R-066. Cytoskeletal and cytogenetic abnormalities during the in-vitro maturation of mouse oocytes exposed to cocaine

The high level of cyclic adenosine monophosphate (cAMP), which is provided to the oocytes from cumulus cells via gap junctional complexes in cumulus-enclosed oocytes (CEOs), is known to contribute to meiotic arrest at the germinal vesicle (GV) stage of CEOs. However, whether intraoocyte cAMP during the period of in vitro maturation (IVM) affects postfertilization developmental competence of mouse oocytes still remains unclear. The aim of this study was to examine the effects of FSH or dibutyryl cAMP (dbcAMP) treatment during IVM on in vitro development of mouse oocytes after in vitro fertilization (IVF). Whether a junctional association between cumulus cells and the oocyte would be essential for a cytoplasmic maturation-promoting effect was also examined. CEOs were isolated from and eCG-primed 3-week-old ICR mouse by rupturing preovulatory follicles with needles in M16 medium with 5% FCS and essential and nonessential amino acids (basal medium). IVM media used were basal medium without (control) or with 100 µm dbcAMP or 1 IU mL–1 FSH. Carbenoxolone (100 µm, CBX), an inhibitor of gap junction, was used to inhibit a junctional association between cumulus cells and the oocyte. Denuded oocytes (DOs) were prepared by repeatedly pipetting in basal medium with 0.2% hyaluronidase. CEOs and DOs were cultured in IVM media at 37�C under 5% CO2 in air for 16.5 h, and then transferred to TYH medium (a modified Krebs-Ringer bicarbonate medium) containing 0.4% BSA, followed by insemination with capacitated sperm. After 6 h of IVF, inseminated oocytes were cultured in KSOM medium with 0.3% BSA. Development to the 2-cell and blastocyst stages was estimated at 24 h and 120 h after IVF, respectively. All experiments were done in 3 replicates, and the statistical analysis was carried out by ANOVA and Fisher's protected least-squares difference (PLSD) test. When CEOs were matured in IVM media, the rates of postfertilization development to the 2-cell and blastocyst stages of oocytes matured in the control medium were very low(29% and 13%, respectively), whereas those of oocytes matured with FSH or dbcAMP significantly increased (FSH: 61% and 52%, dbcAMP: 63 and 57%, respectively, v. control; P < 0.05). Next, when CEOs were matured in basal medium with 1 IU mL–1 FSH and 100 µm CBX, the developmental rate to the 2-cell stage (56%) was similar to that in medium with FSH alone (61%) but the rate to the blastocyst stage (40%) was little lower compared with that in medium with FSH alone (52%), although not significantly different (P > 0.05). Furthermore, when DOs were matured in IVM media, the developmental rates to the blastocyst stage after IVF of the oocytes matured with FSH or dbcAMP significantly increased (FSH: 25%, dbcAMP: 15%; P < 0.05) compared with those in control medium (7%). Taken together, it is suggested that increasing the concentration of intraoocyte cAMP during the IVM period is important to improve the developmental competence after IVF of mouse oocytes, and that the competence is acquired in part in a cumulus-oocyte junctional communication-independent manner.

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Reduced oxygen concentration improves the developmental competence of mouse oocytes following in vitro maturation

Molecular Reproduction and Development ◽

10.1002/mrd.20655 ◽

2007 ◽

Vol 74 (7) ◽

pp. 893-903 ◽

Cited By ~ 34

Author(s):

Kimberly A. Preis ◽

George E. Seidel ◽

David K. Gardner

Keyword(s):

Oxygen Concentration ◽

In Vitro Maturation ◽

Developmental Competence ◽

Mouse Oocytes

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Quercetin improves developmental competence of mouse oocytes by reducing oxidative stress during in vitro maturation

Annals of Animal Science ◽

10.1515/aoas-2017-0029 ◽

2018 ◽

Vol 18 (1) ◽

pp. 87-98

Author(s):

Seyede Zahra Banihosseini ◽

Marefat Ghaffari Novin ◽

Hamid Nazarian ◽

Abbas Piryaei ◽

Siavash Parvardeh ◽

...

Keyword(s):

Oxidative Stress ◽

Embryo Development ◽

In Vitro Maturation ◽

Mature Oocyte ◽

Developmental Competence ◽

Nuclear Maturation ◽

Mouse Oocytes ◽

Blastocyst Rate ◽

And Control

Abstract Quercetin is a natural flavonoid with strong antioxidant activity. In the present study, we evaluate the influence of different concentrations of quercetin (QT) on intracytoplasmic oxidative stress and glutathione (GSH) concentration, during in vitro maturation (IVM) and fertilization in mouse oocytes. IVM was carried out in the presence of control (QT0), 5 (QT5), 10 (QT10), and 20 (QT20) μg/mL of QT. Nuclear maturation, intracellular GSH and ROS content were evaluated following the IVM. In these oocytes, we subsequently evaluated the effect of QT supplementation on embryo development, including 2-cell, 8-cell, and blastocyst rate. The results of the present study showed that the supplementation of 10 μg/mL QT in maturation medium increased the number of MII oocytes. In addition, fertilization and blastocyst rate in QT10 treatment group were significantly higher in comparison to the other groups, and elevated the amount of intracellular GSH content compared to other QT concentrations and control groups. The intracellular ROS level was the lowest among oocytes matured in Q5 and Q10 treatment groups. This result suggested that quercetin dose-dependently improves nuclear maturation and embryo development, via reducing intracytoplasmic oxidative stress in mature oocyte.

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314 MELATONIN ON IN VIVO AND IN VITRO MATURATION OF MOUSE OOCYTES

Reproduction Fertility and Development ◽

10.1071/rdv27n1ab314 ◽

2015 ◽

Vol 27 (1) ◽

pp. 246 ◽

Cited By ~ 1

Author(s):

H. Fernandes ◽

L. Schefer ◽

F. C. Castro ◽

C. L. V. Leal

Keyword(s):

Ovarian Stimulation ◽

In Vitro Maturation ◽

F1 Hybrids ◽

Saline Control ◽

Control Group ◽

Mouse Oocytes ◽

Maturation Rate ◽

Different Doses

Melatonin is a pineal hormone related to the control of the circadian cycle, besides the reproductive seasonality of some animal species, and has shown positive effects on oocyte maturation and embryo development. The aim of this study was to assess the effects of melatonin on in vivo and in vitro maturation of mouse oocytes. Female F1 hybrids (C57BL/6 × CBA; n = 8 per group/treatment) were used in 3 different treatments (trt) groups: (I) in vivo trt: mice received 2 different doses of melatonin injections, 10 and 20 mg kg–1 per IP including a saline control dose (0 mg kg–1 per IP) for 4 days along with ovarian stimulation trt of 5 IU of eCG IP, followed by 5 IU of hCG IP 48 h later, and cumulus-oocyte complexes (COC) were collected 16 h after hCG; (II) mice received a similar in vivo melatonin trt, but ovarian stimulation trt was only 5 IU of eCG, no hCG, and COC were collected after 48 h and subsequently matured in vitro with 0.5 µg mL–1 of FSH for 16 h; (III) in vitro maturation of oocytes: COC were collected 48 h after 5 IU of eCG and maturated in the presence of 3 different doses of melatonin (10–9, 10–6, and 10–3 M) or 0.5 µg mL–1 of FSH (control) for 16 h. In vitro-maturing oocytes were in incubated at 37°C, 5% CO2, and 95% humidity. Maturation rates were evaluated according to the presence of the first polar body under an inverted microscope. Statistical analyses were performed by ANOVA followed by Tukey's test (4 replicates). In the first treatment, 20 mg kg–1 of melatonin showed the highest in vivo maturation rate, 80.3% (61/76), while 10 mg kg–1 of melatonin was 62.4% (53/85) and the saline control group was 69.4% (77/111), but differences were not significant (P > 0.05). For in vitro maturation of oocytes from animals previously treated with melatonin, the 10 mg kg–1 of melatonin group had the highest maturation rate, 53.2% (99/186), in comparison with the saline and 20 mg kg–1 of melatonin groups, which showed 46.6 (88/189) and 39.0% (85/218), respectively; again, no differences were detected (P > 0.05). In the last treatment, the maturation rates increased from 48.9 (43/88) to 53.7 (51/95) and 56.0% (56/100) as the melatonin concentrations decreased from 10–3, 10–6, and 10–9 M, respectively. The control group had the highest rate of 57.3% (55/96), but no statistical differences were observed (P = 0.706). In conclusion, under the conditions studied, melatonin was unable to improve the maturation rate neither after in vivo nor in vitro treatment. However, during in vitro maturation, melatonin alone was as efficient as FSH in promoting maturation in murine oocytes, indicating its potential effect on stimulating meiosis. Therefore, the role of melatonin in stimulating meiosis needs further investigation.Acknowledgments to FAPESP for fellowship (HF) and funding (CLVL).

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