scholarly journals First polar body morphology and blastocyst formation rate in ICSI patients

2002 ◽  
Vol 17 (9) ◽  
pp. 2415-2418 ◽  
Author(s):  
T. Ebner
2011 ◽  
Vol 23 (1) ◽  
pp. 207
Author(s):  
C. Kohata ◽  
H. Funahashi

The maturation rate of oocytes derived from small follicles (SF) is known to be lower than that of oocytes from medium follicles (MF). The objective of this study was to assess the fertilizability and developmental competence of mature SF oocytes that were selected by the presence of the first polar body. Cumulus–oocyte complexes (COC) were aspirated from SF (1 to 2 mm in diameter) or MF (3 to 6 mm in diameter) of prepuberal ovaries. The COC were cultured in modified porcine oocyte medium supplemented with gonadotropins and dibutyryl cAMP for the first 20-h period and then in gonadotropin-free and dibutyryl cAMP-free porcine oocyte medium for another 24 h. Following IVM culture, mature oocytes with the first polar body were selected under a stereomicroscope, co-incubated with spermatozoa in a drop of modified TCM-199 containing 0.4% BSA and 5 mM caffeine for 6 h, and then incubated in porcine zygote medium-5 for 7 days. Sperm penetration, cleavage, and early development of the oocytes were examined before culture in porcine zygote medium-5 on Days 2 and 7 of culture. To analyse the fertilizability and developmental competence of oocytes from the SF and MF groups, sperm penetration, pronuclear formation, cleavage, blastocyst formation, and mean cell number in a blastocyst (as determined by fluorescence observation following Hoechst 33342 staining) were examined. Statistical analysis was performed by ANOVA with a Bonferroni-Dunn post-hoc test (P < 0.05). The percentages of oocytes in which the first polar body could be observed were 51.0 ± 4.5% and 78.5 ± 2.8% for SF- and MF-oocytes, respectively, whereas the maturation rates were 83.8 ± 4.0% and 62.8 ± 4.4% following fixation and staining. When only mature oocytes were co-cultured with sperm for 6 and 9 h, sperm penetration, monospermic penetration, and pronuclear formation were not different (P > 0.33) between mature SF- and MF-oocytes. Although there was no difference in cleavage rates between the mature SF- and MF-oocyte groups, blastocyst formation rate and mean cell number in the blastocyst were higher in mature MF-oocytes (31.0 ± 3.6% and 38.7 ± 1.9 cells, respectively) than in mature SF-oocytes (14.7 ± 3.2% and 31.2 ± 2.0 cells). From these results, we conclude that mature oocytes derived from SF have a similar fertilizability when compared with mature MF-oocytes, but the developmental competence to the blastocyst stage following IVF is significantly lower in mature SF-oocytes than in mature MF-oocytes.


Reproduction ◽  
2006 ◽  
Vol 132 (4) ◽  
pp. 559-570 ◽  
Author(s):  
Tamás Somfai ◽  
Manabu Ozawa ◽  
Junko Noguchi ◽  
Hiroyuki Kaneko ◽  
Katsuhiko Ohnuma ◽  
...  

We investigated nuclear progression and in vitro embryonic development after parthenogenetic activation of porcine oocytes exposed to cytochalasin B (CB) during in vitro maturation (IVM). Nuclear progression was similar in control oocytes and oocytes matured in the presence of 1 μg/ml CB (IVM-CB group) by 37 h IVM; at this time the proportion of oocytes that had reached or passed through the anaphase-I stage did not differ significantly between the IVM-CB and the control groups (61.3 and 69.9% respectively; P < 0.05). After IVM for 37 h, no polar body extrusion was observed in the IVM-CB group. In these oocytes, the two lumps of homologous chromosomes remained in the ooplasm after their segregation and turned into two irregular sets of condensed chromosomes. By 41 h IVM, the double sets of chromosomes had reunited in 89.5% IVM-CB oocytes and formed a single large metaphase plate, whereas 68.8% of the control oocytes had reached the metaphase-II stage by this time. When IVM-CB oocytes cultured for 46 h were stimulated with an electrical pulse and subsequently cultured for 8 h without CB, 39.0% of them extruded a polar body and 82.9% of them had a female pronucleus. Chromosome analysis revealed that the majority of oocytes that extruded a polar body were diploid in both the control and the IVM-CB groups. However, the incidence of polyploidy in the IVM-CB group was higher than that in the control group (P < 0.05). In vitro development of diploid parthenotes in the control and the IVM-CB groups was similar in terms of blastocyst formation rates (45.8 and 42.8% respectively), number of blastomeres (39.9 and 44.4 respectively), the percentage of dead cells (4.3 and 2.9% respectively), and the frequency of apoptotic cells (7.3 and 6.3% respectively). Tetraploid embryos had a lower blastocyst formation rate (25.5%) and number of cells (26.2); however, the proportion of apoptotic nuclei (7.0%) was similar to that in diploid parthenotes. These results suggest that the proportion of homozygous and heterozygous genes does not affect in vitro embryo development to the blastocyst stage.


2004 ◽  
Vol 16 (2) ◽  
pp. 271
Author(s):  
C.S. Park ◽  
D.I. Jin ◽  
M.Y. Kim ◽  
Y.J. Chang ◽  
Y.J. Yi

Efficient activation is essential for the success of animal cloning by nuclear transfer. The aim of this study was to investigate the effects of chemical activation agents on parthenogenetic development of pig oocytes matured in vitro. The medium used for oocyte maturation was TCM-199 supplemented with 26.19mM sodium bicarbonate, 0.9mM sodium pyruvate, 10μgmL−1 insulin, 2μgmL−1 vitamin B12, 25mM HEPES, 10μgmL−1 bovine apotransferrin, 150μM cysteamine, 10IUmL−1 PMSG, 10IUmL−1 hCG, 10ngmL−1 EGF, 0.4% BSA, 75μgmL−1 sodium penicillin G, 50μgmL−1 streptomycin sulfate and 10% pFF. After about 22h of maturation, oocytes were cultured without cysteamine and hormones for 22h at 38.5°C, 5% CO2 in air. Cumulus-free oocytes showing first polar body were selected for activation. Oocytes were activated as follows. First, all oocytes were activated with 25mM HEPES buffered NCSU-23 medium containing 8% ethanol for 10min. After that, in treatment 1, oocytes were incubated in the NCSU-23 medium supplemented with 7.5μgmL−1 cytochalasin B for 3h. In treatment 2, oocytes were incubated in the NCSU-23 medium supplemented with 10μgmL−1 cycloheximide for 3h. In treatment 3, oocytes were incubated in the NCSU-23 medium supplemented with 7.5μgmL−1 cytochalasin B for 1.5h, and then were incubated in the NCSU-23 medium supplemented with 10μgmL−1 cycloheximide for 1.5h. In treatment 4, oocytes were incubated in the NCSU-23 medium supplemented with 7.5μgmL−1 cytochalasin B plus 10μgmL−1 cycloheximide for 3h. Following activation, oocytes were transferred into 500μL NCSU-23 culture medium containing 0.4% BSA for further culture for 20 and 144h. Activated oocytes were fixed and stained for evaluation of activation rate, cleaved oocytes, blastocyst formation rate and cell numbers per blastocyst. Data were analysed by ANOVA and Duncan’s multiple range test using the SAS program. The rate of oocyte activation was higher in treatment 4 (62.1%) than in treatment 1, 2 and 3 (52.0, 49.6 and 58.0%, respectively). The percentage of cleaved oocytes was lower in treatment 1 and 2 (56.9 and 55.2%) than in treatment 3 and 4 (68.8 and 68.5%). The rate of blastocyst formation from the cleaved oocytes was higher in treatment 3 and 4 (19.8 and 22.0%) than in treatment 1 and 2 (12.1 and 11.7%). Mean cells per blastocyst were lowest in treatment 2 (21.2±0.9) compared to treatment 1, 3 and 4 (27.3±2.2, 30.4±3.8 and 30.9±3.4, respectively). In conclusion, cytochalasin B combined with cycloheximide was more efficient for parthenogenetic development of pig oocytes matured in vitro.


2004 ◽  
Vol 19 (10) ◽  
pp. 2334-2339 ◽  
Author(s):  
P.M. Ciotti ◽  
L. Notarangelo ◽  
A.M. Morselli-Labate ◽  
V. Felletti ◽  
E. Porcu ◽  
...  

2006 ◽  
Vol 18 (2) ◽  
pp. 265
Author(s):  
M. P. Milazzotto ◽  
W. B. Feitosa ◽  
R. Simões ◽  
C. M. Mendes ◽  
M. E. O. A. Assumpção ◽  
...  

Activation of in vitro matured oocytes is essential for the success of nuclear transfer embryo production. Oocyte activation is promoted by the release of intracellular calcium and influx of extracellular ions, and can be chemically induced by calcium ionophores such as A23187 (CA) or ionomycin (IO). Electrical stimulation (EL) is an essential stage in nuclear transfer protocols for the fusion of enucleated oocytes with the donor's cell nucleus. Moreover, EL can be used as an alternative method to induce calcium influx through the formation of pores in the plasma membrane. This work aimed to evaluate the effect of electrical pulse vs the use of different calcium ionophores (A23187 or ionomycin) as primary agents of bovine oocyte activation, with or without the addition of BSA, on the rate of blastocyst formation and blastocyst quality. BSA was used to quench the activation process after a 5-min exposure to CA or IO. Cumulus-oocyte complexes were matured in TCM-199 medium with FCS and hormones for 18 h at 38.5�C and 5% CO2 in air. After removal of cumulus cells, oocytes presenting the first polar body were selected and maintained in SOFaa medium to complete 24 h of maturation. They were then divided into five treatments groups 1-CA (CA 5 mM, 5 min); 2-CAB (CA 5 mM, 5 min; BSA, 5 min); 3-IO (IO 5 mM, 5 min); 4-IOB (IO 5 mM, 5 min; BSA, 5 min); and 5-EL (EL 1.5 kV/cm, 20 �s, 2 pulses). After treatments, oocytes were kept in 6-dimethylaminopurine for 3 h and cultured in SOFaa medium for 7 days at 38.5�C and 5% CO2 in air. Rates of cleavage and blastocyst were evaluated respectively on Days 2 and 7 of culture. To evaluate embryo quality, Hoechst 33342/propidium iodide staining was used. Data were evaluated by ANOVA and submitted to LSD test for embryo rates and t-test for embryo quality. Four replicates were carried out with a total of 89 oocytes per treatment. There was a difference (P < 0.05) in rate of development to blastocyst between treatments 1-CA (54.4%a), 3-IO (51.4%a), and 5-EL (54.5%a) compared with 4-IOB (18.3%b). Treatment 2-CAB (39.8%ab) did not show any difference from the others. There was no difference (P > 0.05) among treatments in total number of cells: 1-CA (63.1a), 2-CAB (57.2a), 3-IO (60.9a), 4-IOB (72.4a), and 5-EL (58.4a). However, there was a difference (P < 0.01) in the percentage of viable cells between treatments 1-CA (49.9%a), 2-CAB (45.8%a), 3-IO (64.9%a), and 4-IOB (50.9%a) in comparison to 5-EL (82.7%b). In conclusion, BSA, when associated with IO, had a negative effect on embryonic developmental rates. The different calcium ionophores used and the BSA did not improve embryo quality. Although there were no significant differences between electrical and chemical activation on the rate of blastocyst formation, it is important to point out that higher quality embryos were achieved by using electrical activation. This work was supported by FAPESP 03/00156-9.


1999 ◽  
Vol 72 (4) ◽  
pp. 599-603 ◽  
Author(s):  
Thomas Ebner ◽  
Marianne Moser ◽  
Cemil Yaman ◽  
Oscar Feichtinger ◽  
Johannes Hartl ◽  
...  

Author(s):  
Soo-Hyun Park ◽  
Pil-Soo Jeong ◽  
Ye Eun Joo ◽  
Hyo-Gu Kang ◽  
Min Ju Kim ◽  
...  

Increasing evidence has demonstrated that oxidative stress impairs oocyte maturation, but the underlying mechanisms remain largely unknown. Here, for the first time, we examined the antioxidant role of luteolin in meiotic progression and the underlying mechanisms. Supplementation of 5 μM luteolin increased the rates of first polar body extrusion and blastocyst formation after parthenogenetic activation, and the expression levels of oocyte competence (BMP15 and GDF9)-, mitogen-activated protein kinase (MOS)-, and maturation promoting factor (CDK1 and Cyclin B)-related genes were also improved. Luteolin supplementation decreased intracellular reactive oxygen species levels and increased the expression levels of oxidative stress-related genes (SOD1, SOD2, and CAT). Interestingly, luteolin alleviated defects in cell organelles, including actin filaments, the spindle, mitochondria, the endoplasmic reticulum, and cortical granules, caused by H2O2 exposure. Moreover, luteolin significantly improved the developmental competence of in vitro-fertilized embryos in terms of the cleavage rate, blastocyst formation rate, cell number, cellular survival rate, and gene expression and markedly restored the competencies decreased by H2O2 treatment. These findings revealed that luteolin supplementation during in vitro maturation improves porcine meiotic progression and subsequent embryonic development by protecting various organelle dynamics against oxidative stress, potentially increasing our understanding of the underlying mechanisms governing the relationship between oxidative stress and the meiotic events required for successful oocyte maturation.


2017 ◽  
Vol 29 (1) ◽  
pp. 192
Author(s):  
P. Ferré ◽  
K. X. Nguyen ◽  
T. Wakai ◽  
H. Funahashi

This experiment was undertaken to assess the meiotic and developmental competences of oocytes derived from different sized follicles and denuded of cumulus cells 0, 20, and 44 h after the start of culture for in vitro maturation (IVM). Groups of 60 oocyte-cumulus complexes from small- (SF; <3 mm) and medium-sized follicles (MF; 3–6 mm) were cultured for IVM in porcine oocyte medium with 50 μM β-mercaptoethanol supplemented with 1 mM dibutyryl-cyclic adenosine monophosphate, 10 IU mL−1 of eCG, and 10 IU mL−1 of hCG for 20 h at 39°C and 5% CO2 in air. Then, after washing, they continued culture in fresh β-mercaptoethanol without dibutyryl-cyclic adenosine monophosphate and gonadotropins under the same conditions for another 24 h. At 0, 20, and 44 h of IVM, cumulus cells were removed with 0.1% (wt/vol) hyaluronidase and the denuded oocytes continued IVM culture following the protocol. Mature oocytes with the first polar body were selected, parthenogenetically activated with a single electrical pulse (DC: 1.2 kV/cm, 30 µs), incubated with 4% (wt/vol) BSA and 5 μM cytochalasin B for 4 h, and cultured in porcine zygote medium for 5 days. Cleavage and blastocyst formation rates were observed on Day 2 and 5, respectively. Blastocysts were stained with 4’,6-diamidino-2-phenylindole for cell count assessment. The experiment was replicated 5 times and analysed with a 1- or 2-way ANOVA. If P < 0.05 in ANOVA, a Tukey multiple comparisons test was performed. Regardless of the time of cumulus cell removal, oocytes from MF had significantly higher in rates of maturation, cleavage, and blastocyst rates, as compared with those from SF, whereas there were no significant differences in the cell number of blastocysts between SF and MF (32 v. 34 cells, respectively). When oocytes were denuded before IVM culture, rates of oocyte maturation (37.6% in SF and 50.8% in MF), and blastocyst formation (2.7% in SF and 27.3% in MF) were significantly lower than controls (51.2% in SF and 76% in MF; 25.8% in SF and 48.5% in MF, respectively). When oocytes were denuded 20 h after the start of IVM, oocyte maturation rates were significantly increased (64.1% in SF and 82.5% in MF) as compared with controls, whereas no significant differences were observed in cleavage and blastocyst formation rates in comparison with controls. These results conclude that removing cumulus cells from oocyte-cumulus complexes 20 h after the start of IVM improves the meiotic competence of oocytes derived from both SF and MF, without any reduction of developmental competence of the oocytes following parthenogenetical activation.


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