43 WARMING TEMPERATURE AFFECTS THE VIABILITY AND MEIOTIC COMPETENCE OF IMMATURE PORCINE OOCYTES VITRIFIED IN A CHEMICALLY DEFINED SOLUTION

2014 ◽  
Vol 26 (1) ◽  
pp. 135
Author(s):  
D. Takahashi ◽  
H. Funahashi

The aim of this study was to examine the viability and meiotic competence of porcine oocytes when immature porcine cumulus-oocyte complexes (COC) were pretreated for vitrification at different temperatures (25 and 39°C), vitrified in a chemically defined solution, and warmed at different temperatures (39 and 60°C). Cumulus-oocyte complexes were aspirated from middle-size follicles (3–6 mm in diameter) of abattoir-derived porcine ovaries. After collection, the COC were pretreated with cryoprotectants at different temperatures (25 and 39°C) and vitrified in a serum-free chemically defined solution containing 0.6 mg mL–1 of hydroxypropyl cellulose, basically according to a commercial protocol (Cryotop, Kitazato BioPharma Co. Ltd., Fuji, Japan). The vitrified COC were warmed in 1 M trehalose solution at 39 for 60 s or at 60°C for 30 s. The COC were cultured for in vitro maturation (IVM) in modified porcine oocyte medium (POM) supplemented with 50 μM β-mercaptoethanol, 10 IU mL–1 of eCG, 10 IU mL–1 of hCG, and 1 mM dibutyryl cyclic AMP (dbcAMP) for 20 h and then in the fresh medium without hormonal supplements and dbcAMP for another 24 h. Viability of COC was evaluated under fluorescent microscopy after stain with fluorescein diacetate and propidium iodide. Nuclear maturation of the oocytes was evaluated after 44 h of IVM. Statistical analyses of results from 5 replicated trials were performed by ANOVA with a Bonferroni/Dunn post-hoc test (significance, P < 0.05). Although viabilities of vitrified oocytes after 44 h of IVM [6.0% (9/149) to 37.8% (59/155)] were significantly lower than fresh controls [98.8% (158/160)], the viabilities of vitrified oocytes warmed at 60°C [32.0% (49/160) to 37.8% (59/155)] were significantly higher than those warmed at 39°C [6.0% (9/149) to 10.0% (16/160)]. Maturation rates in vitrified oocytes [2.7% (4/149) to 19.8% (31/155)] were also significantly lower than fresh controls [74.8% (120/160)]. Regardless of temperature during pretreatment for vitrification (25 and 39°C), maturation rate of the oocytes warmed at 60°C after vitrification [16.4% (25/154) to 19.8% (31/155)] was significantly higher than that warmed at 39°C [3.1% (5/160) to 2.7% (4/149)]. In conclusion, these results demonstrate that warming at 60°C for 30 s maintains the viability and meiotic competence of immature porcine COC.

2016 ◽  
Vol 28 (2) ◽  
pp. 235
Author(s):  
J. D. Yoon ◽  
E. Lee ◽  
S.-H. Hyun

Growth differentiation factor-8 (GDF8) is a member of the transforming growth factor-β that has been identified as a strong physiological regulator. SB-431542 (SB) is a specific inhibitor of transforming growth factor-β superfamily type I activin receptor-like kinase (ALK) receptors such as ALK4, ALK5, and ALK7. The purpose of this study is investigation of the effects of GDF8 and SB on porcine oocytes during in vitro maturation and subsequent embryonic development. We first performed ELISA to detect GDF8 concentrations in follicular fluid for each size of follicle; sizes were as follows: small (<3 mm), medium (>3 mm and <6 mm), and large (>6 mm) follicle. After detection of the GDF8 concentration in follicular fluid, we investigated the effect of GDF8 and SB treatment during in vitro maturation (IVM) on nuclear maturation, intracellular glutathione (GSH), and reactive oxygen species (ROS) levels, and embryonic development after IVF and parthenogenetic activation (PA). Data were analysed by ANOVA followed by Duncan using SPSS (Statistical Package for Social Science, IBM, New York, NY, USA) mean ± SEM. The ELISA result showed different concentrations of GDF8 for each grade of follicular fluid: small, 0.479 ng mL–1; medium, 0.668 ng mL–1; and large, 1.318 ng mL–1. During the IVM process, 1.318 ng mL–1 of GDF8 and 5 ng mL–1 of SB were added to the maturation medium as control, SB, SB+GDF8, and GDF8 treatment groups. After 44 h of IVM, GDF8 group (90.4%) showed a significantly higher nuclear maturation rate than control and SB+GDF8 groups (85.4 and 81.7%). The SB group (78.9%) showed significantly reduced nuclear maturation rate compared with control (P < 0.05). The GDF8 treatment group showed a significant decreased intracellular ROS and increased GSH levels compared with other groups (P < 0.05). The SB+GBF8 treatment group showed a significantly better cytoplasmic maturation than the SB treatment group. In the PA embryonic development analysis, the GDF8 treatment group showed a significantly higher blastocyst formation rate compared with other groups (47.9, 37.2, 46.4, and 58.7% respectively; P < 0.05). In the IVF embryonic development analysis, the GDF8 treatment groups showed significantly higher blastocyst formation rate compared with the SB group (28.2 and 42.2%, respectively; P < 0.05). In conclusion, treatment with GDF8 during porcine oocyte IVM improved the embryonic developmental competence via increased cytoplasmic maturation and led to better oocyte maturation from the ALK receptor inhibition by SB.


2018 ◽  
Vol 30 (1) ◽  
pp. 226
Author(s):  
F. C. Castro ◽  
L. Schefer ◽  
K. L. Schwarz ◽  
H. Fernandes ◽  
R. C. Botigelli ◽  
...  

Melatonin mediates several processes in animal reproduction and has drawn attention for its potent antioxidant, anti-apoptotic, anti-inflammatory action and, more recently, for its benefits on oocyte maturation and embryo development in vitro. The aim of this study was to assess the effect of melatonin during the in vitro maturation (IVM) on nuclear maturation of bovine oocytes and gene expression in their corresponding cumulus cells (CC). Bovine cumulus–oocyte complexes (COC) were obtained by aspiration of follicles (2-6 mm) from slaughterhouse ovaries, selected (grades I and II) and transferred to 4 well plates (25-30 COC/well) containing IVM medium [TCM-199 supplemented with sodium bicarbonate (26 mM), sodium pyruvate (0.25 mM), FSH (0.5 µg mL−1), LH (5.0 µg mL−1), 0.3% BSA, and gentamicin (50 µg mL−1)] with 0, 10−5, 10−7, 10−9 or 10−11 M melatonin and cultured for 24 h at 38.5°C and 5% CO2. At the end of IVM, oocytes were stained with Hoechst 33342 (10 μg mL−1) and evaluated for nuclear maturation rate. The CC were evaluated for the expression of antioxidant (SOD1, SOD2, GPX4), pro-apoptotic (P53, BAX) and expansion-related genes (PTX3, HAS1, HAS2). For transcript detection in CC, RNA isolation was performed with TRIzol®Reagent (Invitrogen, Carlsbad, CA, USA) and reverse transcription with High Capacity cDNA Reverse Transcription kit (Applied Biosystems, Foster City, CA, USA). Relative quantification of transcripts was performed by RT-qPCR using 3 endogenous controls (β-actin, GAPDH, PPIA). Nuclear maturation rate and gene expression were tested by ANOVA and means were compared by Tukey’s test (6 replicates). In CC, the different concentrations of melatonin did not significantly alter expression of the investigated genes (P > 0.05), although all concentrations provided a numerical increase in the expression of the antioxidant SOD1 and of the expansion-related genes PTX3 and HAS2. Regarding the pro-apoptotic genes, concentrations of 10−11 and 10−9 M were able to reduce only numerically the expression of BAX and P53, respectively. In oocytes, the rate of nuclear maturation was not different among the tested treatments (P > 0.05), but it was numerically higher in the 10−7 M melatonin treated group compared with the control (69.71 ± 13.76% v. 88.1 ± 12.54%). In conclusion, under the studied conditions, melatonin was unable to improve maturation rate or to affect the expression of antioxidant, pro-apoptotic, and expansion-related genes in CC. Melatonin during IVM has shown variable results in different studies and appears to show different effects depending on culture conditions and parameters studied. In order to take advantage of the possible positive antioxidant effects of melatonin, other culture conditions and parameters should be investigated. In a next step, melatonin will be included during in vitro culture of embryos to evaluate its possible cytoprotective role, because such embryos are more exposed to oxidative stress during in vitro culture, and to investigate its benefits on developmental competence in vitro. This reaesrch was funded by FAPESP (2015/20379-0; 2014/17181-0).


2014 ◽  
Vol 26 (1) ◽  
pp. 202 ◽  
Author(s):  
J. McGill ◽  
G. Reddy ◽  
L. Simon ◽  
G. Wirtu

Compared with other domestic species, embryo technologies are least developed for the dog. This is mainly due to difficulties in producing mature oocytes in vitro. Canine oocytes contain exceptionally high amounts of lipid. High lipid content increases the chilling sensitivity of oocytes and embryos. Mechanical and chemical reductions of the lipid content have been used to improve the cryotolerance of oocytes. Additionally, chemical stimulation of lipid catabolism improved oocyte in vitro maturation (IVM) rates in other species (You et al. 2012 Theriogenology 78, 235–543). Acetyl-CoA carboxylase (ACC) is the rate-limiting enzyme in de novo lipogenesis and its expression has been reported in oocytes and embryos. In somatic cells, inhibition of ACC reduces lipogenesis and enhances β-oxidation. Our hypothesis is that treatment of oocytes with an inhibitor of ACC (CP640186, Pfizer Animal Health, New York, NY, USA) reduces lipid content and improves IVM rate of oocytes. Ovaries were collected from a spay clinic and sliced in HEPES-buffered TCM-199 to recover oocytes. In vitro maturation was conducted at 38.5°C, 5% CO2, and high humidity in TCM-199 supplemented with 1% fetal bovine serum, glutamine, sodium pyruvate, β-mercaptoethanol, oestradiol, epidermal growth factor, and antimicrobial agents (Songsasen et al. Mol. Reprod. Dev. 79, 186–196). During the first 19 to 21 h, the IVM media contained 4 concentrations of the inhibitor (0+DMSO, 0.02, 0.1, and 0.5 μM, designated as treatments 1, 2, 3, and 4, respectively) and then oocytes were transferred to a medium without the inhibitor and cultured for an additional 27 to 29 h. At the end of culture (total of 48 h), oocytes were denuded of cumulus layers, washed, fixed, and stained with Nile red (lipid) and Hoechst-33342 (chromatin), and then mounted on a microscope slide. Lipid content and chromatin status were evaluated using fluorescent microscopy (TRITC and DAPI filters, respectively). The relative lipid content was measured by the corrected total cell fluorescence (CTCF) using ImageJ software (http://rsbweb.nih.gov/ij/). Data on CTCF and proportions of chromatin status of oocytes were analysed using one-way ANOVA (SigmaPlot 11.0). The mean CTCF for each treatment was 5.5 × 109 (n = 51, 5.2 × 109 (n = 44), 4.5 × 109 (n = 31), and 4.8 × 109 (n = 34), respectively (P = 0.3; 4 replicates). At the highest dose, the agent induced relatively more cumulus cell layer expansion but inhibited their attachment to the dish; the latter effect was reversible because cumulus cells attached and proliferated after washing the oocytes of the agent. Metaphase II was rare (≤3.1%); however, the proportion of oocytes developing to ≥GVBD stage (Trt 1 14%, n = 37; Trt 2 41%, n = 56; Trt 3 5%, n = 22; Trt 4 11%, n = 43) was affected by treatments. Our preliminary data indicate that a low concentration of ACC inhibitor has a positive effect on the nuclear maturation of canine oocytes but the effect on lipid content as estimated by using Nile red fluorescence intensity appears to be minimal.


Zygote ◽  
2013 ◽  
Vol 22 (2) ◽  
pp. 286-289 ◽  
Author(s):  
Su Jin Kim ◽  
Ok Jae Koo ◽  
Dae Kee Kwon ◽  
Jung Taek Kang ◽  
Sol Ji Park ◽  
...  

SummaryThe presence of glutamine (Gln) in in vitro maturation (IVM) and in vitro culture (IVC) medium is a more potent factor for improving porcine oocyte and embryo development than other amino acids. However Gln is inherently unstable and spontaneously breaks down into ammonia, and therefore interferes with proper development. To avoid this adverse effect, Gln was replaced in the present study with its stable dipeptide derivative alanyl-glutamine (Ala-Gln) and the effects of this replacement on porcine IVM and IVC were evaluated. Replacement of Gln with Ala-Gln during IVM did not improve nuclear maturation, however numbers of early cleaved embryos were significantly increased after activation. Blastocyst formation rates were also significantly improved by using Ala-Gln during IVM. Replacement of Gln with Ala-Gln during IVC significantly increased total cell numbers in blastocysts. Blastocyst formation rate was also significantly higher when Ala-Gln was used in both IVM and IVC. In conclusion, the use of Ala-Gln rather than Gln gives better results for development in both porcine IVM and IVC.


2005 ◽  
Vol 17 (2) ◽  
pp. 302
Author(s):  
F.Y. Heru ◽  
H.J. Oh ◽  
M.K. Kim ◽  
J. Goo ◽  
M.S. Hossein ◽  
...  

The present study investigated the effects of the estrus cycle stage and serum supplementation on nuclear maturation of canine oocytes. Ovaries were collected from a private clinic after ovariohysterectomy and classified into follicular, luteal, or anestrus stages through a combination of ovarian morphology and vaginal cytology. A total of 2214 oocytes from 196 ovaries (903 oocytes from 96 anestrus ovaries, 609 oocytes from 36 follicular ovaries, and 702 oocytes from 64 luteal ovaries) were used for experiments. The oocyte retrieval per ovary was 10, 19, and 12 for anestrus, follicular and luteal-phase ovaries, respectively. In Exp. 1, immature oocytes were cultured for 72 h in TCM-199 alone or TCM-199 supplemented with 10% canine anestrus (CAS), estrus (CES), or diestrus (CDS) serum or fetal bovine serum (FBS). In Exp. 2, immature oocytes were cultured for 72 h in TCM-199 supplemented with 0, 5, 10, or 20% CES. After staining with Hoechst 33342, chromatin state and position as well as spindle formation were evaluated to determine the stage of meiosis: germinal vesicle (GV) stage, germinal vesicle breakdown (GVBD), metaphase I (MI) stage, metaphase II (MII) stage. The experiments with anestrus and luteal-phase oocytes were repeated eight times and follicular-phase oocytes were repeated six times. Data were subjected to analysis of variance (ANOVA) and protected least significant difference (LSD) test to determine differences among experimental groups by using the Statistical Analysis System (SAS, SAS Institute, Inc., Cary, NC, USA) program. Statistical significance was determined where P value was less than 0.05. In Exp. 1, the in vitro maturation of oocytes up to MII stage was higher when oocytes were collected from ovaries in follicular phase. The maturation rate up to MII stage was 0.0 to 1.7%, 1.3 to 10.2%, and 1.0 to 3.2% for the oocytes collected from the anestrus, follicular, and luteal-phase ovaries, respectively, depending on the culture media used. In basic TCM media only, 0.0, 1.3, and 2.3% oocytes reached the MII stage for anestrus, follicular, and luteal-phase oocytes, respectively. A significantly higher rate of maturation was obtained when oocytes collected from follicular phase were cultured in TCM-199 supplemented with 10% CES (10.2%), compared to 10% CAS (4.0%), CDS (2.7%), FBS (1.3%), or the control (1.3%). In Exp. 2, supplementing with 10% CES induced the highest (P < 0.05) maturation rate to the MII stage in oocytes collected from follicular-stage ovaries (11.5%) compared to supplementing with 0% (1.0%), 5% (1.3%), or 20% CES (5.1%). Supplementing with CES (5, 10, or 20%) did not have a significant effect on nuclear maturation of canine oocytes collected from anestrus or luteal-stage ovaries. In conclusion, supplementing in vitro maturation medium with 10% CES increased nuclear maturation of canine oocytes, and canine oocytes collected from follicular-stage ovaries are the most suitable to complete nuclear maturation in vitro. This study was supported by grants from the Biogreen 21-1000520030100000.


2009 ◽  
Vol 21 (1) ◽  
pp. 218
Author(s):  
Y. Akaki ◽  
K. Yoshioka ◽  
H. Funahashi

Exposure of porcine oocyte–cumulus complexes (OCC) to gonadotropins induces meiotic resumption, but the details of this mechanism are still unknown. The present study was undertaken to examine combinational effects of EGF-like factors and dibutyryl cyclic AMP (dbcAMP) in a chemically defined medium on in vitro maturation (IVM) of porcine oocytes. The OCC were aspirated from 3- to 6-mm-diameter follicles of prepuberal ovaries and used in the current study. The basic culture medium was a chemically defined medium, Porcine Oocyte Medium (POM; Research Institute for the Functional Peptides, Yamagata, Japan). In the first experiment, various concentrations (0, 10, and 1000 ng mL–1) of EGF-like factors (EGF, amphiregulin, and betacellulin) were added to POM during an entire IVM period (44 h). In the second experiment, to determine the additive effect of EGF-like factors, each EGF-like factor with an effective concentration was combined with the others. In the last experiment, to examine the combined effect with dbcAMP, OCC were exposed to EGF (10 ng mL–1), amphiregulin (1000 ng mL–1), and dbcAMP (1 mm) during the first 20 h of IVM and then the culture was continued in the absence of EGF-like factors and dbcAMP. After culture, in all experiments, meiotic resumption and the progress of oocytes were examined after denuding, fixing, and staining. Statistical analyses was performed by ANOVA with a Bonferroni-Dunn post hoc test (significance, P < 0.05). In the first experiment, all treatments without supplementation with 10 ng mL–1 amphiregulin increased the incidence of oocytes maturing to the MII phase, as compared with controls (29.1 to 39.3% v. 11.1%, P < 0.05). In the second experiment, combinations with 2 kinds of EGF-like factor slightly (but not significantly) improved the percentage of oocytes at the MII stage (37.7 to 47.4%). In the last experiment, supplementation with 1 mm dbcAMP during the first 20 h of IVM, regardless of the presence of EGF-like factors, significantly increased the incidence of MII oocytes as compared with controls, whereas the incidence was the highest when 1 mm dbcAMP, 10 ng mL–1 EGF, and 1000 ng mL–1 amphiregulin were supplemented (75.5%). When those oocytes were cultured in a chemically defined medium after in vitro fertilization, the developmental competence of oocytes to the blastocyst stage (25.0%) was not different from oocytes matured in the presence of gonadotropins and dbcAMP during the first 20 h of IVM (17.3%). These observations indicate that supplementation of a chemically defined maturation medium with EGF-like factors and dbcAMP during the first 20 h of IVM can support the meiotic progress and developmental competence of porcine oocytes well. Currently, we are examining the developmental competence of those oocytes after embryo transfer. The results will be presented at the meeting. This study was supported by MAFF AgriBio1605.


2013 ◽  
Vol 25 (1) ◽  
pp. 280
Author(s):  
M. Nakakoji ◽  
H. Funahashi

The degree of cumulus expansion, an important step in oocyte maturation, of porcine cumulus–oocyte complexes (COC) derived from small follicles (SF: 1 to 2 mm in diameter) is known to be lower than those derived from middle follicles (MF: 3 to 6 mm in diameter). The objective of this study was to compare the abilities of hyaluronan (HA) synthesis of COC from SF and MF. Furthermore, the effect of oestradiol during pre-incubation of COC on proliferation of the cumulus cells was examined. Cumulus–oocyte complexes from SF and MF of porcine ovaries were cultured for in vitro maturation [IVM, in modified porcine oocyte medium (Yoshioka et al. 2008 J. Reprod. Dev. 54, 208–213) supplemented with 50 µM β-mercaptoethanol, 10 IU mL–1 of eCG, 10 IU mL–1 of hCG, and 1 mM dbcAMP for 20 h and then in the fresh medium without those supplements for another 24 h]. Hyaluronan production was quantified at 20 h after the start of IVM with a commercial HA-ELISA kit (20 COC/tube × 4 times). The number of cumulus cells was assessed 0 and 20 h after the start of IVM (50 COC × 4 times). Furthermore, proliferation of cumulus cells was examined after pre-culture of COC (n = 40 COC × 5 times) in modified porcine oocyte medium with various concentrations of oestradiol (0, 0.1, 1, and 10 ng mL–1) for 6 h. Statistical analyses of results from 4 to 5 replicated trials were performed by ANOVA with a Bonferroni-Dunn post-hoc test (significance, P < 0.05). The degree of cumulus expansion of COC from MF (n = 152) was higher than that of COC from SF (n = 156). The incidence of metaphase-II oocytes was significantly lower in COC from SF (n = 133; 48.9%) than in COC from MF (n = 148; 74.7%). The HA content of COC was higher in those from MF (20.8 µg/COC) than in those from SF (10.8 µg/COC), whereas the content per cumulus cell was not different because the numbers of cumulus cells at 0 and 20 h were also higher in COC (n = 200 in each group) from MF (3.0 × 103 and 3.3 × 103 cells, respectively) than from SF (2.0 × 103 and 2.5 × 103 cells, respectively). Cumulus cells proliferated significantly in the presence of oestradiol, regardless of the concentration, during pre-incubation for 6 h (2.5 to 2.8 × 103 cells), as compared with the oestradiol-free controls (2.2 × 103 cells). These results demonstrate that the different abilities of cumulus expansion between COC (n = 200 in each group) from SF and MF may be due to the number of cumulus cells per COC. Pre-incubation in the presence of oestradiol stimulates the proliferation of cumulus cells and may improve the oocyte maturation of COC derived from SF.


Author(s):  
N. Mahanta ◽  
D. Bhuyan ◽  
Suresh Kumar ◽  
R. K. Biswas ◽  
D. J. Dutta ◽  
...  

The present study was aimed to evaluate the beneficial effect of different growth factors on in-vitro maturation of porcine oocytes. Ovaries were collected from a local abattoir immediately after slaughter of the animals and transported to the laboratory. A total of 618 type A and type B oocytes were cultured in TCM-199 containing additives with PMSG and hCG for the first 22 hrs and without hormones for subsequent 22 hrs of incubation at 39o C under 5 per cent CO2 level and 90-95 per cent humidity. The effects of supplementation of different growth factors viz., EGF, IGF-I and EGF + IGF-I in the medium were studied. The rate of oocytes with cumulus cells expansion was significantly higher (P less than 0.01) when growth factors were added as compared to control but it did not differ significantly between growth factors. The rate of nuclear maturation of oocytes was significantly higher (P less than 0.01) as compare to control for EGF and EGF + IGF-I but not for IGF-I. There was no significant difference in the rate of oocytes with nuclear maturation between the growth factors studied. It can be concluded from the present study that addition of EGF, IGF-I or EGF + IGF and additives along with hormones (PMSG and hCG for first 20-22 hrs) in TCM-199 Medium gives optimum in-vitro maturation rates in porcine oocytes.


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