170 INFLUENCE OF OOCYTE QUALITY AND DIFFERENT MEDIA SUPPLEMENT ON IN VITRO MATURATION, CLEAVAGE, AND EMBRYO DEVELOPMENT OF BUFFALO (BUBALUS BUBALIS) OOCYTES

2014 ◽  
Vol 26 (1) ◽  
pp. 199
Author(s):  
M. M. Waheed ◽  
K. H. El-Shahat ◽  
A. M. Hammam

A series of 4 factorial-arranged experiments were conducted to study the effect of oocyte quality and different in vitro maturation (IVM) media supplements on IVM, cleavage, and embryo development of buffalo (Bubalus bubalis) oocytes. Buffalo ovaries were collected at a local abattoir in a warm (32–35°C) saline (0.9% NaCl), and oocytes were aspirated using an 18-gauge needle. In experiment 1, oocytes (n = 320) were classified according to the number of cumulus cell layers and morphology of ooplasm as excellent, good, or fair. Oocytes were cultured for IVM, fertilization, and embryo culture (IVMFC) in TCM-199 + 10% FCS. In experiment 2, excellent quality oocytes (n = 237) were subjected to IVM in TCM-199 enriched with either 10% FCS or oestrous buffalo serum (EBS; 20–40 pg mL–1) and then fertilized using frozen–thawed buffalo semen capacitated in Bracket and Oliphant's (BO) medium containing heparin (0.02 mg mL–1) and sodium caffeine benzoate (3.89 mg mL–1). In experiment 3, oocytes (n = 290) were classified into 2 groups; Group 1, without gonadotropins, served as a control; Group 2, in which IVM medium was supplemented with 20 IU mL–1 equine chorionic gonadotropins (eCG). Experiment 4 was carried out to examine the suitable capacitating agent added to BO medium, either heparin or caffeine or both (n = 210 fertilized oocytes). In all experiments (multiple replicates), oocytes (2–6 mm in diameter) were kept at 39°C under 5% CO2 for IVMFC and examined several times for cleavage and embryo development (morula and blastocyst). Statistical analysis was carried out using Chi-squared test. Excellent and good quality oocytes produced a higher (P < 0.05) maturation, cleavage, and morula development rates than poor quality oocytes (70% and 65% v. 33.3%), (50% and 46.2% v. 25%), and (42.9% and 33.3% v. 10%), respectively. Blastocyst production rate was also higher (P < 0.05) for excellent compared with good quality oocytes (28.6% v. 16.7%, respectively). In experiment 2, the IVM and cleavage rates were significantly higher (P < 0.05) in IVM medium plus 10% EBS than those cultured in 10% FCS (73% v. 45% and 50% v. 33.3%, respectively). In experiment 3, the addition of eCG to maturation medium increased (P < 0.05) developmental competence of buffalo oocytes (IVMFC) compared with control medium (16% v. 4%). In experiment 4, the addition of heparin together with caffeine to BO medium produced significantly higher (P < 0.05) cleavage and embryo developmental rates compared with heparin or caffeine alone (56.3% v. 33.3% and 35.7%, respectively; 22.2% v. 10% and 8%, respectively). In conclusion, excellent quality oocytes cultured in IVM medium supplemented with either EBS or eCG and fertilized with capacitated buffalo spermatozoa in BO medium enriched with heparin and caffeine progressively enhanced developmental competence of buffalo oocytes.

2010 ◽  
Vol 22 (1) ◽  
pp. 260
Author(s):  
M. Bertoldo ◽  
P. K. Holyoake ◽  
G. Evans ◽  
C. G. Grupen

Effective in vitro maturation (IVM) is essential for successful in vitro embryo production. The morphology of the cumulus investment before and after IVM may be a useful noninvasive indicator of oocyte quality. In pigs, oocyte developmental competence is reduced during the summer months. The aim of this study was to determine whether the morphology of cumulus-oocyte complexes (COC) before and after IVM are associated with oocyte quality, using COC collected from small and large follicles in summer and winter as models of poor and good oocyte quality. Ovaries were collected from sows slaughtered 4 days after weaning. The COC recovered from small (3-4 mm) and large (5-8 mm) antral follicles were morphologically graded and parthenogenetically activated following IVM during winter (n = 1419; 10 replicates) and summer (n = 2803; 10 replicates). Grade 1 and 2 COC had >2 layers of compact cumulus cells and a homogenous cytoplasm. Grade 3 COC were either partially or fully denuded, had a heterogeneous cytoplasm, or were vacuolated or dark in color. Grade 4 COC had expanded cumulus cells. Cumulus expansion was also assessed subsequent to IVM. The COC recorded as having a cumulus expansion index (CEI) of 1 had the poorest expansion with no detectable response to IVM, whereas those with a CEI of 4 had the greatest amount of expansion, including that of the corona radiata. Data were analyzed using a generalized linear mixed model in GenStat® (release 10, VSN International, Hemel Hempstead, UK). There was an effect of follicle size for Grade 1 COC, with COC from large follicles in both seasons yielding better quality COC (P < 0.05). The proportion of COC in Grade 2 was higher in small follicles during winter compared with large follicles, but there were no differences between follicle sizes during summer (P < 0.05). The proportion of COC with CEI 1 was highest in COC from small follicles during summer (P < 0.05). The proportion of COC from large follicles with CEI 2 was higher during summer compared with winter (P < 0.05). There were no seasonal or follicle size effects on COC with CEI 3 or 4 (P > 0.05). The proportion of oocytes that developed to blastocysts was greater in winter than in summer (39.06% ± 5.67 v. 22.27% ± 4.01; P < 0.05). Oocytes derived from large follicles had a greater ability to form blastocysts compared with those from small follicles (37.13% ± 5.65 v. 23.32% ± 4.56; P < 0.06). Morphological assessment of cumulus cells before and after IVM may be a useful tool to evaluate the effects of follicle size on oocyte developmental competence. However, the results of the present study indicate that cumulus cell morphology is not a good indicator of the effect of season on oocyte developmental competence.


2006 ◽  
Vol 18 (2) ◽  
pp. 272
Author(s):  
K. Kananen-Anttila ◽  
M. Eronen ◽  
J. Matilainen ◽  
M. Kallio ◽  
J. Peippo ◽  
...  

We have studied the effect of suppressed IVM on the developmental competence of bovine oocytes, aiming at elucidating the importance of cytoplasmic maturation in fertilization and embryo development. Six replicates of abattoir-derived oocytes were randomly divided into three IVM groups. Control (n = 950): TCM-199 with glutamax-I (Gibco, Grand Island, NY, USA), 0.25 mM Na-pyruvate, 100 IU mL−1 penicillin and 100 μg mL−1 streptomycin, 50 ng mL−1 FSH, and 10% fetal bovine serum (FBS) (Gibco); Serum+FSH-free (n = 944): same as control but without FSH and FBS; α-amanitin (n = 977): same as control but with 10 μg mL−1 α-amanitin. Nuclear maturation of oocytes was studied 24 h after the onset of IVM, the formation of sperm aster structure 10 hours post-insemination (hpi) and the formation of pronuclei 20 hpi. Sperm aster was visualized with β-tubulin antibody (modified from Navara et al. 1999 Dev. Biol. 162, 29–40). Presumptive zygotes were cultured until Day 7 in modified SOFaaci + 4 mg mL−1 fatty acid-free BSA in 5% O2. Cumulus cell expansion was seen only in the control group. The results of nuclear maturation, fertilization, and embryo development are summarized in Table 1. Serum and FSH deprivation did not have a statistically significant effect on the parameters studied (vs. control). α-amanitin exposure during IVM reduced nuclear maturation, fertilization, and Day 3 embryo cleavage vs. control, and resulted in total blockage of Day 7 blastocyst development. The treatment groups had significantly smaller mean diameters of male pronuclei (control: 14 ± 0.6 μ­m; serum+FSH-free: 12 ± 0.5 μ­m, P < 0.05; α-amanitin: 10 ± 0.6 μ­m, P < 0.001) and sperm asters (control: 86 ± 4 μ­m; serum+FSH-free: 82 ± 4 μ­m, P < 0.01; α-amanitin: 49 ± 7 μm, P < 0.001) (nonparametric Kruskall Wallis and Mann-Whitney U tests) vs. control group. Despite reduction in pronucleus and sperm aster diameter, serum and FSH deprivation during IVM did not affect in vitro developmental competence of bovine oocytes, suggesting a need for re-evaluation of the components of IVM. α-Amanitin exposure in IVM disturbed nuclear maturation, fertilization, and embryo development, indicating the essence of early transcription. Table 1. Average percentages ± (n) for nuclear maturation, fertilization (min two pronuclei), embryo cleavage, and blastocyst development


2024 ◽  
Vol 84 ◽  
Author(s):  
A. Azam ◽  
R. Ejaz ◽  
S. Qadeer ◽  
S. Irum ◽  
A. Ul-Husna ◽  
...  

Abstract The objective of the current study was to investigate the synergistic impact of α-Tocopherol and α-Linolenic acid (100 µM) on IVM and IVC of Nili Ravi buffalo oocytes. Oocytes were obtained from the ovaries of slaughtered buffaloes within two hours after slaughter and brought to laboratory. Buffalo cumulus oocyte complexes were placed randomly in the five experimental groups included; GROUP 1: Maturation media (MM) + 100 µM ALA (control), GROUP 2: MM + 100 µM ALA + 50μM α-Tocopherol, GROUP 3: MM + 100 µM ALA + 100μM α-Tocopherol, GROUP 4: MM + 100 µM ALA + 200 μM α-Tocopherol and GROUP 5: MM + 100 µM ALA + 300 μM α-Tocopherol under an atmosphere of 5% CO2 in air at 38.5 °C for 22-24 h. Cumulus expansion and nuclear maturation status was determined (Experiment 1). In experiment 2, oocytes were matured as in experiment 1. The matured oocytes were then fertilized in Tyrode’s Albumin Lactate Pyruvate (TALP) medium for about 20 h and cultured in synthetic oviductal fluid (SOF) medium to determine effect of α-Linolenic acid (100 µM) and α-Tocopherol in IVM medium on IVC of presumptive zygotes. To study the effect of α-Linolenic acid (100 µM) in IVM media and increasing concentration of α-tocopherol in the culture media on early embryo development (Experiment 3), the presumptive zygotes were randomly distributed into the five experimental groups with increasing concentration of α-tocopherol in culture media. Higher percentage of MII stage oocytes in experiment 1(65.2±2.0), embryos at morula stage in experiment 2 (30.4±1.5) and experiment 3 (22.2±2.0) were obtained. However, overall results for cumulus cell expansion, maturation of oocyte to MII stage and subsequent embryo development among treatments remain statistically similar (P > 0.05). Supplementation of α-tocopherol in maturation media having α-Linolenic acid and/or in embryo culture media did not further enhance in vitro maturation of oocyte or embryo production.


Reproduction ◽  
2003 ◽  
pp. 369-376 ◽  
Author(s):  
S Ikeda ◽  
H Imai ◽  
M Yamada

The aim of this study was to investigate whether apoptosis occurs in cumulus cells during in vitro maturation (IVM) of bovine cumulus-enclosed oocytes (CEOs). The bovine CEOs obtained from ovaries from an abattoir were cultured for 24 h in IVM medium in the presence or absence of 10% (v/v) fetal bovine serum. The developmental competence of enclosed oocytes, as assessed by the development of the blastocyst after IVF, was significantly higher in the serum-treated group than in the control group. The morphological features of apoptosis that were analysed by orcein staining were hardly detectable in the cumulus cells at the start (0 h) of IVM, but were evident at the end (24 h) of IVM both in the control and serum-treated groups. Genomic DNA was extracted from CEOs at 0, 6, 12, 18 and 24 h of IVM and subjected to ligation-mediated PCR (LM-PCR) to detect apoptotic internucleosomal DNA fragmentation. DNA fragmentation was hardly detectable at the start of IVM, but increased in a time-dependent manner as the IVM culture proceeded. DNA fragmentation was not observed in the oocytes, indicating that fragmentation occurs in cumulus cells. The degree of fragmentation was lower in the serum-treated group compared with the control group. The LM-PCR analysis of DNA extracted from CEOs at 24 h of IVM, in which the DNA had been pretreated with Klenow enzyme or T4 DNA polymerase, revealed that the characteristic forms of the DNA ends generated during cumulus cell apoptosis were mainly 3'-overhangs and blunt ends. In conclusion, the results of the present study demonstrate that cumulus cells in bovine CEOs spontaneously undergo apoptosis during IVM. The degree of apoptosis may be correlated with the developmental competence of the enclosed oocytes.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Á Martíne. Moro ◽  
I Lamas-Toranzo ◽  
L González-Brusi ◽  
A Pérez-Gómez ◽  
P Bermejo-Álvarez

Abstract Study question Does cumulus cell mtDNA content correlate with oocyte developmental potential in the bovine model? Summary answer The relative amount of mtDNA content did not vary significantly in oocytes showing different developmental outcomes following IVF What is known already Cumulus cells are closely connected to the oocyte through transzonal projections, serving essential metabolic functions during folliculogenesis. These oocyte-supporting cells are removed and discarded prior to ICSI, thereby constituting an interesting biological material on which to perform molecular analysis aimed to predict oocyte developmental competence. Previous studies have positively associated oocytés mtDNA content with developmental potential in both animal models and women. However, it remains debatable whether mtDNA content in cumulus cells could be used as a proxy to infer oocyte developmental potential. Study design, size, duration Bovine cumulus cells were allocated into three groups according to the developmental potential of the oocyte: 1) oocytes developing to blastocysts following IVF (Bl+Cl+), 2) oocytes cleaving following IVF but arresting their development prior to the blastocyst stage (Bl-Cl+), and 3) oocytes not cleaving following IVF (Bl-Cl-). Relative mtDNA content was analysed in 40 samples/group, each composed by the cumulus cells from one cumulus-oocyte complex (COC). Participants/materials, setting, methods Bovine cumulus-oocyte complexes were obtained from slaughtered cattle and individually matured in vitro (IVM). Following IVM, cumulus cells were removed by hyaluronidase treatment, pelleted, snap frozen in liquid nitrogen and stored at –80 ºC until analysis. Cumulus-free oocytes were fertilized and cultured in vitro individually and development was recorded for each oocyte. Relative mtDNA abundance was determined by qPCR, amplifying a mtDNA sequence (COX1) and a chromosomal sequence (PPIA). Statistical differences were tested by ANOVA. Main results and the role of chance Relative mtDNA abundance did not differ significantly (ANOVA p &gt; 0.05) between the three groups exhibiting different developmental potential (1±0.06 vs. 1.19±0.05 vs. 1.11±0.05, for Bl+Cl+ vs. Bl-Cl+ vs. Bl-Cl-, mean±s.e.m.). Limitations, reasons for caution Experiments were conducted in the bovine model. Although bovine folliculogenesis, monoovulatory ovulation and early embryo development exhibit considerable similarities with that of humans, caution should be taken when extrapolating these data to humans. Wider implications of the findings: The use of molecular markers for oocyte developmental potential in cumulus cells could be used to enhance success rates following single-embryo transfer. Unfortunately, mtDNA in cumulus cells was not found to be a good proxy for oocyte quality. Trial registration number Not applicable


2021 ◽  
Author(s):  
◽  
Aanchal Singh

<p>Oocyte developmental competency is the intrinsic measure of oocyte quality and the capacity for a mature oocyte to support the early stages of embryo development and implantation. Oocyte-secreted factors (OSFs), such as growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15), play a pivotal role in regulating the synchrony of various complex maturation events within the cumulus-oocyte complex (COC) through the induction of paracrine and endocrine signalling. These proteins act synergistically to influence the proliferation and differentiation of granulosa cells (GCs), cumulus cell (CC) expansion, promote survival, ovulation, the attainment of developmental competency and fertility. Species-specific ratios suggest that poly-ovulatory mammals have increased fecundity due to high ratios of GDF9:BMP15, which is directly reflected in their large litter size. Interestingly, it has also been found that higher ratios of GDF9:BMP15 also increased blastocyst rate in sheep implying that these embryos develop from oocytes that are more developmentally competent.  In this study, I investigated the hypothesis that supplementing a commercial in vitro maturation (IVM) system with a high ratio of GDF9:BMP15 would increase the developmental competency sheep oocytes; a species with low-moderate litter size. To test this hypothesis, ovine oocytes were matured in a biphasic IVM system containing GDF9 and BMP15 at three divergent ratios (1:6, 1:1, 6:1). The results herein show that the 6:1 ratio resulted in higher levels of reagent transfer to the ovine oocyte through gap junctions (GJs) after 24 hours of incubation. Similarly, it was also observed that at the higher ratio, glutathione (GSH) levels were higher at 7.5 hours of incubation. The high GDF9:BMP15 ratio also facilitated the increased consumption of pyruvate by the COC consistently throughout the culture period. Importantly, the high GDF9:BMP15 ratio showed higher expression of the gene that encodes GJ (CX43) at 24 hours relative to the control. It was also demonstrated through decreased apoptotic factor (BAX:BCL2) ratios, that the addition of OSFs, regardless of ratio, protected against cell death. In summary, this study provides novel results that support the notion that a high GDF9:BMP15 ratio improves oocyte quality by delaying the timing of meiotic resumption. This subsequently improves the transport of key metabolites and antioxidants to protect against oxidative stress and cell death and aid in the completion of maturation, ultimately resulting in the increased developmental competency observed in high fecundity poly-ovulatory species.</p>


Reproduction ◽  
2001 ◽  
pp. 737-744 ◽  
Author(s):  
Z Roth ◽  
A Arav ◽  
A Bor ◽  
Y Zeron ◽  
R Braw-Tal ◽  
...  

The fertility of dairy cows decreases during the summer and remains low during the cooler autumn although the animals are no longer under heat stress. The aim of this study was to characterize a delayed effect of summer heat stress on oocyte quality in the autumn and to improve oocyte quality by enhanced removal of follicles damaged during the previous summer. Lactating cows (n = 16) were subjected to heat stress during the summer. In autumn, ovarian follicles (3-7 mm in diameter) were aspirated by an ultrasound-guided procedure during four consecutive oestrous cycles. Follicles were aspirated from control cows on day 4 and from treated cows on days 4, 7, 11 and 15 of each oestrous cycle. All cows received PGF(2alpha) and GnRH injections on days 19 and 21, respectively, and maintained cyclicity, as indicated by plasma progesterone concentrations. On day 4 of each cycle, the oocytes recovered were examined morphologically, matured and activated in vitro, and cultured for 8 days. In cycle 1 (early October) both groups showed low percentages of grade 1 oocytes, cleavage, four- and eight-cell embryos, morulae and parthenogenetic blastocysts. Subsequently, the number of grade 1 oocytes increased earlier (cycle 2) in treated than in control cows (cycle 3; P < 0.05). The cleavage rate in the control group remained relatively low throughout (32-58%), whereas in the treated group it increased from 40% (cycle 1) to 75% (cycles 3 and 4; P < 0.05). The number at each stage of embryo development increased slightly but remained low throughout in the control group, whereas in the treated group significant (P < 0.05) increases of all stages were observed in cycles 3 and 4. The results show a delayed effect of summer heat stress on oocyte quality and embryo development in the autumn. Enhanced removal of the impaired cohort of follicles led to earlier emergence of healthy follicles and high quality oocytes in the autumn.


2018 ◽  
Vol 30 (12) ◽  
pp. 1728 ◽  
Author(s):  
M. Arias-Álvarez ◽  
R. M. García-García ◽  
J. López-Tello ◽  
P. G. Rebollar ◽  
A. Gutiérrez-Adán ◽  
...  

The developmental competence of in vitro maturation (IVM) oocytes can be enhanced by antioxidant agents. The present study investigated, for the first time in the rabbit model, the effect of adding α-tocopherol (0, 100, 200 and 400 µM) during IVM on putative transcripts involved in antioxidant defence (superoxide dismutase 2, mitochondrial (SOD2), glutathione peroxidase 1 (GPX1), catalase (CAT)), cell cycle regulation and apoptosis cascade (apoptosis tumour protein 53 (TP53), caspase 3, apoptosis-related cysteine protease (CASP3)), cell cycle progression (cellular cycle V-Akt murine thymoma viral oncogene homologue 1 (AKT1)), cumulus expansion (gap junction protein, alpha 1, 43 kDa (GJA1) and prostaglandin-endoperoxide synthase 2 (prostaglandin G/H synthase and cyclo-oxygenase) (PTGS2)) and metabolism (glucose-6-phosphate dehydrogenase (G6PD)). Meiotic progression, mitochondrial reallocation, cumulus cell apoptosis and the developmental competence of oocytes after IVF were also assessed. Expression of SOD2, CAT, TP53, CASP3 and GJA1 was downregulated in cumulus–oocyte complexes (COCs) after IVM with 100 μM α-tocopherol compared with the group without the antioxidant. The apoptotic rate and the percentage of a non-migrated mitochondrial pattern were lower in COCs cultured with 100 μM α-tocopherol, consistent with better-quality oocytes. In fact, early embryo development was improved when 100 μM α-tocopherol was included in the IVM medium, but remained low compared with in vivo-matured oocytes. In conclusion, the addition of 100 μM α-tocopherol to the maturation medium is a suitable approach to manage oxidative stress and apoptosis, as well as for increasing the in vitro developmental competence of rabbit oocytes.


Sign in / Sign up

Export Citation Format

Share Document