167 Effect of Storage Time and Temperature of a Commercial Embryo Holding Medium on the Maturation Kinetics of Immature Bovine Oocytes

2018 ◽  
Vol 30 (1) ◽  
pp. 223
Author(s):  
O. B. Pascottini ◽  
M. Catteeuw ◽  
A. Van Soom ◽  
G. Opsomer
Keyword(s):  
Oocyte Maturation ◽  
Germinal Vesicle ◽  
Holding Time ◽  
Control Group ◽  
Nuclear Maturation ◽  
Maturation Medium ◽  
Maturation Rate ◽  
Maturation Stages ◽  
Bovine Oocytes ◽  
Kinetics Of

The effect of holding time and temperature during storage of immature bovine oocytes in a commercial embryo holding medium (EHM; Syngro® Ltd., Livingston, United Kingdom) was evaluated. Ovaries were collected at the local slaughterhouse and processed within 2 h. Cumulus-oocyte complexes (COC) were collected and allocated to groups of 60. The COC were held in 1-mL sterile glass osmometer tubes, filled to the top with the EHM to limit the amount of air. Vials were capped and covered with parafilm to ensure a tight seal and prevent leakage. Tubes were stored for 6 h at 4°C, room temperature (RT), or 38.5°C; for 10 h at 4°C and RT; and for 14 h at RT. Next, oocytes were fixed after storage in EHM (immature holding) or fixed after being held in EHM and subsequent 22-h maturation at 38.5°C in 5% CO2 in humidified air (mature holding). Maturation medium consisted of modified bicarbonate-buffered TCM-199 supplemented with gentamycin and epidermal growth factor. During all experiments, a control group was included each time. The control consisted of groups of 60 COC immediately fixed after collection or transferred to maturation medium for 22 h and subsequently fixed. Nuclear maturation of oocytes was assessed after Hoechst 33342 staining, using a 400× magnification fluorescence microscope. A total of 3043 COC were evaluated in 3 replicates. Oocytes maturation stages were classified as (1) oocytes in germinal vesicle stage, (2) oocytes in meiotic progression (diakinesis, metaphase I, or anaphase), (3) matured (telophase I or metaphase II), and (4) degenerated (degraded chromatin). Oocytes remained at the germinal vesicle stage when held in EHM (without subsequent maturation) regardless of holding time and temperature (P > 0.05). When oocytes were held for 6 h and subsequently matured (Table 1), the number of matured oocytes was significantly lower for oocytes held at 38.5°C compared with the other groups (control, RT, and 4°C). When held for 10 h, the oocyte maturation rate was similar between the control and RT groups (P > 0.05), but it was significantly lower in oocytes held at 4°C. Last, when compared with oocytes held at RT for 14 h, the maturation rate was higher in the control group (P < 0.05). To conclude, immature bovine oocytes can be successfully held in EHM at RT for up to 10 h. Storing immature oocytes in EHM can delay oocyte maturation and concomitantly synchronize maturation. Table 1.Kinetics of cumulus-oocyte complex nuclear status after storage in embryo holding medium for different times and temperatures and subsequent 22-h maturation

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.

Effect of exogenous gonadotrophins on ovarian morphology and oocyte maturation in the southern hairy nosed wombat Lasiohinus latifrons during the breeding season

2006 ◽  
Vol 18 (4) ◽  
pp. 477 ◽  
Author(s):  
C. H. McDonald ◽  
D. A. Taggart ◽  
W. G. Breed ◽  
G. V. Druery ◽  
G. A. Shimmin ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Follicular Development ◽  
Germinal Vesicle ◽  
Control Group ◽  
Antral Follicles ◽  
Nuclear Maturation ◽  
Significant Difference ◽  
Ovarian Morphology ◽  
The Mean ◽  
The Right

The effect of the exogenous administration of porcine follicle-stimulating hormone (pFSH) and pregnant mare serum gonadotrophin (PMSG) on ovarian follicular development and oocyte maturation in the southern hairy nosed wombat Lasiorhinus latifrons was investigated. Three experimental groups were administered pFSH at various doses and for different treatment lengths, followed by 25 mg porcine luteinising hormone (pLH) 12 h after the last dose of pFSH. Another group was given PMSG followed 72 h later by 25 mg pLH. Animals were killed 24 h after pLH. The left ovary was fixed for histology and the morphology of the antral follicles was determined, whereas follicular oocytes in the right ovary were aspirated, fixed, stained with 4′,6′-diamidino-2-phenylindole, and viewed for nuclear maturation. There was no significant difference in the mean number of ovarian follicles >1 mm, or in the size class of follicles assessed between control and experimental groups. However, a trend was observed suggesting a possible increase in follicles >3.0 mm in experimental groups compared with control animals. In all females administered exogenous porcine gonadotrophins, but not controls, some of the mural granulosa cells of large tertiary antral follicles had markedly enlarged nuclei (approximately 14 µm in diameter). All oocytes from the control group remained at the germinal vesicle stage, whereas approximately 40% of oocytes retrieved from the pFSH groups and 82.4% retrieved from the PMSG-primed animals had undergone germinal vesicle break down, with a small number reaching meiosis II. The present study shows that exogenous administration of either pFSH or PMSG to hairy nosed wombats can induce follicular growth and oocyte maturation. Such findings could be useful in the development of reproductive technology in this species.

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).

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.

Effects of ghrelin on activation of Akt1 and ERK1/2 pathways during in vitro maturation of bovine oocytes

Zygote ◽  
2017 ◽  
Vol 25 (2) ◽  
pp. 183-189 ◽  
Author(s):  
Thomas-Markos Chouzouris ◽  
Eleni Dovolou ◽  
Fotini Krania ◽  
Ioannis S. Pappas ◽  
Konstantinos Dafopoulos ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Cumulus Cells ◽  
Treated Group ◽  
Control Group ◽  
Dependent Manner ◽  
Nuclear Maturation ◽  
Bovine Oocytes ◽  
Phosphorylation Rate ◽  
Matured Oocyte

SummaryThe purpose of this study was to investigate the possible molecular pathways through which ghrelin accelerates in vitro oocyte maturation. Bovine cumulus–oocyte complexes (COCs), after 18 or 24 h maturation in the absence or the presence of 800 pg ml–1 of acylated ghrelin were either assessed for nuclear maturation or underwent in vitro fertilization in standard media and putative zygotes were cultured in vitro for 8 days. In a subset of COCs the levels of phosphorylated Akt1 and ERK1/2 (MAPK1/3) were assessed at the 0th, 6th, 10th, 18th and 24th hours of in vitro maturation (IVM). At 18 and 24 h no difference existed in the proportion of matured oocytes in the ghrelin-treated group, while in the control group more (P < 0.05) matured oocyte were found at 24 h. Oocyte maturation for 24 h in the presence of ghrelin resulted in substantially reduced (P < 0.05) blastocyst yield(16.3%) in comparison with that obtained after 18 h (30.0%) or to both control groups (29.3% and 26.9%, for 18 and 24 h in maturation, respectively). Ghrelin-treated oocytes expressed lower Akt1 phosphorylation rate at the 10th hour of IVM, and higher ERK1/2 at the 6th and 10th hours of IVM compared with controls. In cumulus cells, at the 18th and 24th hours of IVM Akt1 phosphorylation rate was higher in ghrelin-treated oocytes. Our results imply that ghrelin acts in a different time-dependent manner on bovine oocytes and cumulus cells modulating Akt1 and ERK1/2 phosphorylation, which brings about acceleration of the oocyte maturation process.

The effects of cysteine addition during in vitro maturation on the developmental competence, ROS, GSH and apoptosis level of bovine oocytes exposed to heat stress

Zygote ◽  
2011 ◽  
Vol 20 (3) ◽  
pp. 249-259 ◽  
Author(s):  
Hisashi Nabenishi ◽  
Hiroshi Ohta ◽  
Toshihumi Nishimoto ◽  
Tetsuo Morita ◽  
Koji Ashizawa ◽  
...  
Keyword(s):  
Heat Stress ◽  
Formation Rate ◽  
Cumulus Cells ◽  
Developmental Competence ◽  
Control Group ◽  
Blastocyst Formation ◽  
Nuclear Maturation ◽  
Maturation Medium ◽  
Bovine Oocytes

SummaryIn the present study, we investigated the effects of various concentrations of cysteine (0.0, 0.6, 1.2 and 1.8 mM) added to the maturation medium on nuclear maturation and subsequent embryonic development of bovine oocytes exposed to heat stress (HS: set at 39.5 °C for 5 h, 40.0 °C for 5 h, 40.5 °C for 6 h, and 40.0 °C for 4 h versus 38.5 °C for 20 h as the control group). This regime mimicked the circadian rhythm of the vaginal temperature of lactating dairy cows during the summer season in southwestern Japan. Moreover, we also evaluated the oocyte's reactive oxygen species (ROS) and glutathione (GSH) levels and the apoptosis levels of the oocytes and cumulus cells in the presence or absence of 1.2 mM cysteine. As a result, HS in the without-cysteine group significantly suppressed (p < 0.05) both the nuclear maturation rate up to the metaphase (M)II stage and the blastocyst formation rate compared with that of the control group. In addition, this group showed significantly higher (p < 0.05) ROS levels and significantly lower (p < 0.05) GSH levels than those of the control group. Moreover, the level of TdT-mediated dUTP nick end labelling (TUNEL)-positive cumulus cells in the HS without-cysteine group was significantly higher (p < 0.05) than that of the control group. However, the addition of 1.2 mM cysteine to the maturation medium restored not only the nuclear maturation, blastocyst formation rates and GSH contents, but also increased the ROS and TUNEL-positive levels of the cumulus cells, but not oocytes, to that of the control group. These results indicate that the addition of 1.2 mM cysteine during in vitro maturation (IVM) may alleviate the influence of heat stress for oocyte developmental competence by increasing GSH content and inhibiting the production of oocyte ROS followed by apoptosis of cumulus cells.

Differential effects of linoleic and alpha-linolenic fatty acids on spatial and temporal mitochondrial distribution and activity in bovine oocytes

2012 ◽  
Vol 24 (5) ◽  
pp. 679 ◽  
Author(s):  
Waleed F. Marei ◽  
D. Claire Wathes ◽  
Ali A. Fouladi-Nashta
Keyword(s):  
Membrane Potential ◽  
Oocyte Maturation ◽  
Inhibitory Effect ◽  
Inner Membrane ◽  
Nuclear Maturation ◽  
Mitochondrial Inner Membrane ◽  
Maturation Rate ◽  
Microscope Imaging ◽  
Mitochondrial Distribution ◽  
Bovine Oocytes

Using specific stains and confocal microscope imaging, the patterns of mitochondrial distribution, mitochondrial inner membrane potential and reactive oxygen species (ROS) levels during bovine oocyte maturation were determined in the presence or absence of physiological concentrations of linoleic acid (LA; 100 µM) or α-linolenic acid (ALA; 50 µM). Mitochondrial distribution in control oocytes at 0 h was mainly peripheral and changed to a diffused pattern after 1 h of culture; this was maintained up to 24 h. Mitochondrial clusters were observed during the early hours of maturation (1–4 h); the majority of these were arranged in perinuclear fashion. LA supplementation resulted in: (1) delayed redistribution of the mitochondria from a peripheral to a diffuse pattern and a decreased percentages of oocytes showing perinuclear mitochondrial clusters, (2) decreased mitochondrial inner membrane potential at 1 and 24 h compared with the control and (3) higher ROS levels, associated with a lower nuclear maturation rate. In contrast, ALA supplementation had no effect on mitochondrial distribution and activity and decreased ROS levels compared with the control; this was associated with an increased nuclear maturation rate. In conclusion, LA induced alterations in mitochondrial distribution and activity as well as increasing ROS levels, which mediate, at least in part, the inhibitory effect on oocyte maturation.

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

2013 ◽  
Vol 25 (3) ◽  
pp. 587
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 0.02mgmL–1 (21.5 to 71.8µM, with a mean of ~50µM). 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 50µM 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 24h. 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 1min of exposure to 2.5µM ionomycin followed by 2mM 6-DMAP treatment for 3h. 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&lt;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 50µM 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.

scholarly journals Effect of concentration and exposure period to butyrolactone I on meiosis progression in bovine oocytes

2006 ◽  
Vol 58 (3) ◽  
pp. 354-359 ◽  
Author(s):  
P.R. Adona ◽  
C.L.V. Leal
Keyword(s):  
Drug Concentration ◽  
In Vitro Maturation ◽  
Germinal Vesicle ◽  
Exposure Period ◽  
Culture Period ◽  
Nuclear Maturation ◽  
Bovine Oocytes ◽  
Kinetics Of

The effect of concentration and exposure period of bovine oocytes to butyrolactone I (BLI) on meiotic block and in vitro maturation (IVM) kinetics was studied. In experiment 1, all oocytes were at germinal vesicle stage (GV), after 6h in culture with 0, 50 and 100µM BLI. After 12h, all oocytes cultured with 50 and 100µM BLI remained in GV. After 24h, less oocytes were in GV with 50µM (82%) than with 100µM BLI (99%, P<0.05). In experiment 2, after 6h IVM, 93% of control oocytes (IVM only) were in GV, while treated oocytes (100µM BLI for 6, 12 or 24h prior to IVM) showed less oocytes in GV with increased exposure period to BLI prior to IVM (83 and 73%, for 6h and 12h, P<0.05). For a 24h inhibition, GV rates were similar to 12h (70%, P>0.05). After 18h IVM, metaphase II (MII) rates were similar for all groups (76-81%). In experiment 3, after 6h IVM, 74% of treated oocytes (50 or 100µM BLI for 12h) were in GV. This rate was lower than for control oocytes (97.3%, P<0.05). After 18h IVM more oocytes (~80%, P>0.05) were in MII with BLI than for control (73%, P<0.05). Shorter culture periods require lower BLI concentration for meiotic block; initial nuclear maturation kinetics of oocytes cultured with BLI is accelerated, and this is affected by culture period but not by drug concentration.

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