46 SPINDLE CONFIGURATION OF IN VITRO-MATURED BOVINE OOCYTES EXPOSED TO SODIUM CHLORIDE OR SUCROSE PRIOR TO CRYOTOP VITRIFICATION

It has been previously described that a simple treatment with medium containing elevated NaCl or sucrose concentrations increases the cryotolerance and developmental competence of in vitro-matured porcine oocytes after vitrification and parthenogenetic activation (Lin et al. 2009 Reprod. Fertil. Dev. 21, 338–344). This work was designed to study whether the exposure to increased concentrations of NaCl or sucrose before vitrification improves cryotolerance of in vitro-matured bovine oocytes. In Experiment 1, in vitro-matured oocytes were exposed to different NaCl and sucrose concentrations (from 375 to 808 mOsm) for 1 h. In Experiment 2, and according to the results obtained in the first experiment, oocytes were exposed to 375 mOsm NaCl or sucrose solution, vitrified, and warmed. Nontreated oocytes were used as controls. In both experiments, oocytes were fixed after treatment and microtubule, and chromosome distribution was analysed by immunocitochemistry. All statistical analyses were conducted with the IBM SPSS 19 for Windows (IBM corp., Chicago, IL). ANOVA was performed to analyse differences in meiotic spindle. Statistical significance was set at P < 0.05. After exposure to 375 mOsm of NaCl or sucrose, similar percentages of oocytes showing normal chromosome distribution were obtained compared to the control group (83.4, 71.8, and 85.0%, respectively). Groups treated with higher concentrations (443 to 808 mOsm) triggered significantly lower proportions of normal spindles. After vitrification/warming, no significant differences were observed between nonvitrified oocytes (71.3%) and those treated with NaCl before vitrification/warming procedure (41.9%) when normal chromosome organisation was analysed. Significantly higher percentages of normal chromosome configuration were observed when oocytes were exposed to sucrose before vitrification (34.2%) compared with control-vitrified oocytes (23.3%). However, pretreatment with NaCl or sucrose before vitrification did not trigger significant differences in terms of percentages of normal microtubule configuration (41.9 and 32.9%, respectively) compared with control-vitrified oocytes (40.2 and 24.4%, respectively), although both treatments differed significantly from control (79.1 and 81.7%, respectively). In conclusion, this study showed that a 375-mOsm NaCl or sucrose pretreatment of bovine oocytes before vitrification did not have a deleterious effect on the organisation of the meiotic spindle of vitrified/warmed bovine oocytes. Further experiments are required to investigate whether in vitro-matured oocytes subjected to this osmotic treatment could improve their development competence after being vitrified/warmed.

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346 BOVINE EMBRYO DEVELOPMENT AFTER IVM/IVF/IVC OF OOCYTES STORED FOR 22 H IN VARIOUS MEDIA

Reproduction Fertility and Development ◽

10.1071/rdv19n1ab346 ◽

2007 ◽

Vol 19 (1) ◽

pp. 288

Author(s):

C. Kubota ◽

T. Kojima ◽

T. Nagai ◽

X. Tian ◽

X. Yang

Keyword(s):

Subsequent Development ◽

Industrial Applications ◽

Blastocyst Stage ◽

Developmental Competence ◽

Control Group ◽

Bovine Embryo ◽

Becton Dickinson ◽

In Vitro Storage ◽

Bovine Oocytes

The timing of IVM–IVF–IVC is restricted by the onset of oocyte maturation, and sometimes oocytes must be treated at midnight. If we could regulate the timing of IVM of oocytes without decreasing their developmental competence, the IVM–IVF–IVC system could be a more applied technology. The present study was performed to examine the effects of in vitro storage of bovine oocytes in simple media prior to maturation culture to manipulate the start of IVM. Bovine follicular fluid (bFF), Dulbecco's PBS (PBS), M199 Earle salts (M199), and Earle salts supplemented with 5 mM NaHCO3 (M199A) were used as the fundamental media, after an addition of antibiotics, for in vitro storage of bovine cumulus–oocyte complexes (COCs) collected from ovaries obtained at the slaughterhouse. The fundamental media except for bFF were supplemented with 10&percnt; fetal bovine serum (FBS) or 1 mg mL−1 polyvinyl alcohol (PVA). COCs were collected from follicles (3–8 mm in diameter) and washed twice in each medium; then approximately 50 COCs were submerged in 1 mL of each medium in cryotubes (Falcon #2812, 2.5 mL; Becton Dickinson Labware, Lincoln, NJ, USA), which were stored in a container kept at 38.5°C for 22 h under air-closed condition (in vitro storage: IVS). Subsequently, the stored COCs were in vitro-matured (IVM) for 22 h in M199 with 10&percnt; FBS and 20 µg mL−1 estradiol, fertilized (IVF), and cultured in CR1aa (IVC) for examination of their development to the blastocyst stage (Kubota et al. 1998 Mol. Reprod. Dev. 51, 281–286). Fresh oocytes without IVS were used as controls. The nuclear status of oocytes after IVS–IVM was compared to that of control oocytes by aceto-orcein stain. Their developmental rates to the blastocyst stage after IVM–IVF–IVC were compared between experimental and control groups. The experiment was repeated more than 3 times, and results were statistically analyzed using Student's t-test. When bFF and PBS supplemented with FBS or PVA were used for IVS, the rates of survived COCs after IVS and the development to the blastocyst stage after IVM–IVF–IVC (bFF (n = 87): 0&percnt;, 0&percnt;; PBS/FBS (n = 72): 84&percnt;, 1&percnt;; and PBS/PVA (n = 81): 89&percnt;, 6&percnt;, respectively) were significantly lower than those of the control group (n = 406; 97&percnt; and 29&percnt;, respectively). On the other hand, when M199A supplemented with FBS or PVA was used for IVS, the survival rate after IVS and the developmental rate to the blastocyst stage after IVS–IVM–IVF (M199A/FBS (n = 97): 82&percnt;, 28&percnt;; and M199A/PVA (n = 111): 98&percnt;, 31&percnt;, respectively) did not differ from those of the control group. After IVS, cumulus expansion was not seen and most of the oocyte nuclei reached the GVBD stage. These results suggest that the nuclear maturation progress of bovine oocytes can be regulated for at least 22 h in M199A without any deleterious influence on the number of oocytes surviving at an immature state after the storage and their subsequent development to the blastocyst stage after IVM–IVF–IVC. The delayed maturation allows a flexible fertilization schedule which is advantageous in research and industrial applications.

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25 Effect of taxol and epothilone B on meiotic spindle stabilization in vitrified bovine oocytes

Reproduction Fertility and Development ◽

10.1071/rdv33n2ab25 ◽

2021 ◽

Vol 33 (2) ◽

pp. 120

Author(s):

E. Girka ◽

K. R. Bondioli

Keyword(s):

Ethylene Glycol ◽

Dimethyl Sulfoxide ◽

Recovery Period ◽

Normal Chromosome ◽

Meiotic Spindle ◽

Control Group ◽

Chromosome Arrangement ◽

Epothilone B ◽

Significant Difference ◽

Bovine Oocytes

Vitrification has the potential to be a valuable technique for preservation of bovine oocytes; however, this method often results in abnormal microtubule and chromosome arrangement. The aim of this experiment was to evaluate taxol and epothilone B as meiotic spindle stabilising pretreatments in a vitrification protocol. Bovine oocytes were purchased and matured invitro during shipment. At 18h of maturation, oocytes were divided randomly into control, taxol, and epothilone B treatments (Table 1). All treatments were prepared in invitro maturation (IVM) medium (IVF Biosciences). Partially denuded oocytes were incubated in either control or treatment medium for 15min at 38.5°C before vitrification. Oocytes were incubated in an equilibration solution (10% dimethyl sulfoxide, 10% ethylene glycol) for 5min, transferred to a vitrification solution (20% dimethyl sulfoxide, 20% ethylene glycol, 0.5M sucrose), loaded onto a Cryolock, and plunged into liquid nitrogen within 45s. For warming, a Cryolock was placed directly into a 0.5M sucrose solution and incubated for 3min. Oocytes were transferred to a 0.25M solution for 3min and washed in the basal solution used for vitrification and warming media (Dulbecco’s phosphate-buffered saline, 20% fetal bovine serum). Once warmed, oocytes were transferred to IVM medium for a 4-h recovery period and completely denuded before staining. Staining to evaluate spindle morphology was performed with anti α-tubulin primary antibody and secondary antibody Alexa Fluor 488. Oocytes were also stained with Hoechst to evaluate chromosome arrangement. Both spindle morphology and chromosome arrangement data were analysed using a logistic regression with a binomial response variable (normal/abnormal). Both 0.5μM and 1.0μM Taxol treatments had no effect on either meiotic spindle or chromosome arrangement compared with the control group (P>0.05). The 2.0μM taxol treatment improved chromosome configuration (P<0.05) with no effect on microtubule distribution compared with the control group (P>0.05). All epothilone B treatments resulted in disruption of microtubule distribution and chromosome arrangement compared with control (P<0.001) and resulted in a consistent abnormality hypothesised to be tubulin polymerization. These results indicate that taxol is capable of increasing the occurrence of normal chromosome arrangement in vitrified bovine oocytes and that epothilone B may cause additional harm to the oocyte that is not associated with the metaphase plate. Table 1. Effect of stabilisation agents on meiotic spindle of invitro-matured bovine oocytes Treatment n Normal microtubule distribution (%) Normal chromosome arrangement (%) Control 100 44 47 0.5μM Taxol 104 44 37 1.0μM Taxol 98 43 56 2.0μM Taxol 102 49 62a 0.5μM Epothilone B 103 11b 11b 1.0μM Epothilone B 97 6b 8b 2.0μM Epothilone B 100 2b 1b aP<0.05;. bP<0.001: Different superscripts within a column indicate a significant difference.

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

Reproduction Fertility and Development ◽

10.1071/rdv18n2ab329 ◽

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 μÂm; serum+FSH-free: 12 ± 0.5 μÂm, P < 0.05; α-amanitin: 10 ± 0.6 μÂm, P < 0.001) and sperm asters (control: 86 ± 4 μÂm; serum+FSH-free: 82 ± 4 μÂm, 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

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Developmental competence and expression of the MATER and ZAR1 genes in immature bovine oocytes selected by brilliant cresyl blue

Zygote ◽

10.1017/s0967199409990219 ◽

2009 ◽

Vol 18 (3) ◽

pp. 209-216 ◽

Cited By ~ 11

Author(s):

Gustavo Bruno Mota ◽

Ribrio Ivan Tavares Pereira Batista ◽

Raquel Varella Serapião ◽

Mariana Cortes Boité ◽

João Henrique Moreira Viana ◽

...

Keyword(s):

Developmental Competence ◽

Control Group ◽

Blue Dye ◽

Brilliant Cresyl Blue ◽

Immature Oocytes ◽

Relative Expression ◽

Cresyl Blue ◽

Blastocyst Rate ◽

Bovine Oocytes

SummaryThe objective of this work was to evaluate the selection of immature bovine oocytes by brilliant cresyl blue dye (BCB) and expression of transcripts MATER and ZAR1. Cumulus–oocyte complexes (COCs) from slaughterhouse ovaries were exposed to BCB diluted in mDPBS and incubated for 60 min at 38.5 °C in humidified air. After exposure those COCs were distributed in two groups, according to their cytoplasm colour: BCB+ (coloured cytoplasm) or BCB− (colourless cytoplasm). The control group was submitted to in vitro maturation (IVM) immediately after morphological selection and holding control group COCs were exposed to mDPBS without BCB but in the same incubation conditions of BCB+ and BCB− group. The COCs of all groups were submitted to IVM, in vitro fertilization (IVF) and in vitro culture (IVC). Cleavage rate (72 h post-insemination) was similar between control (65.3%) and BCB+ (64.4%) groups, but greater than (p < 0.05) holding control (49.8%) and BCB− (51.3%) groups. Blastocyst rate (192 h post-insemination) was not different between BCB+ (18.5%) and control (16.3%) groups, but greater (p < 0.05) than BCB− (8.4%) group. No difference was found for blastocyst rate between holding control group (14.2%), control and BCB+ groups. The relative expression of MATER and ZAR1 genes was evaluated by real-time PCR in immature oocytes collected from the control, holding control, BCB+ and BCB− groups. Despite the relative expression of MATER in holding control, BCB+ and BCB− were down regulated in comparison to control group there was no statistical difference (p > 0.05) in the relative expression of MATER and ZAR1 transcripts among groups. The results indicate that the BCB dye detects immature oocyte populations with different developmental competence, although no improvement in in vitro embryo production using oocytes exposed or not to BCB was observed. Development competence of immature oocytes exposed to BCB does not seem to be associated with variations in the expression of MATER and ZAR1 transcripts.

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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 ◽

10.1017/s0967199411000220 ◽

2011 ◽

Vol 20 (3) ◽

pp. 249-259 ◽

Cited By ~ 50

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.

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166 THE EFFECT OF TEMPERATURE DURING STORAGE OF IN VITRO-MATURED BOVINE OOCYTES IN A HEPES-BUFFERED MEDIUM ON DEVELOPMENTAL COMPETENCE

Reproduction Fertility and Development ◽

10.1071/rdv28n2ab166 ◽

2016 ◽

Vol 28 (2) ◽

pp. 213

Author(s):

T. Suttirojpattana ◽

T. Somfai ◽

S. Matoba ◽

T. Nagai ◽

R. Parnpai ◽

...

Keyword(s):

Polar Body ◽

Calf Serum ◽

Cell Number ◽

Developmental Competence ◽

Effect Of Temperature ◽

Control Group ◽

Atp Content ◽

Developmental Rates ◽

Bovine Oocytes

The objective of this study was to clarify the effect of the temperature during liquid storage in in vitro matured (IVM) bovine oocytes. IVM bovine oocytes were stored in Eppendorf tube containing 1 mL HEPES TCM-199 supplemented with 10% (v/v) new born calf serum at different temperatures (4°C, 15°C, 25°C, and 38.5°C) for 20 h. The developmental rates of stored and not stored (control) oocytes to the blastocyst stage, cell numbers in resultant blastocysts, and fertilization normality were evaluated after in vitro fertilization and in vitro culture. The ATP content, reduced glutathione (GSH) content, and apoptosis rates in oocytes were also determined in stored and control groups. At least 3 replicates were conducted for each experiment. The data were analysed by 1-way ANOVA followed by post hoc Fisher’s protected least significantly difference test. Percentage data were transformed to arc-sine before analysis. All of the storage groups (4, 15, 25, and 38.5°C groups, respectively) showed significantly lower blastocyst developmental rates (8.5, 14.9, 19.3, and 24.5%, respectively) compared with the control group (39.8%; P < 0.05). Within the storage groups, the 25°C and the 38.5°C groups exhibited the greatest rate of blastocyst formation. In contrast, the total cell number of the 38.5°C group was significantly lower than that of control group (P < 0.05), whereas that of the 25°C group was similar with the control group. The frequency of normal emission of the second polar body (2PB) was significantly greater in the control group compared with the storage groups (P < 0.05). The 2PB emission rate was significantly lower in the 38.5°C group compared with the 4°C group (P < 0.05) but not different from those of the 15°C and 25°C storage groups. The percentage of male pronuclear formation in the control group was significantly higher than those in the stored groups (P < 0.05) except for the 25°C group. During storage at 4°C, the ATP content was significantly decreased compared with the control group (1.3 v. 1.7 pmol; P < 0.05); however, in the 25°C and 38.5°C groups, the ATP content (2.0 and 1.9 pmol, respectively) was significantly higher than that in the control group (1.7 pmol; P < 0.05); whereas the 15°C group showed the same ATP level compared with the control group. Storage of oocytes for 20 h reduced the GSH content compared with the control group without storage (P < 0.05); however, there were no significant differences among storage groups. Annexin-V staining revealed increased incidences of early apoptotic oocytes in the 4°C and 15°C groups (P < 0.05) compared with other groups. In conclusion, based on the embryo developmental competence of stored oocytes and quality of resultant blastocysts, 25°C was determined as the most suitable temperature for temporal storage of matured bovine oocytes. The study was supported by the NARO Institute of Livestock and Grassland Science, Japan (N32G4126), and the Royal Golden Jubilee-PhD scholarship (2.B.TS/53/F.2).

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Multiple aster formation is frequently observed in bovine oocytes retrieved from 1-day stored ovaries

Zygote ◽

10.1017/s096719941400080x ◽

2015 ◽

Vol 24 (1) ◽

pp. 115-120 ◽

Cited By ~ 1

Author(s):

H. Hara ◽

M. Tagiri ◽

M. Hirabayashi ◽

S. Hochi

Keyword(s):

Coiled Coil ◽

Developmental Competence ◽

Control Group ◽

Rock Inhibitor ◽

Developmental Potential ◽

Suppression Effect ◽

Bovine Ovary ◽

Bovine Oocytes ◽

Short Term Culture

SummaryWe have recently reported that multiple aster formation after in vitro fertilization (IVF) was one of the factors that negatively affected the developmental competence of vitrified-warmed bovine matured oocytes, and that short-term culture of the post-warm oocytes with an inhibitor of Rho-associated coiled-coil kinase (ROCK) suppressed the multiple aster formation and improved the blastocyst yield. The present study was conducted to investigate whether increased multiple aster formation following IVF was involved in impaired developmental competence of stored ovary-derived bovine oocytes. Oocytes retrieved from 1-day stored ovaries had lower developmental potential to day 8 blastocysts when compared with those from fresh ovaries (37 versus 63%). Immunostaining of α-tubulin 10 h post-IVF revealed that a higher incidence of multiple aster formation occurred in oocytes retrieved from stored ovaries than from fresh ovaries (31 versus 15%). Treatment of post-in vitro maturated (post-IVM) oocytes with ROCK inhibitor for 2 h significantly suppressed the incidence of multiple aster formation (10 versus 32% in the control group). However, the suppression effect of ROCK inhibitor on multiple aster formation in IVM/IVF oocytes did not improve blastocyst yield from stored ovary-derived oocytes (41 versus 37% in the control group). These results suggested that the higher incidence of multiple aster formation by bovine ovary storage was not responsible for the decreased developmental competence of IVF oocytes.

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235RETINOID-DEPENDENT MRNA EXPRESSION IN BOVINE OOCYTES PREMATURED AND/OR MATURED IN VITRO

Reproduction Fertility and Development ◽

10.1071/rdv16n1ab235 ◽

2004 ◽

Vol 16 (2) ◽

pp. 238

Author(s):

E. Gomez ◽

C. Diez ◽

E. Moran ◽

A. Rodriguez ◽

L.J. Royo ◽

...

Keyword(s):

Cell Cycle ◽

Mrna Expression ◽

Cumulus Cells ◽

Cyclin B1 ◽

Defined Medium ◽

Developmental Competence ◽

Control Group ◽

Free Oxygen Radicals ◽

Bovine Oocytes

As a transcription factor, retinoic acid (RA) can activate or silence a wide number of genes, thus inducing differentiation in cell systems and playing a role in cell cycle regulation. However, little is known of RA-dependent gene expression in the oocyte. Bovine oocytes and cumulus cells express most RA receptors, and the presence of 9-cis-RA during in vitro maturation (IVM) is beneficial to oocyte development (Duque et al., 2002 Hum. Reprod. 17, 2706–2714; Hidalgo et al., 2003 Reproduction 125, 409–416). The present work analyzes the relative abundance of various developmentally important gene transcripts in bovine oocytes during in vitro prematuration and/or maturation. Cumulus-oocyte complexes (COCs) were manipulated in defined medium with polyvinyl-alcohol (DM-PVA). Those COCs undergoing prematuration were cultured for 24h in DM-PVA with 25μM roscovitine. For IVM, some prematured COCs were cultured for 24h in DM-PVA containing pFSH, LH and E2. Incubations were made at 39°C in an atmosphere of 5% CO2 in air and high humidity. Within experiments, COCs were cultured with nM 9-cis-RA 5, in 1% ethanol (both as vehicle and inhibitor of endogenous RA synthesis), 3% ethanol, 5% ethanol and untreated. Using Real Time PCR (10 oocytes per group) (Rizos et al., 2003 Biol. Reprod. 68, 236) we examined the relative mRNA expression of genes involved in protection against free oxygen radicals (Mn-superoxide dismutase, MnSOD), glucose metabolism (glucose-6-phosphate dehydrogenase, G6PDH) and cell cycle events (Cyclin B1 and H1). Data (of 4 replicates) were analyzed by ANOVA and Duncan test (P<0.05). Regarding immature oocytes, prematuration in 1% ethanol increased cyclin B1 expression and decreased cyclin H1, while 9-cis-RA increased G6PDH. Maturation without additives increased cyclin B1 and G6PDH, but decreased cyclin H1 and MnSOD expression;; opposite trends were observed under increasing ethanol dosages (3% and 5%). Maturation with 1% ethanol or 9-cis-RA enhanced cyclin B1 and G6PDH, while reducing cyclin H1 and MnSOD expressions. The presence of 9-cis-RA during both prematuration and maturation processes tended to show more prominent effects than the ones observed when it was present only during prematuration or maturation alone. In our study, in presence of 9-cis-RA during both prematuration and maturation processes, the expression of cyclin B1 and G6PDH tended to increase, while cyclin H1 and MnSOD tended to decrease. However, the differences with the control group without additives were not significant. Our study during both prematuration and maturation processes show that beneficial effects of RA on oocyte developmental competence may not be related to the alteration of mRNA expression of the four genes analyzed. Grant support: Spanish Ministry of Science and Technology (AGL-2002-01175; 2003-05783).

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Abilities of cumulus and granulosa cells to enhance the developmental competence of bovine oocytes during in vitro maturation period are promoted by midkine; a possible implication of its apoptosis suppressing effects

Reproduction ◽

10.1530/rep.1.01066 ◽

2006 ◽

Vol 132 (4) ◽

pp. 549-557 ◽

Cited By ~ 24

Author(s):

S Ikeda ◽

K Saeki ◽

H Imai ◽

M Yamada

Keyword(s):

Dna Fragmentation ◽

Granulosa Cells ◽

Cumulus Cell ◽

Cumulus Cells ◽

Blastocyst Stage ◽

Developmental Competence ◽

Control Group ◽

Blastocyst Development ◽

Bovine Oocytes

We previously reported that when midkine (MK), a heparin-binding growth differentiation factor was used inin vitromaturation (IVM) culture of bovine cumulus-enclosed oocytes (CEOs), their developmental competence to the blastocyst stage afterin vitrofertilization (IVF) was enhanced and the effect of MK might be mediated by its action upon mural granulosa cells and cumulus cells that closely surround the oocyte. In the present study, when denuded oocytes (DOs) were matured in IVM medium with or without MK (200 ng/ml) in the presence or absence of isolated cumulus cell masses and subjected to IVF, the enhancing effects of MK on the developmental competence of DOs to the blastocyst stage after IVF were exerted only in the presence of cumulus cells. In addition, we prepared the conditioned media of granulosa cells cultured with or without 200 ng MK/ml (CMMK+ or CMMK− respectively) and examined their effects on the IVM of DOs in terms of their developmental competence to the blastocyst stage after IVF. The supplementation of CMMK+ into IVM medium at 40% (v/v) significantly enhanced the blastocyst development compared with the no additive control and the CMMK− supplemented groups. Furthermore, the effects of MK during IVM of bovine CEOs on the cumulus cell apoptosis were investigated. CEOs were cultured up to 24 h in IVM medium without (control) or with 200 ng MK/ml. The genomic DNA was extracted from CEOs at 0, 6, 12, 18 and 24 h of IVM and subjected to ligation-mediated PCR (LM-PCR) to detect the apoptotic internucleosomal DNA fragmentation. DNA fragmentation was scarcely detected at the start of IVM, whereas it increased time-dependently as the IVM culture progressed. The degree of the fragmentation was significantly lower in the MK-treatment group compared with the control group at 18 and 24 h of IVM. The apoptosis-suppressing effect of MK on cumulus cells was further confirmedin situby using TUNEL on CEOs. In conclusion, data from the present study further confirmed that MK enhances the developmental competence of bovine oocytes via cumulus and granulosa cells. It was also demonstrated that MK suppresses the apoptosis that occurs in cumulus cells during the period of IVM of bovine CEOs. The putative soluble factor(s) from cumulus cells was suggested from the experiment using CMMK+ . MK may promote the production of such factors in part by its anti-apoptotic effects on cumulus cells.

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Effect of exogenous DMNPE-caged ATP on in vitro-matured bovine oocytes prior to parthenogenetic activation, fertilisation and nuclear transfer

Reproduction Fertility and Development ◽

10.1071/rd04055 ◽

2004 ◽

Vol 16 (8) ◽

pp. 781 ◽

Cited By ~ 1

Author(s):

Jun Xue ◽

Melissa A. Cooney ◽

Vanessa J. Hall ◽

Natasha A. Korfiatis ◽

R. Tayfur Tecirlioglu ◽

...

Keyword(s):

Nuclear Transfer ◽

Calcium Oscillations ◽

Developmental Competence ◽

Control Group ◽

Dependent Manner ◽

Blastocyst Development ◽

Cell Numbers ◽

Caged Atp ◽

Bovine Oocytes

Adenosine triphosphate (ATP) plays an important role during fertilisation of the mammalian oocyte through its ability to alter the frequency and duration of calcium oscillations. It has also been shown that higher ATP levels correlate with increased developmental competence in bovine and human oocytes. During somatic cell nuclear transfer (NT), the incoming nucleus is remodelled extensively, undoubtedly using a variety of ATP-dependent enzymes. The aim of the present study was to determine whether additional exogenous ATP influences activation of parthenogenetic (PA), in vitro-fertilised (IVF) or cloned (NT) in vitro-matured bovine oocytes. Blastocyst development and cell numbers in PA embryos were found to increase in a dose-dependent manner following the photorelease of 0, 50, 100, 500 and 1000 μm DMNPE-caged ATP (adenosine 5′-triphosphate, P3-(1-(4,5-dimethoxy-2-nitrophenyl)ethyl) ester, disodium salt). No cleavage was found following release of 2 and 5 mm DMNPE-caged ATP or with DMNPE-caged ATP (not photoreleased). There were also no differences in blastocyst rates or cell numbers between the control group and groups treated with caged, but not photoreleased, ATP. The addition of exogenous ATP before IVF or to NT couplets did not result in a significant increase in blastocyst development or cell number. Embryo transfer is necessary to determine whether exogenous ATP can positively affect reprogramming, resulting in higher cloned pregnancy rates or live-term births.

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