In vitro maturation of oocytes from non-stimulated common wombats

2003 ◽  
Vol 15 (5) ◽  
pp. 303 ◽  
Author(s):  
M. Cleary ◽  
M. West ◽  
J. Shaw ◽  
G. Jenkin ◽  
A. Trounson

Assisted reproductive techniques, such as in vitro oocyte maturation in conjunction with in vitro fertilisation, may be used as a tool to manipulate reproduction. Using the common wombat as a model for the critically endangered northern hairy-nosed wombat, the present study examined whether oocyte maturation could be achieved under field conditions. At the time of collection, no oocytes were at the metaphase II (MII) stage (0/42). After 60 h culture using the submarine incubation system, 34% of oocytes (24/70) matured to telophase/MII, as indicated by the presence of a polar body. The proportion of oocytes that reached MII was higher for oocytes collected from follicles >2 mm in diameter compared with follicles <2 mm (40% v. 22%, respectively). The presence of cumulus cells alone did not influence the maturation potential. Oocytes without cumulus cells collected from follicles >2 mm in diameter had the highest maturation rate (58%). Maturation was not affected by the reproductive status of the common wombat or a delay of up to 5 h before oocyte collection. In conclusion, the present study demonstrated that oocytes collected from non-stimulated common wombats can mature to MII in culture.

2012 ◽  
Vol 24 (1) ◽  
pp. 211
Author(s):  
A. M. Lichtenauer ◽  
L. D. Spate ◽  
R. S. Prather ◽  
J. A. Green

Biochemical differences exist between oocytes that give rise to viable blastocysts and oocytes that give rise to embryos that are developmentally compromised. For example, specific proteolytic enzymes (e.g. cathepsin B) are transcriptionally abundant in in vitro-matured bovine oocytes from prepubertal heifers that have diminished developmental potential. The effects of the cysteine proteinase inhibitor, E-64, was recently investigated in bovine cumulus–oocyte complexes (COC) that represented both poor- and good-quality oocytes. Those reports revealed that the addition of E-64 promoted both oocyte maturation and subsequent embryo development. This project sought to determine if similar results would be obtained in a porcine oocyte/embryo culture system. Inclusion of 10 and 20 μM E-64 in maturation medium was performed. Maturation rates of porcine COC in 20 μM E-64 were elevated compared to those incubated in 10 μM E-64 (74% vs 53%; P < 0.05) or without E-64 (55%; P < 0.05: N = 1750 oocytes tested). Successful maturation to metaphase II was based on the presence of a polar body and a uniform cytoplasm 44 h after follicular aspiration. Based on these preliminary results and the earlier bovine work, it was hypothesized that the E-64 was having little influence on normal oocytes, but was promoting maturation of low-quality oocytes, possibly those that were beginning to degenerate. Consequently, 20 μM of E-64 was added to the maturation media of COC segregated based on morphological characteristics of the oocytes. Good COC had a homogeneous cytoplasm and greater than 3 layers of cumulus cells; the COC were considered poor if they displayed a nonhomogeneous cytoplasm and 1 layer or less of cumulus cells, yet were still considered fertilizable. Without E-64, an increase in maturation was measured when good oocytes were compared to poor oocytes (52% vs 29%; P < 0.05: N = 1600). No significant differences in maturation were observed between good oocytes incubated in the presence or absence of E-64. Likewise, no significant differences were observed between poor oocytes incubated in the presence or absence of E-64. The percentage of maturation of good oocytes cultured in E-64 was significantly higher than that of poor oocytes cultured with E-64 (67% vs 43%; P < 0.05). Maturation with the inhibitor did not significantly affect the subsequent cleavage or blastocyst rates of embryos that arose from these oocyte groups after fertilization. These experiments suggest that inhibition of cysteine proteinases significantly promotes oocyte maturation, as was seen in previous bovine work. Our data did not support the hypothesis that cysteine proteinase inhibition was selectively improving maturation of poor oocytes within the pool. It remains possible that increased maturation in good oocytes is a result of cysteine inhibition on juvenile oocytes that morphologically appeared good and the effect was less on already degenerated oocytes that appeared poor. Differences between treatments were determined by ANOVA with post-test by Tukey's multiple comparison test.


2015 ◽  
Vol 27 (1) ◽  
pp. 112 ◽  
Author(s):  
Y. H. Choi ◽  
I. C. Velez ◽  
B. Macías-García ◽  
K. Hinrichs

In equine cloning, the scarcity of equine oocytes places emphasis on development of the most efficient nuclear transfer (NT) methods possible. In other species, using oocytes matured for the shortest duration needed to reach metaphase II has increased NT efficiency. In the present study, we examined the effect of duration of oocyte maturation at the time of enucleation on equine cloned blastocyst production. Oocytes were collected from live mares by transvaginal ultrasound-guided aspiration of all visible follicles ≥5 mm in diameter. The oocytes were held overnight (16–22 h) at room temperature, matured in vitro, and reconstructed with donor cells as described in our previous study (Choi et al. 2013 Theriogenology 79, 791–796). In Experiment 1, oocytes were divided into 2 groups and matured for 20 or 24 h. After enucleation, oocytes were reconstructed by direct injection of donor cells. Reconstructed oocytes were held for 5 h and then activated by treatment with 5 μM ionomycin for 4 min, then injection with sperm extract, followed by incubation in 2 mM 6-DMAP for 4 h. The activated reconstructed oocytes were cultured in global human embryo culture medium under 5% CO2, 6% O2, and 89% N2 at 38.2°C for 7 to 11 days (20 mM glucose was added at Day 5) and blastocyst rate was recorded. Because a low maturation rate was found at 20 h in Experiment 1, in Experiment 2 oocytes were denuded at 20 h and those that were mature were enucleated and used for NT; those that had not cast out a polar body at 20 h were cultured for an additional 3 h (20 + 3h) and then evaluated for polar body formation and used for NT, which was conducted as in Experiment 1. Data were analysed by Fisher's exact test. In Experiment 1, 203 oocytes were collected in 46 aspiration sessions. The rate of oocyte maturation to metaphase II was significantly lower for oocytes cultured for 20 h (35/116, 30%), than for those cultured for 24 h (47/80, 59%). However, the rate of blastocyst development was significantly higher for oocytes cultured for 20 h (11/27, 41%) than for 24 h (2/38, 5%). In Experiment 2, 89 oocytes were collected in 18 aspiration sessions. After 20 h of maturation culture, 22 oocytes were mature (25%). After an additional 3 h of culture, 21 additional oocytes had matured. There were no significant differences between the two treatments (20 and 20 + 3h) in reconstruction rates (77%, 17/22, and 90%, 19/21, respectively) or blastocyst rates (24%, 4/17, and 32%, 6/19, respectively). These results indicate that duration of in vitro maturation, or the duration of presence of cumulus cells, influences blastocyst development after somatic cell NT in the horse. This appears to be due to a benefit of using oocytes immediately after they reach metaphase II; if this is ensured as in Experiment 2, the duration of maturation itself had no effect.This work was supported by the American Quarter Horse Foundation, the Link Equine Research Endowment Fund, Texas A&M University, and by Ms. Kit Knotts.


2021 ◽  
Vol 10 (2) ◽  
pp. 46
Author(s):  
Sepvian Dewi Kurniawati ◽  
Suryanie Sarudji ◽  
Widjiati Widjiati

This study was aimed to determine the effect of urea in maturation medium on in vitro oocyte maturation rate. The medium used was TCM-199 added with Hepes, NaHCO3, Kanamycin 0.15 IU/mL, PMSG, 0.15 IU/mL hCG, and 10% FBS. Cumulus oocyte complexes (COCs) of cows derived from follicle aspiration were divided into three groups. In control group (P0), the COCs were matured in vitro in a maturation medium without urea addition, meanwhile in the P1 and P2 groups, the medium was added with urea 20 and 40 mg/dL, respectively. Each petri dish contained three drops of maturation medium (300 µl/drops) according to the groups. Microdrops were coated with mineral oil and then incubated in a 5% CO2 incubator, at 39 ˚C with maximum humidity. Aceto-orcein staining was conducted to evaluate the maturation of oocytes based on the achievement of metaphase II phase that is indicated by the presence of metaphase plate and/or first polar body. The result showed that the oocyte maturation rates of P0, P1, and P2 were 51.25, 52.43 (p >0.05), and 46.88 % (p <0.05) respectively. It could be concluded that the presence of urea at 40 mg/dL in maturation medium reduced the percentage of bovine oocyte maturation in vitro.


2019 ◽  
Vol 31 (1) ◽  
pp. 212
Author(s):  
Y. Honkawa ◽  
Y. Gen ◽  
S.-H. Hyon ◽  
C. Kubota

Epigallocatechin-3-gallate (EGCG) is a major ingredient of catechin polyphenols, and a strong antioxidant compound. Huang et al. (2018 Asian-australas. J. Anim. Sci.) reported that adding 50μM EGCG can improve the bovine oocyte maturation rate. In this research, we investigated the effect of EGCG supplementation on different periods in bovine IVF. Cumulus-oocyte complex (COC) collected from ovaries of slaughtered cows were cultured in maturation medium (20 to 30 oocytes per 100-µL droplet), which consisted of TCM-199 with Earle’s salts and 25mM HEPES supplemented with 10% (vol/vol) fetal bovine serum (FBS), 1µg mL−1 oestradiol, 0.02mg mL−1 FSH, and antibiotics at 38.5°C in a humidified atmosphere of 5% CO2 in air for 24h (in vitro maturation, IVM). After IVM, COC were fertilized in the fertilization medium (modified Brackett-Oliphant media supplemented with 10 µgmL−1 heparin, 10mM caffeine, and 3mg mL−1 BSA) for 6h using semen of one bull at final sperm concentration of 1×107 mL−1 (IVF). After IVF, COC were denuded and cultured in culture medium [CR1aa supplemented with 10% (vol/vol) FBS and antibiotics] at 38.5°C in a humidified atmosphere of 5% O2, 5% CO2, and 90%N2 for 8 days (in vitro culture, IVC). The EGCG was supplemented at 10, 25, 50, and 100M in IVM medium; 25 and 50 µM in IVF medium; and 50 and 100 µM in IVC medium. After 24h in IVM medium, COC were denuded by pipetting, fixed in 3:1 ethanol:acetic acid for 24h and then checked for nuclear and polar body by using aceto-orcein stain. After 18h in IVF, the pronucleus in zygote was fixed in 3:1 ethanol:acetic acid for 24h and checked by aceto-orcein staining. Embryo development was evaluated by counting the total number of embryos that had reached compacted morula by 6 to 8 days after IVF. Significant differences were analysed by chi-squared test and residual analysis. A P-value&lt;0.05 was considered statistically significant. When EGCG was added to IVM, there was no significant difference of oocyte maturation rate between all concentrations (0v. 10v. 25v. 50v. 100 μM: 73.9% v. 56.7% v. 76.7% v. 72.7% v. 63.5%). When EGCG was added to IVF, there was no significant difference of fertilized rate (0v. 25v. 50 μM: 59.4% v. 73.7% v. 64.9%). When EGCG was added to IVC, there was no significant difference in development rate (0v. 50v. 100 μM: 26.2% v. 15.7% v. 22.0%). In this research, EGCG addition did not affect bovine in vitro fertilization.


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.


2019 ◽  
Vol 35 (1-2) ◽  
pp. 7-12
Author(s):  
MN Sharif ◽  
SM Choudhury ◽  
MM Rahman ◽  
MM Rahman ◽  
NS Juyena ◽  
...  

Cryopreservation of oocytes and embryos by vitrification can have advantages in assisted reproductive technologies (ARTs) in mammals. The aim of this study was to establish an effective vitrification procedure and cryodevice for goat’s oocytes in Bangladesh. Cumulus oocyte complexes (COCs) were collected from ovaries from slaughterhouse. COCs with more than 3 layers of cumulus cells were selected. COCs were vitrified by two-step procedure using 7.5% and 15% dimethyl sulphoxide (DMSO) as cryoprotective agent (CPA), loaded on Cryotop or French mini-straw, then directly plunged into liquid nitrogen (LN2). Then the COCs containing Cryotop or French mini-straws were warmed in 0.25 M sucrose and 20% FBS-supplemented tissue culture medium (TCM) 199 followed by in vitro culture in 50 μl droplets of bicarbonate-buffered TCM 199 supplemented with 10% FBS, pyruvate, FSH and oestradiol for 24 h at 39°C with 5% CO2 in humidified air. After maturation culture, oocytes were denuded and examined under inverted microscope for presence of polar body as the indication of maturation. The in vitro maturation rate of goat’s oocytes after vitrification and warming was 39.3 ± 6.8%, 31.3 ± 9.4%, 61.6 ± 14.2% when using Cryotop (cryodevice), French mini-straws and without vitrification (control), respectively. Maturation rate was significantly higher (P<0.05) without vitrification. It is suggested that both Cryotop and French mini-straw are efficient cryodevices for vitrification of goat’s oocytes and further investigation is required to optimize the protocol for vitrification and warming procedure for the satisfactory survival of goat’s oocytes. The Bangladesh Veterinarian (2018) 35(1&2): 7-12


2018 ◽  
Vol 30 (1) ◽  
pp. 217
Author(s):  
M. Rubessa ◽  
D. Weisgerber ◽  
S. Bessler ◽  
J. Bertels ◽  
B. Harley ◽  
...  

The in vitro production of bovine embryos has dramatically increased in recent years, and with it the demand of stable media with a long shelf-life. In this experiment we evaluated the impact of the freeze-dried in vitro maturation (IVM) medium (Mdry) on in vitro oocyte maturation. We compared the standard IVM and the Mdry media. Medium M199 was used as base for the IVM medium. The percentage of metaphase II oocytes and embryo production were evaluated. Media solutions (10 mL) were aliquoted into 50-mL conical tubes and lyophilized to form a powder concentrate using a Genesis freeze-dryer (VirTis, Gardener, NY, USA). Lyophilization consisted of a constant cooling from 20°C to –10°C at a constant rate of 1°C/min with a 2-h hold at –10°C before sublimation at 0°C. The Mdry medium was held at –80°C for 4 months (only serum and hormones were added before the incubation). When the IVM medium was rehydrated, the pH were adjusted to 7.4. The percentage of mature oocytes was evaluated after 24 h of maturation. The oocytes were stained with Hoechst 33342, and only oocytes with metaphase and a polar body were evaluated as matured. Abattoir-derived Holstein oocytes (n = 540) were in vitro matured (25–30/well in 400 µL) and fertilized with sexed semen, according to standard procedures (Rubessa et al. 2011 Theriogenology 76, 1347-1355). The oocytes were split for analysis (432 were used for IVP and 108 for maturation rate) over 6 replicates. Twenty hours after IVF, presumptive zygotes were cultured in SOF medium at 39°C with 5% CO2, 7% O2, and 88% N2. On Day 7, embryo yields were assessed. All recorded parameters were subjected to a Student’s t-test. The parameters compared were maturation rate, cleavage rate, blastocyst rate and the percentage of embryos cleaved. The α level was set at 0.05. All data were expressed as quadratic means and mean standard deviations. The results showed no differences between the 2 groups (75.9% v. 74.1%) (t = 0.37; SD = 12.69; P = 0.36; df = 5) when we compared the nuclear maturation; however, when we evaluated embryo production, we found the Mdry treatment had a higher cleavage percentage (t = 2.39; SD = 14.81; P = 0.02; df = 5) and total embryos produced (t = 2.49; SD = 5.6; P = 0.02; df = 5) compared with the control (Table 1.). These results showed that lyophilization can be a valid method to increase the shelf life of IVP media. More replicates must be done in order to understand why the freeze-dried media produced more embryos. Table 1.Mean (SD in parentheses) percentage cleavage and blastocysts


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
J Garratt ◽  
B Raikundalia ◽  
M Rimington ◽  
K Ahuja ◽  
N Macklon ◽  
...  

Abstract Study question Which clinical parameters predict a high oocyte maturation rate in patients undergoing IVF treatment? Summary answer Time between oocyte collection and insemination demonstrated significant association with oocyte maturation and represents a parameter that could be optimised in IVF cycles. What is known already Oocyte maturation is an important factor determining IVF outcomes and can be a rate-limiting step for patients undergoing treatment. A number of clinical and laboratory variables may affect this process, including the choice of trigger prior to oocyte collection, and certain laboratory procedures. Identification of which of these are predictors of maturation in individual centres enables local protocols to be optimised. Study design, size, duration This is a retrospective study of 714 oocyte collections from 661 women between January 2020 to November 2020 treated in a large, single centre in the UK. Subsequent fertilisation on fresh oocytes consisted of 371 IVF and 343 ICSI cycles. Participants/materials, setting, methods Patient and treatment data was collected by clinical staff at time of treatment. Either GnRH agonist, hCG or double trigger were administered 36 hours before collection. Prior to ICSI, oocyte maturation was assessed by visualisation of polar body (PB) extrusion. After IVF, the number of 2PNs plus unfertilised oocytes with PB extrusion were assessed. Univariate analyses consisted of Mann-Whitney test, t-test, Fisher’s Exact test or ANOVA. Potential predictors were investigated by logistic regression. Main results and the role of chance The end point was maturation rate, defined as high (greater or equal to 70%) or low (less than 70%). Factors predictive of a high rate included insemination more than 4 hours after collection. Oocytes inseminated over 4 hours post-collection displayed significantly higher maturation rates than oocytes inseminated less than 2 hours after collection (69% and 61% respectively; P = 0.01). Oocytes inseminated between 2–4 hours also had higher maturation than those inseminated less than 2 hours post-collection, but this did not reach significance (67% and 61%, respectively; P = 0.06). Further, oocytes fertilised by ICSI had significantly higher maturation than conventional IVF (77% and 67%, respectively, P &lt; 0.001). No significant difference in oocyte maturation between triggers was observed. Similarly, neither age, AMH, a diagnosis of PCOS or number of oocytes collected predicted oocyte maturation in univariate analysis. Logistic regression analysis showed only time between oocyte collection and insemination (aOR 2.12; 95% CI 1.03–4.38; P = 0.04) to be a significant independent predictor. Limitations, reasons for caution Varying means of data collection across clinics and between clinical staff inevitably leads to provision of incomplete data and should be taken into consideration alongside interpretation. Prescription bias of specific triggers to certain patient demographics should be noted. Wider implications of the findings: Collectively, these results suggest that greater time between oocyte collection and insemination could be recommended to IVF clinics that wish to optimise their oocyte maturation. Triggering final maturation with GnRH agonist versus hCG or dual trigger did not have a significant effect on oocyte maturation when adjusted for confounders. Trial registration number Not applicable


2015 ◽  
Vol 49 (6) ◽  
Author(s):  
S. S. Deka ◽  
D. J. Kalita ◽  
S. Sarma ◽  
D. J. Dutta

Sixty healthy ovaries were collected from local slaughter house. Oocytes from small and medium sized follicles (2-8 mm in diameter) were selected for oocyte collection using aspiration followed by slicing . A and B category ( cumulus oocyte complexes (COCs) with more than 5 layers and 3-5 layers respectively of compact cumulus cells surrounding the zona pellucida) were selected for <italic>in vitro</italic> maturation. A total of 361 oocytes were found to be matured with overall mean maturation rate of 82.59 ± 0.02%. The mean number of grade A, B and C oocytes recovered per ovary was 4.26 ± 0.53, 3.05 ± 0.31 and 1.25 ± 0.19, respectively. The overall recovery of grade A, B and C oocytes were 256, 183 and 74 . Out of 439 oocytes 58.86 ± 0.05%, 33.23 ±0.04 % and 9.90 ± 0.04 % showed +++, ++ and + degrees of cumulus expansion, respectively. It was concluded that aspiration followed by slicing is an ideal method for maximum yield of oocytes and <italic>in vitro</italic> maturation in indigenous cow of Assam.


Sign in / Sign up

Export Citation Format

Share Document