D J Donoghue

Keyword(s):

Protein Kinase ◽

Oocyte Maturation ◽

Xenopus Oocytes ◽

Germinal Vesicle ◽

Cyclin B1 ◽

Phosphorylation Sites ◽

Germinal Vesicle Breakdown ◽

Regulatory Phosphorylation

The p34cdc2 protein kinase is a component of maturation-promoting factor, the master regulator of the cell cycle in all eukaryotes. The activity of p34cdc2 is itself tightly regulated by phosphorylation and dephosphorylation. Predicted regulatory phosphorylation sites of Xenopus p34cdc2 were mutated in vitro, and in vitro-transcribed RNAs were injected into Xenopus oocytes. The cdc2 single mutants Thr-14----Ala and Tyr-15----Phe did not induce germinal vesicle breakdown (BVBD) upon microinjection into oocytes. In contrast, the cdc2 double mutant Ala-14/Phe-15 did induce GVBD. Both the Ala-14 and Ala-14/Phe-15p34cdc2 mutants were shown to coimmunoprecipitate cyclin B1 and to phosphorylate histone H1 in immune complex kinase assays. Microinjection of antisense oligonucleotides to c-mosXe was used to demonstrate the role of mos protein synthesis in the induction of GVBD by the Ala-14/Phe-15 cdc2 mutant. Thr-161 was also mutated. p34cdc2 single mutants Ala-161 and Glu-161 and triple mutants Ala-14/Phe-15/Ala-161 and Ala-14/Phe-15/Glu-161 failed to induce GVBD in oocytes and showed a decreased binding to cyclin B1 in coimmunoprecipitations. Each of the cdc2 mutants was also assayed by coinjection with cyclin B1 or c-mosXe RNA into oocytes. Several of the cdc2 mutants were found to affect the kinetics of cyclin B1 and/or mos-induced GVBD upon coinjection, although none affected the rate of progesterone-induced maturation. We demonstrate here the significance of Thr-14, Tyr-15, and Thr-161 of p34cdc2 in Xenopus oocyte maturation. In addition, these results suggest a regulatory role for mosXe in induction of oocyte maturation by the cdc2 mutant Ala-14/Phe-15.

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The egg membrane microdomain-associated uroplakin III-Src system becomes functional during oocyte maturation and is required for bidirectional gamete signaling at fertilization in Xenopus laevis

Development ◽

10.1242/dev.105510 ◽

2014 ◽

Vol 141 (8) ◽

pp. 1705-1714 ◽

Cited By ~ 19

Author(s):

A. K. M. Mahbub Hasan ◽

A. Hashimoto ◽

Y. Maekawa ◽

T. Matsumoto ◽

S. Kushima ◽

...

Keyword(s):

Xenopus Laevis ◽

Oocyte Maturation ◽

Membrane Microdomain ◽

Egg Membrane

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Role of zinc in the control of oocyte maturation in Xenopus laevis

Biomedical Research ◽

10.2220/biomedres.21.165 ◽

2000 ◽

Vol 21 (3) ◽

pp. 165-168 ◽

Cited By ~ 1

Author(s):

KEN-ICHI WATANABE ◽

TOSHINOBU TOKUMOTO ◽

KATSUTOSHI ISHIKAWA

Keyword(s):

Xenopus Laevis ◽

Oocyte Maturation

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Phosphorylation and protein synthetic events in Xenopus laevis oocytes microinjected with pp60v-src

Molecular and Cellular Biology ◽

10.1128/mcb.5.12.3629-3633.1985 ◽

1985 ◽

Vol 5 (12) ◽

pp. 3629-3633

Author(s):

J G Spivack ◽

J L Maller

Keyword(s):

Xenopus Laevis ◽

Oocyte Maturation ◽

Rous Sarcoma Virus ◽

Actinomycin D ◽

Meiotic Maturation ◽

Xenopus Laevis Oocytes ◽

Rous Sarcoma ◽

Contrast Exposure ◽

Sarcoma Virus ◽

Qualitative Changes

Microinjection of purified pp60v-src, the transforming protein of Rous sarcoma virus, into Xenopus laevis oocytes accelerated the rate of progesterone- or insulin-induced meiotic maturation. This acceleration was abolished by incubating the oocytes with cycloheximide or puromycin during a 2-h interval between pp60v-src microinjection and progesterone addition. In contrast, exposure to actinomycin D did not alter the acceleration of maturation by microinjected pp60v-src. Associated with progesterone treatment and pp60v-src microinjection were a number of qualitative changes in phosphoproteins; a few of these changes are common to both stimuli. These results indicate that the action of pp60v-src in oocytes involves both phosphorylation and protein synthetic events that affect oocyte maturation.

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Insulin-stimulated oocyte maturation requires insulin receptor substrate 1 and interaction with the SH2 domains of phosphatidylinositol 3-kinase

Molecular and Cellular Biology ◽

10.1128/mcb.13.11.6653-6660.1993 ◽

1993 ◽

Vol 13 (11) ◽

pp. 6653-6660

Author(s):

L M Chuang ◽

M G Myers ◽

J M Backer ◽

S E Shoelson ◽

M F White ◽

...

Keyword(s):

Phospholipase C ◽

Oocyte Maturation ◽

Germinal Vesicle ◽

Sh2 Domain ◽

Glutathione S Transferase ◽

Hormonal Stimulation ◽

Germinal Vesicle Breakdown ◽

Sh2 Domains ◽

Igf I ◽

Phospholipase C Gamma

Xenopus oocytes from unprimed frogs possess insulin-like growth factor I (IGF-I) receptors but lack insulin and IGF-I receptor substrate 1 (IRS-1), the endogenous substrate of this kinase, and fail to show downstream responses to hormonal stimulation. Microinjection of recombinant IRS-1 protein enhances insulin-stimulated phosphatidylinositol (PtdIns) 3-kinase activity and restores the germinal vesicle breakdown response. Activation of PtdIns 3-kinase results from formation of a complex between phosphorylated IRS-1 and the p85 subunit of PtdIns 3-kinase. Microinjection of a phosphonopeptide containing a pYMXM motif with high affinity for the src homology 2 (SH2) domain of PtdIns 3-kinase p85 inhibits IRS-1 association with and activation of the PtdIns 3-kinase. Formation of the IRS-1-PtdIns 3-kinase complex and insulin-stimulated PtdIns 3-kinase activation are also inhibited by microinjection of a glutathione S-transferase fusion protein containing the SH2 domain of p85. This effect occurs in a concentration-dependent fashion and results in a parallel loss of hormone-stimulated oocyte maturation. These inhibitory effects are specific and are not mimicked by glutathione S-transferase fusion proteins expressing the SH2 domains of ras-GAP or phospholipase C gamma. Moreover, injection of the SH2 domains of p85, ras-GAP, and phospholipase C gamma do not interfere with progesterone-induced oocyte maturation. These data demonstrate that phosphorylation of IRS-1 plays an essential role in IGF-I and insulin signaling in oocyte maturation and that this effect occurs through interactions of the phosphorylated YMXM/YXXM motifs of IRS-1 with SH2 domains of PtdIns 3-kinase or some related molecules.

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Ha-rasVal-12,Thr-59 activates S6 kinase and p34cdc2 kinase in Xenopus oocytes: evidence for c-mosxe-dependent and -independent pathways

Molecular and Cellular Biology ◽

10.1128/mcb.10.1.310-315.1990 ◽

1990 ◽

Vol 10 (1) ◽

pp. 310-315

Author(s):

C B Barrett ◽

R M Schroetke ◽

F A Van der Hoorn ◽

S K Nordeen ◽

J L Maller

Keyword(s):

Protein Kinase ◽

Oocyte Maturation ◽

Antisense Oligonucleotides ◽

Xenopus Oocytes ◽

Germinal Vesicle ◽

Protein Product ◽

Germinal Vesicle Breakdown ◽

S6 Kinase ◽

Kinase Activation ◽

Histone Kinase

Treatment with insulin or progesterone or microinjection of the transforming protein product of Ha-rasVal-12,Thr-59 (p21) is known to induce germinal vesicle breakdown in Xenopus oocytes. We have investigated the effect of p21 on S6 kinase and the H1 histone kinase of maturation-promoting factor in the presence and absence of antisense oligonucleotides against the c-mosxe proto-oncogene. Injection of p21 led to a rapid increase in S6 phosphorylation, with kinetics similar to those previously observed with insulin. Microinjection of c-mosxe antisense oligonucleotides inhibited germinal vesicle breakdown induced by p21 and totally abolished S6 kinase activation by insulin or progesterone but only partially inhibited activation by p21. However, the activation of p34cdc2 protein kinase by all three stimuli was blocked by antisense oligonucleotides. The results suggest that in oocyte maturation c-mosxe functions downstream of p21 but upstream of p34cdc2 and S6 kinase activation, although not all p21-induced events require c-mosxe.

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Inactivation of glucocorticoids by 11β-hydroxysteroid dehydrogenase enzymes increases during the meiotic maturation of porcine oocytes

Reproduction ◽

10.1530/rep-08-0289 ◽

2008 ◽

Vol 136 (6) ◽

pp. 725-732 ◽

Cited By ~ 11

Author(s):

Rachel J Webb ◽

Neera Sunak ◽

Lisa Wren ◽

Anthony E Michael

Keyword(s):

Oocyte Maturation ◽

Enzyme Activities ◽

Germinal Vesicle ◽

Hydroxysteroid Dehydrogenase ◽

Target Cells ◽

Cortisol Metabolism ◽

Enzymatic Inactivation ◽

Glucocorticoid Metabolism ◽

Ovarian Cyst Fluid

Recent reports have shown that glucocorticoids can modulate oocyte maturation in both teleost fish and mammals. Within potential target cells, the actions of physiological glucocorticoids are modulated by 11β-hydroxysteroid dehydrogenase (HSD11B) isoenzymes that catalyse the interconversion of cortisol and cortisone. Hence, the objective of this study was to establish whether HSD11B enzymes mediate cortisol–cortisone metabolism in porcine oocytes and, if so, whether the rate of glucocorticoid metabolism changes during oocyte maturation. Enzyme activities were measured in cumulus–oocyte complexes (COCs) and denuded oocytes (DOs) using radiometric conversion assays. While COCs and DOs oxidised cortisol to inert cortisone, there was no detectable regeneration of cortisol from cortisone. The rate of cortisol oxidation was higher in expanded COCs than in compact COCs containing germinal vesicle (GV) stage oocytes (111±6 vs 2041±115 fmol cortisone/oocyte.24 h; P<0.001). Likewise, HSD11B activities were 17±1 fold higher in DOs from expanded COCs than in those from compact COCs (P<0.001). When GV stage oocytes were subject to a 48 h in vitro maturation protocol, the enzyme activities were significantly increased from 146±18 to 1857±276 fmol cortisone/oocyte.24 h in GV versus MII stage oocytes respectively (P<0.001). Cortisol metabolism was inhibited by established pharmacological inhibitors of HSD11B (glycyrrhetinic acid and carbenoxolone), and by porcine follicular and ovarian cyst fluid. We conclude that an HSD11B enzyme (or enzymes) functions within porcine oocytes to oxidise cortisol, and that this enzymatic inactivation of cortisol increases during oocyte maturation.

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