scholarly journals Chemical manipulation of glucose metabolism in porcine oocytes: effects on nuclear and cytoplasmic maturation in vitro

Reproduction ◽  
2006 ◽  
Vol 131 (2) ◽  
pp. 289-298 ◽  
Author(s):  
Jason R Herrick ◽  
Amber M Brad ◽  
Rebecca L Krisher

The objectives of this study were to manipulate metabolism of glucose through glycolysis and the pentose phosphate pathway (PPP) in porcine oocytes during in vitro maturation, and determine the effects of this manipulation on meiotic progression, intracellular glutathione (GSX) concentrations and embryonic development. Cumulus-oocyte complexes isolated from abattoir ovaries were matured (40–44 h) in Purdue Porcine Medium for maturation alone (control) or supplemented with pyrroline-5 carboxylate (PC, 0.1 μM; PPP stimulator), diphenyleneiodonium (DPI, 0.1 μM; PPP inhibitor), dinitrophenol (DNP, 10 μM; glycolytic stimulator), hexametaphosphate (HMP, 100 μM; glycolytic inhibitor), PC + HMP or DNP + DPI. At the conclusion of in vitro maturation, cumulus cells were removed and oocytes were randomly allocated for analysis of GSX, metabolism and nuclear maturation, or in vitro fertilization and embryo culture. Both DPI and DNP + DPI decreased (P ≤ 0.05) the activity of glycolysis and the PPP, increased (P ≤ 0.05) the percentage of immature oocytes, and decreased (P ≤ 0.05) the proportion of mature oocytes compared with control oocytes and oocytes from the other treatments. Embryonic development (cleavage and blastocyst stage) and the intracellular content of GSX were also decreased (P ≤ 0.05) following exposure to DPI or DNP + DPI compared with control oocytes and oocytes from the other treatments. Oocyte metabolism, nuclear maturation, GSX content and embryonic development were unaffected (P > 0.05) following exposure to PC, DNP, HMP or PC + HMP. Our results suggest that metabolism of glucose through the PPP and/or glycolysis plays a key role in the control of nuclear and cytoplasmic maturation of porcine oocytes in vitro.

1997 ◽  
Vol 9 (8) ◽  
pp. 763 ◽  
Author(s):  
K. S. Kim ◽  
N. Minami ◽  
M. Yamada ◽  
K. Utsumi

The present study examined the time-dependent effects of follicular cells on the fertilizability of oocytes and their subsequent development to blastocysts. The percentages of oocytes reaching the metaphase-II stage of maturation rose from 51·3% after 16 h of culture to 86·2% at 28 h (cumulus-intact oocytes; CIO) and, for the same time points, from 65·4% to 83·3% (corona-enclosed oocytes; CO) and 54·3% to 88·9% (denuded oocytes; DO), respectively. When DO were cultured for more than 24 h before insemination, fertilization rates were significantly lower compared with CIO and CO. The maximum rates of development to blastocysts were observed when the oocytes were cultured for 24 h in the CIO group (22·1%), 20 h in the CO group (19· 7%) and 18 h in the DO group (9·2%), respectively. These results suggest that (i) the presence of cumulus cells or corona cells during maturation is not necessary for nuclear maturation of oocytes; (ii) the attachment of corona cells to the oocytes during maturation is important for the further development to the blastocyst stage, and (iii) the presence of attached cumulus and/or corona cells during maturation in vitro extends the maturation period required for further development to the blastocyst stage.


2010 ◽  
Vol 22 (1) ◽  
pp. 322
Author(s):  
I. Carvalhais ◽  
M. Faheem ◽  
A. Habibi ◽  
A. Geraldo ◽  
R. Agrícola ◽  
...  

Many factors act together to prepare the immature oocyte for successful development to a competent embryo after fertilization. Defects in oocyte maturation and further development can possibly be caused by the oocyte quality or an inadequate nuclear maturation or even by a failure of both. In the present study, the effect of COCs quality on meiotic development and further embryo-development after in vitro fertilization was evaluated. A total of 3604 COCs was separated according to their morphological aspect and were classified as A, B, and C categories. Briefly, in class A, oocytes possessed compact layers of cumulus cells, being difficult to evaluate their number having a homogenous ooplasm with uniform color. In class B, oocytes show more or equal to five layers of cumulus cells, easily identifiable under a stereomicroscope and/or granulations in the ooplasm. In class C, some granulation was observed in oocytes with about three layers of cumulus cells. The total number of oocytes was divided into two groups (I and II) in which in the group I, COCs (n = 540) were fixed 0, 6, 12, 18, 24, and 30 h following ovarian aspiration, DNA was stained with aceto-orcein, and the nucleus were observed under a phase contrast microscope. In the Group II, COCs (n = 3064) were fertilized with frozen/thawed bull semen after 24 h of maturation, which was made in M199 medium (Sigma, St, Louis, MO, USA). The development of the embryos was evaluated on the third and seventh day after fertilization. Embryos were co-cultured with monolayers of granulosa cells in 45 μL droplets of B2 medium (CCD Laboratory, Paris, France), supplemented with 10% serum under mineral oil, at 39°C and 5% CO2 in air. It was observed that, other than the oocytes achieved metaphase II at 24 h was greater for the oocytes classified as A (65.4%), and B (61.0%) greater than C (51.2%), no statistical difference was observed between oocyte quality and capability to maturation. As far as the embryonic development is concerned, the same tendency was observed for the cleavage and for the morulae/blastocyst stage after 7 days after fertilization (P < 0.001). The percentages of cleaved oocytes classified as A, B, and C, were respectively 65.2%, 58.4%, and 48.0%. The development to the morulae/blastocyst stage of the cleaved embryos was A = 38.5%/27.4%, B = 33.6%/25.0%, and C = 30.9%/17.2% (Table 1). The results of our study clearly demonstrate that the morphology of the oocytes plays an important role on the in vitro embryonic developmental competence after fertilization. Table 1.Development of oocytes according to COCs quality, evaluated 3 and 7 days after fertilization The first author is supported by the Regional Foundation for Science and Technology of the Azores Government. This study was supported by the IBBA Institute grant number M2.1.2/I/022/2008 CITA-A is fully acknowledged.


Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1594
Author(s):  
Zhi Yin ◽  
Jing-Tao Sun ◽  
Hong-Di Cui ◽  
Chao-Qian Jiang ◽  
Yu-Ting Zhang ◽  
...  

To investigate the effects of tannins (TA) on porcine oocyte in vitro maturation (IVM), different concentrations of TA (0, 1, 10 and 100 μg/mL) were supplemented with a maturation medium and the COCs and subsequent embryonic development were examined. The results showed that 10 µg/mL TA significantly improved the cumulus expansion index (CEI), cumulus-expansion-related genes (PTGS1, PTGS2, PTX-3, TNFAIP6 and HAS2) expression and blastocyst formation rates after parthenogenetic activation (PA), in vitro fertilization (IVF) and somatic cell nuclear transfer (SCNT) compared to the control groups, but not oocyte nuclear maturation. Nevertheless, 10 µg/mL TA dramatically enhanced the mRNA expression of oocyte-development-related genes (BMP15, GDF9, CDC2 and CYCLIN B1), GSH, ATP, SOD1, PGC1α, BMP15, GDF9 and CDC2 levels and reduced intracellular ROS level in porcine oocytes. These results indicated that porcine oocyte cytoplasmic maturation was improved by 10 µg/mL TA treatment during IVM. In contrast, a high concentration of TA (100 μg/mL) significantly decreased the CEI and PTGS1, PTGS2, PTX-3 and HAS2 mRNA expressions in cumulus cells, and reduced oocyte nuclear maturation and the total cell numbers/blastocyst. In general, these data showed that 10 μg/mL TA supplementation has beneficial effects on oocyte cytoplasmic maturation and subsequent embryonic development in pigs.


2006 ◽  
Vol 18 (2) ◽  
pp. 249 ◽  
Author(s):  
N. Maedomari ◽  
N. Kashiwazaki ◽  
M. Ozawa ◽  
A. Takizawa ◽  
J. Noguchi ◽  
...  

It is generally accepted that cumulus cells (CCs) support the nuclear maturation of immature oocytes in mammals. However, the precise mechanism of interaction between cumulus cells and oocytes has not been clarified. Furthermore, the role of cumulus cells in embryonic development has not been reported. In the present study, the effect of denuding cumulus cells from porcine oocytes on oocyte maturation, ertilization, and their subsequent development to the blastocyst stage was examined in vitro. In vitro maturation, fertilization, and culture were carried out as previously reported (Kikuchi et al. 2002 Biol. Reprod. 66, 1033-1041). Porcine cumulus-oocyte complexes (COCs) were collected; some of them were completely denuded of cumulus cells immediately after the collection (DO-0 group). The remaining intact COCs and the DO-0 oocytes were cultured for 24 h in the presence of dbcAMP and hormones. After the initial culture, some of the intact COCs were denuded either completely (DO-24 group) or partially (H-DO-24 group). Additionally, some of DO-24 oocytes were co-cultured with the cumulus cells removed at 0 h and pre-cultured for 24 h (DO-24 + CCs group). The denuded oocytes in each experimental group and intact COCs (control) were further cultured for total 46 h. The remaining oocytes with a first polar body were either examined for the levels of intracellular glutathione (GSH) or fertilized in vitro with frozen-thawed boar spermatozoa. The inseminated oocytes were cultured and examined for their fertilization status after 10 h and for their developmental competence after 6 days. Data were analyzed by ANOVA, followed by the Duncan's multiple range tests. The maturation rates of all denuded groups were significantly lower (P < 0.05; 34.3 to 45.0%) than that of the control group (64.5%). Intracellular GSH concentrations of all denuded groups were also significantly lower (P < 0.05; 4.03 to 7.00 pmol/oocyte) than that of the control group (9.60 pmol/oocyte); however, the GSH level of H-DO-24 oocytes was significantly higher (P < 0.05) than the GSH levels in the other denuded groups. Male pronuclear formation rates of completely denuded oocytes (DO-0, DO-24, and DO-24 + CCs groups) were significantly lower (P < 0.05; 41.4 to 59.3%) than those of the control (89.4%) and the H-DO-24 (80.0%) groups. The blastocyst rate of the control group was significantly higher (P < 0.05; 19.9%) than that of H-DO-24 group (11.6%), and these rates were significantly higher (P < 0.05) than those of the completely denuded groups (3.0 to 4.5%). The results suggest that the presence of cumulus cells during maturation culture improves nuclear maturation of oocytes and plays an important role in embryonic development to the blastocyst stage in vitro.


2006 ◽  
Vol 18 (2) ◽  
pp. 276
Author(s):  
C.-K. Park ◽  
J.-Y. An ◽  
S.-J. Sa ◽  
H.-T. Cheong ◽  
B.-K. Yang ◽  
...  

Plasminogen activators (PAs) are serine proteases, known to be secreted by a large number of cell type. PAs are reported to play a role in variety of physiologic processes, including fibrinolysis, ovulation, mammary involution, implantation, and fertilization. The present study investigated the effects of cumulus cells and porcine follicular fluid (pFF) on PA activity and oocyte maturation in vitro in the pig. Porcine oocytes were harvested from slaughterhouse ovaries, selected, and matured in modified North Carolina State University-23 (NCSU-23) media. After culture, cumulus-oocyte complexes (COCs) and denuded oocytes (DOs) were separately put into microtubes containing 20 �L of sample buffer [5.0% (w:v) sodium dodecyl sulfate, 20% (v:v) glycerol, and 0.0025% (w:v) bromophenol blue in 0.125 M Tris-HCl buffer] and frozen at -80�C until used for zymographic analysis. Differences in data were evaluated by Duncan's multiple-range test using the General Linear Models procedure in the Statistical Analysis System (SAS Institue, Inc., Cary, NC, USA). To determine the effect of porcine follicular fluid (pFF) on PA activity in porcine oocytes during maturation, the COCs and DOs were incubated in NCSU-23 medium with or without 10% (v/v) pFF for 0, 24, or 48 h. In the presence of cumulus cells, the proportions of oocytes matured to metaphase-II stage were significantly (P < 0.05) higher in medium with pFF than without pFF (69.8% vs. 37.7%, respectively). When COCs and DOs were cultured in the presence of pFF, tissue-type PA (tPA), urokinase-type PA (uPA), and tPA-PA inhibitor (tPA-PAI) were observed in COCs, and PA activities were higher at 48 h than 24 h. However, no PA activity was detected in DOs. Under the same conditions, when COCs and DOs were cultured in the absence of pFF, tPA and tPA-PAI were observed in COCs, and PA activities were increased as duration of culture increased. However, no PA activity was detected in DOs. When porcine oocytes were cultured in the presence of pFF, the activities of tPA-PAI, tPA, and uPA were observed in conditioned medium with COCs and DOs cultured for 24 h and 48 h. In the absence of pFF, PA activities were observed only in conditioned medium with COCs, and no PA activities were detected in conditioned medium with DOs. On the other hand, three plasminogen-dependent lytic bands (tPA-PAI, tPA, and uPA) were observed in pFF cultures. Particularly uPA activity was higher than the other kinds of PA activity. When oocytes and cumulus cells were separated from porcine COCs at 0 h of cultrue, tPA-PAI, tPA, and uPA were detected in cumulus cells at 48-h culture, but no PA activities were in DOs. The presence of pFF and cumulus cells in maturation medium stimulated not only nuclear and cytoplasmic maturation in porcine COCs, but also PA production by cumulus cells and COCs. It is possible that PAs produced by cumulus cells migrated through the gap junction between oocyte and cumulus cells. These results suggest that porcine oocytes have no ability to produce PA themselves.


2010 ◽  
Vol 22 (1) ◽  
pp. 324 ◽  
Author(s):  
M. De los Reyes ◽  
D. Luna ◽  
J. Palomino

Low development of IVM canine oocytes could be in part attributed to an impaired cytoplasmic maturation. In mammalian oocytes, migration and the redistribution of cortical granules (CGs) around the periphery of the oocyte contribute to the inhibition of polyspermy and it is an important criterion to evaluate cytoplasmic maturation. The state of nuclear maturation and the distribution of CGs were evaluated in canine oocytes cultured for different periods in order to compare the synchrony of nuclear and cytoplasmic maturation during in vitro maturation. Bitch ovaries at different stages of the estrous cycle were obtained following ovariectomy. COCs with compact cumulus cells showing a homogeneous cytoplasm were selected for experiments. Thirty-six COCs were processed at immature stage, placed in PBS medium until evaluation. A total of 275 COCs were matured in vitro for 48, 72, and 96 h in TCM-199 with Earle’s salt supplemented with 25 mM Hepes, 10% FCS, 0.25 mM pyruvate, 10 IU mL-1 of hCG, 300 IU mL-1 penicillin, and 20 mg mL-1 streptomycin, at 38.5°C and 5% CO2. At each culture period, the oocytes were stained with Lens culinaris agglutinin (LCA), labeled with fluorescein isothiocyanate, and the CGs distributions were examined under a fluorescent microscope. The nuclear status of the denuded oocytes was determined by DAPI staining under a fluorescence microscope. For each treatment, at least four replicates were performed and the data was analyzed by ANOVA using Tukey’s test to determine the differences P < 0.05. Three types of CGs distribution were distinguished during canine oocyte maturation: (1) homogeneous distribution throughout the cytoplasm including the cortex; (2) heterogeneous (clusters) within the cytoplasm and (3) densely distributed beneath the oolemma. Nuclear stages were classified as immature or germinal vesicle (GV) stage; resumption of meiosis or germinal vesicle break down (GVBD); metaphase I to telophase I (MI toTel I); and mature or second metaphase (MII). The distribution patterns of GCs were different (P < 0.05) among oocytes cultured for different periods and the nuclear maturation status also differed between oocytes cultured for different intervals (P < 0.05). Most (>84%) of the immature oocytes at GV showed a uniform distribution of CGs throughout the cytoplasm. At 48 h of culture, CGs distribution was mainly Type 2 (25%) and 3 (61%) and the oocytes were at GVBD (33%) and MI-Tel I (33%) stages. Most nuclei of the type 3 oocytes were in the MI (40%) and MII (11%) stages, corresponding to those oocytes matured for 72 (88%) or 96 h (71%). These results indicate that canine oocytes migrate to the cortex during IVM and this process is not finished before 72 h of culture. In addition, although the re-distribution of the CGs occurred in parallel with nuclear maturation, the oocytes cannot always proceed to the MII stage; however, in such oocytes the CGs are distributed beneath the oolemma. Supported by Grant FONDECYT 1080618.


Zygote ◽  
2020 ◽  
pp. 1-6
Author(s):  
Ji-Eun Park ◽  
Sang-Hee Lee ◽  
Yong Hwangbo ◽  
Choon-Keun Park

Summary The aim of the present study was to investigate the effects of porcine follicular fluid (pFF) from large-sized (LFF; >8 mm in diameter) and medium-sized (MFF; 3–6 mm in diameter) follicles on the maturation and developmental competence of porcine oocytes. Cumulus–oocyte complexes (COCs) were collected from follicles 3–6 mm in diameter. The collected COCs were incubated for 22 h with LFF or MFF (in vitro maturation (IVM)-I stage) and were incubated subsequently for 22 h with LFF or MFF (IVM-II stage). Cumulus expansion was confirmed after the IVM-I stage and nuclear maturation was evaluated after the IVM-II stage. Intracellular glutathione (GSH) and reactive oxygen species (ROS) levels were measured and embryonic development was evaluated. Relative cumulus expansion and GSH levels were higher in the LFF group compared with in the MFF group after the IVM-I stage (P < 0.05). After the IVM-II stage, the numbers of oocytes in metaphase-II were increased in the LFF group and GSH content was higher in all of the LFF treatment groups compared with in the MFF treatment groups during both IVM stages (P < 0.05). ROS levels were reduced by LFF treatment regardless of IVM stage (P < 0.05). Blastocyst formation and the total numbers of cells in blastocysts were increased in all LFF treatment groups compared with the control group (P < 0.05). These results suggested that pFF from large follicles at the IVM stage could improve nucleic and cytoplasmic maturation status and further embryonic development through reducing ROS levels and enhancing responsiveness to gonadotropins.


2012 ◽  
Vol 24 (8) ◽  
pp. 1048 ◽  
Author(s):  
B. D. Whitaker ◽  
S. J. Casey ◽  
R. Taupier

The effects of supplementation with 1.5 mM n-acetyl-l-cysteine (NAC) during in vitro oocyte maturation were studied. Oocytes were supplemented with 1.5 mM NAC during maturation for 0 to 24 h, 24 to 48 h, or 0 to 48 h then subjected to IVF and embryo development. Oocytes were evaluated after maturation for intracellular glutathione concentration, superoxide dismutase and glutathione peroxidase activities and DNA fragmentation. Fertilisation and embryonic development success were also evaluated. There was no effect of treatment on intracellular glutathione concentrations, enzyme activities or fertilisation success rates. Supplementing NAC during maturation significantly decreased (P < 0.05) the percentage of oocytes with fragmented DNA compared with no NAC supplementation. Supplementing NAC from 24 to 48 h or 0 to 48 h resulted in a significantly higher (P < 0.05) percentage of oocytes with male pronuclei than for oocytes from the other treatment groups. There was no difference in the percentage of embryos cleaved by 48 h after IVF between treatment groups. Supplementing NAC from 24 to 48 h or 0 to 48 h resulted in a significantly higher (P < 0.05) percentage of embryos reaching the blastocyst stage by 144 h after IVF compared with the other treatment groups. These results indicate that supplementation of the oocyte maturation medium with 1.5 mM NAC, specifically during the last 24 h, improves male pronucleus formation and blastocyst development in pigs.


2014 ◽  
Vol 26 (1) ◽  
pp. 201
Author(s):  
J.-H. Tan ◽  
Y.-B. Wang ◽  
H.-L. Xie ◽  
Q. Li ◽  
X.-Y. Liu ◽  
...  

It is well known that oocyte maturation consists of 2 processes: nuclear maturation and cytoplasmic maturation. Nuclear maturation refers to resumption of the first meiosis and extrusion of the first polar body (PB1), and cytoplasmic maturation is manifested as acquisition of the ability to complete pre-implantation development. Although it is recognised that energy supply is essential for oocyte maturation and there have been many reports on the effect of glucose metabolism on oocyte nuclear maturation, studies on the effect of glucose metabolism on ooplasmic maturation are limited. In the present study, goat oocytes recovered from slaughterhouse ovaries were cultured for 24 h in a simplified CR1 (sCR1) medium (NaCl, KCl, NaHCO3, CaCl2, BSA, and eCG) supplemented with glucose (10 mM) and/or lactate (3.5 mM) in the presence or absence of pentose phosphate pathway (PPP) inhibitor dehydroepiandrosterone (DHEA, 100 μM) or glycolysis inhibitor iodoacetate (1 μM). At the end of maturation culture, oocytes with PB1 were either activated by treatment with ionomycin plus 6-DMAP to observe embryo development, or assayed for total glutathione concentrations (GSX) and reduced glutathione (GSH)/oxidized glutathione (GSSG) ratios. Embryos were cultured for 9 days in CR1aa medium (NaCl, KCl, NaHCO3, calcium lactate, sodium pyruvate, glutamine, EAA, NEAA, and FCS) at 38.5°C under 5% CO2 in humidified air. In the absence of inhibitors, oocyte maturation rates of 82, 65, and 76%, and blastocyst rates of 7, 0, and 7%, were obtained, respectively, after oocytes were matured in sCR1 supplemented with glucose, lactate, or both. When oocytes were matured in sCR1 containing glucose and lactate in the presence of DHEA or iodoacetate, oocyte maturation rates were 69 and 67%, respectively, with no blastocyst produced in either case. However, whereas the presence of DHEA produced 12% morulae, no morulae were observed in the presence of iodoacetate. Furthermore, GSX concentrations (pmol/oocyte) were 8.5, 6.5, and 7.2, whereas GSH/GSSG ratios were 1.8, 0.3, and 0.5, respectively, after oocyte maturation without inhibitors or with 300 μM DHEA or 3 μM iodoacetate. The difference in GSX concentration was statistically significant (P < 0.05; one-way ANOVA) between DHEA and iodoacetate. In conclusion, using a culture system (sCR1 containing 3.5 mM lactate) that sustained oocyte nuclear maturation but did not support blastocyst development, we have studied the effect of PPP and glycolysis of glucose metabolism on the cytoplasmic maturation of goat oocytes. The results suggest that both PPP and glycolysis are essential for ooplasmic maturation of goat oocytes, and that both promote oocyte cytoplasmic maturation by increasing glutathione synthesis and reduction. This study was supported by grants from the National Basic Research Program of China (Nos. 2012CB944403 and 2014CB138503) and the China National Natural Science Foundation (Nos. 31272444 and 30972096).


Zygote ◽  
2007 ◽  
Vol 15 (4) ◽  
pp. 347-353 ◽  
Author(s):  
S.R. Lee ◽  
B.S. Kim ◽  
J-W. Kim ◽  
M.O. Kim ◽  
S.H. Kim ◽  
...  

SummaryIn this study we have investigated the efficiency of in vitro maturation (IVM) as a basic way to study the development of canine oocytes after in vitro fertilization (IVF). We decided, therefore, to perform two-part experiments. Firstly, experiment I compared the effects of TCM199 without fetal bovine serum (FBS) with TCM199 supplemented with 5% FBS on the in vitro nuclear maturation rate of canine oocytes. For the efficiency of meiotic development to the metaphase II (MII) stage, we found that 4.7% (4/64) of all oocytes grown in TCM199 without FBS developed to the MII stage compared with only 1.7% (1/59) of those grown in TCM199 with 5% FBS for 48 h. Therefore, FBS did not increase in vitro nuclear maturation. In experiment II, the cleavage rate of canine oocytes used for IVF was investigated following heparin treatment. Canine oocytes were fertilized in four groups: Fert–TALP medium without heparin (Fert I) or Fert–TALP medium supplemented with 10, 20 or 30 µg/ml heparin (Fert II, Fert III, Fert IV, respectively). Oocytes that were grown for 24 h in Fert I following fertilization showed the highest rate of all of the groups, 6.5% (5/77) and developed to the early morula stage. Markedly, the oocytes cultured in Fert I for 24 h following insemination had a higher rate of embryonic development than other groups. We can assert that, unlike findings in other mammals, heparin treatment in canine IVF does not increase the efficiency of the fertilization rate and is therefore not an important factor.


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