• Journal of Embryo Transfer
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• v.22 no.3
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• pp.155-160
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• 2007

During in vitro culture of mammalian oocytes and embryos, the cells are exposed to the risks that cause cell injury or death. Numerous studies have been reported that the cell injury may be induced by the action of free radicals generated by auto-oxidation. This study was undertaken to investigate the optimal culture condition system for in vitro culture of porcine embryos. We first evaluated the effect of culture media on the porcine embryo development. NCSU-23 and PZM-5, culture medium tested, were failed to produce significant difference on the rate of blastocyst formation. In NCSU-23, the developmental rate was slightly higher than that in PZM-5. During in vitro maturation (IVM), fertilizaton (IVF), and culture (IVC) under 5 or 20% oxygen ($O_2$), the rates of cleavage and development were insignificantly different from each other under our culture condition (20% $O_2$, in NCSU-23), the mean cell number per blastocyst was $40{\pm}10$. These results showed that medium and $O_2$ concentration had no significant effect on the development of porcine embryos.

• Reproductive and Developmental Biology
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• v.36 no.3
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• pp.173-181
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• 2012

Sphingosine-1-phosphate (S1P) has a many function involved proliferation, differentiation and survival of many cells. In this study, to investigate whether S1P improve the developmental competence of porcine embryos, 50 nM of S1P were supplemented during in vitro maturation (with EGF or without EGF) medium and/or in vitro culture (IVC) medium. Addition of S1P was significantly increased the rate of oocytes reaching metaphase II (MII) compared to the control (83.5 vs. 64.1%) in without EGF medium, but not with EGF medium (89.5 vs. 84.6%). When treated with $1{\mu}M$ of N1N-dimethylsphingosine (DMS), a sphingosine kinase inhibitor which is blocked endogenous generation of S1P, the meiotic progression rates to MII stage (without EGF: 45.2 and with EGF: 66.7%) were significantly decreased and degeneration rates (without EGF: 51.2 and with EGF: 30.1%) were increased in both medium compared to control group during IVM periods. Also, the rates of blastocyst formation was significantly increased in the S1P treated group compared to control group (29.0 vs. 19.2%) of EGF supplemented medium, whereas there were no effect in the EGF free medium (9.0 vs. 10.5%). After 12 h IVM, the phosphorylation of ERK1 and ERK2, which is major signaling pathway of MAP kinase, were increased in the S1P group than that of control or DMS group. When supplemented of S1P during IVC, the rates of blastocyst formation and total cell number (30.2% and 40.6) were significantly increased in S1P-treated group compared with control (20.1% and 32.5), DMS (12.3% and 25.1), and S1P plus DMS group (24.7% and 33.6). The percentage of apoptosis nuclei in the S1P group was significantly decreased than other groups. Also, the rates of blastocyst formation (26.7 vs. 14%) and total cell number (42.8 vs. 32.5) were significantly increased in the S1P group than those of control group when S1P added during the entire IVM and IVC periods. Taken together, our results indicate that S1P supplementation in IVM and/or IVC medium affects beneficial effect of meiotic maturation and subsequent developmental competence of porcine embryos.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.3
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• pp.258-264
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• 2020

This study investigated the effect of variation in the number of somatic-cell-cloned embryos and their developmental stage at transfer on pregnancy, as well as the influence of the estrus status of recipient pigs on in vivo development of cloned porcine embryos after embryo transfer. For somatic cell nuclear transfer (SCNT), fibroblast cells were obtained from a male porcine fetus. Recipient oocytes were collected from prepubertal gilts at a local abattoir and then cultured. After SCNT, reconstructed embryos of different numbers and developmental stages were transferred into recipient pigs. The developmental stage of the cloned embryos and the number of transferred embryos per surrogate showed no significant differences in terms of the resulting cloning efficiency. However, the pregnancy rate improved gradually as the number of transferred cloned embryos was increased from 100-150 or 151-200 to 201-300 per recipient. In pre-, peri-, and post-ovulation stages, pregnancy rates of 28.6%, 41.8%, and 67.6% and 16, 52, and 74 offspring were recorded, respectively. The number of cloned embryos and estrus status of the recipient pig at the time of transfer of the cloned embryo affect the efficiency of pig production; therefore, these variables should be particularly considered in order to increase the efficiency of somatic cell pig cloning.

• Reproductive and Developmental Biology
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• v.30 no.2
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• pp.125-133
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• 2006

This study was conducted to detect the apoptosis incidence in blastocysts and to compare the abundance of Bax, Bcl2L1, VEGF and FGFR2 in in vitro fertilized (IVF), parthenogenetic (PAT) and nuclear transfer (NT) embryos. Oocytes matured for 40 hr were enucleated and reconstructed with confluenced fetal fibroblasts (FFs) derived from a ${\sim}45$ day fetus. Reconstructed eggs were then fused with 2 DC pulses (2.0 kV/cm, $30{\mu}sec$) and cultured with $7.5{\mu}g/ml$ cytochalasin B for 3 hr. Parthenotes (PAT) were produced with the same electric strength and culture for NT eggs. The embryos were cultured in NCSU-23 medium at $39^{\circ}C,\;5%\;CO_2,\;5%\l;O_2$ in air. In 3 runs, set of 10 embryos at the 4-cell to blastocyst stages were used to extract total RNA for analyzing the gene expression patterns of pro-apoptotic (Bax), anti-apoptotic (Bcl2L1), vasculogenesis (VEGF), implantation (FGFR2III) using real-time quantitative PCR. Cleavage and blastocyst rates were significantly higher (P<0.05) in IVF and PAT ($79.3{\pm}8.5\;and\;25.5{\pm}6.1,\;and\;85.0{\pm}6.4\;and\;38.6{\pm}5.5$, respectively)than NT counterparts ($65.1{\pm}5.2\;and\;15.6{\pm}3.0$, respectively). Significantly higher (P<0.05) total cells were observed in IVF controls and PAT ($34.7{\pm}5.8\;and\;38.1{\pm}4.1$) than NT embryos ($24.8{\pm}3.2$). Apoptosis index was significantly lower (P<0.05) in IVF than NT embryos. The Relative abundances (RA) of Bax and VEGF were significantly higher (P<0.05) at blastocyst stage in NT than IVF control. The RA of Bcl2L1 and FGFR2III were significantly higher (P<0.05) at blastocyst stage in IVF than NT. The present study observed the abnormal gene expressions in NT embryos at various developmental stages, suggesting certain clues to find out the cause of the low efficiency of NT to term.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.4
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• pp.585-592
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• 2017

Objective: The present study investigates pre- and post-implantation developmental competence of nuclear-transferred porcine embryos derived from male and female fetal fibroblasts. Methods: Male and female fetal fibroblasts were transferred to in vitro-matured enucleated oocytes and in vitro and in vivo developmental competence of reconstructed embryos was investigated. And, a total of 6,789 female fibroblast nuclear-transferred embryos were surgically transferred into 41 surrogate gilts and 4,746 male fibroblast nuclear-transferred embryos were surgically transferred into 25 surrogate gilts. Results: The competence to develop into blastocysts was not significantly different between the sexes. The mean cell number of female and male cloned blastocysts obtained by in vivo culture ($143.8{\pm}10.5$ to $159.2{\pm}14.8$) was higher than that of in vitro culture of somatic cell nuclear transfer (SCNT) groups ($31.4{\pm}8.3$ to $33.4{\pm}11.1$). After embryo transfer, 5 pregnant gilts from each treatment delivered 15 female and 22 male piglets. The average birth weight of the cloned piglets, gestation length, and the postnatal survival rates were not significantly different (p<0.05) between sexes. Conclusion: The present study found that the sex difference of the nuclear donor does not affect the developmental rate of porcine SCNT embryos. Furthermore, postnatal survivability of the cloned piglets was not affected by the sex of the donor cell.

• Korean Journal of Animal Reproduction
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• v.26 no.2
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• pp.143-151
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• 2002

The present study was conducted to investigate the effects of antioxidants and growth factors on early development of porcine follicular oocytes fertilized in vitro. The embryos without cumulus cells were transferred into NCSU 23 medium and cultured for 5~6 days. The proportions of embryos developed to morula and blastocyst stages were significantly higher (P＜0.05) in medium with 1.0(21.1%) and 2.0mM(22.3%) NAC than in control (14.7%) and 0.5mM NAC (12.2%). When the embryos were cultured in medium with ebselen, the highest proportion(36.9%) of embryos developed to morula or blastocyst stages was obtained in medium with 10 $\mu$M ebselen. Higher proportions of embryos were developed to rnorula and blastocyst stages during culture with 100$\mu$M than control, 50 and 200$\mu$M glutathione. The EGF and PDGF were evaluated as growth factors supplemented to the culture medium for in vitro development of porcine embryos. The proportions of embryos developed to morular and blastocyst stages were significantly higher (P＜0.05) in medium with 100ng/m1 ECF than control, 10 and 50ng/$m\ell$ EGF. However, the proportions of embryos developed to morular and blastocyst stages were not significantly different among concentrations of PDGF. In conclusions, these results indicate that NAC, ebselen and glutathione or EGF and PDGF can increase the proportion of embryos that develop beyond morula stage.

• Journal of Embryo Transfer
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• v.25 no.1
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• pp.1-7
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• 2010

The objective of this study was to examine the effect of vitamin B (pantothenic acid, folic acid, and myo-inositol) that was supplemented to embryo culture medium on in vitro development of parthenogenetically activated (PA) pig embryos. Cumulus-oocyte complexes derived from slaughtered ovaries were matured in TCM-199 supplemented with porcine follicular fluid, cysteine, pyruvate, EGF, insulin, and hormones (hCG and eCG) for the first 22 h and then further cultured in hormone-free medium for an additional 22 h. After maturation culture, metaphase II oocytes that extruded 1st polar body were electrically activated and treated with $5.0\;{\mu}g/ml$ cytochalasin B for 4 h. Then, PA embryos were cultured for 7 days in a modified NCSU-23 that was supplemented with pantothenic acid, myo-inositol, or folic acid at different concentrations ($3{\sim}300\;{\mu}M$) according to the experimental design. Myo-inositol added to culture medium did not show any beneficial or inhibitory effects on embryo cleavage and blastocyst formation. However, $300\;{\mu}M$ pantothenic acid significantly inhibited blastocyst formation compared to control (no addition) (24% vs. 36%, p<0.05). Folic acid ($300\;{\mu}M$) significantly (p<0.05) increased blastocyst formation (56%) compared to control (41%). Our results demonstrated that in vitro development of PA embryos was significantly influenced by vitamin B and addition of $300\;{\mu}M$ folic acid to culture medium improved in vitro development of pig PA embryos.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.26-26
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• 2003

Hyaluronic acid (HA)-binding sites have been shown the diagnostic potential fur assessment of sperm maturity, which is related to male fertility. This study was designed to evaluate chromosomal patterns in porcine embryos produced by in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) with non- or HA-binding sperm (HABS). For binding of sperm with HA, sperm incubated in 10 ${mu}ell$ drop containing HA (0.8 mg/ml)-agarose (0.8%) mixture for 15 min. IVF and ICSI with non- or HA-bound sperm examined with matured oocytes at 44 hr after in vitro maturation. Embryos were cultured in 50 ${mu}ell$ of NCSU 23 containing 0.5% BSA for 5 days and then in 50 ${mu}ell$ of NCSU 23 containing 10% FBS for 2 days. For the evaluation of chromosomal aneuploidies, chromosome 1 sub-metacentric specific probe was used in sperm and embryos by fluorescence in situ hybridization (FISH). The frequency of aneuploidy sperm for chromosome 1 was 6.25%. The significant differences following IVF and ICSI with non- or HA-bound sperm were not observed in blastocyst formation rates (18.6, 23.5, and 23.8%) and cell number (61.8 $\pm$ 12.5, 55.5 $\pm$ 7.3, and 59.3 $\pm$ 9.6). Moreover, the percentage of diploidy in 4-cell stage embryos was 57.1% (IVF), 68.8% (ICSI), and 76.3% (ICSI-HABS). These results suggest that HA-binding sites may be a material for selection of normal sperm for ICSI. Therefore HA selection of normal sperm may be reduce the loss to embryonic mortality prior to embryo transfer in pig.

• Reproductive and Developmental Biology
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• v.32 no.2
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• pp.135-140
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• 2008

Recent studies on nuclear transfer and induced pluripotent stem cells have demonstrated that differentiated somatic cells can be returned to the undifferentiated state by reversing their developmental process. These epigenetically reprogrammed somatic cells may again be differentiated into various cell types, and used for cell replacement therapies through autologous transplantation to treat many degenerative diseases. To date, however, reprogramming of somatic cells into undifferentiated cells has been extremely inefficient. Hence, reliable markers to identify the event of reprogramming would assist effective selection of reprogrammed cells. In this study, a transgene construct encoding enhanced green fluorescent protein (EGFP) under the regulation of human Oct4 promoter was developed as a reporter for the reprogramming of somatic cells. Microinjection of the transgene construct into pronuclei of fertilized mouse eggs resulted in the emission of green fluorescence, suggesting that the undifferentiated cytoplasmic environment provided by fertilized eggs induces the expression of EGFP. Next, the transgene construct was introduced into human embryonic fibroblasts, and the nuclei from these cells were transferred into enucleated porcine oocytes. Along with their in vitro development, nuclear transfer embryos emitted green fluorescence, suggesting the reprogramming of donor nuclei in nuclear transfer embryos. The results of the present study demonstrate that expression of the transgene under the regulation of human Oct4 promoter coincides with epigenetic reprogramming, and may be used as a convenient marker that non-invasively reflects reprogramming of somatic cells.

• Journal of Embryo Transfer
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• v.32 no.4
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• pp.337-342
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• 2017

The present study was aimed to determine the effects of green tea extract (GTE) and beta-mercaptoethanol (${\beta}-ME$) supplementation in boar sperm freezing extender on in vitro fertilization (IVF) and reactive oxygen species (ROS) and glutathione (GSH) levels of presumptive zygotes (PZs). Experimental groups were allocated into lactose egg yolk (LEY) without antioxidant (control), GTE (1,000 mg/l in LEY) and ${\beta}-ME$ ($50{\mu}M$ in LEY). In freezing, spermatozoa extended with LEY were cooled to $5^{\circ}C$ for 3 h and then kept at $5^{\circ}C$ for 30 min following dilution with LEY containing 9% glycerol and 1.5% Equex STM. The final sperm concentration was $1{\times}10^8/ml$. Spermatozoa were loaded into straws and frozen in nitrogen vapor for 20 min. For IVF, oocytes were matured in NCSU-23 medium and co-cultured with spermatozoa following thawing at $37^{\circ}C$ for 25 sec. At 12 h following IVF, IVF parameters (sperm penetration and monospermy) were evaluated. In addition, GSH and ROS levels of PZs were determined by Cell Tracker Blue CMF2HC and DCHFDA, respectively. IVF parameters did not show any significant difference among the experimental groups. GSH and ROS levels of PZs were not significantly different between groups. In conclusion, antioxidant supplementation in boar sperm freezing could not influence IVF parameters, ROS and GSH levels of PZs.