188 Improvement of bovine oocyte maturation invitro through cytokine supplementation

2020 ◽  
Vol 32 (2) ◽  
pp. 222
Author(s):  
K. S. Stoecklein ◽  
M. S. Ortega ◽  
L. Spate ◽  
C. N. Murphy ◽  
R. S. Prather
Keyword(s):  
Oocyte Maturation ◽  
Lipid Content ◽  
Fixed Effects ◽  
Treatment Time ◽  
Blastocyst Stage ◽  
Control Group ◽  
Detectable Effect ◽  
High Fertility ◽  
Developmental Potential ◽  
Maturation Medium

Oocyte competence is one of the key factors determining the proportion of embryos that develop to the blastocyst stage. There is vast evidence that IVM oocytes exhibit less developmental potential than their invivo counterparts. Here, we tested whether supplementation of three cytokines [FGF2 (40 ngmL−1), LIF (20ngmL−1), and IGF1 (20 ngmL−1), termed FLI] improved oocyte maturation, and as a consequence, preimplantation development of bovine embryos invitro. In the first experiment, cumulus-oocyte complexes (COCs) were collected from abattoir-derived ovaries and placed in maturation medium,±FLI, for 18 to 22h. At the end of maturation, COCs were fertilized with sperm from a single Holstein bull known to have high fertility. After an 18- to 20-h fertilization period, putative zygotes were cultured in synthetic oviductal fluid for 8 days. The number of embryos that underwent at least one cellular division (cleavage) and the number of embryos that developed to the blastocyst stage was recorded on Days 3 and 8 after insemination, respectively. The COCs supplemented with FLI (n=554) and controls (n=534) were evaluated across 5 replicates. There was no difference in the cleavage rate (P>0.05) between the two treatments. Development to the blastocyst stage was higher (P=0.05) for FLI-treated COCs (34.9%±1.96) than for the control group (23.9%±1.96). In a second experiment, COCs (n=204) supplemented±FLI were collected and fixed at 6, 12, 18, and 24h after placement in maturation medium. The number of transzonal projections in the COCs was determined by localization of actin filaments by using confocal microscopy. Data were analysed by ANOVA using the GLM procedure of SAS software (version 9.4; SAS Institute Inc.). The model included treatment, time, and the interaction of treatment×time as fixed effects. There was no difference (P>0.05) in the number of transzonal projections at 6h (166.3±8.6 vs. 143.9±8.8) and 12h (107.8±8.4 vs. 128.3±7.7) between FLI-treated and control COCs. However, FLI-treated COCs had fewer (P<0.05) transzonal projections at 18h (67.9±7.8 vs. 100.1±7.7) and 24h (56.4±7.2 vs. 80.6±7.4) compared with the controls. There was a significant treatment×time interaction (P=0.006). In a third experiment, we tested whether the timing of transzonal projection disassociation affected lipid accumulation in the embryo. Blastocysts (n=59) on Day 8 produced from COCs matured±FLI were collected and lipid content was determined by using Nile Red staining. There was no difference (P>0.05) in lipid content between treatments. Thus, supplementation of maturation medium with FLI accelerates the disassociation of transzonal projections in COCs and improves subsequent embryonic development to the blastocyst stage while having no detectable effect on lipid content. Further research is necessary to understand how these cytokines modulate IVM of bovine oocytes. This project was supported by Food for the 21st Century and the Clifton Murphy scholarship fund.

PSX-B-11 Comparing effects of FGF2 and IGF1 on the development competence of parthenogenetic activated bovine oocytes maturing in vitro

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 327-328
Author(s):  
Galina Singina
Keyword(s):  
Growth Factor ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Total Cell ◽  
Control Group ◽  
Total Cell Number ◽  
Developmental Potential ◽  
Maturation Medium ◽  
Bovine Oocytes

Abstract The oocyte quality acquired during in vitro maturation (IVM) are the main limitative factors affecting the embryo production. The aim of the present research was to study effects of fibroblast growth factor 2 (FGF2) and insulin-like growth factor 1 (IGF1) during IVM of bovine oocytes on their developmental potential after parthenogenetic activation. Bovine cumulus-oocyte complexes (COC; n = 1176) were cultured for 22h in either standard maturation medium (TCM-199 supplemented with 10% fetal calf serum (FCS), 0.2 mM sodium pyruvate, 10 μg/ml FSH and 10 μg/ml LH; Control) or maturation medium supplemented with different concentrations (5–160 ng/ml) of FGF2 and IGF1. After IVM, matured oocytes activated by sequential treatment with ionomycin followed by DMAP and cyclohexamide and then cultured up to the blastocyst stage. The obtained blastocysts were fixed, and the total cell number and the level of apoptosis were determined using DAPI and TUNEL staining. The data from 4 replicates (77–91 oocytes per treatment) were analyzed by ANOVA. Cleavage rates of activated oocytes did not differ between groups and ranged from 63.7 to 68.1%. The addition of 10, 20 and 40 ng/ml of FGF2 to the IVM medium led to an increase in the yield of blastocysts [from 19.6±1.8% (Control) to 35.2±3.4, 29.8±1.9 and 31.1±2.1%, respectively (P<0.05)] and in the total cell number in embryos that developed to the blastocyst stage (P<0.05). Meanwhile, the blastocyst yield and the total cell number in blastocysts in the IGF1-treated groups were similar to that in the control group. No effects of both growth factors on the proportion of apoptotic nuclei in blastocysts (5.3–7.1%) were observed. Thus, FGF2 (but not IGF1) are able to maintain competence for parthenogenetic development of bovine COC during their maturation invitro. Supported by RFBR (18-29-07089) and the Ministry of Science and Higher Education of Russia.

scholarly journals Improved cryopreservation of in vitro produced bovine embryos using FGF2, LIF, and IGF1

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0243727
Author(s):  
Katy S. Stoecklein ◽  
M. Sofia Ortega ◽  
Lee D. Spate ◽  
Clifton N. Murphy ◽  
Randall S. Prather
Keyword(s):  
Growth Factor ◽  
Oocyte Maturation ◽  
Production Systems ◽  
Blastocyst Stage ◽  
High Fertility ◽  
Bovine Embryos ◽  
Embryo Culture Medium ◽  
Maturation Medium ◽  
Stage Embryo

In vitro embryo production systems are limited by their inability to consistently produce embryos with the competency to develop to the blastocyst stage, survive cryopreservation, and establish a pregnancy. Previous work identified a combination of three cytokines [fibroblast growth factor 2 (FGF2), leukemia inhibitory factor (LIF), and insulin-like growth factor 1 (IGF1)], called FLI, that we hypothesize improve preimplantation development of bovine embryos in vitro. To test this hypothesis, FLI was supplemented into oocyte maturation or embryo culture medium. Embryos were produced in vitro using abattoir-derived oocytes and fertilized with sperm from a single bull known to have high fertility. After an 18–20 h fertilization period, putative zygotes were cultured in synthetic oviductal fluid (SOF) for 8 days. The addition of FLI to the oocyte maturation medium increased (P < 0.05) the dissociation of transzonal projections at 12, 18, and 24 h of maturation, as well as, the proportion of oocytes that reached the metaphase II stage of meiosis. Additionally, lipid content was decreased (P < 0.05) in the blastocyst stage embryo. The addition of FLI during the culture period increased development to the blastocyst stage, cytoskeleton integrity, and survival following slow freezing, as well as, decreased post thaw cell apoptosis (P < 0.05). In conclusion, the supplementation of these cytokines in vitro has the potential to alleviate some of the challenges associated with the cryo-survival of in vitro produced bovine embryos through improving embryo development and embryo quality.

Improvement of the developmental competence of canine oocyte using caffeine supplementation during IVM at different maturation time

Zygote ◽  
2018 ◽  
Vol 26 (2) ◽  
pp. 162-167 ◽  
Author(s):  
Mohamed Fathi ◽  
A. Salama ◽  
Magdy R. Badr
Keyword(s):  
Developmental Competence ◽  
Control Group ◽  
Free Medium ◽  
Maturation Time ◽  
Fluid Medium ◽  
Developmental Potential ◽  
Nuclear Maturation ◽  
Maturation Medium ◽  
Oviductal Fluid

SummaryThe aim of the current study was to investigate the effect of caffeine supplementation during in vitro maturation (IVM) for different maturation times on the developmental potential of canine oocytes recovered from ovariohysterectomized bitches. The recovered cumulus–oocytes complexes were in vitro matured for 72 h. Here, 10 mM caffeine was added to the maturation medium for different incubation times (caffeine from 0–72 h maturation, caffeine for the first 24 h of maturation only, caffeine addition from 24 to 48 h maturation time, caffeine addition from 48 to 72 h maturation or in caffeine-free medium, control group). The matured oocytes were in vitro fertilized using frozen–thawed spermatozoa. The presumptive zygotes were in vitro cultured in synthetic oviductal fluid medium for 5 days. The results showed that both maturation and fertilization rates were significantly higher (P ˂ 0.05) using caffeine-treated medium for the first 24 h of maturation compared with the control and other two groups of caffeine treatment (from 24 to 48 h and from 48 to 72 h), whereas use of caffeine-treated medium for a 0–72 h incubation time did not affect these rates (P > 0.05). Interestingly, the matured oocytes in caffeine-supplemented medium for the first 24 h or from 0–72 h showed a significant (P ˂ 0.05) increase in the total number of cleaved embryos compared with the control group. In conclusion, supplementation of the maturation medium with 10 mM caffeine for the first 24 h of maturation or during the whole maturation time (0–72 h) improved nuclear maturation and subsequent embryo development preimplantation following in vitro fertilization.

Erratum to: 264 EXOGENOUS LINOLENIC ACID IN OOCYTE MATURATION MEDIA PROMOTES NUCLEAR MATURATION AND PARTHENOGENETIC PREIMPLANTATION EMBRYONIC DEVELOPMENT IN THE GOAT

2013 ◽  
Vol 25 (1) ◽  
pp. 280
Author(s):  
A. Veshkini ◽  
A.-A. Khadem ◽  
M. Soleimani ◽  
R. Jahanbin ◽  
M. Salehi ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Linolenic Acid ◽  
Oocyte Maturation ◽  
Mass Spectrometry Analysis ◽  
Control Group ◽  
Parthenogenetic Activation ◽  
Nuclear Maturation ◽  
Maturation Medium ◽  
Wide Range ◽  
And Control

Dietary intakes of polyunsaturated fatty acids are thought to mediate a wide range of actions in reproductive tissues. This includes the effects on ovarian follicle and corpus luteum functions via improved energy efficiency as well as providing precursors for the synthesis of signalling molecules such as steroids and prostaglandins. An appropriate level of α-linolenic acid (ALA) in the oocyte maturation medium has been shown to induce molecular changes associated with oocyte maturation and embryo developmental competence. In that light, we hypothesised that supplementation of exogenous ALA to maturation media could enhance nuclear maturation and embryonic development in the goat. A preliminary experiment was executed to measure the level of ALA in antral follicles by gas chromatography/mass spectrometry analysis. Our results revealed that the concentration of ALA in follicular fluids ranged from 0.006 to 0.02 mg mL–1 (21.5 to 71.8 µM, with a mean of ~50 µM). To test the effect of ALA on the competence of goat oocytes to complete meiotic maturation to metaphase II and sustain embryonic development, ovaries were obtained from a local abattoir. Cumulus–oocyte complexes were recovered by the slicing method followed by selection of oocytes with a homogenous cytoplasm and at least three layers of compact cumulus cells. The cumulus–oocyte complexes were placed in maturation media supplemented with 50 µM ALA. Oocytes in the control group were incubated in the same maturation medium without ALA. In vitro maturation (IVM) was performed in a humidified atmosphere containing 5% CO2, 5% O2, and 90% N2 at 38.5°C for 24 h. After IVM, several oocytes from the treatment (n = 170) and control (n = 166) groups were stained with Hoechst and were evaluated in relation to their metaphase-II rate. Other groups of oocytes from both the treatment (n = 70) and control (n = 61) groups were subjected to parthenogenetic activation by applying 1 min of exposure to 2.5 µM ionomycin followed by 2 mM 6-DMAP treatment for 3 h. After activation, oocytes were cultured in CR1aa medium for 7 days under the conditions stated above. Four replications were performed. Differences in developmental rates were analysed for significance by one-way ANOVA using SAS version 8.0 (SAS Institute Inc., Cary, NC, USA), considering P < 0.05 to be significant. As a result, supplementation of the maturation media with ALA did not appear to affect cumulus expansion. In contrast, IVM of goat oocytes in the presence of ALA resulted in a significantly higher maturation rate compared with maturation without ALA supplementation (66.4% v. 57.9%). Likewise, addition of ALA to the IVM medium significantly increased the rate of cleavage (60.1% v. 52.4%) and blastocyst formation (22.6% v. 14.9%), calculated from the activated oocytes. Collectively, the results of our study show that supplementation of IVM media with 50 µM ALA promotes nuclear maturation, increases cleavage rate, and results in higher blastocyst rate in goat oocytes after parthenogenetic activation. Thus, providing appropriate levels of ALA in maturation media could have beneficial effects on embryo development and reproductive efficiency in the goat.

165 FETAL CALF SERUM INFLUENCES CYCLIC GMP PATHWAY, WHICH IN TURN AFFECTS THE LIPID CONTENT IN IN VITRO-MATURED BOVINE OOCYTES

2014 ◽  
Vol 26 (1) ◽  
pp. 196
Author(s):  
K. R. L. Schwarz ◽  
R. C. Botigelli ◽  
F. C. Castro ◽  
M. R. Chiaratti ◽  
C. L. V. Leal
Keyword(s):  
Lipid Content ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Cumulus Cells ◽  
Control Group ◽  
Maturation Medium ◽  
Cgmp Pathway ◽  
Bovine Oocytes ◽  
Synthesis And Degradation

The sensitivity of IVP embryos to cryopreservation is often associated with lipid accumulation in the cytoplasm induced by the presence of fetal calf serum (FCS) during culture. Intracellular levels of cyclic (c)AMP and cGMP are involved in the regulation of lipolysis in adipocytes; high levels stimulate lipolysis whereas low levels lead to lipogenesis. Both nucleotides are present in bovine oocytes, together with the enzymes for their synthesis and degradation. The aim of this study was to analysis the effect of FCS on the cGMP pathway and the influence of cGMP on cytoplasmic lipids in bovine oocytes. In experiments 1 and 2, cumulus–oocyte complexes (COC) were cultured for 24 h in maturation medium with different proportions of FCS (2 and 10%) and a control group was matured with 0.4% BSA. After this period, transcripts for cGMP pathway were assessed by real-time PCR (GUCY1B3 and PDE5, cGMP synthesis and degradation enzymes, respectively; experiment 1) in oocytes and cumulus cells, and cGMP levels were measured in COC using commercial enzyme immunoassay kits (EIA; experiment 2). In experiments 3 and 4, COC were matured for 24 h with 0.4% BSA and different concentrations of the phosphodiesterase (PDE)5 inhibitor (0, 10–7, and 10–5 M sildenafil) to inhibit cGMP degradation and a control group was matured with 0.4% BSA. The nucleotide levels were measured in COC (experiment 3) and the oocytes were stained with Nile Red (1 μg mL–1) for evaluation of lipid content (experiment 4). Statistical analyses were performed by ANOVA followed by Tukey post hoc test using SAS software (SAS Institute Inc., Cary, NC, USA). Data for gene expression from 5 replicates and for cGMP measurements and lipid content from 3 replicates were log10-transformed into before analyses. The level of significance was 5%. The presence of FCS reduced GUCY1B3 expression in both cells and increased PDE5A in cumulus cells (P < 0.05). In experiment 2, the groups treated with 2 (0.64 fmol/COC) and 10% FCS (1.04 fmol/COC) showed decreased cGMP levels compared with control (9.46 fmol/COC; P < 0.05). In experiment 3, inhibition of PDE5A increased cGMP levels in the treated groups (36 and 56 fmol/COC for 10–7 and 10–5 M sildenafil, respectively) compared with control (9.5 fmol/COC; P < 0.05). Therefore, sildenafil showed inverse effects compared with FCS (experiment 2). In experiment 4, oocytes treated with 10–7 and 10–5 M sildenafil showed a reduced lipid content compared with controls (11.6 ± 9.4 v. 13.9 μm2 fluorescence intensity, respectively; P < 0.05). The results suggest that FCS in maturation medium affects the cGMP pathway, interfering with the transcription of genes that control its levels, which in turn results in nucleotide reduction. Inhibition of PDE5 increases cGMP levels and reduces the lipid content of oocytes, indicating that changes in this pathway caused by FCS may affect lipid metabolism of oocytes. More studies are underway to better understand this mechanism. The authors acknowledge FAPESP 2012/00170-0 for financial support.

53 Effect of anthocyanin supplementation in bovine pre-implantation embryonic development during invitro maturation of oocytes

2021 ◽  
Vol 33 (2) ◽  
pp. 133
Author(s):  
A. Zegarra ◽  
J. Rivas ◽  
A. Gallegos ◽  
E. Mellisho
Keyword(s):  
Embryonic Development ◽  
Decisive Role ◽  
Blastocyst Stage ◽  
Control Group ◽  
Blastocyst Development ◽  
Maturation Medium ◽  
Advanced Stages ◽  
Commercial Medium ◽  
Antioxidant Effects

Oocyte protection against reactive oxygen species (ROS) during invitro maturation (IVM) may play a decisive role in pre-implantation embryonic development. For instance, anthocyanins have shown greater antioxidant effects than vitamins C and E. The objective of this study was to determine the anthocyanin supplementation level that influences quantity and quality of bovine blastocysts development during IVM. Cumulus–oocyte complexes (COC) were recovered from 185 abattoir ovaries in 6 sessions and classified (Grade 1 and 2) for maturation. Oocytes were in IVM in commercial medium (Vitrogen®) supplemented with anthocyanin (pelargonidin chloride) at different concentrations: 0 (control), 1, 10, 20, and 40μM, in droplets of 70μL with 12 to 15 COC at 38.5°C, 5% CO2 and 90% humidity for 22to 24h. Sperm selection was performed by Percoll gradient method (45/90%) with centrifugation at 600×g for 6min. The final concentration for IVF was 2×106 sperm mL−1. A total of 462 oocytes were used in the experiment (6 replicates). Presumptive zygotes were invitro cultured (IVC) in commercial medium (Vitrogen) in droplets of 70µL with 12–15 zygotes at 38°C, 5% CO2, and 90% humidity until the blastocyst stage (Day 7 of culture). The cleavage (Day 2), morulae (Day 4), and blastocyst (Day 7) rates were measured during IVC. The data were processed with non-parametric tests (Kruskal–Wallis test with independent samples, P&lt;0.05) using IBM SPSS Statistics 2.0 for Windows. The results in the control group of cleavage, morulae, and blastocyst rates were 67.3, 27.0, and 22.1%, respectively. Although, numerically, anthocyanin at 1μM resulted in a higher blastocyst rate (28.8%) and anthocyanin at 10μM resulted in a greater number of blastocysts of advanced stages (65.0%), anthocyanin supplementation during IVM did not influence the quantity and quality of bovine blastocyst development (P&gt;0.05). In conclusion, the supplementation of anthocyanin to the maturation medium did not affect invitro development of bovine embryos. Complementary studies at the cellular and gene expression level may be required.

Paradoxical effects of kisspeptin: it enhances oocyte in vitro maturation but has an adverse impact on hatched blastocysts during in vitro culture

2012 ◽  
Vol 24 (5) ◽  
pp. 656 ◽  
Author(s):  
Islam M. Saadeldin ◽  
Ok Jae Koo ◽  
Jung Taek Kang ◽  
Dae Kee Kwon ◽  
Sol Ji Park ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
In Vitro Maturation ◽  
Formation Rate ◽  
Early Period ◽  
Threshold Effect ◽  
Developmental Competence ◽  
Control Group ◽  
Maturation Medium ◽  
Paradoxical Effects

Kisspeptin (Kp) is best known as a multifunctional peptide with roles in reproduction, the cardiovascular system and cancer. In the present study the expression of kisspeptin hierarchy elements (KISS1, GNRH1 and LHB) and their receptors (KISS1R, GNRHR and LHCGR, respectively) in porcine ovary and in cumulus–oocyte complexes (COCs) were investigated, as were its effects on the in vitro maturation (IVM) of oocytes and their subsequent ability to sustain preimplantation embryo competence after parthenogenetic electrical activation. Kp system elements were expressed and affected IVM of oocytes when maturation medium was supplemented with 10–6 M Kp. Oocyte maturation, maternal gene expression (MOS, GDF9 and BMP15), blastocyst formation rate, blastocyst hatching and blastocyst total cell count were all significantly increased when oocytes were matured in medium containing Kp compared with the control group (without Kp). A Kp antagonist (p234) at 4 × 10–6 M interfered with this hierarchy but did not influence the threshold effect of gonadotrophins on oocyte maturation. FSH was critical and permissive to Kp action on COCs by increasing the relative expression of KISS1R. In contrast, Kp significantly increased apoptosis, the expression of pro-apoptotic gene, BAK1, and suppressed trophoblast outgrowths from hatched blastocysts cultured on feeder cells. The present study provides the first functional evidence of the Kp hierarchy in porcine COCs and its role in enhancing oocyte maturation and subsequent developmental competence in an autocrine–paracrine manner. However, Kp supplementation may have a harmful impact on cultured hatched blastocysts reflecting systemic or local regulation during the critical early period of embryonic development.

Development of porcine oocytes from preovulatory follicles of different sizes after maturation in media supplemented with follicular fluids

2000 ◽  
Vol 12 (4) ◽  
pp. 133 ◽  
Author(s):  
Ki-Won Yoon ◽  
Tae-Young Shin ◽  
Jong-Im Park ◽  
Sangho Roh ◽  
Jeong M. Lim ◽  
...  
Keyword(s):  
Blastocyst Stage ◽  
Developmental Potential ◽  
Large Follicle ◽  
In Vitro Development ◽  
Maturation Medium ◽  
Preovulatory Follicles ◽  
Vitro Development ◽  
Small Follicle ◽  
Follicular Fluids

The development of porcine oocytes from large (3.1–8.0 mm in diameter) or small (<3.1 mm) follicles was examined after maturation culture in medium containing porcine follicular fluid (pFF). Large follicles yielded larger (256 m v. 221 m; P<0.05) cumulus–oocyte complexes and more (22 v. 14%) morphologically normal oocytes than small follicles (Experiment 1). In Experiments 2–4, maturation media supplemented with mixed pFF (10%) from small and large follicles was used. More oocytes from large follicles matured (58% v. 91%), formed pronuclei (81% v. 90%) and developed to the blastocyst stage (2% v. 10%) than oocytes from small follicles. In Experiments 5–7, the effects of pFF collected from either small or large follicles on oocyte development were examined. Regardless of the source of oocytes, large-follicle-derived pFF more significantly enhanced preimplantation development than did small-follicle-derived pFF. The highest rate of blastocyst formation (16%) was found when oocytes from large follicles were cultured in maturation medium containing large-follicle-derived pFF. These results suggest that oocytes from large follicles have greater developmental potential than oocytes from small follicles, and that the origin of pFF, which is added to the maturation media, might be an important factor for improving in vitro development of porcine oocytes.

scholarly journals Pengaruh urea dalam media maturasi in vitro terhadap tingkat maturasi oosit sapi

2021 ◽  
Vol 10 (2) ◽  
pp. 46
Author(s):  
Sepvian Dewi Kurniawati ◽  
Suryanie Sarudji ◽  
Widjiati Widjiati
Keyword(s):  
Oocyte Maturation ◽  
Polar Body ◽  
Metaphase Plate ◽  
Petri Dish ◽  
Control Group ◽  
Maturation Medium ◽  
First Polar Body ◽  
Maturation Rate ◽  
Follicle Aspiration

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

scholarly journals Use of Melatonin in the In Vitro Production of Bovine Embryos

2020 ◽  
Vol 21 ◽  
Author(s):  
Alan da Silva LIRA ◽  
Ricardo de Macedo CHAVES ◽  
Felipe de Jesus MORAES JUNIOR ◽  
Sergio Henrique COSTA JUNIOR ◽  
Brenda Karine Lima do AMARAL ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
In Vitro Maturation ◽  
Control Group ◽  
Bovine Embryos ◽  
In Vitro Production ◽  
Maturation Medium ◽  
Significant Difference ◽  
Maturation Rate ◽  
Vitro Production

ABSTRACT We aimed to assess the effects of melatonin in the in vitro production of bovine embryos. Our experiment was conducted at the Laboratório de Reprodução Animal of the Universidade Estadual do Maranhão. The cumulus-oocyte complexes (COCs) were distributed among treatments at concentrations of 0, 10-1, 10-3 and 10-5 µMol/L melatonin. Our experiment was further divided into two: the first was to assess the effect of different concentrations of melatonin (treatments) on the maturation rate of COCs, and the second was to assess the effects of melatonin treatments on the in vitro production of bovine embryos. The results from the first experiment demonstrated no significant difference between the in vitro maturation rate of the cultivated COCs in treatments with melatonin. In the second experiment, however, melatonin treatments yielded statistically higher cleavage, morula and blastocyst rates in the 10-5 µM group (52.9%, 52.9%, and 35.3%, respectively), and lower rates in the 10-1 µM group (19.5%, 19.5% and 7.8%, respectively), compared to the others. The control group (no melatonin) and the 10-3 µM group showed similar results. We concluded that supplementation of melatonin in the in vitro maturation medium resulted in no improvement in the oocyte maturation rate, but in the in vitro production of embryos at different concentrations, the 10-5 µM group displayed better results, but with no improvement in the variables (P < 0.05).

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