Differential effects of repeated ovarian stimulation on cytoplasmic and spindle organization in metaphase II mouse oocytes matured in vivo and in vitro

2001 ◽  
Vol 16 (4) ◽  
pp. 757-764 ◽  
Author(s):  
Jonathan Van Blerkom ◽  
Patrick Davis
2015 ◽  
Vol 27 (1) ◽  
pp. 246 ◽  
Author(s):  
H. Fernandes ◽  
L. Schefer ◽  
F. C. Castro ◽  
C. L. V. Leal

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).


2014 ◽  
Vol 26 (8) ◽  
pp. 1084 ◽  
Author(s):  
Yu-Ting Shen ◽  
Yue-Qiang Song ◽  
Xiao-Qin He ◽  
Fei Zhang ◽  
Xin Huang ◽  
...  

Meiosis produces haploid gametes for sexual reproduction. Triphenyltin chloride (TPTCL) is a highly bioaccumulated and toxic environmental oestrogen; however, its effect on oocyte meiosis remains unknown. We examined the effect of TPTCL on mouse oocyte meiotic maturation in vitro and in vivo. In vitro, TPTCL inhibited germinal vesicle breakdown (GVBD) and first polar body extrusion (PBE) in a dose-dependent manner. The spindle microtubules completely disassembled and the chromosomes condensed after oocytes were exposed to 5 or 10 μg mL–1 TPTCL. γ-Tubulin protein was abnormally localised near chromosomes rather than on the spindle poles. In vivo, mice received TPTCL by oral gavage for 10 days. The general condition of the mice deteriorated and the ovary coefficient was reduced (P < 0.05). The number of secondary and mature ovarian follicles was significantly reduced by 10 mg kg–1 TPTCL (P < 0.05). GVBD decreased in a non-significant, dose-dependent manner (P > 0.05). PBE was inhibited with 10 mg kg–1 TPTCL (P < 0.05). The spindles of in vitro and in vivo metaphase II oocytes were disassembled with 10 mg kg–1 TPTCL. These results suggest that TPTCL seriously affects meiotic maturation by disturbing cell-cycle progression, disturbing the microtubule cytoskeleton and inhibiting follicle development in mouse oocytes.


2019 ◽  
Vol 38 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Tamar Margalit ◽  
Avi Ben-Haroush ◽  
Roni Garor ◽  
Naomi Kotler ◽  
Dania Shefer ◽  
...  
Keyword(s):  

2001 ◽  
Vol 34 (3-4) ◽  
Author(s):  
ASIM RAHMAN ◽  
MAHMOOD ALAM ◽  
SUDHA RAO ◽  
LIN CAI ◽  
CLARK LUTHER T. ◽  
...  

Zygote ◽  
2006 ◽  
Vol 14 (1) ◽  
pp. 81-87 ◽  
Author(s):  
P.N. Moreira ◽  
R. Fernández-Gonzalez ◽  
M.A. Ramirez ◽  
M. Pérez-Crespo ◽  
D. Rizos ◽  
...  

It is well known that the preimplantation culture environment to which embryos are exposed influences the expression of developmentally important genes. Recently, it has been reported that MEMα, a culture medium commonly used for somatic cells, allows high rates of preimplantation development and development to term of mouse somatic cell nuclear transfer (SCNT) embryos. The objective of this study was to compare the differential effects of this medium and of the nuclear transfer procedure on the relative mRNA abundance of several genes with key roles during preimplantation. The relative mRNA levels of nine genes (Glut 1, Glut 5, G6PDH, Bax, Survivin, Gpx 1, Oct4, mTert and IGF2bp1) were quantified at blastocyst stage on cumulus cell cloned embryos cultured in MEMα, as well as on in vivo cultured and MEMα cultured controls. Only three of the nine transcripts analysed (Glut 5, Gpx 1 and Igf2bp1) were significantly down-regulated at blastocyst stage in in vitro produced controls. However, most genes analysed in our MEMα cultured cloned embryos showed altered transcription levels. Interestingly, between cloned and in vitro produced controls only the transcription levels measured for Glut 1 were significantly different. This result suggests that Glut 1 may be a good marker for embryo quality after cumulus cell nuclear transfer.


2004 ◽  
Vol 19 (12) ◽  
pp. 2889-2899 ◽  
Author(s):  
Alexandra Sanfins ◽  
Carlos E. Plancha ◽  
Eric W. Overstrom ◽  
David F. Albertini

1983 ◽  
Vol 147 (6) ◽  
pp. 633-639 ◽  
Author(s):  
N. Laufer ◽  
B.M. Pratt ◽  
A.H. DeCherney ◽  
F. Naftolin ◽  
M. Merino ◽  
...  

2021 ◽  
Vol 202 ◽  
pp. 108362
Author(s):  
VijayKrishna Raghunathan ◽  
Sydney Garrison Edwards ◽  
Brian C. Leonard ◽  
Soohyun Kim ◽  
Alexander T. Evashenk ◽  
...  

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