Reactive oxygen species (ROS) production and F-actin cytoskeleton dynamics play important roles in the survival rate of blastocysts after the vitrifiedwarming process. However, the protective effects of Mito-TEMPO against cryo-injury and viability through F-actin aggregation and mitochondrial-specific ROS production in vitrificated-warmed bovine embryos have not been investigated. The aims of the present study were to: (1) determine the effects of Mito-TEMPO on embryonic developmental competence and quality by F-actin stabilization during in vitro culturing (IVC), and (2) confirm the effects of Mito-TEMPO through F-actin structure on the cryotolerance of vitrification-warming in Mito-TEMPO exposed in vitro production (IVP) of bovine blastocysts. Bovine zygotes were cultured with 0.1 μM Mito-TEMPO treatment for 2 days of IVC. Mito-TEMPO (0.1 μM) exposed bovine embryos slightly improved in blastocyst developmental rates compared to the non-treated group. Moreover, the viability of vitrified-warmed blastocysts from Mito-TEMPO treated embryos significantly increased (p < 0.05, non-treated group: 66.7 ± 3.2% vs Mito-TEMPO treated group: 79.2 ± 5.9%; re-expanded at 24 hours). Mito-TEMPO exposed embryos strengthened the F-actin structure and arrangement in the blastocyst after vitrification-warming. Furthermore, the addition of Mito-TEMPO into the IVC medium enhanced embryonic survival and quality through F-actin stabilization after the vitrification-warming procedure. Overall, our results suggest that supplementing the culture with 0.1 μM Mito- TEMPO improves the embryonic quality and cryo-survival of IVP bovine blastocysts.

Vitrification methods are commonly used for mammalian reproduction through the long-term storage of blastocyst produced in vitro. However, the survival and quality of embryos following vitrification are significantly low compared with blastocyst from in vitro production (IVP). This study evaluates that the survival of frozen-thawed bovine embryos was relevant to mitochondrial superoxide derived mitochondrial activity. Here we present supplementation of the cryopreservation medium with Mito- TEMPO (0.1 μM) induced a significant (p < 0.001; non-treated group: 56.8 ± 8.7%, reexpanded at 24 h vs Mito-TEMPO treated group: 77.5 ± 8.9%, re-expanded at 24 h) improvement in survival rate of cryopreserved-thawed bovine blastocyst. To confirm the quality of vitrified blastocyst after thawing, DNA fragmentation of survived embryos was examined by TUNEL assay. As a result, TUNEL positive cells rates of frozenthawed embryos were lower in the Mito-TEMPO treated group (4.2 ± 1.4%) than the non-treated group (7.1 ± 3.5%). In addition, we investigated the intracellular ROS and mitochondrial specific superoxide production using DCF-DA and Mito-SOX staining in survived bovine embryos following vitrification depending on Mito-TEMPO treatment. As expected, intracellular ROS levels and superoxide production of vitrified blastocysts after cryopreservation were significantly reduced (p < 0.05) according to Mito-TEMPO supplement in freezing medium. Also, mitochondrial activity measured by MitoTracker Orange staining increased in the frozen-thawed embryos with Mito-TEMPO compared with non-treated group. These results indicate that the treatment of Mito-TEMPO during cryopreservation might induce reduction in DNA fragmentation and apoptosis-related ROS production, consequently increasing mitochondrial activation for developmental capacity of frozen-thawed embryos.

Cryopreservation is used for blastocyst preservation of most mammalian embryos and is an important technique for breeding. We aimed to compare the efficiency of the cryopreservation method using the standard Cryotop device and the ReproCarrier device, a domestic product manufactured in Korea. The efficacy of the two devices was analyzed based on the survival rate, intracellular levels of reactive oxygen species (ROS), and apoptosis of the vitrified bovine blastocysts. The survival rates of the vitrified-warmed blastocysts were similar between the ReproCarrier group (58.4 ± 17.7%) and Cryotop group (59.9 ± 14.1%). Intracellular ROS levels and apoptotic index were determined by DCFDA staining and TUNEL assay. Changes in intracellular ROS levels, number of total nuclei, and cellular apoptosis of vitrified blastocysts after cryopreservation were not significantly different between the two groups. These results indicate that the ReproCarrier device method is as effective as the standard Cryotop method for vitrification of bovine blastocysts in vitro.

The establishment of porcine embryonic stem cells (ESCs) from porcine somatic cell nuclear transfer (SCNT) blastocysts is influenced by in vitro culture day of porcine reconstructed embryo and feeder cell type. Therefore, the objective of the present study was to determine the optimal in vitro culture period for reconstructed porcine SCNT embryos and mouse embryonic fibroblast (MEF) feeder cell type for enhancing colony formation efficiency from the inner cell mass (ICM) of porcine SCNT blastocysts and their outgrowth. As the results, porcine SCNT blastocysts produced through in vitro culture of the reconstructed embryos for 8 days showed significantly increased efficiency in the formation of colonies, compared to those for 7 days. Moreover, MEF feeder cells derived from outbred ICR mice showed numerically the highest efficiency of colony formation in blastocysts produced through in vitro culture of porcine SCNT embryos for 8 days and porcine ESCs with typical ESC morphology were maintained more successfully over Passage 2 on outbred ICR mice-derived MEF feeder cells than on MEF feeder cells derived from inbred C57BL/6 and hybrid B6CBAF1 mice. Overall, the harmonization of porcine SCNT blastocysts produced through in vitro culture of the reconstructed embryos for 8 days and MEF feeder cells derived from outbred ICR mice will greatly contribute to the successful establishment of ESCs derived from porcine SCNT blastocysts.

Although somatic cell nuclear transfer (SCNT)-derived embryonic stem cells (ESCs) in pigs have great potential, their use is limited because the establishment efficiency of ESCs is extremely low. Accordingly, we tried to develop in-vitro culture system stimulating production of SCNT blastocysts with high performance in the colony formation and formation of colonies derived from SCNT blastocysts for enhancing production efficiency of porcine ESCs. For these, SCNT blastocysts produced in various types of embryo culture medium were cultured in different ESC culture medium and optimal culture medium was determined by comparing colony formation efficiency. As the results, ICM of porcine SCNT blastocysts produced through sequential culture of porcine SCNT embryos in the modified porcine zygote medium (PZM)-5 and the PZM-5F showed the best formation efficiency of colonies in α-MEM-based medium. In conclusion, appropriate combination of the embryo culture medium and ESC culture medium will greatly contribute to successful establishment of ESCs derived from SCNT embryos.

The expression of MMPs in the development of the fertilized egg has a very important role in cell configuration. Objective To evaluate the clinical, the effect of differentially expressed MMPs on serum and serum - free medium on the maturation of blastocysts. The expression patterns of MMPs in serum and serum-free medium were compared at 6 h, 18 h and at the blastocyst stage using real-time PCR, ELISA and immunofluorescence. The results showed that the expression of MMPs was increased in the embryos of the serum medium, as a result of analysis of MMPs and TIMPs, MMP-2 was expressed in the cytoplasm of embryos in the serum-free medium, And it was found to be higher in expression than MMP-9. The serum medium was different from the bloodless badge: overall, TIMPs showed a higher expression in the ovarian cells than cyanosis, and TIMP-3 was more pronounced. Development rate of blastocyst according to in vitro culture method was higher than that of serum - free medium (61.22% 60/98) and serum - free medium (48.28% 28/58). Analysis of the protein release locations of MMPs and TIMPs showed that MMPs and TIMPs are highly expressed in serum mediums, focusing on the inner cell mass. However, very low expression appeared in the tropoblast. On the other hand, serum - free medium showed different expression from serum medium and TIMPs expression was generally low. Therefore, in the case of serum media, the expression of MMPs is highly expressed in the cytoplasm of the fertilized egg, increasing the reconstruction of cells.

As a part of the effort to improve post-transfer survival rate of embryos in Korean black goats, a technique for laparoscopic uterine transfer of blastocysts was carried out. A total of 26 transferrable embryos (morula to expanded blastocysts) were transferred to 13 recipient goats via transabdominal laparoscopic method. In consequence of our hormone protocol, 65% of the recipients (13/20) were found to have synchronized estrus. After confirmation of corpus luteum in each recipient goat, a Babcock laparoscopic forceps was inserted into the lower abdominal cavity to hold a uterine horn and fasten it near the peritoneum without causing injury. Then 7.5cm long 16G IV catheter was inserted directly into the uterine lumen through the abdominal wall. After removal of the stylet of the IV catheter, the embryo transfer tube (identical in size to the stylet and loaded with blastocysts) was inserted into the uterine lumen through the catheter to unload the embryos. Of the 13 estrus synchronized recipients, 9 were transferred blastocysts and 4 were transferred molurae (2 embryos in each recipient) in uterine ipsilateral to the ovary with corpus luteum. Four of the 9 recipients which blastocysts were transferred using this method has been confirmed pregnant (44.4% pregnancy rate).

Cryopreservation has been applied successfully in many mammalian species. Nevertheless, pig embryos, because of their greater susceptibility to cryoinjuries, have shown a reduced developmental competence. The aim of this study was to evaluate the survival status of vitrified-warmed porcine embryos. Forced blastocoele collapse (FBC) and non-FBC blastocysts are vitrified and concomitantly cultured in culture media which were supplemented with/without fetal bovine serum (FBS). Porcine vitrified-warmed embryos were examined in four different methods: group A, non- FBC without FBS; group B, non-FBC with FBS; group C, FBC without FBS; group D, FBC with FBS. After culture, differences in survival rates of blastocysts derived from vitrified-warmed porcine embryos were found in group A∼D (39.5 (A) vs 52.5 (B) and 54.8 (C) vs 66.7% (D), respectively, p<0.05). Reactive oxygen species (ROS) level of survived blastocysts was lower in group D than that of another groups (p<0.05). Moreover, total cell number of survived blastocysts was higher in group D than that of other groups (p<0.05). Otherwise, group D showed significantly lower number of apoptotic cells than other groups (2.0±1.5 vs 3.2±2.1, 2.8±1.9, and 2.7±1.6, respectively, p<0.05). Taken together, these results showed that FBS/FBC improves the developmental competence of vitrified porcine embryos by modulating intracellular levels of ROS and the apoptotic index during the vitrification/warming procedure. Therefore, we suggest that FBS and FBC are effective treatment techniques during the vitrification/warming procedures of porcine blastocysts.

Growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are oocyte-specific growth factors that regulate many critical processes involved in early folliculogenesis and oocyte maturation. In this study, effects of GDF9 and BMP15 treatment during in vitro maturation of porcine oocytes upon development after parthenogenetic activation were investigated. Neither GDF, BMP15 alone nor in combination affects the number and viability of cumulus cells or the rates of oocyte maturation and blastocyst development. However, the treatment of GDF9 on porcine oocytes increased the number of trophectodermal (TE) cells of blastocysts derived from activated oocytes (P<0.05). The treatment of BMP15 increased the cell numbers of both inner cell mass (ICM) and TE cells (P<0.05). The treatment with the combination of GDF9 and BMP15 further increased the numbers of ICM and TE cells, compared with GDF9 or BMP15 treatment alone (P<0.05). In conclusion, the treatment of GDF9 or BMP15 (or both) enhanced the quality of blastocysts via the increased number of ICM and/or TE cells.

This study aimed at investigating whether a porcine follicular fluid (pFF) supplementation positively affects the characteristics of donor cells and the developmental competence of porcine cloned embryos. Ear fibroblast cells (donor cell) from an Massachusetts General Hospital miniature pig were cultured in different culture methods: (1) Dulbecco's modified Eagle's medium (DMEM)+10% FBS (Control); (2) DMEM+0.5% FBS (SS); and (3) DMEM+10% FBS+10% pFF (pFF) for 72 h. In each conditioned medium, the concentrations of 4 amino acids (Thr, Glu, Pro, and Val) in the pFF group were significantly different from those in the control group (p<0.05 or p<0.01). The proliferation of the cells cultured in the SS group was significantly lower than that of the other treatment groups (p<0.01). The population of apoptotic and necrotic cells in the SS group was significantly higher than that of either the control or the pFF group (p<0.01). The number of embryos that cleaved (p<0.05) and developed into blastocysts (p<0.01) in the SS group was significantly lower than that of either the control or the pFF group. Compared to other groups, the blastocysts produced from the donor cells in the pFF group had higher total cells and lower apoptotic cells (p<0.05). It can be concluded that pFF supplementation in the donor cell culture medium positively affects cell death, cell cycle and quality of the cloned blastocyst.

Porcine has been known to have a great impact on the studies of organ transplantation, biomaterial production and specific biomodel development such as transgenic animals. To achieve such therapeutic purposes, establishment of porcine embryonic stem cells (pESCs) will be needed. Especially, in vitro differentiation toward neural cells from pESCs can be a useful tool for the study of early neural development and neurodegenerative disorders. In addition, these cells can also be used in cell replacement therapies and drug development for neuroprotective and/or neurotoxic reagents. Although several studies reported the successful isolation of pES-like cells, it has been a big challenge to determine optimal conditions to generate pESCs without loss of pluripotency for a long time. The present study was performed for generation and characterization of putative pESCs, and differentiation into neurons and astrocytes. In this study, porcine blastocysts were produced by parthenogenetically activated oocytes. The putative pESCs were cultured in pESC growth media supplemented with a growth factor and cytokines (bFGF, LIF and SCF). Subculture of pESCs was conducted by mechanical dissociation using syringe needles after 4-5 days of incubation. As results, six putative pESC lines were maintained over thirty passages. The putative pESCs were compact, round, flat, and single layered, which were similar to human embryonic stem cell morphologically. Six pES-like cells were positive for alkaline phosphatase activity at every three passages. Furthermore, Oct-3/4, Sox-2, Nanog and SSEA-4 were shown to be expressed in those cells. Also, normal karyotypes of pESCs were observed by Giemsa-staining. Differentiation potential into the three germ layers of the putative pESCs was demonstrated by the formation of embryoid bodies (EB). Besides, the study of ESC is very important in aspect of its application to not only the cell-based replacement therapies but also cellular differentiation research. Our results also showed that RA and N2 supplements activated the neural differentiation in pESC5. Neurofilament-l60 were expressed in neural precursor cells. The expression of markers for specific neural lineages, such as Microtubule-associated protein-2 expressed in matured neuron, was also induced from embryonic neural progenitors. In summary, the pESCs were generated from the parthenogenetically activated blastocysts and the typical characteristics of the cells were maintained for the long term culture. Furthermore, it was successful to differentiate the pESCs into various neural lineages through in vitro neurogenesis system. Eventually, pESCs will be excellent biomedicine in incurable and/or zoonotic diseases by regenerating the damaged tissue.

Although somatic cell nuclear transfer (SCNT) has successfully been produced cloned animals in several species, the cloning efficiency is extremely low. It is generally believed that the low cloning efficiency is mainly attributed to faulty epigenetic modifications underlying the aberrant reprogramming of donor cell nuclei in recipient cytoplasm after SCNT. The nuclear reprogramming process involves epigenetic modifications, such as DNA demethylation and histone acetylation, which may be a key factor in improving the cloning efficiency. Recently, the histone deacetylase inhibitors (HDACi), such as trichosatin A (TSA) and m-carboxycinnamic acid bishydroxamide (CBHA), to increase histone acetylation have been used to improve the developmental competence of SCNT embryos. Therefore, we compared the effects of TSA with CBHA on the in vitro developmental competence and pluripotency-related gene expressions (Nanog, Oct3/4 and Sox2) in porcine cloned blastocysts. The porcine cloned embryos were treated with a 50 nM concentration of TSA or a 100 μm concentration of CBHA during the in vitro early culture (10h) after cell fusion and then were assessed to cleavage rate, development to the blastocyst stage and pluripotency-related gene expressions in NT blastocysts. All data was analyzed by chi-square. Following 4-5 replicates (245, 200 and 222 for NT, TSA and CBHA treated NT embryos respectively) there was no difference between normal NT and CBHA treated NT embryos, whereas TSA treated NT embryos was significantly decreased for cleavage rate (p<0.05). The developmental competence to the blastocyst stage in CBHA treated NT embryos (18.9%) significantly increased than that of normal NT and TSA treated NT embryos (9.4% and 11.5%) (p<0.05). In addition, all of pluripotent transcription factors (Nanog, Oct3/4 and Sox2) were highly expressed in the CBHA treated NT embryos, however, Sox2 and Oct3/4 were expressed in TSA treated NT embryos and Sox2 was only expressed in normal NT embryos (p<0.05). In conclusion, the treatment of CBHA as a histone deacetylase inhibitor significantly increased the developmental competence of porcine NT embryos and pluripotency- related gene expressions (Nanog, Oct3/4 and Sox2) in NT blastocysts.

In this study, synergic effects of MEM vitamins (MEMv) and beta-mercaptoethanol (bME) supplemented to porcine maturation medium on reactive oxygen species (ROS) of oocytes and embryos, and apoptosis of blastocysts were determined. Cumulus-oocyte- complexes (COCs) were allocated into four treatment groups: 0.05X MEMv, 25 uM bME, 0.05X MEMv + 25 uM bME or a group without MEMv + bME. In experiment 1, COCs were cultured in four respective treatment groups based on NCSU-23 medium for 44 h at 39℃ in a 5% CO2 atmosphere. We evaluated ROS of oocytes. In experiment 2, COCs were cultured in four respective treatment groups and then were fertilized in vitro (IVF) or activated by chemical or electrical method. We determined ROS of early stage embryos (2 cell-4 cells) and apoptosis of blastocysts. DCHFDA for ROS level and TdT-mediated dUTP nick end labelling (TUNEL) for apoptosis were used. As a result, ROS level of oocytes was not significant difference among experimental groups. In early stage embryos produced by IVF, MEMv + bME group showed significantly lower ROS level than that of control group (p<0.05). Level of apoptosis in blastocysts of the MEMv + bME group was significantly lower than that of the control group (p<0.05). In early stage embryos produced by chemical activation, ROS level of MEMv + bME group was significantly lower than that of bME group (p<0.05) without significant difference with those of control and MEMv group. Level of apoptosis in blastocysts in the MEMv + bME group was significantly lower than that of the control group (p<0.05). In early stage embryos produced by electrical activation, ROS level of MEMv + bME group was significantly lower than that of control (p<0.05). However, apoptosis level of blastocyst was not significant difference among experimental groups. In conclusion, the present study indicates that the addition of MEM vitamins and betamercaptoethanol during in vitro maturation is able to alleviate the production of ROS and apoptosis.

Freezing of bovine blastocysts has been proposed as a tool to improve the feasibility of cattle production by using embryo transfer technique. However, the low efficiency of frozen-thawed embryos survival and further development is a crucial problem. Thus, we examined the effect of artificial shrinkage before vitrification of bovine expanded, hatched and SCNT embryos on the survival rate, apoptosis index and further development after thawing. Expanded, hatched and SCNT embryos were vitrified after artificial shrinkage, which was performed by puncturing the blastocoele with a pulled pasteur pipet. Artificial shrinkage of the blastocyst was achieved after pushing a pulled pasteur pipet into the blastocoele cavity until it contracted. The shrunken and not shrunken embryos were exposed to cryoprotectant solution in 7.5% ethylene glycol-7.5% DMSOPBS with 20% FBS for 5 min. They were placed in a small volume of vitrification solution (15% ethylene glycol+15% DMSO+PBS+20% FBS+0.5 M sucrose) and plunged into liquid nitrogen on a cryotop. Then, after thawing, cryoprotectant was diluted in 1.0 M, 0.5 M, 0.25 M, and 0 M sucrose for 1, 3, 5, and 5 min. Under the optimal conditions, overall efficiency of the survival rate of bovine expanded, hatched, SCNT embryos in artificial shrinkage groups was higher compared with non-artificial shrinkage groups (p< 0.05). Especially, the numbers of TUNEL-positive nuclei in artificial shrinkage groups were significantly reduced than those of non-artificial shrinkage groups among frozen-thawed expanded, hatched, and SCNT blastocysts (p< 0.05). Our results showed that survival rates in cryopreserved expanded, hatched, SCNT embryos could be improved by reducing the fluid content. Therefore, we suggest that artificial shrinkage method is a effective pretreatment technique for the cryotop vitrification of expanded, hatched, SCNT bovine blastocysts.

Previously, we reported that the osmolarity conditions in the satellite region were affected CpG DNA methylation status while Pre-1 sequence was not affected CpG DNA methylation in pNT blastocyst stage. This study was conducted to investigate the DNA methylation status of repeat sequences in pig nuclear transfer (pNT) embryos produced under different osmolarity culture conditions. Control group of pNT embryos was cultured in PZM-3 for six days. Other two treatment groups of pNT embryos were cultured in modified PZM-3 with 138 mM NaCl or 0.05 M sucrose (mPZM-3, 320 mOsmol) for two days, and then cultured in PZM-3 (270 mOsmol) for four days. The DNA methylation status of the Pre-1 sequences in blastocysts was characterized using a bisulfite-sequencing method. Intriguingly, in the present study, we found the unique DNA methylation at several non-CpG sequences at the Pre-1 sequences in all groups. The non-CpG methylation was hypermethylated in all three groups, including in vivo group (86.90% of PZM- 3; 83.87% of NaCl; 84.82% of sucrose; 90.94% of in vivo embryos). To determine whether certain non-CpG methylated sites were preferentially methylated, we also investigated the methylation degree of CpA, CpT and CpC. Excepting in vivo group, preference of methylation was CpT>CpC>CpA in all three groups investigated. These results indicate that DNA methylation of Pre-1 sequences was hypermethylated in CpG as well as non-CpG site, regardless modification of osmolarity in a culture media.

Pluripotent embryonic stem (ES) cells isolated from inner cell mass (ICM) of blastocyst-stage embryos are capable of differentiating into various cell lineages and demonstrate germ-line transmission in experimentally produced chimeras. These cells have a great potential as tools for transgenic animal production, screening of newly-developed drugs, and cell therapy. Miniature pigs, selectively bred pigs for small size, offer several advantages over large breed pigs in biomedical research including human disease model and xenotransplantation. In the present study, factors affecting primary culture of somatic cell nuclear transfer blastocysts from miniature pigs for isolation of ES cells were investigated. Formation of primary colonies occurred only on STO cells in human ES medium. In contrast, no ICM outgrowth was observed on mouse embryonic fibroblasts (MEF) in porcine ES medium. Plating intact blastocysts and isolated ICM resulted in comparable attachment on feeder layer and primary colony formation. After subculture of ES-like colonies, two putative ES cell lines were isolated. Colonies of putative ES cells morphologically resembled murine ES cells. These cells were maintained in culture up to three passages, but lost by spontaneous differentiation. The present study demonstrates factors involved in the early stage of nuclear transfer ES cell isolation in miniature pigs. However, long-term maintenance and characterization of nuclear transfer ES cells in miniature pigs are remained to be done in further studies.