225 DEVELOPMENTAL COMPETENCE AND QUALITY OF PIG EMBRYOS OBTAINED FROM STANDARD IN VITRO FERTILIZATION OR INTRACYTOPLASMIC SPERM INJECTION

2013 ◽  
Vol 25 (1) ◽  
pp. 260 ◽  
Author(s):  
I. Grad-Mandryk ◽  
J. Kosenyuk ◽  
B. Gajda

In vitro production of porcine embryos is still relatively inefficient. The main reasons for this limited performance are polyspermy after IVF and the poor developmental ability of obtained zygotes. Intracytoplasmic sperm injection (ICSI) is one possible solution to eliminate polyspermy. The aim of this study was to compare the developmental competence of pig zygotes, total cell number, and DNA fragmentation of pig blastocysts derived from IVF or ICSI. Cumulus–oocyte complexes were obtained by aspiration from antral follicles of ovaries collected from slaughtered gilts. The oocytes were then cultured in modified TC-199 medium to metaphase II for 42 h. Semen for IVF was incubated in modified capacitation medium (M199) for 1 h. The sperm fraction (1 × 106 cells mL–1) was introduced into droplets containing oocytes, and then gametes were co-incubated for 4 h in modified TC-199 medium. Intracytoplasmic sperm injection was performed using a mechanical micromanipulator (Research Instruments Limited, Cornwall, UK). Micromanipulation was carried out in modified NCSU-37 medium. The tails of spermatozoa were broken, and then single spermatozoa were aspirated into the injection pipette. The oocyte was fixed by a holding pipette, and the sperm head was then introduced into the oocyte cytoplasm. Presumptive zygotes were cultured in vitro for 144 h in NCSU-23 medium. The embryo quality criteria were developmental competence (morula and blastocyst rates), total cell number per blastocyst, and degree of apoptosis assessed by TUNEL staining. Data were analysed by chi-squared test. The experiment was performed on 136 zygotes (6 replicates) obtained after IVF and 83 zygotes (4 replicates) obtained after ICSI. Percentages of embryos developed to the morula and blastocyst stages were 42.3 ± 6.1 and 28.8 ± 4.7 after IVF, respectively, and 51.7 ± 15.4 and 34.5 ± 18.9 after ICSI, respectively (no differences were observed). Significant differences were noticed in total number of cells per blastocyst between embryos after IVF and ICSI (33.7 ± 5.39 v. 22.8 ± 3.22; P < 0.01). However, there was no difference in the degree of apoptosis between IVF and ICSI embryos (5.14 ± 3.49 and 6.14 ± 4.88, respectively). Our preliminary studies demonstrated a higher proportion of cell numbers in IVF-derived embryos compared with those produced by ICSI, but the developmental competence and degree of apoptosis, as evaluated by the TUNEL method, in both groups were comparable. This study was funded by project N N311 516140 by the NCN, Poland.

2010 ◽  
Vol 22 (7) ◽  
pp. 1074 ◽  
Author(s):  
Michele M. Pereira ◽  
Marco A. Machado ◽  
Fernanda Q. Costa ◽  
Raquel V. Serapiao ◽  
Joao H. M. Viana ◽  
...  

With an aim to improve the in vitro production of bovine embryos, the present study investigated the effect of serum and oxygen tension during IVM on oocyte developmental competence. Four experimental groups were evaluated: G1, 10% oestrus cow serum (OCS) with 20% O2; G2, 0.1% polyvinyl alcohol (PVA) with 20% O2; G3, 10% OCS with 5% O2; and G4, 0.1% PVA with 5% O2. The proportion of MII oocytes, blastocyst rates and total cell number were not affected (P > 0.05) when the OCS was replaced with PVA under 5% O2, whereas a higher (P < 0.05) blastocyst rate and total cell number were found with OCS compared with PVA under 20% O2. The apoptosis index was lower in blastocysts from oocytes matured with PVA under 5% O2 (G4) compared with other groups (G1, G2 and G3), but no differences (P > 0.05) were found in maturation and blastocyst rates. Significant differences were found in the amount of specific transcripts in oocytes matured under different conditions. In conclusion maturation with PVA and 5% O2 provides an efficient in vitro culture condition for the maturation of bovine oocytes.


2019 ◽  
Vol 31 (1) ◽  
pp. 210
Author(s):  
G. Singina ◽  
E. Shedova ◽  
T. Taradajnic ◽  
V. Konnova ◽  
E. Tsyndrina

To date, considerable progress has been achieved in in vitro production (IVP) technologies in cattle; however, developmental potentials of oocytes matured in vitro remain low compared with in vivo-matured oocytes. Thus, a better understanding of different aspects of oocyte maturation may allow us to increase the embryo development rate. Our study was aimed to assess the effects of progesterone (P4) and prolactin (PRL) on the bovine oocyte developmental competence. Bovine cumulus-enclosed oocytes (CEO) were matured using either one-step or two-step maturation conditions. For the one-step protocol, CEO were cultured for 24h in TCM-199 supplemented with 10% fetal calf serum (FCS), 10μg mL−1 porcine FSH, and 10μg mL−1 ovine LH (standard medium). For the two-step procedure, CEO were first cultured for 16h in the standard medium (n=1263) and then transferred to 1 of 3 experimental media and cultured for additional 8h in either absence or presence of either P4 (50 ng mL−1) or bovine PRL (50ng mL−1). The 3 media tested in the two-step maturation were (1) TCM-199 containing 10% FCS (group 1), (2) TCM-199 containing 3mg mL−1 BSA (group 2), or (3) Fert-TALP medium supplemented with 6mg mL−1 BSA (group 3). Fert-TALP was selected because it can potentially be used throughout maturation and fertilization. Following in vitro maturation, all oocytes underwent an IVF/in vitro culture procedure as described previously (Singina et al. 2014 Reprod. Fertil. Devel. 26, 154). The embryo development was evaluated at Days 2 and 7 for cleavage and blastocyst rates. In addition, obtained blastocysts were fixed, and the total cell number and the level of apoptosis were determined using 4′,6-diamidino-2-phenylindole (DAPI) and TUNEL staining. The data from 4 to 5 replicates (113-159 oocytes per treatment) were analysed by ANOVA. For oocytes matured for 24h in the one-step culture, the cleavage rate, blastocyst rate, total cell number, and apoptotic nuclei per blastocyst were 66.1±1.1, 23.7±2.0, 71.4±9.1, and 4.8±1.2%, respectively. For the two-step culture, the cleavage rate did not differ from that of the one-step culture system, ranging from 64.8 to 76.5%. Also, no effects of the two-step systems were observed on total cell number (63.0-78.8) or the proportion of apoptotic nuclei (3.3-5.3%) at the blastocyst stage. The culture of CEO in group 1 (without the supplements) had a reduced blastocyst rate (17.4±0.4%; P&lt;0.05) compared with the standard one-step maturation group, and the addition of P4 (but not PRL) improved the blastocyst yield (P&lt;0.05). Furthermore, when P4 (but not PRL) was added to group 2 and group 3 media, blastocyst rates increased significantly (32.9±3.1 and 32.8±2.7%, respectively) compared with those of the one-step group (P&lt;0.05), but did not differ from those of untreated groups 2 and 3 (26.2±2.7 and 30.0±3.0%, respectively). Our data indicate that P4 supplementation during the terminal phase of two-step IVM can enhance the developmental competence of bovine oocytes and that the nature of this effect depends on the composition of IVM medium, whereas no effect of PRL supplementation was observed. The study was supported by RFBR (No. 17-29-08035).


2012 ◽  
Vol 24 (1) ◽  
pp. 207
Author(s):  
Y. Jeon ◽  
S.-S. Kwak ◽  
S.-A. Jeong ◽  
R. Salehi ◽  
Y. H. Seong ◽  
...  

Trans-ε-viniferin is a naturally occurring polyphenol belonging to the stilbenoids family. Trans-ε-viniferin is isolated from Vitis amurensis, 1 of the most common wild grapes in Korea, Japan and China. We investigated the effects of trans-ε-viniferin on in vitro maturation (IVM) and developmental competence after IVF or parthenogenesis (PA). At the laboratory of Veterinary Pharmacology, College of Veterinary Medicine, Chungbuk National University, trans-ε-viniferin was purified from the leaves and stems of Vitis amurensis. Data were analyzed with SPSS 17.0 using Duncan's multiple range test. First, in total, 594 cumulus–oocyte complexes (COC) were used for the evaluation of nuclear maturation. The COC were matured in TCM-199 medium supplemented with various concentrations of trans-ε-viniferin (0, 0.1, 0.5, 1.0 and 5.0 μM) with 10% porcine follicular fluid, 10 IU mL–1 of eCG and 10 IU mL–1 of hCG. After 22 h in maturation culture, the COC were cultured in hormone-free medium supplemented with various concentrations of trans-ε-viniferin for an additional 22 h and then nuclear maturation was evaluated. Second, in total, 300 matured oocytes were used to examine the effects of different trans-ε-viniferin concentrations (0, 0.5 and 5.0 μM) on porcine oocyte intracellular glutathione (GSH) and reactive oxygen species (ROS) levels. Lastly, the developmental competence of oocytes matured with different concentrations of trans-ε-viniferin (0, 0.5 and 5.0 μM) was evaluated after IVF or PA. In total, 711 embryos were evaluated. As results, we observed that trans-ε-viniferin treatment during IVM did not improve the nuclear maturation of oocytes in any group (84.2, 86.6, 85.5, 83.3 and 79.2%, respectively), but significantly increased (P < 0.05) intracellular GSH levels in the 0.5 μM group (0 μM vs 0.5 μM; 14.6 vs 16.8 pmol oocyte–1) and reduced ROS levels (0 μM vs 0.5 μM and 50 μM; 174.6 vs 25.7 and 23.8 pixel oocyte–1). Oocytes treated with trans-ε-viniferin during IVM did not have significantly different cleavage rates or blastocyst formation rates after IVF, but total cell numbers were significantly higher (P < 0.05) in the 0.5 and 5.0 μM treatment groups (53.6 ± 4.0 and 47.9 ± 3.1) compared to the control group (36.4 ± 2.2). The PA embryos showed similar results; there were no significant differences in cleavage rates and blastocyst formation rates, but the total cell number significantly increased in the 0.5 and 5.0 μM treatment groups (59.6 ± 4.2 and 60.8 ± 4.6) compared to the control group (43.1 ± 2.1). In conclusion, these results indicate that trans-ε-viniferin treatment during porcine IVM increased total cell number of blastocysts, possibly through increasing intracellular GSH synthesis and reducing ROS levels. This work was supported by a grant from the Korea institute of Planning & Evaluation for Technology in Food, Agriculture, Forestry & Fisheries, Republic of Korea.


2014 ◽  
Vol 26 (1) ◽  
pp. 156 ◽  
Author(s):  
E. R. Lliteras ◽  
M. Chong ◽  
S. Andries ◽  
E. Merckx ◽  
E. P. A. Jorssen ◽  
...  

The production of excessive levels of reactive oxygen species can be a major problem during in vitro embryo culture. Although studies have shown that supplementation with exogenous antioxidants can improve embryo quality, the results are controversial among researchers. In this study, we examined the effects of different concentrations of β-mercaptoethanol (β-ME) added to the culture media, on cleavage rates, the quality and developmental competence of in vitro-produced bovine embryos. The embryos were produced in vitro as described previously (Van Hoeck et al., 2013). Briefly, in total, 753 grade I cumulus–oocyte complexes (COC) from 2- to 6-mm-diameter follicles were matured in groups of 50 in 500 μL of TCM with 20 ng mL–1 EGF for 24 h, fertilized in groups of 100 in 500 μL of fertilization medium for 20 h (5% CO2, 38.5°C). Presumptive zygotes were denuded and randomly assigned to 4 treatments with different concentrations of β-ME: 0 μM (control), 50 μM, 100 μM, and 150 μM. They were cultured in groups of  ±25 in 50 μL of SOF supplemented with ITS (10 μg mL–1 insulin; 5.5 μg mL–1 transferrin; 6.7 ng mL–1 selenium) and 2% BSA and covered with mineral oil (5% O2, 5% CO2, 38.5°C). At 48 h post-insemination (p.i.), cleavage rate was evaluated and expressed as the number of cleaved embryos on total number of oocytes. At Day 7 p.i., blastocyst rate was determined (number of blastocysts on total number of oocytes), blastocysts were fixed in 4% paraformaldehyde, and total cell number was determined by DAPI staining. Data were analysed by ANOVA and post hoc test. Comparable cleavage rates were obtained in treated groups: control (80.8%), 50 μM (77.7%), 100 μM (77.9%), and 150 μM (73.6%; P > 0.05). Also, no significant effect of treatment could be found on blastocyst rates: control (36%), 50 μM (36.5%), 100 μM (38.4%), and 150 μM (30.4%). The total cell number per blastocyst increased significantly (P < 0.05) using 100 μM of β-ME compared with the controls (158.0 ± 24.3 v. 123.2 ± 9.72, respectively). These results suggest that the inclusion of 100 μM β-ME during in vitro embryo culture could be used for production of high quality bovine blastocysts.


2011 ◽  
Vol 23 (1) ◽  
pp. 130
Author(s):  
J. Li ◽  
J. Adamsen ◽  
R. Li ◽  
H. Pedersen ◽  
Y. Liu ◽  
...  

One of the primary factors influencing the developmental ability of cloned embryos is the oocyte′s diameter (Hirao et al. 1994 J. Reprod. Fertil. 100, 333–339). However, the oocyte donor's age (i.e. its sexual maturity) is also important to consider, because a high proportion of immature oocytes can be expected (Ikeda and Takahashi 2003 Reprod. Fertil. Dev. 15, 215–221). The present study was to investigate the effect of diameter of oocytes collected from prepubertal gilts weighing 100 to 120 kg on the developmental ability of cloned and parthenogenetically activated (PA) embryos. Cumulus–oocyte complexes collected from ovaries of prepubertal gilts were in vitro matured for 42 to 44 h as described for sow oocytes (Li et al. 2008 Theriog 70, 800–808). After removal of the cumulus cells, the matured oocytes were sorted into 2 groups based on visual inspection: large (L) and small (S) oocytes, whereas non-sorted oocytes were used as control (C). In addition, 1 batch from each of the 3 groups of oocytes had their mean size measured. Subsequently, all 3 groups were used for handmade cloning (HMC; Li et al. 2009 Reprod. Domest. Anim. 44, 122–127) or parthenogenetic activation (PA; Kragh et al. 2005 Theriogenology 64, 1536–1545). Then a chemical activation with 5 μg mL–1 cytochalasin B and 10 μg mL–1 cycloheximide in PZM-3 medium was applied for 4 h on both HMC and PA embryos. Finally, the activated embryos were washed and cultured in PZM-3 medium using the WOW system. The embryo development was evaluated by cleavage rate (Day 2), blastocyst rate (Day 6), and total cell number in blastocysts. Data were analysed by ANOVA with single factor in Excel (Microsoft Excel 2007, Redmond, WA, USA). The results showed (Table 1) that by simple visual observation, oocytes could be easily sorted into the following groups: L group (mean diameter 110 μm, from 105 to 116 μm), S group (mean diameter 101 μm, from 93 to 106 μm) and C group (mean diameter 107 μm, from 93 to 116 μm). Cleavage rates and total cell number were similar in the 3 groups. However, the blastocyst rate in L group either for HMC or PA was higher than S group. The data confirm that prepubertal gilt oocytes are useful for cloning and PA, but developmental rates can be increased by selection of large oocytes by simple visual observation. Table 1.Data analysis results


2014 ◽  
Vol 26 (1) ◽  
pp. 190
Author(s):  
E. Kim ◽  
Y. Jeon ◽  
J. D. Yoon ◽  
L. Cai ◽  
S. U. Hwang ◽  
...  

The objective was to investigate the effects of zinc (Zn) insufficiency during in vitro maturation (IVM) of porcine oocytes. Zinc insufficiency was induced by treatment of Zn chelator, N,N,N′,N′-tetrakis-(2-pyridylmethyl)-ethylendiamine (TPEN). In experiment 1, we investigated the effect of duration of Zn insufficiency in IVM on oocytes maturation and subsequent embryonic development after parthenogenetic activation (PA). First, 10 μM TPEN was added to the IVM medium for 0, 7, 15, or 22 h. After TPEN treatment, 10 μM Zn were supplemented on IVM medium except in the 0 h group. Reductions in the nuclear maturation rates were dependent on TPEN duration. The 0-h-treated oocytes showed 83.9 ± 3.9% metaphase II (MII) rate; the 7-h-treated oocytes had significantly lower MII rate (44.8 ± 3.0%) than 0-h-treated oocytes. The majority of 15- and 22-h-treated oocytes were arrested at metaphase I (MI rate: 98.0 ± 1.0 and 97.2 ± 1.7%, MII rate: 0 and 0%, respectively). Embryonic developmental competence was similar to maturation results. Reduction in cleavage and blastocyst (BL) rates were also dependent on duration of TPEN treatment (cleavage rate: 65.3 ± 1.4, 42.6 ± 4.8, 2.6 ± 0.1, and 3.0 ± 1.6%; BL formation rate: 29.3 ± 2.8, 9.2 ± 1.5, 0, and 0% for 0, 7, 15, and 22 h). Total cell number of BL was also significantly different. Total cell number of BL in the 0-h-treated group (51.4 ± 4.5) was significantly higher than that in the 7-h-treated group (23.2 ± 1.6). In experiment 2, to confirm that the Zn insufficiency caused oocyte immaturities and loss of developmental competence in TPEN-treated oocytes, we investigated nuclear maturation and subsequent embryonic development following 3 groups: (1) non treatment (control); (2) 10 μM TPEN treatment during 22 h of IVM; (3) 10 μM TPEN + 10 μM Zn treatment during 22 h of IVM. Only TPEN-treated oocytes and TPEN+Zn-treated oocytes showed contrasting results. Oocyte maturation rates and subsequent embryonic development competence in TPEN with Zn-treated oocytes were similar to control (MII rate: 93.0 ± 1.2 and 92.7 ± 1.8%, BL formation rate: 42.0 ± 6.7 and 40.0 ± 7.5% for TPEN+Zn-treated oocytes and control). These results were significantly different compared with only TPEN-treated oocytes’ results (MII rate: 0.61 ± 0.61%, BL formation rate: 0%). In conclusion, Zn is an essential element for successful oocyte maturation and embryo development in porcine. Zinc insufficiency caused meiotic block and had lasting effects on early embryo development. This work was supported, in part, by a grant from the Next-Generation BioGreen 21 Program (No. PJ00956901), Rural Development Administration, and the National Research Foundation of Korea Grant funded by the Korean Government (NRF-2012R1A1A4A01004885, NRF-2013R1A2A2A04008751), Republic of Korea.


2009 ◽  
Vol 21 (1) ◽  
pp. 224
Author(s):  
M. M. Pereira ◽  
F. Q. Costa ◽  
P. H. A. Campos ◽  
R. V. Serapiao ◽  
J. Polisseni ◽  
...  

In vitro maturation (IVM) is a critical step in in vitro bovine embryo production. A number of factors can influence the IVM environment, such as media composition and protein supplementation. Serum and higher O2 tension have been shown to reduce embryo quality; however, little is known about the effects of serum and O2 tension during IVM on embryo quality and development. This study aimed to evaluate the effect of serum and O2 tension on IVM of bovine oocytes. Immature oocytes obtained from slaughterhouse ovaries were randomly distributed in 4 groups of IVM: G1 (n = 253), 0.1% polyvinyl alcohol (PVA) in air; G2 (n = 248), 10% inactivated estrous cow serum (ECS) in air; G3 (n = 270), 0.1% PVA under 5% O2; and G4 (n = 236), 10% ECS under 5% O2. In vitro maturation was performed with TCM-199 culture medium supplemented with 20 μg mL–1 FSH, under 5% CO2 at 38.5°C for 24 h. After maturation, oocytes were in vitro fertilized with 2.0 × 106 sperm mL–1 in Fert TALP medium, supplemented with heparin, for 20 h. Presumptive zygotes were denuded by vortexing and cultured in CR2aa medium with 2.5% fetal calf serum under 5% CO2 and 5% O2 at 38.5°C. Cleavage rate was evaluated 72 h postfertilization, and blastocyst rate and total cell number were evaluated 8 days postfertilization. Morphological classification of embryos was performed at Day 8 according to the International Embryo Transfer Society manual (1998). Cleavage, blastocyst, and grade 1 embryo rates were analyzed by chi-square, and total cell number was analyzed by ANOVA, with means compared by LSD. Results are presented as mean ± SEM. There was no difference (P > 0.05) in cleavage rates among G1, G2, and G4 (61.6, 65.3, and 57.6%, respectively), but cleavage rate was lower (P < 0.05) in G3 (52.5%). Blastocyst rates among G1, G3, and G4 (15.8, 17.7, and 20.3%, respectively) were similar (P > 0.05). However, blastocyst rate in G2 (25.0%) was higher (P < 0.05) than in G1 and G3, but was similar to G4 (P > 0.05). Total cell number was similar (P > 0.05) among G2 (194.1 ± 13.1), G3 (173.3 ± 9.0), and G4 (163.8 ± 8.7), but was lower (P < 0.05) in G1 (124.5 ± 11.4). The grade 1 embryo rate was lower (P < 0.05) in G1 (70.3%) than in G2 (89.5%), but was similar (P > 0.05) to G3 (77.0%) and G4 (83.9%). The results suggest that IVM with PVA in TCM-199 medium under 5% O2 can be performed without reducing embryo development and quality, when compared with ECS. On the other hand, oocyte developmental competence seems to be affected when IVM is performed with PVA under air conditions. Financial support: CNPq, FAPEMIG.


2004 ◽  
Vol 16 (2) ◽  
pp. 146
Author(s):  
S. Kim ◽  
D.H. Nam ◽  
Y.W. Jung ◽  
H.S. Kim ◽  
S.H. Lee ◽  
...  

The developmental potential of in vitro production of embryos is affected by various factors, including the culture system, oocyte quality, the presence of serum, and embryo paracrine and autocrine growth factors. Insulin-like growth factor is a good stimulator of oocyte maturation and embryo development. The present study investigated the effect of insulin-like growth factor-I (IGF-I) supplement on the preimplantation development of porcine embryos derived from in vitro fertilization (IVF) and somatic cell nuclear transfer (SCNT). Developmental competence was evaluated by monitoring the numbers of 2-cell embryos and blastocysts at Days 2 and 7, respectively. The number of total cells and inner cell mass (ICM) cells in blastocysts were counted after differential staining at Day 7. All data were analyzed by ANOVA using a Generalized Linear Model (SAS). In Experiment 1, a total of 2,462 in vitro-matured oocytes (527, 458, 498, 481 and 498, respectively) were inseminated with frozen-thawed boar semen and subsequently cultured in North Carolina State University (NCSU)-23 medium supplemented with various concentrations of IGF-1 (0, 1, 10, 50 and 100ngmL−1). As a result, significant model effects on the development to the 2-cell stage (P=0.033) and to the blastocyst stage (P=0.0067) were found, and more blastocysts (16.9, 16.6, 17.5, 21.8 and 14.7 %, respectively) were obtained in medium supplemented with 50ngmL−1 of IGF-I. Moreover, increase in the total cell number (56.5, 53.2, 74.0, 76.4 and 58.4) and ICM (6.6, 5.8, 9.3, 9.4 and 6.1) cells was observed in IVF embryos cultured in NCSU-23 medium supplemented with 50ngmL−1 IGF-1. In Experiment 2, porcine cloned embryos were produced by our standard protocol using fetal fibroblasts as donor cells (Hyun SH et al., 2003 Theriogenology 59, 1641–1649) and cultured in NCSU-23 supplemented with the same concentration of IGF-1 as Experiment 1. As a result, a total of 501 reconstructed oocytes (99, 98, 102, 99 and 96, respectively) were cultured and significant model effects on the development to the 2-cell stage (P=0.0179) were found. More blastocysts (10.5, 11.2, 11.8, 20.8 and 10.1%) were produced when embryos were cultured in NCSU-23 medium supplemented with 50ngmL−1, even though no statistical significance was found (P=0.1182). Increases in the total cell number (42.7, 46.0, 45.9, 51.1 and 38.2) and ICM cells (3.8, 3.8, 5.6, 6.6 and 4.8, respectively) were observed in cloned embryos cultured in NCSU-23 medium supplemented with 50ngmL−1 of IGF-I. In conclusion, the present study demonstrated that IGF-1 at the concentration of 50ngmL−1 improves the development of preimplantion embryos derived from IVF and SCNT. This study was supported by the Advanced Backbone IT Technology Development (IMT 2000-C1-1).


2010 ◽  
Vol 22 (1) ◽  
pp. 335
Author(s):  
V. Van Hoeck ◽  
J. L. M. R. Leroy ◽  
S. Andries ◽  
P. E. J. Bols

High non-esterified fatty acid (NEFA) concentrations in the blood, associated with negative energy balance (NEB), obesity or diabetes Type II are known to alter the follicular micro-environment. These environmental changes have been associated with disappointing fertility outcome through disabled ovarian cell function and oocyte’s developmental competence. Our hypothesis was that elevated NEFA concentrations during final oocyte maturation might hamper the quality of the pre-implantation embryo as well. To assess embryo quality, the present study focused on total cell number and apoptotic index in 7-day-old embryos. Applied NEFA concentrations in the maturation medium were based on analyses in the follicular fluid of high yielding dairy cows early post partum during NEB. Bovine cumulus-oocyte complexes were exposed to 1) physiological NEFA concentrations, i.e. a combination of basal palmitic (25 μM), stearic (50 μM) and oleic acid (75 μM) concentrations (CONTROL), 2) elevated NEFA concentrations, i.e. a combination of high palmitic (75 μM), stearic (150 μM) and oleic acid (200 μM) concentrations (HIGH COMBI) and 3) elevated palmitic acid (75 μM) concentrations (HIGH PA). Palmitic acid has been recognized as a major saturated fatty acid in terms of cellular toxicity. After serum-free in vitro maturation (24 h) and fertilization (22 h), zygotes were cultured in SOF medium with 5% serum for 7 days. Blastocysts were evaluated for developmental competence, total cell number (by Propidium Iodide staining) and apoptotic index (by TUNEL detection kit). In total, 684 oocytes were cultured in 3 replicates. Data were analyzed with binary logistic regression and a mixed model ANOVA. Preliminary research showed that maturation in a combination of basal NEFA concentrations has no effect on oocyte’s developmental competence compared to the standard serum free maturation system. In the present study, maturation in HIGH COMBI resulted in significantly lower blastocyst rates (21.4%) compared to CONTROL (30.1%) (P = 0.03). No significant effect of HIGH PA maturation on blastocyst rate (24.1%) could be found. Also total cell number tended to be lower in the HIGH COMBI (104.7 ± 26.1) compared to CONTROL (125.8 ± 29.4) (P = 0.08). The apoptotic index was significantly increased in the HIGH PA group (0.22 ± 0.12) compared to the CONTROL group (0.11 ± 0.07) (P = 0.02) and tended to be higher than the HIGH COMBI group (0.14 ± 0.12) (P = 0.06). Maternal metabolic conditions, leading to increased lipolysis and high NEFA concentrations, can hamper fertility through a reduction of the oocyte’s developmental competence. The data of the present study furthermore suggest that elevated NEFAs might induce a negative carry over effect from the oocyte during its maturation to the embryo quality. This may ultimately lead to embryonic mortality and thus to a disappointing fertility outcome. Veerle Van Hoeck is supported by the Special Research Fund, University of Antwerp (Grant 22590).


2009 ◽  
Vol 21 (1) ◽  
pp. 123
Author(s):  
H. J. Oh ◽  
J. E. Park ◽  
M. J. Kim ◽  
S. G. Hong ◽  
J. T. Kang ◽  
...  

Epigenetic reprogramming such as acetylation in somatic cell nuclear transfer (SCNT) has been known as one of problems in cloned embryos. For resolving this acetylation reprogramming, many investigators recently have reported the effect of long-term culture of post-activated SCNT embryos using trichostatin A (TSA), a histone deacetylase inhibitor (HDACi). The objective of this study is to investigate the effect of short-term TSA treatment on in vitro developmental ability and the quality of bovine SCNT embryos. Immature oocytes were aspirated from abattoir-derived ovaries, matured in vitro for 22 h, and enucleated. A bovine fetal fibroblast was placed into the enucleated oocyte and fused by electrical stimulation. The fused couplets were activated by 4-min incubation in 10 μm ionomycin, followed by 4 h of culture in 1.9 mm 6-dimethylaminopurine with or without TSA (0, 50, or 100 nm). The SCNT embryos were subsequently cultured in modified synthetic oviduct fluid medium for 8 days. Developmental competence was assessed by blastocyst formation and total cell number. Total cell numbers were determined by staining with bisbenzimide 33342. As results, developmental competence to blastocysts was higher in 100 nm than control (36.7 v. 27.9%, P < 0.05). In blastocyst hatching rate, TSA 100 nm group (19.5%) at 8 days showed an increased pattern as opposed to control and TSA 50 nm group (11.1 and 12.7%; P < 0.05). No significant differences in two cell and morula stage were observed among treatment groups. In terms of development to hatching stage of blastocysts, TSA 100 nm group (19.5%) at 8 days has a significant effect compared to control and TSA 50 nm group (11.1 and 12.7%; P < 0.05). Total cell number of blastocysts derived from TSA 100 nm was significantly higher (P < 0.05) than that in TSA 50 nm (116 v. 100), whereas there was not significant difference between control and TSA 100 nm. In conclusion, short-term culture with high concentration of TSA improved the blastocysts formation however total cell number of blastocysts showed contradictory result. The epigenetic modification by TSA treatment on bovine SCNT needs further investigation. This study was financially supported by KOSEF (grant # M10625030005-08N250300510) and the Korean MEST, through the BK21 program for Veterinary Science.


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