scholarly journals 132 BLASTOCYST DEVELOPMENT OF EQUINE OOCYTES WITH LOW MEIOTIC COMPETENCE HELD IN ROSCOVITINE BEFORE IN VITRO MATURATION

2005 ◽  
Vol 17 (2) ◽  
pp. 216
Author(s):  
Y.H. Choi ◽  
L.B. Love ◽  
D.D. Varner ◽  
K. Hinrichs
Keyword(s):  
Epithelial Cells ◽  
In Vitro Maturation ◽  
Developmental Competence ◽  
Blastocyst Development ◽  
Exact Test ◽  
Nuclear Maturation ◽  
Significant Difference ◽  
Chromatin Configuration ◽  
Meiotic Competence

At the time of recovery, immature equine oocytes may be separated into those with either expanded cumuli (Ex) or compact cumuli (Cp). The Cp oocytes originate from viable follicles but are largely juvenile, with low meiotic competence (20 to 30% maturation to MII), and possibly reduced developmental competence. We previously found that in Cp oocytes recovered immediately after slaughter, suppression of meiosis with roscovitine for 24 h before maturation increased embryo development at 4 days after intracytoplasmic sperm injection (ICSI; Franz et al. 2003 Reproduction 125, 693–700). The present study was conducted to evaluate the effect of roscovitine suppression on nuclear maturation and blastocyst formation of Cp oocytes recovered after transport of ovaries from the abattoir (i.e. recovered 5–9 h after slaughter). Compact oocytes recovered from transported ovaries were cultured in M199 with 10% FBS containing 66 μM roscovitine with or without an oil cover. After 16–18 or 24 h, oocytes were fixed to examine the chromatin configuration. Treatment for 16–18 h without oil resulted in the lowest rate of meiotic resumption (0%); thus this treatment was utilized in further studies. Resumption in other treatments ranged from 3 to 6%. Following roscovitine suppression, oocytes were cultured for 30 h in M199 with 10% FBS and 5 μU mL−1 FSH for maturation; control oocytes were cultured for 30 h in the same medium immediately after recovery. Mature oocytes were subjected to ICSI, then cultured in DMEM/F-12 with 10% FBS with or without co-culture with equine oviductal epithelial cells under mineral oil in 5% CO2 in air at 38.2°C, and then evaluated at 7.5 days. Progression to MII (82/376, 22%) after maturation of roscovitine-treated oocytes was similar to that for control oocytes (74/395, 19%). There was no significant difference in cleavage rates after ICSI (72–78%) among treatments. Development to blastocyst was highest in roscovitine-treated oocytes in DMEM/F-12 with co-culture (11/30, 37%); this was significantly higher than that of non-treated oocytes in DMEM/F-12 alone (5/36, 14%), but similar to that of non-treated/DMEM/F-12/co-culture (10/37, 27%) and roscovitine/DMEM/F-12 alone (8/39, 21%). These data indicate that roscovitine induces a fully reversible meiotic suppression in Cp equine oocytes recovered 5–9 h after slaughter, and that this suppression does not harm subsequent developmental competence. This treatment may be used to manipulate the time of onset of maturation of equine oocytes for ease of subsequent procedures. Co-culture with oviductal epithelial cells tended to increase blastocyst rate (P = 0.1, Fisher's exact test) in contrast to our previous findings with embryos from Ex oocytes (Choi et al. 2004 Biol. Reprod. 70, 1231–1238). Further work is needed to determine whether this is related to differences in intrinsic developmental competence between oocyte types. This work was supported by the Link Equine Research Endowment Fund (Texas A&M University).

233. Oxygen concentration during in vitro maturation of murine oocytes affects blastocyst cell lineage

2005 ◽  
Vol 17 (9) ◽  
pp. 91
Author(s):  
K. M. Banwell ◽  
M. Lane ◽  
D. L. Russell ◽  
K. L. Kind ◽  
J. G. Thompson
Keyword(s):  
Embryo Development ◽  
In Vitro Maturation ◽  
Cell Lineage ◽  
Developmental Competence ◽  
Embryo Viability ◽  
Blastocyst Development ◽  
Treatment Groups ◽  
Significant Difference ◽  
O2 Concentration

Follicular antral oxygen tension is thought to influence subsequent oocyte developmental competence. Despite this, in vitro maturation (IVM) is routinely performed in either 5 or 20% O2 and while low O2 has been shown to be beneficial to embryo development in many species, the effect of altering O2 concentration during IVM has not been adequately investigated. Here we investigated the effects of a range of O2 concentrations during IVM on meiotic maturation and subsequent embryo development after IVF. Ovaries from eCG-stimulated CBA F1 female mice (21 days) were collected and intact cumulus oocyte complexes (COCs) cultured for 17–18 h under 2, 5, 10 or 20% O2 (6% CO2 and balance of N2). Matured COCs were denuded of cumulus cells, fixed and stained (1% aceto-orcein) for visualisation of maturation status. No significant difference in maturation rates between treatment groups was observed. Following IVF (performed under 5% O2, 6% CO2 and balance of N2), no difference in fertilisation rates between treatment groups was observed in a randomly selected cohort 7 h post-fertilisation. There was also no significant difference in cleavage rates after 24 h or ability to reach blastocyst stage after 96 h, with a tendency (P = 0.079) for more blastocysts in 2% O2. However there was a significant increase in the number of trophectoderm cells present in the resulting blastocysts (P < 0.05) in the 2% O2 group (35 ± 2.1) compared to 20% O2 (25 ± 2.8). Our data suggests that O2 concentration during IVM does not influence nuclear maturation or subsequent fertilisation, cleavage and blastocyst development rates. However, maturation in 2% O2 significantly alters subsequent cell lineage within blastocysts to favour trophectoderm development. Such skewed trophectoderm cell number may influence embryo viability. Funded by NHMRC and NIH.

scholarly journals Development to Blastocyst Stage of Pig Oocytes Matured, Fertilized and Electroactivated In Vitro

2002 ◽  
Vol 45 (6) ◽  
pp. 547-556
Author(s):  
N. R. Mtango ◽  
M. D. Varisanga ◽  
D. Y. Juan ◽  
P. Wongrisekeao ◽  
T. Suzuki
Keyword(s):  
In Vitro Maturation ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Cleavage Rate ◽  
Vitro Fertilization ◽  
Nuclear Maturation ◽  
Significant Difference ◽  
Activation Rates ◽  
Oviduct Fluid

Abstract. This study was designed 1) to determine the effectiveness of two in vitro maturation (IVM) media (tissue culture medium [TCM] and modified synthetic oviduct fluid supplemented with amino acids [mSOFaa]), 2) to compare the effects of two in vitro fertilization (IVF) media (modified Tris-buffered medium [mTBM] and mSOFaa) on the developmental competence of pig oocytes, and 3) to test the activation ability of IVM pig oocytes matured in TCM or mSOFaa, electroactivated and cultured in mSOFaa. The nuclear maturation rates were similar between IVM media (91.0 % vs. 89.0 %). A similar result was obtained when the activation rates were 54.2 % in TCM and 56.0 % in mSOFaa, and the blastocyst rates were 7.9 % and 6.1 %, respectively. There was no significant difference between mSOFaa and mTBM in the percentage of embryos with two pronuclei 33.2 % vs. 13.8 % or polypronuclei 5.3 % vs. 13.4 %. The cleavage rate was the same in both media. The medium mSOFaa gave a significantly higher (P< 0.05) blastocyst rate than mTBM (12.7 % vs. 3.9 %). We concluded that mSOFaa can enhance in vitro maturation, fertilization and culture of pig oocytes.

154 THE EFFECT OF ZINC ON PORCINE IN VITRO MATURATION AND SUBSEQUENT EMBRYONIC DEVELOPMENT AFTER IN VITRO FERTILIZATION

2014 ◽  
Vol 26 (1) ◽  
pp. 191
Author(s):  
Y. Jeon ◽  
J. D. Yoon ◽  
L. Cai ◽  
S. U. Hwang ◽  
E. Kim ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Inductively Coupled Plasma ◽  
In Vitro Maturation ◽  
Formation Rate ◽  
Developmental Competence ◽  
Developmental Potential ◽  
Vitro Fertilization ◽  
Nuclear Maturation ◽  
Significant Difference

Zinc (Zn) is one of the abundant transition metals in biology and is an essential component of most cells. However, there are few reports about the effect of Zn in porcine oocytes. The objective was to investigate the effects of supplementary Zn during in vitro maturation (IVM) of porcine oocytes. We investigated nuclear maturation, intracellular glutathione (GSH) levels, reactive oxygen species (ROS) levels, and subsequent embryonic development after IVF. Before the experiment, Zn concentrations in IVM medium and body fluids were measured using inductively coupled plasma spectrophotometer (sensitivity: 1 μM) and treatment concentrations were determined. Zinc concentration was 12.6 μM in porcine plasma and 12.9 μM in porcine follicular fluid. We confirmed that Zn was not detected in IVM medium. A total of 541 cumulus–oocyte complexes (COC) were used for the evaluation of nuclear maturation. The COC were matured in TCM-199 medium supplemented with various concentrations of Zn (0, 6, 12, 18, and 24 μM). After 44 h of IVM, no significant difference was observed in all groups (metaphase II rate: 85.7, 88.7, 90.4, 90.3, and 87.2%, respectively). A total of 100 matured oocytes were examined for the effects of different Zn concentrations (0, 6, 12, 18, and 24 μM) on porcine oocyte intracellular GSH and ROS levels, which were measured through fluorescent staining and image analysis program. The groups of 12, 18, and 24 μM showed a significant (P < 0.05) increase in intracellular GSH levels (1.45, 1.67, and 1.78, respectively) compared with the control and 6 μM group (1.00 and 1.08, respectively). The intracellular ROS level of oocytes matured with 12, 18, and 24 μM (0.82, 0.68, and 0.55) were significantly (P < 0.05) decreased compared with the control and 6 μM groups (1.00 and 1.03, respectively). Finally, the developmental competence of oocytes matured with different concentrations of Zn (0, 6, 12, 18, and 24 μM) was evaluated after IVF. There were no significantly different in cleavage rates. However, cleavage patterns and blastocyst (BL) formation were different. Fragmented embryo ratio of the 12 μM group (14.9%) was significantly lower than that of the other groups (control, 6, 18, and 24 μM: 26.4, 17.8, 18.4, and 18.0%, respectively). Oocytes treated with 12 μM Zn during IVM had a significantly higher BL formation rate (28.2%) after IVF compared with the control (19.8%). In conclusion, these results indicate that Zn treatment as body fluid concentration during IVM improved the developmental potential of IVF in porcine embryos by increasing the intracellular GSH concentration and decreasing the ROS level. This work was supported, in part, by a grant from the Next-Generation Bio Green 21 Program (No. PJ00956901), Rural Development Administration, and the National Research Foundation of Korea Grant funded by the Korean Government (NRF-2012R1A1A4A01004885, NRF-2013R1A2A2A04008751), Republic of Korea.

Effect of GnRH treatment on the maturation and in vitro development of oocytes collected from 4- to 6-week-old Merino lambs

2007 ◽  
Vol 19 (8) ◽  
pp. 947 ◽  
Author(s):  
Jennifer M. Kelly ◽  
David O. Kleemann ◽  
W. M. Chis Maxwell ◽  
Simon K. Walker
Keyword(s):  
In Vitro Maturation ◽  
Germinal Vesicle ◽  
Developmental Competence ◽  
Blastocyst Development ◽  
Cleavage Rate ◽  
Germinal Vesicle Breakdown ◽  
Nuclear Maturation ◽  
Oocyte Collection ◽  
Vitro Development

Two experiments were conducted in Merino lambs to examine the effects of gonadotrophin-releasing hormone (GnRH) treatment on the developmental competence of oocytes collected after pretreatment with follicle stimulating hormone (FSH). The first experiment examined the effects of six GnRH treatment times (control and GnRH administered 2, 4, 6, 8 and 10 h before oocyte collection) and four in vitro maturation (IVM) periods (18, 20, 22, 24 h) on the rate of oocyte nuclear maturation. The second experiment examined the effect of five GnRH treatment times (control and GnRH administered 2, 4, 6 and 8 h before oocyte collection) and three IVM periods (20, 22, 24 h) on the development of oocytes and embryos after in vitro maturation, fertilisation and culture. In Experiment 1, GnRH treatment did not influence the mean number of cumulus-oocyte-complexes (COCs) collected or COC morphology at the time of collection. However, treatment changed (P < 0.01) the distribution of follicle size and this was primarily due to a marked reduction in the number of follicles with diameters <2 mm. In addition, GnRH treatment at 6 and 8 h increased (P < 0.01) the proportion of oocytes that developed to Metaphase II (MII) (63.2 and 72.6%, respectively) compared with other treatment times (range 52.9–59.9%). Nuclear maturation was influenced by a significant (P < 0.05) interaction between GnRH treatment and IVM period due to a disproportionately greater number of oocytes at the germinal vesicle breakdown (GVBD) stage for the 2 and 4 h GnRH treatments compared with other treatments. In Experiment 2, cleavage rate (range 63.5–85.9%) was highest when GnRH was administered 8 h before collection but the percentage of cleaved oocytes that developed into blastocysts (range 10.0–35.0%) was significantly (P < 0.05) lower for the 6 and 8 h GnRH treatments compared with the control and the 2 h GnRH treatment. These results demonstrate that GnRH treatment before oocyte collection can improve nuclear maturation and cleavage rates in lamb oocytes but that these improvements are not reflected in improved rates of blastocyst development. It is speculated that this discrepancy may result from GnRH treatment either adversely affecting cytoplasmic maturation or inducing asynchrony between the maturation of the nuclear and cytoplasmic components of the oocyte.

scholarly journals Impact of L-carnitine supplementation on the in vitro developmental competence and cryotolerance of buffalo embryos

2021 ◽  
pp. 3164-3169
Author(s):  
Mohamed M. M. El-Sokary ◽  
Al-Shimaa Al-H. H. El-Naby ◽  
Amal R. Abd El Hameed ◽  
Karima Gh. M. Mahmoud ◽  
T. H. Scholkamy
Keyword(s):  
Embryo Culture ◽  
In Vitro Maturation ◽  
Culture Media ◽  
Effective Concentration ◽  
Developmental Competence ◽  
Carnitine Supplementation ◽  
Oocyte Developmental Competence ◽  
High Lipid ◽  
Significant Difference

Background and Aim: Despite many trials, buffalo embryos have poor cryosurvivability because of their high lipid content. L-carnitine was found to be a lipid-reducing agent when added to oocyte and embryo culture media. The study aimed to determine the most effective concentration of L-carnitine to improve the oocyte developmental competence and cryotolerance of buffalo embryos. Materials and Methods: In vitro maturation and embryo culture media were supplemented with four concentrations of L-carnitine: 0 (control), 0.25, 0.5, and 1 mM. Good-quality embryos on 7 days were vitrified using mixtures of dimethyl sulfoxide and ethylene glycol at two concentrations (3.5 and 7 M). Results: The result showed that the cleavage and morula rates were significantly (p<0.05) higher in the 0.5 mM group. Blastocyst rates were significantly (p<0.05) higher at both 0.5 and 1 mM. The rates of viable embryos directly after thawing were significantly (p<0.05) increased in the 0.5 mM group. No significant difference was found in embryos cultured for 24 h after warming among all the groups. Conclusion: The addition of L-carnitine at a concentration of 0.5 mM to the culture media improves the oocyte developmental competence and cryotolerance of buffalo embryos directly after warming but not after 24 h of culture. Nevertheless, further studies must identify how L-carnitine exerts its beneficial micromechanisms.

The effects of brain-derived neurotrophic factor and metformin on in vitro developmental competence of bovine oocytes

Zygote ◽  
2009 ◽  
Vol 17 (3) ◽  
pp. 187-193 ◽  
Author(s):  
So Gun Hong ◽  
Goo Jang ◽  
Hyun Ju Oh ◽  
Ok Jae Koo ◽  
Jung Eun Park ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Embryo Development ◽  
Neurotrophic Factor ◽  
Brain Derived Neurotrophic Factor ◽  
Early Embryo ◽  
Developmental Competence ◽  
Blastocyst Development ◽  
Cell Stage ◽  
Significant Difference

SummaryBrain-derived neurotrophic factor (BDNF) signalling via tyrosine kinase B receptors may play an important role in ovarian development and function. It has been reported that metformin elevates the activity of Tyrosine kinase receptors and may amplify BDNF signalling. The objective of this study was to investigate the effect of BDNF during in vitro maturation (IVM) and/or in vitro culture (IVC) (Experiment 1), and to evaluate the collaborative effect of BDNF and metformin treatment on the developmental competence of bovine in vitro fertilized (IVF) embryos (Experiment 2). In Experiment 1, BDNF, which was added to our previously established IVM systems, significantly increased the proportions of MII oocytes at both 10 ng/ml (86.7%) and 100 ng/ml (85.4%) compared with the control (64.0%). However, there was no statistically significant difference in blastocyst development between the control or BDNF-supplemented groups. In Experiment 2, in order to investigate the effect of BDNF (10 ng/ml) and/or metformin (10−5 M) per se, TCM-199 without serum and hormones was used as the control IVM medium. The BDNF (48.3%) and BDNF plus metformin (56.5%) significantly enhanced the proportions of MII oocytes compared with the control (34.4%). Although, BDNF or metformin alone had no effect in embryo development, BDNF plus metformin significantly improved early embryo development to the 8–16-cell stage compared with the control (16.5 vs. 5.5%). In conclusion, the combination of BDNF and metformin may have a collaborative effect during the IVM period. These results could further contribute to the establishment of a more efficient bovine in vitro embryo production system.

scholarly journals Effects of Short-Term Inhibition of Rho Kinase on Dromedary Camel Oocyte In Vitro Maturation

Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 750
Author(s):  
Hammed A. Tukur ◽  
Riyadh S. Aljumaah ◽  
Ayman Abdel-Aziz Swelum ◽  
Abdullah N. Alowaimer ◽  
Mutassim Abdelrahman ◽  
...  
Keyword(s):  
In Vitro Maturation ◽  
Rho Kinase ◽  
Positive Outcome ◽  
Dromedary Camel ◽  
Second Phase ◽  
Short Term ◽  
Rock Inhibitor ◽  
Nuclear Maturation ◽  
Significant Difference

This is the first report on a biphasic in vitro maturation (IVM) approach with a meiotic inhibitor to improve dromedary camel IVM. Spontaneous meiotic resumption poses a major setback for in vitro matured oocytes. The overall objective of this study was to improve in vitro maturation of dromedary camel oocytes using ROCK inhibitor (Y-27632) in a biphasic IVM to prevent spontaneous meiotic resumption. In the first experiment, we cultured immature cumulus–oocyte complexes (COCs, n = 375) in a prematuration medium supplemented with ROCK inhibitor (RI) for 2 h, 4 h, 6 h, and 24 h before submission to normal in vitro maturation to complete 28 h. The control was cultured for 28 h in the absence of RI. In the first phase of experiment two, we cultured COCs (n = 480) in the presence or absence (control) of RI for 2 h, 4 h, 6 h, and 24 h, and conducted real-time relative quantitative PCR (qPCR) on selected mRNA transcripts. The same was done in the second phase, but qPCR was done after completion of normal IVM. Assessment of nuclear maturation showed that pre-IVM for 4 h yielded an increase in MII oocyte (54.67% vs. 26.6% of control; p < 0.05). As expected, the same group showed the highest degree (2) of cumulus expansion. In experiment 2, qPCR results showed significantly higher expression of ACTB and BCL2 in the RI group treated for 4 h when compared with the other groups. However, their relative quantification after biphasic IVM did not reveal any significant difference, except for the positive response of BCL2 and BAX/BCL2 ratio after 4 and 6 h biphasic IVM. In conclusion, RI prevents premature oocyte maturation and gave a significantly positive outcome during the 4 h treatment. This finding is a paradigm for future investigation on dromedary camel biphasic IVM and for improving the outcome of IVM in this species.

scholarly journals Effect of Hyaluronan on Developmental Competence and Quality of Oocytes and Obtained Blastocysts fromIn VitroMaturation of Bovine Oocytes

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Jolanta Opiela ◽  
Joanna Romanek ◽  
Daniel Lipiński ◽  
Zdzisław Smorąg
Keyword(s):  
Dna Fragmentation ◽  
Oocyte Maturation ◽  
Developmental Competence ◽  
Meiotic Maturation ◽  
Nuclear Maturation ◽  
Significant Difference ◽  
The Mean ◽  
Bovine Oocytes

The objective of the present study was to evaluate the effect of hyaluronan (HA) during IVM on meiotic maturation, embryonic development, and the quality of oocytes, granulosa cells (GC), and obtained blastocysts. COCs were maturedin vitroin control medium and medium with additional 0.035% or 0.07% of exogenous HA. The meiotic maturity did not differ between the analysed groups. The best rate and the highest quality of obtained blastocysts were observed when 0.07% HA was used. A highly significant difference (P<0.001) was noted in the mean number of apoptotic nuclei per blastocyst and in the DCI between the 0.07% HA and the control blastocysts (P<0.01). Our results suggest that addition of 0.035% HA and 0.07% HA to oocyte maturation media does not affect oocyte nuclear maturation and DNA fragmentation. However, the addition of 0.07% HA during IVM decreases the level of blastocysts DNA fragmentation. Finally, our results suggest that it may be risky to increase the HA concentration during IVM above 0.07% as we found significantly higherBaxmRNA expression levels in GC cultured with 0.07% HA. The final concentration of HA being supplemented to oocyte maturation media is critical for the success of the IVP procedure.

44 PRODUCTION OF LIVE PIGLETS AFTER CRYOPRESERVATION OF IMMATURE PORCINE OOCYTES

2014 ◽  
Vol 26 (1) ◽  
pp. 136
Author(s):  
T. Somfai ◽  
K. Kikuchi ◽  
K. Yoshioka ◽  
F. Tanihara ◽  
H. Kaneko ◽  
...  
Keyword(s):  
Polar Body ◽  
Petri Dish ◽  
Developmental Competence ◽  
Basic Medium ◽  
High Survival ◽  
Blastocyst Development ◽  
Nuclear Maturation ◽  
First Polar Body ◽  
Vitrification Solution

Development to term of vitrified porcine follicular oocytes is reported in the present study. Immature cumulus-oocyte complexes (COC) were collected from slaughtered prepubertal gilts and were vitrified according to our method published recently (Somfai et al. 2013 J. Reprod. Dev., in press). Briefly, after pretreatment with 7.5 μg mL–1 of cytochalasin B (CB) for 30 min in modified NCSU-37 (a basic medium, BM) at 38.5°C, groups of 88 to 121 COC were equilibrated in a mixture of 2% ethylene glycol (EG), 2% propylene glycol (PG), and 7.5 μg mL–1 CB for 13 to 15 min. Then, COC were washed in vitrification solution (17.5% EG, 17.5% PG, 5% polyvinyl pyrrolidone, and 0.3 M trehalose in BM) and then dropped with 2 μL of vitrification solution onto the surface of aluminum foil floating on liquid nitrogen (LN2). Microdroplets (each containing 10–25 COC) were transferred into cryotubes. After storage in LN2 for 2 to 4 weeks, the oocytes were warmed by dropping the microdroplets directly into 2.5 mL of warming solution (0.4 M trehalose in BM) kept in a 35-mm Petri dish on a 42°C hotplate for less than 1 min. Then, the warming dish was placed on a 38°C hotplate and COC were consecutively transferred for 1-min periods into BM containing 0.2, 0.1, or 0.05 M trehalose at 38°C. The COC were matured in vitro for 44 h using porcine oocyte medium (POM) supplemented with 10% follicular fluid (Yoshioka et al. 2008 J. Reprod. Dev. 54, 208–213). Then, oocytes were denuded, and their live/dead status and nuclear maturation were determined by their morphology and the presence of the first polar body, respectively. To assess their developmental competence, vitrified and non-vitrified (control) oocytes were in vitro fertilized (IVF; Kikuchi et al. 2002 Biol. Reprod. 66, 1033–1041) and then in vitro cultured in porcine zygote medium-5 (PZM-5; Yoshioka et al. 2008 J. Reprod. Dev. 54, 208–213). Blastocyst rates were recorded on Days 5, 6, and 7 of culture (Day 0 = the day of IVF). The experiment was replicated 4 times. Data were analysed with 1-way ANOVA and the Tukey test. The results revealed that 86.4% (364/424) of oocytes survived after vitrification, which was significantly lower (P < 0.05) than that of controls [100% (326/326)]. Live oocytes in vitrified and control groups did not differ statistically in terms of nuclear maturation (63.9 v. 65.3%). Blastocyst rates of surviving vitrified oocytes were significantly lower compared with controls on Days 5 (2.4 v. 12.7%), 6 (4.8 v. 17.6%), and 7 (5.6 v. 18.4%). To test their ability to develop to term, 16 and 27 blastocysts on Day 5 developing from vitrified COC were transferred into 2 recipients. Both recipients became pregnant and farrowed a total of 10 live piglets (4 and 6 piglets, respectively). These data demonstrate that large groups of immature porcine oocytes could be cryopreserved by this method showing high survival and maturation rates. Furthermore, despite a low rate of blastocyst development, transfer of Day-5 blastocysts generated from vitrified oocytes resulted in piglet production for the first time in the world. Partially supported by JSPS and HAS under the Japan-Hungary Research Cooperative Program.

172 DETERMINING THE REQUIREMENTS FOR LH AND FSH DURING SHEEP IN VITRO OOCYTE MATURATION

2014 ◽  
Vol 26 (1) ◽  
pp. 200 ◽  
Author(s):  
C. de Frutos ◽  
R. Vicente-Perez ◽  
P. J. Ross
Keyword(s):  
Oocyte Maturation ◽  
In Vitro Maturation ◽  
Mixed Logit ◽  
Cumulus Cells ◽  
Pituitary Hormones ◽  
Developmental Competence ◽  
Cumulus Expansion ◽  
Nuclear Maturation ◽  
Grade 3

In vitro maturation (IVM) of oocytes in domestic animals is a widespread practice of research and commercial relevance. Gonadotropic hormones are typically supplemented to the IVM medium to stimulate resumption of meiosis, progression to metaphase II (MII), and oocyte developmental competence. The common use of pituitary-derived products presents 2 problems: contamination from other pituitary hormones and inconsistences from batch-to-batch variation. Recombinant hormones can help circumvent these issues and identify specific gonadotropin requirements for in vitro maturation. The aim of the present study was to determine the effect of supplementing recombinant bovine LH and/or FSH (AspenBio) to the maturation of ovine oocytes in terms of cumulus expansion and progression to the MII stage. Abattoir-derived sheep cumulus–oocyte complexes (COC) were obtained from 1- to 5-mm-diameter antral follicles by ovary slicing. Oocytes with a homogeneous cytoplasm surrounded by at least 3 layers of cumulus cells were selected and cultured in serum-free IVM medium (Cotterill et al. 2012 Reproduction 144, 195–207) at 38.5°C and 5% CO2. The COC obtained from 8 replicates were allocated into 4 experimental groups: (1) no hormones; (2) 1.5 μg mL–1 recombinant bovine LH (rbLH); (3) 1.5 μg mL–1 recombinant bovine FSH (rbFSH); and (4) rbLH and rbFSH. The expansion of cumulus cells was recorded in each group after 24 h of IVM and COC classified as (1) very poor or no cumulus expansion (grade 1); (2) limited cumulus expansion (grade 2); and (3) full cumulus expansion (grade 3). Nuclear maturation in the 4 treatments was evaluated by assessing progression to the MII stage via DNA staining with Hoechst 33342 and fluorescence imaging. The effect of treatment on the observed proportion of MII oocytes was evaluated using a mixed logit model including treatment and replicate as fixed and random effects, respectively. Culture in IVM medium in the absence of gonadotropins or in the presence of rbLH resulted in poor cumulus expansion (grade 1). The supplementation of IVM medium with rbFSH (with or without rbLH) yielded a high degree of cumulus expansion (grades 2–3). Likewise, addition of rbFSH enhanced progression of oocytes to the MII stage, whereas use of rbLH, although it had an effect on progression to MII, did not augment the effect of rbFSH (Table 1). These results indicate that rbFSH is necessary and sufficient to induce sheep oocyte maturation in a high proportion of oocytes. Table 1.Cumulus expansion and oocyte nuclear stage after IVM

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