scholarly journals 274 NUCLEAR MATURATION KINETICS AND IN VITRO EMBRYO DEVELOPMENT OF BOVINE OOCYTES TREATED WITH BUTYROLACTONE I COMBINED OR NOT WITH ROSCOVITINE

2005 ◽  
Vol 17 (2) ◽  
pp. 287
Author(s):  
P.R. Adona ◽  
M.D. Quetglas ◽  
P.R.L. Pires ◽  
C.L.V. Leal
Keyword(s):  
Embryo Development ◽  
Kinase Inhibitors ◽  
Point Group ◽  
Germinal Vesicle ◽  
Oocyte Competence ◽  
Cell Numbers ◽  
Nuclear Maturation ◽  
Developmental Rates ◽  
Bovine Oocytes

Cyclin-dependent kinase inhibitors (CDKIs) have been used for prematuration culture the aim at improving oocyte competence. However, CDKIs seem to accelerate nuclear maturation (Hashimoto et al., 2002 Biol. Reprod. 66, 1696–1701). The aim of the present work was to compare the effect of butyrolactone I (BLI) alone or combined with roscovitine (ROS) at low dose (Ponderato et al, 2001 Mol. Reprod. Dev. 60, 579–585) on nuclear maturation kinetics and embryo development. To assess maturation kinetics (Experiment 1), oocytes were cultured in 100 μM BLI (B) or 6.25 μM BLI + 12.5 μM ROS (BR) in TCM-199 for 24 h. After prematuration, oocytes were submitted to in vitro maturation (IVM in TCM-199 + 0.5 μg mL−1 FSH, 50 μg mL−1 LH, 10% FCS) for another 24 h. Oocytes were fixed every 3 h (40–50 oocytes/time point/group in 4 replicates) to assess nuclear status. In Experiment 2, oocytes were submitted to prematuration, but the inhibitors were diluted in TCM-199 or DMEM. IVM lasted 21 h in DMEM (same hormone supplementation as in TCM-199 + 5% FCS and 50 ng mL−1 EGF). After IVM, all groups (140–150 oocytes/group in 7 replicates) were in vitro fertilized. Oocytes and sperm (2 × 106 sperm cells mL−1) were co-cultured for 18 h. Embryos were cultured in CR2aa in co-culture with granulosa cells for 8 days. All cultures were in microdrops under oil, at 38.5°C under 5% CO2 in air. In both experiments, control oocytes (C) were submitted only to IVM. Data were analyzed by GLM and GENMOD procedures (SAS program; SAS Institute, Inc., Cary, NC, USA), for Experiments 1 (4 replicates) and 2 (7 replicates), respectively. Cell numbers were analyzed by ANOVA and Tukey test. In Experiment 1, at 0 h, C and B oocytes were all (100%) at germinal vesicle stage (GV). BR had less GV oocytes (89 ± 1%, P < 0.05), indicating that BR was less effective in maintaining meiotic block for 24 h. After 3 h IVM, B and BR had less oocytes in GV (85 ± 2 and 80 ± 1%, respectively; P > 0.05) than C (100%, P < 0.05), suggesting an acceleration of oocyte maturation. At 12 h, however, most oocytes were at intermediate stages (metaphase I to telophase I) in all groups (78 ± 1–83 ± 2%, P > 0.05). After 21 and 24 h, all groups had similar metaphase II (MII) rates (77 ± 1–89 ± 1 for 21 h and 85 ± 2–96 ± 8 for 24 h P > 0.05). These results suggest that after 12 h, meiosis acceleration was less evident and oocytes proceeded nuclear maturation at similar rates. In Experiment 2, cleavage (79 ± 3–84 ± 3%, P > 0.05) and Day 7 blastocyst rates (26 ± 4–37 ± 4%, P > 0.05) were similar for all groups. After 8 days in culture, all groups presented similar blastocyst rates (35 ± 4–40 ± 4%, P > 0.05), except for the group prematured with BR in DMEM, which presented lower blastocyst rates (32.3 ± 4%) only when compared with C (40 ± 4%, P < 0.05). Hatching rates were similar (10 ± 3–16 ± %3, P > 0.05) as were total cell numbers (141 ± 5–170 ± 10). In conclusion: (a) BR is less effective in maintaining meiosis block; (b) B and BR accelerate the first half of meiosis progression in about 3 h; and (c) BR used in DMEM during prematuration may negatively affect developmental rates. Financial support was provided by Fapesp, Brazil.

Meiotic inhibition with different cyclin-dependent kinase inhibitors in bovine oocytes and its effects on maturation and embryo development

Zygote ◽  
2004 ◽  
Vol 12 (3) ◽  
pp. 197-204 ◽  
Author(s):  
Paulo Roberto Adona ◽  
Cláudia Lima Verde Leal
Keyword(s):  
Embryo Development ◽  
Kinase Inhibitors ◽  
Germinal Vesicle ◽  
Oocyte Activation ◽  
Cyclin Dependent Kinase ◽  
Nuclear Maturation ◽  
Inhibition Control ◽  
Inhibition Experiment ◽  
Bovine Oocytes

Cyclin-dependent kinase inhibitors (CDKIs) such as butyrolactone I (BL-I) and roscovitine (ROS) maintain bovine oocytes blocked at the germinal vesicle (GV) stage. Bohemine (BOH), another CDKI, has been used for oocyte activation. The objective of this study was to determine whether BOH blocks meiosis and to compare its efficiency with other CDKIs (ROS and BL-I). Oocytes were cultured for 24 h in 0, 50, 100 and 150 μM BOH to determine the best concentration for blocking meiosis (experiment 1). GV rates were 3.3%, 64.5%, 83.3% and 88.9% (0, 50, 100 and 150 μM, respectively). Experiment 2 compared meiotic inhibition efficiency of BOH (100 μM), ROS (25 μM) and BL-I (100 μM). BL-I presented the highest GV rates (97.5%). BOH and ROS were similar to each other (85.4% and 79.9%, respectively). To assess the reversibility of meiotic inhibition (experiment 3), oocytes underwent in vitro maturation (IVM) for 18 h after the 24 h inhibition. Control oocytes were submitted to IVM for 18 h (C18) or 24 h (C24). Maturation rates were either similar to (ROS and BL-I: 96.0% and 93.6%, respectively) or superior to (BOH, 96.9%) C24 (91.0%). All groups were superior to C18 (82.5%). In experiment 4, oocytes were treated as in experiment 3 and then in vitro fertilized and cultured for 8 days. Blastocyst rates for BL-I (32.3%) were similar to C24 (35.0%), while those for BOH (20.2%) and ROS (24.2%) were inferior. All groups were inferior to C18 (43.4%). The results show that: (a) BOH inhibits meiosis resumption; (b) BL-I is the most effective of the CDKIs tested for blocking meiosis; (c) culture of oocytes with meiosis inhibitors is fully reversible in terms of nuclear maturation but they may either decrease (BOH and ROS) or maintain (BL-I) embryo development rates.

scholarly journals Maintenance of meiotic arrest in bovine oocytes using the S-enantiomer of roscovitine: effects on maturation, fertilization and subsequent embryo development in vitro

Reproduction ◽  
2005 ◽  
Vol 129 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Pilar Coy ◽  
Raquel Romar ◽  
Rebecca R Payton ◽  
Lisa McCann ◽  
Arnold M Saxton ◽  
...  
Keyword(s):  
Embryo Development ◽  
Lens Culinaris ◽  
Germinal Vesicle ◽  
Fluorescein Isothiocyanate ◽  
Cortical Granule ◽  
Nuclear Maturation ◽  
Development In Vitro ◽  
Hoechst Staining ◽  
Bovine Oocytes

The overall objective was to evaluate the effectiveness of the S-enantiomer of roscovitine (inhibitor of p34cdc2/cyclin B kinase) to maintain bovine cumulus–oocyte complexes at the germinal vesicle (GV) stage for extended times after removal from antral follicles without compromising subsequent maturation, fertilization and embryo development. Oocytes were cultured in 0, 12.5, 25 or 50 μmol/l S-roscovitine for 24 h. Hoechst staining showed that 50 μmol/l S-roscovitine maintained >90% of oocytes at the GV stage and inhibited gonadotropin-induced cumulus expansion. Fewer oocytes underwent nuclear maturation after in vitro maturation (Hoechst staining) when cultured in 50 μmol/l S-roscovitine for 66 versus 21 or 42 h. Zona pellucida (ZP) hardening (pronase resistance), cortical granule types (lens culinaris agglutinin–fluorescein isothiocyanate), nuclear maturation and fertilization with frozen-thawed spermatozoa (Hoechst staining) were assessed after culture of oocytes in 50 μmol/l S-roscovitine for 0, 24 or 48 h. Neither ZP hardening, nor nuclear maturation nor fertilization were altered by roscovitine culture for 48 h. A higher proportion of oocytes had a type III cortical granule pattern (premature translocation to the oolemma) after roscovitine culture for 48 h. However, embryo development was not compromised as cleavage, development to 8–16 cell and blastocyst stages were at least comparable in control and roscovitine-treated oocytes. In conclusion, the studies have shown that S-roscovitine reversibly maintained bovine oocytes at the GV stage for 48 h. However, maintenance of oocytes in static culture for 48 h was not sufficient to improve development above non-treated controls.

45 THE EFFECT OF MEIOTIC STAGE OF BOVINE OOCYTES ON THE SURVIVAL OF VITRIFIED CUMULUS–OOCYTE COMPLEXES

2012 ◽  
Vol 24 (1) ◽  
pp. 135 ◽  
Author(s):  
J. R. Prentice ◽  
J. Singh ◽  
M. Anzar
Keyword(s):  
Embryo Development ◽  
Culture System ◽  
In Vitro Maturation ◽  
Germinal Vesicle ◽  
Early Embryo ◽  
Time Intervals ◽  
Early Embryo Development ◽  
In Vitro Culture System ◽  
Bovine Oocytes

Vitrification is a rapid freezing method in which cells/tissues are frozen in a glass state without ice crystal formation. However, vitrification of bovine oocytes is challenging due to their complex structure and sensitivity to chilling. Oocytes at the germinal vesicle (GV) stage of maturation are thought to be less prone to chromosomal and microtubular damage during cryopreservation because no spindle is present and genetic material is contained within the nucleus. However, immature oocytes are thought to be more sensitive to osmotic stress and have lower cell membrane stability than mature, metaphase II (MII) stage oocytes. The present studies aimed to validate the in vitro culture system used in our laboratory and to evaluate the effect of vitrification of bovine cumulus-oocyte complexes (COC) at different meiotic stages on their in vitro maturation (IVM), cleavage and early embryo development. Analyses were conducted on each dataset with PROC GLIMMIX in SAS using binary distribution (for yes/no response variable) and considering replicate as a random factor. In Experiment 1, meiotic progression of oocytes was evaluated at different time intervals during IVM. The following COC stages were predominantly found at different IVM time intervals: GV (89%) at 0 h, GV (47%) and germinal vesicle breakdown (GVBD; 44%) at 6 h, metaphase I (MI; 90%) at 12 h and MII (84%) at 22 h (n > 62 oocytes at each time group). In Experiment 2, bovine COC at 0, 6, 12 and 22 h of IVM were exposed to vitrification solution (15% dimethyl sulfoxide + 15% ethylene glycol + 0.5 M sucrose + 20% CS in TCM-199), loaded onto a cryotop device and vitrified by plunging in liquid nitrogen. Following warming (1 min in 0.5 M sucrose + 20% CS in TCM-199), COC completed 22 h of IVM and the nuclear stage was evaluated with lamin A/C-4′6-diamidino-2-phenylindole staining. Upon completion of 22 h of IVM, 23, 23, 35 and 89% of oocytes from 0-, 6-, 12- and 22-h groups, respectively were detected at MII (P < 0.0001). In Experiment 3, cleavage and embryo development of oocytes vitrified at 0, 12 and 22 h of IVM were evaluated. The cleavage rate did not differ among vitrification groups (i.e. 14% at 0 h, 17% at 12 h and 14% at 22 h; P = 0.825). Cleavage and blastocyst rates were higher (P < 0.0001) in the non-vitrified (control) group than in vitrified groups (i.e. 73 vs 15% and 22 vs 0.3%, respectively). In conclusion, the maturation kinetics validated our in vitro culture system and vitrification adversely affected the ability of bovine oocytes to undergo in vitro maturation to the MII stage, in vitro fertilization and early embryo development. Vitrification of oocytes at GV, MI and MII stages of nuclear maturation did not differ in their subsequent survivability. This study was supported by the Canadian Animal Genetic Resources Program, Agriculture and Agri-Food Canada.

329 SUPPRESSION OF BOVINE OOCYTE IVM BY SERUM AND FSH DEPRIVATION OR BY α-AMANITIN: EFFECT ON FERTILIZATION AND EMBRYO DEVELOPMENT

2006 ◽  
Vol 18 (2) ◽  
pp. 272
Author(s):  
K. Kananen-Anttila ◽  
M. Eronen ◽  
J. Matilainen ◽  
M. Kallio ◽  
J. Peippo ◽  
...  
Keyword(s):  
Embryo Development ◽  
Cumulus Cell ◽  
Developmental Competence ◽  
Control Group ◽  
Blastocyst Development ◽  
Nuclear Maturation ◽  
Embryo Cleavage ◽  
Bovine Oocytes ◽  
Sperm Aster

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

169 Nuclear Maturation Kinetics and In Vitro Fecundation of Immature Bovine Oocytes Injected into Preovulatory Follicles

2018 ◽  
Vol 30 (1) ◽  
pp. 224
Author(s):  
L. M. S. Simoes ◽  
A. P. C. Santos ◽  
E. A. Lima ◽  
R. E. Orlandi ◽  
M. P. Bottino ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Germinal Vesicle ◽  
Causative Factor ◽  
Nuclear Maturation ◽  
Preovulatory Follicles ◽  
Fertilization Capacity ◽  
Bovine Oocytes ◽  
Metaphase I

The objective was to evaluate in vitro nuclear maturation and fecundation kinetics of oocytes injected into preovulatory follicles of synchronized cows using the intra-follicular oocyte injection (IFOI) technique. In experiment 1, 438 immature abattoir-bovine cumulus–oocyte complexes (COC) of grades I, II, and III were randomly allocated to 1 of 3 groups: Matvitro (n = 111), COC matured in vitro for 22 h; Matvivo20 (n = 172) and Matvivo30 (n = 155), 30 oocytes were injected into each preovulatory follicle of pre-synchronized recipients. In Matvivo20, oocytes were matured for 19.8 ± 0.1 h and in Matvivo30, for 28.3 ± 0.1 h. All cows received 12.5 mg of LH (Lutropin, Bioniche, Canada) at IFOI (Matvivo20) or 10 h after IFOI (Matvivo30). Oocytes from Matvivo20 and Matvivo30 were aspirated 20 h after LH injection for assessment of oocyte maturation and recovery rates. Oocytes were evaluated according to maturation kinetics as germinal vesicle, metaphase I, anaphase I, telophase I, metaphase II, parthenogenetically activated, and degenerated (chromosomal aberrations, presence of diffuse or indefinite chromatin). In experiment 2, immature abattoir-bovine COC (n = 202) of grades I, II, and III were randomly distributed into 2 groups: Matvitro (n = 103), COC were matured and fertilized in vitro; Matvivo (n = 99), same as Matvivo20 protocol, and COC fertilized in vitro. Presumptive zygotes were evaluated as fertilized, unfertilized, or polyspermic. Statistical analyses were performed by the GLIMMIX procedure of SAS (SAS Institute Inc., Cary, NC, USA). Recovery rate was lower (P < 0.001) in Matvivo20 (52.9%, 91/172) compared with Matvivo30 (72.9%, 113/155). Germinal vesicle (P = 0.94), metaphase I (P = 0.98), anaphase I (P = 0.99), and telophase I (P = 0.20) rates were similar. However, there were differences in metaphase II [Matvitro: 81.0% (90/111)a, Matvivo20: 74.5% (35/47)a, and Matvivo30: 41.6% (32/77)b; P = 0.001], degenerate [Matvitro: 5.4% (6/111)c, Matvivo20: 21.3% (10/47)b and Matvivo30: 48.1% (37/77); P = 0.001] and parthenogenetically activated [Matvitro: 0.0% (0/111)b, Matvivo20: 0.0% (0/47)b and Matvivo30: 9.1% (7/77)a; P = 0.001]. Polyspermic (P = 0.18) and abnormal (P = 0.98) rates were similar. However, there was a higher rate (P = 0.05) of fertilized oocytes in Matvivo (60.6%, 60/99) than in Matvitro (46.6%, 48/103). In conclusion, oocyte maturation in vivo after IFOI for 20 h does not alter maturation kinetics and increases in vitro oocyte fertilization capacity. However, the 10-h increase in intra-follicular oocyte permanence decreased the proportion of viable oocytes. Thus, the oocyte maturation phase is not the limiting causative factor for the low IFOI-embryo production rates.

Insulin influences developmental competence of bovine oocytes cultured in α-MEM plus follicle-simulating hormone

Zygote ◽  
2014 ◽  
Vol 23 (4) ◽  
pp. 563-572 ◽  
Author(s):  
Gustavo Bruno Mota ◽  
Ingrid Oliveira e Silva ◽  
Danielle Kaiser de Souza ◽  
Flavia Tuany ◽  
Michele Munk Pereira ◽  
...  
Keyword(s):  
Basal Medium ◽  
Developmental Competence ◽  
Cleavage Rate ◽  
Serum Free ◽  
Oocyte Competence ◽  
Nuclear Maturation ◽  
Blastocyst Rate ◽  
Defined Culture ◽  
Bovine Oocytes

SummaryThe aim of this study was to evaluate the dose–response effect of insulin, plus follicle-simulating hormone (FSH) at a fixed concentration, in a serum-free defined culture medium (DCM) on the in vitro maturation of bovine cumulus–oocyte complexes (COCs). For oocyte nuclear maturation, the expression levels of GDF9, GLUT1, PRDX1 and HSP70.1 transcripts related to oocyte and embryo developmental competence were analysed. For in vitro maturation (IVM), cumulus–oocyte complexes from slaughterhouse ovaries were distributed into four groups based on insulin concentration added to serum-free DCM, which was composed of alpha minimum essential medium (α-MEM), as basal medium: (1) DCM control: 0 ng/ml; (2) DCM1: 1 ng/ml; (3) DCM10: 10 ng/ml; and (4) DCM100: 100 ng/ml. After IVM, the nuclear status of a sample of oocytes was analysed and the other oocytes were submitted for in vitro fertilization (IVF) and in vitro culture (IVC). Different concentrations of insulin did not affect significantly the nuclear maturation and cleavage rate (72 h post-insemination) across all groups. Blastocyst rate (192 h post-insemination) did not differ in DCM control (24.3%), DCM1 (27.0%) and DCM10 (26.3%) groups, but the DCM100 (36.1%) group showed a greater blastocyst rate (P < 0.05) than the DCM control. Insulin concentrations of 1, 10, or 100 ng/ml decreased the relative levels of GDF9 and HSP70-1 transcripts in oocytes at the end of IVM (P < 0.05). The transcripts levels of PRDX1 decreased (P < 0.05) only when 10 or 100 ng/ml insulin was added to the DCM medium. No difference in levels of GLUT1 transcripts (P > 0.05) was observed at the different insulin concentrations. The results indicated that insulin added to DCM influenced levels of transcripts related to cellular stress (HSP70-1 and PRDX1) and oocyte competence (GDF9) in bovine oocytes and at higher concentrations enhanced blastocyst production.

180 LONG-TERM TRANSPORTATION OF BOVINE OOCYTES WITH MEIOTIC BLOCKERS: EFFECTS ON NUCLEAR MATURATION

2017 ◽  
Vol 29 (1) ◽  
pp. 198
Author(s):  
P. C. Dall'Acqua ◽  
B. C. S. Leao ◽  
N. A. S. Rocha-Frigoni ◽  
G. B. Nunes ◽  
M. Ambrogi ◽  
...  
Keyword(s):  
Kinase Inhibitor ◽  
Growth Factor Receptor ◽  
Germinal Vesicle ◽  
Inhibitory Effect ◽  
Study Data ◽  
Receptor Protein ◽  
Nuclear Maturation ◽  
Meiotic Inhibitors ◽  
Bovine Oocytes

The aim of this study was to assess the blockade and the reversal of meiosis block in bovine oocytes treated with a cyclin-dependent kinase inhibitor (butyrolactone-I; BL) combined or not with a selective inhibitor of epidermal growth factor receptor protein (tyrphostin AG 1478; AG) in a prematuration (PM) culture during oocyte transport. Cumulus-oocyte complexes (n = 4107) were transported in PM medium (TCM-199 with bicarbonate and 0.3% BSA) supplemented with one of the following inhibitors: 50 µM BL; 100 µM BL; 1 µM AG; 50 µM BL + 1 µM AG; or 100 µM BL + 1µM AG. Cumulus-oocyte complexes were transported in well-sealed polystyrene tubes (30 oocytes/tube) containing 200 μL of PM medium covered with mineral oil and gassed with 5% O2, 5% CO2, and 90% N2. The tubes were packed in a portable incubator (Thawing Unit MT 35/42, Minitub, Tiefenbach, Germany) at 38.5°C for 22 h. Afterward, treated oocytes were removed from meiotic inhibitors, transferred to in vitro maturation (IVM) medium (TCM-199 with bicarbonate, 0.5 mg mL−1 of FSH, 100 IU mL−1 of hCG, and 10% FCS), and cultured in a bench-top incubator (Thermo Fisher Scientific, Waltham, MA, USA) under 38.5°C and 5% CO2 in air for 20, 22, 24, or 26 h. The control groups were IVM for 20, 22, 24, or 26 h in IVM medium in the bench-top incubator at 38.5°C and 5% CO2 in air (Control; C) or in the portable incubator under the same conditions used for the treated groups (Transport Control; TC). For meiosis evaluation, oocytes were stained with 1% Hoescht immediately after follicle removal (0 h), at 6 and 22 h of PM, and after 20, 22, 24, and 26 h of IVM, and were classified as immature (germinal vesicle; GV) or mature (metaphase II; MII); intermediate phases of meiosis (GV breakdown, metaphase I, anaphase I, or telophase I) were not demonstrated in this study. Data were analysed by ANOVA followed by Tukey’s test (P < 0.05) and are presented as mean ± standard error of the mean. The GV rates after 6 h of transport did not differ (P > 0.05) between 0-h oocytes (88.6 ± 2.3%) and the treated groups (70.3 ± 1.9% to 79.3 ± 2.2%); although GV rates of C (49.5 ± 2.4%) and TC (49.5 ± 2.4%) groups differed (P < 0.05) from 0-h oocytes, they did not differ from treated oocytes with the exception of the 1 µM AG group (79.3 ± 2.2%), which differed from TC (P < 0.05). After 22 h of transport, the GV rates of treated oocytes (50.3 ± 5.5 to 70.3 ± 6.6%) did not differ (P > 0.05) from 0-h oocytes (88.6 ± 2.3%) and were higher (P < 0.05) than C (4.6 ± 2.8%) and TC (8.3 ± 4.5%) that had the highest MII rates (68.4 ± 5.3 and 75.5 ± 2.0%, respectively, for C and TC) compared with the other groups (0 to 13.2 ± 10.2%). After meiotic inhibitors removal and IVM, meiosis block was fully reversed and there were no differences (P > 0.05) in the rates of MII between treated oocytes and C and TC groups after 20 (56.6%, averaged), 22 (57.7%, averaged), 24 (66.2%, averaged), or 26 h of IVM (57.0%, averaged). In conclusion, the meiotic inhibitors were effective in maintaining the majority of treated oocytes in GV stage after 22 h of transport and the inhibitory effect was fully reverted after its removal. Research was supported by FAPESP and CAPES.

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.

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