The Role of Ca2 + in Maturation and Reprogramming of Bovine Oocytes: A System Study of Low-Calcium Model

[Ca2+]i is essential for mammalian oocyte maturation and early embryonic development, as those processes are Ca2+ dependent. In the present study, we investigated the effect of [Ca2+]i on in vitro maturation and reprogramming of oocytes in a lower calcium model of oocyte at metaphase II (MII) stage, which was established by adding cell-permeant Ca2+ chelator BAPTA-AM to the maturation medium. Results showed that the extrusion of the first polar body (PB1) was delayed, and oocyte cytoplasmic maturation, including mitochondrial and endoplasmic reticulum distribution, was impaired in lower calcium model. The low-calcium-model oocytes presented a poor developmental phenotype of somatic cell nuclear transfer (SCNT) embryos at the beginning of activation of zygotic genome. At the same time, oxidative stress and apoptosis were observed in the low-calcium-model oocytes; subsequently, an RNA-seq analysis of the lower-calcium-model oocytes screened 24 genes responsible for the poor oocyte reprogramming, and six genes (ID1, SOX2, DPPA3, ASF1A, MSL3, and KDM6B) were identified by quantitative PCR. Analyzing the expression of these genes is helpful to elucidate the mechanisms of [Ca2+]i regulating oocyte reprogramming. The most significant difference gene in this enriched item was ID1. Our results showed that the low calcium might give rise to oxidative stress and apoptosis, resulting in impaired maturation of bovine oocytes and possibly affecting subsequent reprogramming ability through the reduction of ID1.

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H1foo is essential for in vitro meiotic maturation of bovine oocytes

Zygote ◽

10.1017/s0967199414000021 ◽

2014 ◽

Vol 23 (3) ◽

pp. 416-425 ◽

Cited By ~ 13

Author(s):

Yan Yun ◽

Peng An ◽

Jing Ning ◽

Gui-Ming Zhao ◽

Wen-Lin Yang ◽

...

Keyword(s):

Oocyte Maturation ◽

Polar Body ◽

Linker Histone ◽

Meiotic Maturation ◽

Control Group ◽

Bovine Oocyte ◽

First Polar Body ◽

Effective Sirnas ◽

Bovine Oocytes

SummaryOocyte-specific linker histone, H1foo, is localized on the oocyte chromosomes during the process of meiotic maturation, and is essential for mouse oocyte maturation. Bovine H1foo has been identified, and its expression profile throughout oocyte maturation and early embryo development has been established. However, it has not been confirmed if H1foo is indispensable during bovine oocyte maturation. Effective siRNAs against H1foo were screened in HeLa cells, and then siRNA was microinjected into bovine oocytes to down-regulate H1foo expression. H1foo overexpression was achieved via mRNA injection. Reverse transcription polymerase chain reaction (RT-PCR) results indicated that H1foo was up-regulated by 200% and down-regulated by 70%. Based on the first polar body extrusion (PB1E) rate, H1foo overexpression apparently promoted meiotic progression. The knockdown of H1foo significantly impaired bovine oocyte maturation compared with H1foo overexpression and control groups (H1foo overexpression = 88.7%, H1foo siRNA = 41.2%, control = 71.2%; P < 0.05). This decrease can be rescued by co-injection of a modified H1foo mRNA that has escaped from the siRNA target. However, the H1e (somatic linker histone) overexpression had no effect on PB1E rate when compared with the control group. Therefore we concluded that H1foo is essential for bovine oocyte maturation and its overexpression stimulates the process.

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Selective degradation of maternal and embryonic transcripts in in vitro produced bovine oocytes and embryos using sequence specific double-stranded RNA

Reproduction ◽

10.1530/rep.1.01040 ◽

2006 ◽

Vol 131 (5) ◽

pp. 861-874 ◽

Cited By ~ 38

Author(s):

Korakot Nganvongpanit ◽

Heike Müller ◽

Franca Rings ◽

Michael Hoelker ◽

Danyel Jennen ◽

...

Keyword(s):

Inner Cell Mass ◽

Polar Body ◽

Cell Mass ◽

Free Water ◽

Double Stranded Rna ◽

Immature Oocytes ◽

Selective Degradation ◽

First Polar Body ◽

Bovine Oocytes

RNA interference (RNAi) has been used for selective degradation of an mRNA transcript or inhibiting its translation to a functional protein in various species. Here, we applied the RNAi approach to suppress the expression of the maternal transcript C-mos and embryonic transcripts Oct-4 in bovine oocytes and embryos respectively, using microinjection of sequence-specific double-stranded RNA (dsRNA). For this, 435 bp C-mos and 341 bp Oct-4 dsRNA were synthesized and microinjected into the cytoplasm of immature oocytes and zygotes respectively. In experiment 1, immature oocytes were categorized into three groups: those injected with C-mos dsRNA, RNase-free water and uninjected controls. In experiment 2,in vitroproduced zygotes were categorized into three groups: those injected with Oct-4 dsRNA, RNase-free water and uninjected controls. The developmental phenotypes, the level of mRNA and protein expression were investigated after treatment in both experiments. Microinjection of C-mos dsRNA has resulted in 70% reduction of C-mos transcript after maturation compared to the water-injected and uninjected controls (P<0.01). Microinjection of zygotes with Oct-4 dsRNA has resulted in 72% reduction in transcript abundance at the blastocyst stage compared to the uninjected control zygotes (P<0.01). Moreover, a significant reduction in the number of inner cell mass (ICM) cells was observed in Oct-4 dsRNA-injected embryos compared to the other groups. From oocytes injected with C-mos dsRNA, 60% showed the extrusion of the first polar body compared to 50% in water-injected and 44% in uninjected controls. Moreover, only oocytes injected with C-mos dsRNA showed spontaneous activation. In conclusion, our results demonstrated that sequence-specific dsRNA can be used to knockdown maternal or embryonic transcripts in bovine embryogenesis.

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228 microRNA REGULATION OF GENES IN BOVINE OOCYTES AND EMBRYOS

Reproduction Fertility and Development ◽

10.1071/rdv22n1ab228 ◽

2010 ◽

Vol 22 (1) ◽

pp. 272

Author(s):

J. P. Barfield ◽

G. J. Bouma ◽

G. E. Seidel Jr

Keyword(s):

Mirna Expression ◽

Polar Body ◽

Prostaglandin F2α ◽

Defined Medium ◽

Tight Junction Formation ◽

First Polar Body ◽

Lysis Buffer ◽

Bovine Oocytes

Little is known about expression of microRNA (miRNA) in bovine oocytes and pre-implantation embryos. These molecules likely have an important role in regulating development. For example, differences in quality of oocytes matured in vivo v. in vitro might be due, in part, to altered miRNA expression. In Experiment 1, in vivo-matured COC were collected by transvaginal aspiration of 7 superstimulated cows 21 to 23 h after GnRH injection, given 48 h after prostaglandin F2α and the last of 6 FSH injections given b.i.d. Oocytes aspirated from abattoir ovaries were matured in vitro for 23 h in a chemically defined medium. After vortexing, maturation of both groups of oocytes was confirmed by visualization of the first polar body, and oocytes were snap frozen in mirVana lysis buffer (Applied Biosciences, Foster City, CA, USA). In Experiment 2, in vitro-matured oocytes were generated as described. Subsets were fertilized in vitro or activated parthenogenetically by incubation in 5-μM ionomycin for 5 min followed by 10 μg mL-1 cycloheximide plus 5 μg mL-1 cytochalasin B for 5 h. After 18 h and 12 h, respectively, fertilized and activated oocytes were centrifuged at 10 000 × g for 10 min to enable visualization of pronuclei. Zygotes with 2 polar bodies and 2 pronuclei and parthenotes with 2 pronuclei were snap frozen in mirVana lysis buffer. Total RNA was extracted from 30 pooled oocytes for each replicate using the mirVana MiRNA Isolation Kit (Ambion, Inc., Austin, TX, USA). Reverse transcription of RNA was performed using the QuantiMir RT kit (System Biosciences, Mountain View, CA, USA), and miRNA expression was evaluated by real-time PCR using the Mouse miRNome Profiler plate, which contains primers for 384 miRNA (System Biosciences). Three plates were analyzed for each group (30 oocytes per plate). Changes in relative expression levels were analyzed with a t-test of values normalized to miR-181a, which was consistently expressed in all samples. In Experiment 1, compared with in vitro-matured oocytes, in vivo-matured oocytes had 11-fold higher (P = 0.02) expression of miR-375, which targets numerous genes involved in electron transport chain and oxidative phosphorylation pathways according to the bioinformatic database mirGator. MiR-291a-5p, miR-494, miR-539, and miR-547 were expressed in in vivo-matured oocytes only; the converse was found for miR-575-5p. Results from Experiment 2 are in the table. Major pathways associated with potential targets of the detected miRNA include TGF-beta signaling, Wnt signaling, tight junction formation, DNA replication reactome, steroid biosynthesis, mRNA processing binding reactome, and glutamate metabolism. Several of these candidate miRNA might be important for regulation of bovine oocyte maturation and embryo development. Table 1.Experiment 2: Fold change expression of miRNA

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40 TRICHOSTATIN A TREATMENT EFFECTS ON IN VITRO DEVELOPMENT OF INTERSPECIES NUCLEAR TRANSFER CAT EMBRYOS DEPEND ON RECIPIENT CYTOPLASM SPECIES

Reproduction Fertility and Development ◽

10.1071/rdv27n1ab40 ◽

2015 ◽

Vol 27 (1) ◽

pp. 113

Author(s):

L. T. K. Do ◽

Y. Sato ◽

M. Taniguchi ◽

T. Otoi

Keyword(s):

Nuclear Transfer ◽

Treatment Effects ◽

Trichostatin A ◽

Polar Body ◽

Blastocyst Stage ◽

Control Group ◽

Fluid Medium ◽

First Polar Body ◽

Bovine Oocytes

The developmental ability of interspecies somatic cell nuclear transfer (iSCNT) embryos decreases as the taxonomic distance between the donor and recipient species increases. Treatment of cat iSCNT embryos using bovine oocytes with 50 nM of trichostatin A (TSA) improves in vitro embryonic development (Wittayarat et al. 2013 Cell. Reprogram. 15, 301–308). This study investigated whether the TSA treatment effects differ between the development of cat iSCNT embryos reconstructed with porcine and bovine oocytes. Porcine and bovine cumulus-oocyte complexes were in vitro matured for 44 h and 24 h, respectively. After cumulus cell removal, enucleation was performed by aspiration of the metaphase II plate and the first polar body using a piezo-driven pipette. A cat fibroblast cell was then injected into cytoplasm of successfully enucleated oocyte. Reconstructed cybrids were electrically activated by a single 1.5 kV cm–1 pulse for 100 µs (pig-cat embryos), or a 2.3 kV cm–1 pulse for 30 µs (cow-cat embryos). Pig-cat and cow-cat embryos were cultured in porcine zygote medium (PZM)-5 and modified synthetic oviducal fluid medium (mSOF), respectively. After electrical activation, pig-cat and cow-cat embryos were cultured in medium supplemented with 5 µg mL–1 cytochalasin B + 50 nM TSA (TSA group) or without TSA (control group), and the cow-cat embryo medium was also supplemented with 10 µg mL–1 cycloheximide. After 2 h, TSA-treated pig-cat and cow-cat embryos were incubated in medium supplemented with TSA for 22 h, followed by 48 h incubation without TSA. Pig-cat and cow-cat control embryos were cultured in medium without TSA for 70 h after activation. Then, all pig-cat and cow-cat embryos were cultured in porcine blastocyst medium (PBM) or mSOF medium supplemented with 5% fetal bovine serum, respectively, for 5 additional days. Four to seven replicates were performed for each experiment. Data were analysed using Student's t-test. For pig-cat embryos, no difference was observed in cleavage rates between both groups, but development to the blastocyst stage was higher in the pig control group (n = 147, 8.0%) than that of pig TSA group (n = 131, 0.7%; P < 0.05). In contrast, development to the blastocyst stage in cow-cat embryos was not observed in the cow control group (n = 125, 0%), but it was observed in cow TSA group (n = 136, 3.7%). These results indicate that TSA treatment effects are species-specific, but those effects remain to be clarified.

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Developmental competence in vivo and in vitro of in vitro-matured equine oocytes fertilized by intracytoplasmic sperm injection with fresh or frozen-thawed spermatozoa

Reproduction ◽

10.1530/rep.0.1230455 ◽

2002 ◽

pp. 455-465 ◽

Cited By ~ 74

Author(s):

YH Choi ◽

CC Love ◽

LB Love ◽

DD Varner ◽

S Brinsko ◽

...

Keyword(s):

Intracytoplasmic Sperm Injection ◽

Polar Body ◽

Cumulus Cells ◽

Fertilization Rate ◽

Developmental Competence ◽

Cleavage Rate ◽

First Polar Body ◽

Bovine Oocytes

This study was undertaken to evaluate the development of equine oocytes in vitro and in vivo after intracytoplasmic sperm injection (ICSI) with either fresh or frozen-thawed spermatozoa, without the use of additional activation treatments. Oocytes were collected from ovaries obtained from an abattoir and oocytes classified as having expanded cumulus cells were matured in M199 with 10% fetal bovine serum and 5 microU FSH ml(-1). After 24-26 h of in vitro maturation, oocytes with a first polar body were selected for manipulation. Fresh ejaculated stallion spermatozoa were used for the experiment after swim-up for 20 min in sperm-Tyrode's albumen lactate pyruvate. Frozen-thawed spermatozoa from the same stallion were treated in a similar way. Spermatozoa were immobilized and injected into the oocytes using a Piezo drill. Presumptive zygotes were cultured in G1.2 medium for 20 or 96 h after the injection was administered, or were transferred to the oviducts of recipient mares and recovered 96 h later. In addition, bovine oocytes with first polar bodies were injected with the two types of stallion spermatozoa and fixed 20 h after injection to examine pronuclear formation. Fertilization rate (pronucleus formation and cleavage) at 20 h after injection of spermatozoa was not significantly different between fresh and frozen-thawed sperm groups in either equine or bovine oocytes. Pronucleus formation after injection of spermatozoa into bovine oocytes was significantly higher than that for equine oocytes (P < 0.05). There were no significant differences in cleavage rate or average number of nuclei at 96 h between equine oocytes injected with fresh or frozen-thawed spermatozoa. However, embryos developed in vivo for 96 h had a significantly higher number of nuclei in both sperm treatments compared with those cultured in vitro. These results indicate that good activation rates may be obtained after injection of either fresh or frozen-thawed equine spermatozoa without additional activation treatment. Injection of frozen-thawed equine spermatozoa results in similar embryo development to that obtained with fresh equine spermatozoa. In vitro culture of equine zygotes in G1.2 medium results in a similar cleavage rate but reduced number of cells compared with in vivo culture within the oviduct. Bovine oocytes may be useful as models for assessing sperm function in horses.

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Grape Seed Proanthocyanidin Ameliorates FB1-Induced Meiotic Defects in Porcine Oocytes

Toxins ◽

10.3390/toxins13120841 ◽

2021 ◽

Vol 13 (12) ◽

pp. 841

Author(s):

Wenhui Li ◽

Yijing He ◽

Hongyu Zhao ◽

Lei Peng ◽

Jia Li ◽

...

Keyword(s):

Oxidative Stress ◽

Polar Body ◽

Grape Seed ◽

Ros Generation ◽

Mrna Levels ◽

Blastocyst Development ◽

Cleavage Rate ◽

First Polar Body ◽

Grape Seed Proanthocyanidin

Fumonisin B1 (FB1), as the most prevalent and toxic fumonisin, poses a health threat to humans and animals. The cytotoxicity of FB1 is closely related to oxidative stress and apoptosis. The purpose of this study is to explore whether Grape seed proanthocyanidin (GSP), a natural antioxidant, could alleviate the meiotic maturation defects of oocytes caused by FB1 exposure. Porcine cumulus oocyte complexes (COCs) were treated with 30 μM FB1 alone or cotreated with 100, 200 and 300 μM GSP during in vitro maturation for 44 h. The results show that 200 μM GSP cotreatment observably ameliorated the toxic effects of FB1 exposure, showing to be promoting first polar body extrusion and improving the subsequent cleavage rate and blastocyst development rate. Moreover, 200 μM GSP cotreatment restored cell cycle progression, reduced the proportion of aberrant spindles, improved actin distribution and protected mitochondrial function in FB1-exposed oocytes. Furthermore, reactive oxygen species (ROS) generation was significantly decreased and the mRNA levels of CAT, SOD2 and GSH-PX were obviously increased in the 200 μM GSP cotreatment group. Notably, the incidence of early apoptosis and autophagy level were also significantly decreased after GSP cotreatment and the mRNA expression levels of BAX, CASPASE3, LC3 and ATG5 were markedly decreased, whereas BCL2 and mTOR were observably increased in the oocytes after GSP cotreatment. Together, these results indicate that GSP could exert significant preventive effects on FB1-induced oocyte defects by ameliorating oxidative stress through repairing mitochondrial dysfunction.

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

Ovozoa Journal of Animal Reproduction ◽

10.20473/ovz.v10i2.2021.46-52 ◽

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.

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298RED DEER (CERVUS ELAPHUS) PARTHENOGENETIC BLASTOCYSTS PRODUCED USING IONOMYCIN/6DMAP ACTIVATION

Reproduction Fertility and Development ◽

10.1071/rdv16n1ab298 ◽

2004 ◽

Vol 16 (2) ◽

pp. 268 ◽

Cited By ~ 2

Author(s):

S.E. Beaumont ◽

D.K. Berg ◽

G.W. Asher

Keyword(s):

Red Deer ◽

Polar Body ◽

Negative Control ◽

Blastocyst Development ◽

Cell Counts ◽

First Polar Body ◽

Significant Difference ◽

Chi Square Analysis ◽

Polar Body Extrusion

Successful activation of red deer oocytes is a necessary prerequisite for the cloning of red deer individuals with desirable genetic characteristics. To investigate this, an established biphasic protocol used for oocyte activation in sheep was investigated for suitability. The method chosen was 5μM Ionomycin for 5min followed by 2mM 6DMAP for 3h ( Loi P et al., 1998 Biol. Reprod. 58, 1177–1187). The medium used during activation and subsequent culture was Deer Synthetic Oviduct Fluid, which has been shown to support routine in vitro fertilization and blastocyst development (15%) of in vitro-matured red deer oocytes (DSOF, Berg D et al., 2003 Theriogenology 59, 189–205). Red deer abattoir-derived COCs were matured in vitro for 22h before random allocation across 3 treatment groups comprising a standard IVF group, the activation group and a negative control group exposed to medium only. Activation treatment oocytes were stripped of cumulus by vortexing in 0.1% hyaluronidase before selecting for first polar body extrusion. First-step activation was performed in medium comprising HEPES-buffered IVF-DSOF containing 4mM Ca2+. Second-step activation used 3mM Ca2+ early DSOF under 7% O2, 5% CO2, and 88% N2 at 38.5°C. Standard IVF was conducted at 23h post-IVM using 4mM Ca2+ IVF-DSOF and 0.5×106mL−1 final sperm concentration. Following activation and IVF, oocytes were washed 3 times in HEPES DSOF before culture for 7 days in sequential DSOF with late DSOF on Day 4 containing 1.5mM Ca2+. Cleavage was assessed 24h after activation, and all blastocysts were fixed for cell counts. Four replicates of each treatment were performed. Cleavage and blastocyst rates were examined by chi-square analysis and cell numbers by ANOVA. First polar body extrusion rate was 84%. Cleavage was similar between the activation treatment and IVF (P>0.05 ); but a significant difference was found in blastocyst development rates (P<0.05) with the Ionomycin and 6DMAP protocol being superior to the IVF treatment. Exposure to high Ca2+ media alone resulted in only 5% of the negative control oocytes cleaving to 2 cells. Results show that Ionomycin and 6DMAP are effective in activating red deer oocytes and DSOF is a suitable medium to produce parthenogenetic blastocysts.

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271 ASSESSMENT OF NUCLEAR STATUS OF ACTIVATED BOVINE OOCYTES MATURED IN DIFFERENT MATURATION CONDITIONS IN VITRO

Reproduction Fertility and Development ◽

10.1071/rdv17n2ab271 ◽

2005 ◽

Vol 17 (2) ◽

pp. 285

Author(s):

J.I. Park ◽

Y. Jang

Keyword(s):

Oocyte Maturation ◽

Polar Body ◽

Calf Serum ◽

Chi Square ◽

Cell Stage ◽

Maturation Medium ◽

Second Polar Body ◽

Humidified Air ◽

Bovine Oocytes

This study was carried out to assess the nuclear status after parthenogenetic activation in in vitro matured oocytes under different conditions. Bovine ovaries were collected from slaughtered cows at a local abattoir. Oocytes were aspirated from follicles of 3–8 mm in diameter and transferred to maturation medium: tissue culture medium (TCM)-199 supplemented with 10% (v/v) fetal calf serum, 100 mg/mL l-cysteine, 20 mg/mL sodium pyruvate, gonadotropins (each 250 IU of eCG and hCG/mL), and 10 mg/mL epidermal growth factor, with or without 5 mM hypotaurine and taurine. Oocytes were cultured at 38.9°C in 5% CO2 in humidified air. After 24 h of culture, oocytes with polar body were selected and submitted to activation treatments. Oocytes were exposed to calcium ionomycin (5 μM for 5 min) followed by incubation with 6-DMAP (2 mM), roscovitine (50 μM), or 6-DMAP + roscovitine for 3.5 h. After activation, oocytes were cultured in mSOF medium containing 0.8% BSA at 38.9°C in 5% CO2, 5% O2 in humidified air for 16 h and stained with Hoechst 33342 or aceto-orcein for assessment of nuclear status. Nuclear status was recorded as follows: 1PB (polar body) + 1PN (pronucleus), 2PB + 1PN and others. Data were analyzed using chi-square test. The maturation rate of bovine oocytes cultured in maturation medium containing hypotaurine/taurine (89.3%, n = 84) was higher (P < 0.05) than those cultured without hypotaurine/taurine (72%, n = 93). In the oocytes matured with hypotaurine/taurine, the rates of diploid activation (1PB + 1PN) were 84% (n = 50) in oocytes treated with 6-DMAP + roscovitine, 78.6% (n = 56) with 6-DMAP, and 52% (n = 50) with roscovitine. In the oocytes matured without hypotaurine/taurine, the rates of diploid activation were 80% (n = 60) in oocytes treated with 6-DMAP + roscovitine, 72% (n = 50) with 6-DMAP, and 54% (n = 50) with roscovitine. The rates of diploid activation were not different in oocytes matured with or without hypotaurine/taurine and among activation treatments. The oocytes treated with roscovitine showed a lower rate (P < 0.05) of diploid activation and higher rate (39.3–40%) of second polar body extrusion (1PN + 2PB) than the other activation groups in both maturation conditions. Cleavage rates to 2-cell stage were 40–45% in all groups. Development rate of blastocysts were 7–10% in all the groups treated with 6-DMAP and 6-DMAP + roscovitine and no blastocysts were obtained from the groups treated with roscovitine alone. Hypotaurine/taurine are known to be stable and potent antioxidants, and have shown the properties of supporting oocyte maturation and further embryonic development (Guerin and Menezo 1995 Zygote 3, 333–43; Mizushima and Fukui 2001 Theriogenology 55, 1432–45). In this study, although the effectiveness of hypotaurine/taurine on promoting oocyte maturation was observed, there were no significant improvements in the rate of diploid activation in oocytes matured with hypotaurine/taurine. These results suggest that the nuclear status of activated oocytes may not have a direct relationship with the enhanced maturation condition. This work was supported by BioGreen 21 Program(#1000520030100000-1), Republic of Korea.

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Resveratrol Hinders Postovulatory Aging by Modulating Oxidative Stress in Porcine Oocytes

Molecules ◽

10.3390/molecules26216346 ◽

2021 ◽

Vol 26 (21) ◽

pp. 6346

Author(s):

Benazir Abbasi ◽

Yan Dong ◽

Rong Rui

Keyword(s):

Oxidative Stress ◽

Polar Body ◽

Treated Group ◽

Control Group ◽

Relative Level ◽

Antioxidant Genes ◽

First Polar Body ◽

Postovulatory Aging ◽

Relative Mrna Expression

Postovulatory aging of the mammalian oocytes causes deterioration of oocytes through several factors including oxidative stress. Keeping that in mind, we aimed to investigate the potential of a well-known antioxidant, resveratrol (RV), to evaluate the adverse effects of postovulatory aging in porcine oocytes. After in vitro maturation (IVM), a group of (25–30) oocytes (in three replicates) were exposed to 0, 1, 2, and 4 μmol/L of RV, respectively. The results revealed that the first polar body (PB1) extrusion rate of the oocytes significantly increased when the RV concentration reached up to 2 μmol/L (p < 0.05). Considering optimum RV concentration of 2 μmol/L, the potential of RV was evaluated in oocytes aged for 24 and 48 h. We used fluorescence microscopy to detect the relative level of reactive oxygen species (ROS), while GHS contents were measured through the enzymatic method. Our results revealed that aged groups (24 h and 48 h) treated with RV (2 μmol/L) showed higher (p < 0.05) ROS fluorescence intensity than the control group, but lower (p < 0.05) than untreated aged groups. The GSH content in untreated aged groups (24 h and 48 h) was lower (p < 0.05) than RV-treated groups, but both groups showed higher levels than the control. Similarly, the relative expression of the genes involved in antioxidant activity (CAT, GPXGSH-Px, and SOD1) in RV-treated groups was lower (p < 0.05) as compared to the control group but higher than that of untreated aged groups. Moreover, the relative mRNA expression of caspase-3 and Bax in RV-treated groups was higher (p < 0.05) than the control group but lower than untreated groups. Furthermore, the expression of Bcl-2 in the RV-treated group was significantly lower than control but higher than untreated aged groups. Taken together, our findings revealed that the RV can increase the expression of antioxidant genes by decreasing the level of ROS, and its potent antiapoptotic effects resisted against the decline in mitochondrial membrane potential in aged oocytes.

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