286 DEVELOPMENTAL CAPACITY OF PREPUBERTAL BOVINE OOCYTES CULTURED WITH CYCLIC AMP MODULATORS

2015 ◽  
Vol 27 (1) ◽  
pp. 232 ◽  
Author(s):  
S. M. Bernal ◽  
J. Heinzmann ◽  
D. Herrmann ◽  
U. Baulain ◽  
K.-G. Hadeler ◽  
...  
Keyword(s):  
Oocyte Retrieval ◽  
Developmental Competence ◽  
Vitro Fertilization ◽  
Lactating Cows ◽  
Developmental Capacity ◽  
Commercial Breeding ◽  
Bovine Oocytes ◽  
One Way Anova ◽  
Dmso Vehicle Control

Prepubertal bovine donors are currently used for commercial breeding to accelerate the genetic gain and decrease the generation interval. Nevertheless, it has been reported that their oocyte developmental competence is lower than in adult females. Addition of cAMP regulators during in vitro maturation (IVM) has been suggested to enhance blastocysts rates (Albuz et al. 2010 Hum. Reprod. 25, 2999–3011). Here, we evaluated the effects of the cAMP modulators forskolin, 3-Isobutyl-1-methylxanthine (IBMX), and cilostamide during extended IVM on the developmental capacity of oocytes from prepubertal and adult bovine females. A total of 1851 oocytes from 24 lactating cows (>2 lactations) and 24 prepubertal donors (6–10 mo old) were collected by transvaginal oocyte recovery (OPU) twice per week and divided into 3 experiment groups: (1) TCM24 (OPU medium: PBS; 24 h of IVM; standard protocol/control); (2) cAMP30 [OPU medium: PBS-IBMX (500 μM); 2 h pre-IVM culture using forskolin (100 μM)-IBMX (500 μM) and 30 h of IVM adding cilostamide (20 μM)], and (3) DMSO30 [cAMP modulators are diluted in DMSO)/vehicle control; OPU medium: PBS-DMSO (46.3 mM); 2 h pre-IVM culture (280 mM DMSO) and 30 h IVM (5.6 mM DMSO)]. Following IVM, oocytes were either submitted to in vitro fertilization and embryo culture or fixed in 1% glutaraldehyde at 9, 20, 24, and 30 h after IVM and stained with Hoechst to evaluate their nuclear status. One-way ANOVA was implemented to evaluate recovered oocytes and meiotic stages. The Glimmix procedure from SAS/STAT was performed to compare blastocyst and cleavage rates. Total number of oocytes and IVM-suitable oocytes per donor per OPU session were similar in adult and prepubertal donors (total number/IVM suitable; prepubertal donors: 6.7/4.2, 6.4/4.0, 6.5/3.8; cows: 6.2/4.7, 6.2/4.4, 6.2/4.5 for TCM24, cAMP30 and DMSO30, respectively). At 9 h, cAMP regulators were able to maintain meiotic arrest in prepubertal and adult donors (GV: 80.0 and 40.9%, respectively) compared to standard IVM (GV: 61.1 and 31.2%) and DMSO30 (GV: 40.0 and 26.6%) protocols (P < 0.05). Using the cAMP30 protocol, the percentage of oocytes that reached MII stage at 20 h was lower in adult (4.5%) and prepubertal donors (5.26%) compared to the DMSO30 (50.0 and 42.8%, respectively) and TCM24 (56.2 and 44.4% respectively) protocols. Metaphase II rates after either 24 or 30 h were similar among treatments (prepubertal donors: 88.2, 70.5, and 84.2%; cows: 71.4, 85.7, and 81.2% for TCM24, cAMP30, and DMSO30, respectively; P > 0.05). Cleavage rates (prepubertal donors: 63.4, 54.9, and 52.1%, cows: 56.1, 57.8, and 51.6% for TCM24, cAMP30, and DMSO30, respectively) and blastocysts/presumptive zygotes rates (prepubertal donors: 26.2, 19.6, and 16.2%; cows: 27.5, 28.1, and 21.5% for TCM24, cAMP30, and DMSO30, respectively) did not show significant differences (P > 0.05). Although cAMP modulators delayed the progression through meiosis in adult and prepubertal oocytes, similar blastocysts rates were obtained. Our results suggest so far that oocyte retrieval and competence in prepubertal donors can be similar to that of the adult donors with and without addition of cAMP modulators.

scholarly journals Protein kinases influence bovine oocyte competence during short-term treatment with recombinant human follicle stimulating hormone

Reproduction ◽  
2005 ◽  
Vol 130 (3) ◽  
pp. 303-310 ◽  
Author(s):  
Atef Ali ◽  
Marc-André Sirard
Keyword(s):  
Protein Kinase ◽  
Follicle Stimulating Hormone ◽  
Term Treatment ◽  
Developmental Competence ◽  
Blastocyst Formation ◽  
Short Term ◽  
Short Term Treatment ◽  
Developmental Capacity ◽  
Bovine Oocytes

The aim of this study was to investigate the effect of short-term treatment (first 2 or 6 h) with recombinant human follicle-stimulating hormone (r-hFSH) during in vitro maturation (IVM) on the developmental competence of bovine oocytes. The roles of protein kinase A (PKA) and protein kinase C (PKC) (possibly involved in FSH response), were investigated using activators (Sp-cAMPS, PMA) or inhibitors (Rp-cAMPS, sphingosine) of these two protein kinases, respectively. The developmental competence of bovine oocytes was measured by the rate of blastocyst formation after in vitro fertilization (IVF). Our results showed that when cumulus–oocyte complexes (COCs) were cultured with r-hFSH for the first 6 h, a highly significant (P < 0.0001) improvement is seen in blastocyst development rate as a proportion of oocytes in culture compared with those matured with r-hFSH for the first 2 or 24 h. A transient exposure (6 h) to the highest dose (100 μM) of forskolin (an activator of adenylate cyclase) increased (P < 0.05) the rate of blastocyst formation. But the PKA inhibitors (Rp-cAMPS) did not affect the stimulatory effects of r-hFSH on the blastocyst yield. However, stimulation of PKC by low doses of PMA (0.1–0.5 μM) during short-term treatment, enhanced (P < 0.0001) the developmental capacity of oocytes, while sphingosine (a specific inhibitor of PKC) inhibited (P < 0.05) the stimulatory effects of r-hFSH on the rate of blastocyst formation. Our results indicate that although the developmental capacity of bovine oocytes in vitro can be modulated by both the PKA, and the PKC pathways, the activation of PKC during short-term treatment can mimic the effect of r-hFSH on the cytoplasmic maturation in bovine oocytes in vitro.

272 DEVELOPMENTAL COMPETENCE OF OOCYTES OBTAINED FROM BOS TAURUS AND BOS INDICUS DAIRY COWS RAISED IN A TROPICAL CLIMATE

2006 ◽  
Vol 18 (2) ◽  
pp. 243
Author(s):  
L. S. A. Camargo ◽  
J. H. M. Viana ◽  
W. F. Sa ◽  
A. M. Ferreira ◽  
A. A. Ramos ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Calf Serum ◽  
Developmental Competence ◽  
Tropical Region ◽  
Humid Atmosphere ◽  
Vitro Fertilization ◽  
Developmental Capacity

The effects of heat stress on Bos taurus reproductive performance in tropical and subtropical regions are well known, and have been associated with lower oocyte developmental capacity. The aim of this study was to evaluate the developmental competence of oocytes from Bos taurus (Holstein) and Bos indicus (Gyr) dairy cows raised in a Brazilian tropical region, located at 21°35′S latitude, 43°51′W longitude, and 435 meters altitude. Cumulus–oocyte complexes (COCs) were recovered by oocyte pickup (OPU) from mature non-lactating Holstein (n = 9) and Gyr (n = 13) donor cows between the end of spring and the beginning of autumn, with at least two OPU sessions/cow. COCs were in vitro-maturated in TCM-199 (GIBCO, Grand Island, NY, USA) with 10% inactivated estrus cow serum for 24 h under 5% CO2 at 38.5°C in air. Bos taurus and Bos indicus semen with similar cleavage rates, previously evaluated by in vitro fertilization with oocytes obtained from slaughterhouse ovaries, were used to reduce bull effect. Holstein and Gyr spermatozoa were obtained through swim-up method and co-incubated with Holstein (n = 390) and Gyr (n = 505) oocytes, respectively, in Fert-TALP medium (Parrish et al. 1988 Biol. Reprod. 38, 1171–1180) supplemented with 10 μg/mL heparin (Sigma-Aldrich, Sao Paulo, Brazil) and 6 mg/mL fatty acid-free bovine albumin (Sigma) for 18 h in 5% CO2 at 38.5°C in air. Presumptive zygotes were co-cultured with their own cumulus cells in CR2aa medium (Wilkinson et al. 1996 Theriogenology 45, 41–49) supplemented with 10% fetal calf serum in humid atmosphere of 5% CO2 at 38.5°C in air. On Day 7 to 8 of co-culture, Gyr and Holstein blastocysts were assessed and those classified as grade 1 (IETS Manual) were transferred to synchronized Bos indicus × Bos taurus crossbred recipients managed under the same nutritional and environmental conditions. Pregnancy diagnosis was performed between 35 and 50 days after estrus. Cleavage, blastocyst, and pregnancy rates were analyzed by chi-square test. Cleavage and blastocyst rates were greater (P < 0.05) in Gyr than in Holstein (66.7% vs. 53.1% for cleavage and 19.6% vs. 10.8% for blastocyst, respectively), but the pregnancy rate was similar (P > 0.05; 44.5% vs. 60% for Gyr and Holstein, respectively). These results show that Gyr oocytes obtained in a tropical region have greater developmental capacity than Holstein oocytes, suggesting an interaction between genotype and environment that influences the success of an in vitro embryo production program; nevertheless, the blastocyst viability after transferring to recipients is similar for both breeds.

169 INFLUENCE OF TIME BEFORE BOS INDICUS OOCYTE ASPIRATION ON EMBRYO DEVELOPMENTAL COMPETENCE, EXPRESSION OF MATER AND OCT-4, AND FOLLICULAR STEROID CONCENTRATION

2014 ◽  
Vol 26 (1) ◽  
pp. 198
Author(s):  
R. Urrego ◽  
E. Herrera ◽  
N. Chavarría ◽  
O. Camargo ◽  
N. Rodriguez-Osorio
Keyword(s):  
Follicular Fluid ◽  
Mrna Abundance ◽  
Developmental Competence ◽  
Progesterone Concentration ◽  
Vitro Fertilization ◽  
Oocyte Competence ◽  
Group I ◽  
Group Ii ◽  
Bovine Oocytes

The ability of bovine embryos to develop to the blastocyst stage, to implant, and to generate healthy offspring, depends greatly on the oocyte contribution. Oocyte competence is attributed to its close communication with the follicular environment and to its capacity to synthesise and store great amounts of mRNA. Higher developmental competence of bovine oocytes has been associated with the expression of certain genes and with the steroid concentration in the follicular fluid. Hence, the aim of this study was to establish the influence of OCT-4 and MATER mRNA abundance in the oocyte and the influence of progesterone and oestradiol follicular fluid concentration on the competence of bovine oocytes retrieved 30 min or 4 h after slaughter. Cumulus–oocyte complexes (COC) were left in postmortem ovaries for 30 min (Group I) or 4 h (Group II) at 30°C before aspiration. Progesterone and oestradiol concentrations were measured in the follicular fluid in both groups by immunoassay using an Immulite 2000 analyzer. Immature oocytes were evaluated for MATER and OCT-4 mRNA abundance by real-time PCR (total RNA isolated from pools of 100 oocytes per repeat) or were subjected to in vitro maturation (IVM), in vitro fertilization (IVF), and in vitro culture (IVC). For in vitro embryo production, 455 (Group I) and 470 (Group II) COC were used in three repeats. Progesterone concentration was lower (P ≤ 0.05) in Group II than in Group I. Conversely, oestradiol concentration did not vary between groups. Similarly, Group II oocytes exhibited the highest (P < 0.05) MATER and OCT-4 abundance. For embryo development, there were no significant differences between cleavage rates (72 h post-insemination) between both groups. However, blastocyst (168 h post-insemination) and hatching (216 h post-insemination) rates in Group II were greater (P < 0.05) with 21.3 compared with 30.7% and 54.2 compared with 75.3%, respectively. These results indicate that progesterone concentration in the follicle and the abundance of MATER and OCT-4 transcripts could be good predictors of embryo developmental competence and that retrieving COC 4 h after slaughter could increase blastocyst and hatching rates. This work was supported by COLCIENCIAS COD 122852128473 Colombia.

scholarly journals Histone deacetylase inhibitor during in vitro maturation decreases developmental capacity of bovine oocytes

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247518
Author(s):  
Thais Preisser Pontelo ◽  
Mauricio Machaim Franco ◽  
Taynan Stonoga Kawamoto ◽  
Felippe Manoel Costa Caixeta ◽  
Ligiane de Oliveira Leme ◽  
...  
Keyword(s):  
Embryo Development ◽  
In Vitro Maturation ◽  
Embryo Quality ◽  
Cumulus Cells ◽  
Developmental Competence ◽  
Nuclear Maturation ◽  
Deacetylase Inhibitor ◽  
Developmental Capacity ◽  
Bovine Oocytes

This study aimed to evaluate the effect of scriptaid during pre-maturation (PIVM) and/or maturation (IVM) on developmental competence of bovine oocytes. Cumulus-oocyte complexes (COCs) were submitted to PIVM for 6 h in the presence or absence of scriptaid. COCs were distributed into five groups: T1-IVM for 22 h, T2-PIVM for 6 h and IVM for 22 h, T3-PIVM with scriptaid for 6 h and IVM for 22 h, T4-PIVM for 6 h and IVM with scriptaid for 22 h, and T5-PIVM with scriptaid for 6 h and IVM with scriptaid for 22 h. Nuclear maturation, gene expression, cumulus cells (CCs) expansion, and embryo development and quality were evaluated. At the end of maturation, all groups presented the majority of oocytes in MII (P>0.05). Only HAT1 gene was differentially expressed (P<0.01) in oocytes with different treatments. Regarding embryo development at D7, T4 (23%) and T5 (18%) had lower blastocyst rate (P<0.05) than the other treatments (T1 = 35%, T2 = 37% and T3 = 32%). No effect was observed when scriptaid in PIVM was used in less competent oocytes (P>0.05). In conclusion, presence of scriptaid in PIVM and/or IVM did not improve developmental competence or embryo quality.

184 EFFECT OF HISTONE DEACETYLASE INHIBITOR ON DEVELOPMENT OF EMBRYOS DERIVED FROM HEAT-SHOCKED BOVINE OOCYTES

2017 ◽  
Vol 29 (1) ◽  
pp. 200
Author(s):  
V. R. A. Mendes ◽  
R. B. S. Dias ◽  
J. F. S. Souza ◽  
E. D. Souza ◽  
C. C. R. Quintao ◽  
...  
Keyword(s):  
Heat Shock ◽  
Histone Deacetylase ◽  
Histone Deacetylase Inhibitor ◽  
Negative Impact ◽  
Developmental Competence ◽  
Cleavage Rate ◽  
Vitro Fertilization ◽  
Deacetylase Inhibitor ◽  
Bovine Oocytes

Heat shock affects the oocyte developmental competence and embryonic gene expression. We found that the chromatin organisation of embryos derived from heat-shocked oocytes can also be affected (Camargo et al. 2015 Reprod. Fert. Dev. 27, 132). This study aimed to evaluate whether Scriptaid, a histone deacetylase inhibitor able to modulate the chromatin structure, could influence the development of embryos derived from heat-shocked oocytes. Bovine oocytes were in vitro-matured under conventional temperature (38.5°C) for 24 h (non-heat-shock; NHS group) or under 41.5°C for 12 h followed by 38.5°C for 12 h (heat-shock; HS group). In vitro fertilization was performed under 38.5°C with 5% CO2 in air for 20 h. Right after the end of fertilization the presumptive zygotes from the NHS or HS groups were denuded and randomly exposed to 500 nM Scriptaid for 0, 12, or 24 h, comprising 6 treatments as followa: NHS-0 h (NHS without Scriptaid, n = 185); NHS-12 h (NHS plus Scriptaid for 12 h, n = 178); NHS-24 h (NHS plus Scriptaid for 24 h, n = 177); HS-0 h (HS without Scriptaid, n = 187); HS-12 h (HS plus Scriptaid for 12 h, n = 180); and HS-24 h (HS plus Scriptaid for 24 h, n = 183). After Scriptaid exposure, zygotes were cultured in CR2aa plus 2.5% FCS at 38.5°C with 5% CO2, 5% O2, and 90% N2. Cleavage rate was calculated on Day 2 (44 h post-fertilization) and blastocyst rates on Day 7 and 8 post-fertilization. Six replicates were carried out and data was analysed by logistic regression (Proc Logistic, SAS 9.2, SAS Institute Inc., Cary, NC). Significant data were interpreted as odd ratios considering the 95% confidence interval. Values are shown as mean ± standard error of the mean. There was no difference (P > 0.05) among NHS treatments (NHS-0 h, NHS-12 h, and NHS-24 h) as well as among HS treatments (HS-0 h, HS-12 h, and HS-24 h) for cleavage and blastocyst rates at Day 7. At Day 8, however, the blastocyst rate in the NHS group decreased (P < 0.05) as the time of zygote exposure to Scriptaid increased to 24 h (33.9 ± 2.8 and 24.2 ± 1.6% for NHS-0 h and NHS-24 h, respectively), whereas no difference (P > 0.05) was found in the HS group (20.7 ± 1.5, 21.2 ± 1.6, and 20.5 ± 2.4% for HS-0 h, HS-12 h, and HS-24 h, respectively). Comparison between NHS and HS treatments showed that cleavage and blastocyst rates at Day 7 and 8 of NHS-0 h (88.7 ± 2.8, 30.1 ± 1.5, and 33.9 ± 2.8%, respectively) were superior (P < 0.05) to HS-0 h (79.3 ± 3.2, 16.9 ± 1.0, and 20.7 ± 1.5%, respectively). Differences (P < 0.05) between NHS-12 h and HS-12 h on blastocyst rates at Day 7 (32.8 ± 3.8 v. 20.6 ± 1.7%, respectively) and at Day 8 (31.7 ± 2.7 v. 21.2 ± 1.6%, respectively) were also found. However, no difference (P > 0.05) between NHS-24 h and HS-24 h was found. We showed that Scriptaid for 24 h right after IVF has a negative impact on further development of zygotes derived from oocytes matured under conventional temperature (NHS group), in contrast to zygotes derived from oocytes matured under high temperature (HS group). We concluded that the effect of Scriptaid on embryo development is influenced by the temperature during oocyte maturation. Supported by FAPEMIG, CAPES, and CNPq.

scholarly journals The developmental competence of bovine oocytes matured in vitro using thymosin beta 4

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Joanna Romanek ◽  
Joanna Jurkiewicz ◽  
Agnieszka Wierzchoś-Hilczer ◽  
Jolanta Opiela
Keyword(s):  
Developmental Competence ◽  
Vitro Fertilization ◽  
Thymosin Beta 4 ◽  
Maturation Medium ◽  
Significant Difference ◽  
The Mean ◽  
Bovine Oocytes ◽  
Positive Effect

AbstractThe aim of this study was to examine the effect of thymosin beta 4 (Tβ4) during in vitro maturation (IVM) of oocytes and subsequent embryonic development after in vitro fertilization as well as to assess the quality of obtained blastocysts. COCs were matured in vitro in 4 different media: 1. control medium; 2. control media supplemented with 50 ng/mL Tβ4; 3. control media supplemented with 0.5 mg/mL Tβ4; and 4. control media supplemented with 1 mg/mL Tβ4. The quality of the developed blastocysts was analysed by the TUNEL method. The number of cleaved eggs was significantly higher (P < 0.05) when gametes were matured in the presence of 50 ng/mL Tβ4 than it was using the other types of media. Additionally, the largest number of blastocysts was observed when 0.5 mg Tβ4 was added to the medium (P < 0.05). No significant difference was noted in the mean number of apoptotic nuclei per blastocyst or in the mean number of nuclei per blastocyst in any of the analysed groups. In conclusion, Tβ4 supplementation (50 ng/mL) in maturation medium increased the number of cleaved oocytes, and the number of blastocysts obtained increased when 0.5 mg/mL Tβ4 was used. This positive effect was not observed when higher a higher concentration of Tβ4 (1 mg/mL) was used.

scholarly journals The Presence of Immature GV− Stage Oocytes during IVF/ICSI Is a Marker of Poor Oocyte Quality: A Pilot Study

2020 ◽  
Vol 8 (1) ◽  
pp. 4
Author(s):  
Pia Astbury ◽  
Goutham N. Subramanian ◽  
Jessica Greaney ◽  
Chris Roling ◽  
Jacqui Irving ◽  
...  
Keyword(s):  
Dna Damage ◽  
Pilot Study ◽  
Germinal Vesicle ◽  
Oocyte Retrieval ◽  
Oocyte Quality ◽  
Outcome Data ◽  
Developmental Competence ◽  
Success Rates ◽  
Vitro Fertilization

Here we investigate whether the presence of germinal vesicle-stage oocytes (GV− oocytes) reflects poor oocyte developmental competence (or quality). This was a prospective, non-randomised, cohort pilot-study involving 60 patients undergoing in vitro fertilization/ intracytoplasmic sperm injection for whom complete pregnancy outcome data were available. Patients in whom GV− oocytes were retrieved (GV+) at transvaginal oocyte retrieval (TVOR) were compared with those from whom no GVs were retrieved (GV−). We found that GV+ (n = 29) and GV− (n = 31) patients were similarly aged (35.4 vs. 36.4 years; p = 0.446). GV+ patients had a mean of 2.41 ± 2.03 GVs and comparable yields of MII oocytes to GV− patients (11 ± 6.88 vs. 8.26 ± 4.84; p = 0.077). Compared with GV− patients, GV+ patients had markedly lower implantation rates (11.8% vs. 30.2%; p = 0.022) as well as oocyte utilisation rates for clinical pregnancy (2.3% vs. 6.8%; p = 0.018) and live-birth (1.9% vs. 5.7%; p = 0.029). DNA damage levels measured using γH2AX immunostaining were not different in oocytes from women <36 years versus those ≥36 years (p = 0.606). Thus, patients who have GV− stage oocytes at TVOR exhibit poor oocyte quality reflected in reduced per-oocyte pregnancy success rates and uniformly high levels of oocyte DNA damage.

scholarly journals Meiotic inhibition of bovine oocytes in medium supplemented with a serum replacer and hormones: effects on meiosis progression and developmental capacity

Zygote ◽  
2010 ◽  
Vol 19 (2) ◽  
pp. 107-116 ◽  
Author(s):  
Letícia Siqueira Sá Barretto ◽  
Viviane Sgobbi Dias Caiado Castro ◽  
Joaquim Mansano Garcia ◽  
Gisele Zoccal Mingoti
Keyword(s):  
Embryonic Development ◽  
Embryo Development ◽  
Developmental Competence ◽  
Meiotic Arrest ◽  
Nuclear Maturation ◽  
Developmental Capacity ◽  
Bovine Oocytes ◽  
Kinetics Of ◽  
Hatching Rates

SummaryAiming to improve the developmental competence of bovine oocytes during meiotic block, this study evaluated the effects of a serum replacer (Knockout SR®) and hormones (gonadotropins and estradiol) supplementation of prematuration medium (TCM119 with 0.5 mM IBMX [IBMX group] or 25 μM roscovitine [ROSC group]) on the kinetics of oocyte nuclear maturation and embryo development. Most IBMX and ROSC oocytes prematured for 8 h culture remained in the GV stage (70.3% and 73.1%, respectively; p > 0.05) similar to Control 8 h (63.5%) and to control immature oocytes (Control 0 h, 92.5%). After prematuration for 16 h, no oocytes remained in the GV stage at similar rates to those recently aspirated (p < 0.05); GV rates in ROSC (32.4%) were higher (p < 0.05) than in the Control 16 h group (8.6%), but similar (p > 0.05) to IBMX (9.7%). After in vitro maturation (IMV) for 24 h, metaphase II (MII) rates for oocytes prematured during 8 h were similar (p > 0.05) between control and treatments (65.0–71.7%). Similarly, MII rates oocytes prematured during 16 h were similar (p > 0.05) between all groups (45.9–60.4%). Cleavage rates (67.8–78.2%), embryonic development in day-7 (25.0–35.6%) and hatching rates in day-8 (2.5–11.3%) oocytes blocked during 8 h were similar for all groups (p > 0.05). Results indicate that addition of Knockout SR® and hormones to meiotic block culture with IBMX and roscovitine negatively affected meiotic arrest, but did not impair oocyte nuclear maturation and acquisition of developmental competence.

scholarly journals Effect of Ethanol on Parthenogenetic Activation and α-Tocopherol Supplementation during In Vitro Maturation on Developmental Competence of Summer-Collected Bovine Oocytes

2021 ◽  
Vol 43 (3) ◽  
pp. 2253-2265
Author(s):  
Francisco Báez ◽  
Belén Gómez ◽  
Victoria de Brun ◽  
Nélida Rodríguez-Osorio ◽  
Carolina Viñoles
Keyword(s):  
In Vitro Maturation ◽  
Apoptotic Index ◽  
Developmental Competence ◽  
Vitro Fertilization ◽  
Parthenogenetic Activation ◽  
Oocyte Competence ◽  
Maturation Medium ◽  
Bovine Oocytes

The use of α-tocopherol during in vitro maturation (IVM) is an alternative to minimize the adverse effects of heat stress on oocyte competence. However, α-tocopherol is diluted in ethanol, which can induce oocyte parthenogenetic activation (PA). This study aimed to evaluate the role of ethanol concentration on PA and the effect of α-tocopherol supplementation during IVM on the developmental competence and the expression of key genes in blastocysts derived from summer-collected oocytes. All in vitro embryo production was conducted at 5% O2, 5% CO2 at 38.5 °C. Experiment 1: oocytes were cultured with or without 0.05% ethanol. As positive PA control matured oocytes were subjected to 3% or 7% ethanol for 7 min. Oocytes from all groups were placed in fertilization medium (22 h) and culture medium (9 days). Ethanol at 0.05% during IVM did not induce oocyte PA, however, 3% and 7% ethanol were effective parthenogenetic inductors. Experiment 2: oocytes were cultured in maturation medium supplemented with 0, 50, 100 and 200 μM α-tocopherol, diluted in 0.05% ethanol. After in vitro fertilization and embryo culture, we assessed blastocyst apoptotic index and the transcription of a panel of genes. The results showed that supplementation with 100 μM α-tocopherol reduced apoptotic index and increased the expression of SOD2. In conclusion, 100 μM α-tocopherol, diluted in 0.05% ethanol, can be used during IVM to embryonic quality.

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