Developmental competence of bovine oocytes after specific inhibition of MPF kinase activity: Effect of estradiol supplementation and follicle size

The concentrations of electrolytes (Na, K, Cl, Mg and Ca) and glucose in small follicle (SF) follicular fluid (SFF) and large follicle (LF) follicular fluid (LFF) from slaughterhouse-derived ovaries were studied. Oocytes were matured in medium based on synthetic oviductal fluid. The effects of various concentrations of electrolytes (Na, K, Ca and Mg) and glucose in the maturation medium on the progression of nuclear maturation and subsequent development were also studied. K in SFF was significantly greater than that in LFF. The Mg concentration in follicular fluid (FF) is 2.0–2.3 mM, which is greater than the concentration present in medium generally used for culture. The glucose concentration in FF is about 3.5–3.9 mM and rapidly decreases during the preservation of ovaries. LF oocytes resumed nuclear maturation and progressed to the M2 stage significantly faster than those collected from SF oocytes. In addition, more LF oocytes developed to blastocysts than did SF oocytes. Changing the Na/K ratio in the maturation medium from 16 to 24 did not affect either the progression of nuclear maturation or the rate of development. A low concentration of Mg (0.5 mM) combined with a low Ca concentration (0.5 mM) inhibited the rate of development, but did not affect the progression of nuclear maturation. On the other hand, increasing the Mg concentration to 2.0 mM from 0.5 mM hastened the progression of nuclear maturation and improved the rate of blastulation, irrespective of the Ca concentration. The progression of nuclear maturation was faster and the rate of development was greater with 5.56 mM glucose than with 1.5 mM glucose. The difference in time needed to progress to M2 among the experiment was about 2–3 h. Therefore, prolonging the maturation periods from 21 to 24 h did not change the rate of development. Our results show that the concentrations of Mg and glucose in the maturation medium and the follicle size enveloping the oocyte affect the progression of nuclear maturation and subsequent development. The time requirement for oocytes to reach M2 is strongly related to the developmental competence of the oocytes.

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High developmental competence of cattle oocytes maintained at the germinal vesicle stage for 24 hours in culture by specific inhibition of MPF kinase activity

Molecular Reproduction and Development ◽

10.1002/(sici)1098-2795(200001)55:1<89::aid-mrd12>3.0.co;2-m ◽

2000 ◽

Vol 55 (1) ◽

pp. 89-95 ◽

Cited By ~ 131

Author(s):

Pascal Mermillod ◽

Milan Tomanek ◽

R�jane Marchal ◽

Laurent Meijer

Keyword(s):

Kinase Activity ◽

Germinal Vesicle ◽

Developmental Competence ◽

Specific Inhibition

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The Influence of Morphology, Follicle Size and Bcl-2 and Bax Transcripts on the Developmental Competence of Bovine Oocytes

Reproduction in Domestic Animals ◽

10.1111/rda.12325 ◽

2014 ◽

Vol 49 (4) ◽

pp. 576-583 ◽

Cited By ~ 9

Author(s):

THC De Bem ◽

PR Adona ◽

FF Bressan ◽

LG Mesquita ◽

MR Chiaratti ◽

...

Keyword(s):

Developmental Competence ◽

Follicle Size ◽

Bovine Oocytes

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Effects of androgens, progesterone and their antagonists on the developmental competence of in vitro matured bovine oocytes

J Reprod Fertil ◽

10.1530/reprod/119.2.261 ◽

2000 ◽

Vol 119 (2) ◽

pp. 261-269 ◽

Cited By ~ 28

Author(s):

C. Silva

Keyword(s):

Developmental Competence ◽

Bovine Oocytes

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Activation of bovine oocytes by protein synthesis inhibitors: new findings on the role of MPF/MAPKs†

Biology of Reproduction ◽

10.1093/biolre/ioab019 ◽

2021 ◽

Author(s):

Cecilia Valencia ◽

Felipe Alonso Pérez ◽

Carola Matus ◽

Ricardo Felmer ◽

María Elena Arias

Keyword(s):

Protein Synthesis ◽

Kinase Activity ◽

Cyclin B1 ◽

Protein Synthesis Inhibitors ◽

Vitro Fertilization ◽

New Findings ◽

Bovine Oocytes ◽

Dependent Pathway

Abstract The present study evaluated the mechanism by which protein synthesis inhibitors activate bovine oocytes. The aim was to analyze the dynamics of MPF and MAPKs. MII oocytes were activated with ionomycin (Io), ionomycin+anisomycin (ANY) and ionomycin+cycloheximide (CHX) and by in vitro fertilization (IVF). The expression of cyclin B1, p-CDK1, p-ERK1/2, p-JNK, and p-P38 were evaluated by immunodetection and the kinase activity of ERK1/2 was measured by enzyme assay. Evaluations at 1, 4, and 15 hours postactivation (hpa) showed that the expression of cyclin B1 was not modified by the treatments. ANY inactivated MPF by p-CDK1Thr14-Tyr15 at 4 hpa (P < 0.05), CHX increased pre-MPF (p-CDK1Thr161 and p-CDK1Thr14-Tyr15) at 1 hpa and IVF increased p-CDK1Thr14-Tyr15 at 17 hours postfertilization (hpf) (P < 0.05). ANY and CHX reduced the levels of p-ERK1/2 at 4 hpa (P < 0.05) and its activity at 4 and 1 hpa, respectively (P < 0.05). Meanwhile, IVF increased p-ERK1/2 at 6 hpf (P < 0.05); however, its kinase activity decreased at 6 hpf (P < 0.05). p-JNK in ANY, CHX, and IVF oocytes decreased at 4 hpa (P < 0.05). p-P38 was only observed at 1 hpa, with no differences between treatments. In conclusion, activation of bovine oocytes by ANY, CHX, and IVF inactivates MPF by CDK1-dependent specific phosphorylation without cyclin B1 degradation. ANY or CHX promoted this inactivation, which seemed to be more delayed in the physiological activation (IVF). Both inhibitors modulated MPF activity via an ERK1/2-independent pathway, whereas IVF activated the bovine oocytes via an ERK1/2-dependent pathway. Finally, ANY does not activate the JNK and P38 kinase pathways.

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N-acetyl-L-cysteine Improves the Developmental Competence of Bovine Oocytes and Embryos Cultured In Vitro by Attenuating Oxidative Damage and Apoptosis

Antioxidants ◽

10.3390/antiox10060860 ◽

2021 ◽

Vol 10 (6) ◽

pp. 860

Author(s):

Wu-Sheng Sun ◽

Hoon Jang ◽

Mi-Ryung Park ◽

Keon Bong Oh ◽

Haesun Lee ◽

...

Keyword(s):

Embryonic Development ◽

Early Stage ◽

Developmental Competence ◽

Beneficial Effects ◽

Developmental Rates ◽

A Cell ◽

Bovine Oocytes ◽

Dose Dependent

Oxidative stress has been suggested to negatively affect oocyte and embryo quality and developmental competence, resulting in failure to reach full term. In this study, we investigated the effect of N-acetyl-L-cysteine (NAC), a cell-permeating antioxidant, on developmental competence and the quality of oocytes and embryos upon supplementation (0.1–10 mM) in maturation and culture medium in vitro using slaughterhouse-derived oocytes and embryos. The results show that treating oocytes with 1.0 mM NAC for 8 h during in vitro maturation attenuated the intracellular reactive oxygen species (ROS) (p < 0.05) and upregulated intracellular glutathione levels (p < 0.01) in oocytes. Interestingly, we found that NAC affects early embryonic development, not only in a dose-dependent, but also in a stage-specific, manner. Significantly (p < 0.05) decreased cleavage rates (90.25% vs. 81.46%) were observed during the early stage (days 0–2), while significantly (p < 0.05) increased developmental rates (38.20% vs. 44.46%) were observed during the later stage (from day 3) of embryonic development. In particular, NAC supplementation decreased the proportion of apoptotic blastomeres significantly (p < 0.05), resulting in enhanced hatching capability and developmental rates during the in vitro culture of embryos. Taken together, our results suggest that NAC supplementation has beneficial effects on bovine oocytes and embryos through the prevention of apoptosis and the elimination of oxygen free radicals during maturation and culture in vitro.

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Heat Shock Protein 70 Improves In Vitro Embryo Yield and Quality from Heat Stressed Bovine Oocytes

Animals ◽

10.3390/ani11061794 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1794

Author(s):

Konstantina Stamperna ◽

Themistoklis Giannoulis ◽

Eleni Dovolou ◽

Maria Kalemkeridou ◽

Ioannis Nanas ◽

...

Keyword(s):

Gene Expression ◽

Heat Shock ◽

Heat Shock Protein ◽

Heat Shock Protein 70 ◽

Cumulus Cells ◽

Intramolecular Interactions ◽

Developmental Competence ◽

Embryo Yield ◽

Bovine Oocytes

Heat shock protein 70 (HSP70) is a chaperon that stabilizes unfolded or partially folded proteins, preventing inappropriate inter- and intramolecular interactions. Here, we examined the developmental competence of in vitro matured oocytes exposed to heat stress with or without HSP70. Bovine oocytes were matured for 24 h at 39 °C without (group C39) or with HSP70 (group H39) and at 41 °C for the first 6 h, followed by 16 h at 39 °C with (group H41) or without HSP70 (group C41). After insemination, zygotes were cultured for 9 days at 39 °C. Cleavage and embryo yield were assessed 48 h post insemination and on days 7, 8, 9, respectively. Gene expression was assessed by RT-PCR in oocytes, cumulus cells and blastocysts. In C41, blastocysts formation rate was lower than in C39 and on day 9 it was lower than in H41. In oocytes, HSP70 enhanced the expression of three HSP genes regardless of incubation temperature. HSP70 at 39 °C led to tight coordination of gene expression in oocytes and blastocysts, but not in cumulus cells. Our results imply that HSP70, by preventing apoptosis, supporting signal transduction, and increasing antioxidant protection of the embryo, protects heat stressed maturing bovine oocyte and restores its developmental competence.

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