Heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2/B1) is an N6-methyladenosine (m6A) RNA modification regulator and a key determinant of premRNA processing, mRNA metabolism and transportation in cells. Currently, m6A reader proteins such as hnRNPA2/B1 and YTHDF2 has functional roles in mice embryo. However, the role of hnRNPA2/B1 in porcine embryogenic development are unclear. Here, we investigated the developmental competence and mRNA expression levels in porcine parthenogenetic embryos after hnRNPA2/B1 knock-down. HhnRNPA2/B1 was localized in the nucleus during subsequent embryonic development since zygote stage. After hnRNPA2/B1 knock-down using double stranded RNA injection, blastocyst formation rate decreased than that in the control group. Moreover, hnRNPA2/B1 knock-down embryos show developmental delay after compaction. In blastocyste stage, total cell number was decreased. Interestingly, gene expression patterns revealed that transcription of Pou5f1, Sox2, TRFP2C, Cdx2 and PARD6B decreased without changing the junction protein, ZO1, OCLN, and CDH1. Thus, hnRNPA2/B1 is necessary for porcine early embryo development by regulating gene expression through epigenetic RNA modification.

The purpose of this study was to analyze whether FSH and LH hormone treatment directly or indirectly affect embryo development in embryonic development. To determine this, we compared the development of embryonic cells through the expression pattern of MMPs. As a result, 33.8% of blastocysts were formed in FSH added group, 20.8% in LH added group and 10% in FSH + LH added group. In addition, the activity of MMP-9 was highly detected in the FSH-added group, and the expression of Casp-3 was much lower than that of the other groups. These results suggest that the addition of FSH seems to increase the activity of MMP-9 in embryonic cells, and that LH, on the contrary, may activate MMP-2 activity. In addition, the expression level of MMP-2 in the FSH-added group was high in the Trophoblast cell group and in the LH-added group, the hormone ideal secretion might affect the development of the embryonic cell.

Alpha-linolenic acid (ALA; n-3 18:3), a one of omega-3 fatty acid, is mainly contained in chloroplast of plant and ALA is an essential fatty acid, not synthesized in mammalian body, it must be supplied from foods. Polyspermy is especially high on in vitro fertilization (IVF) in pigs, which is a major obstacle to in vitro embryo production systems. In our previous study, when ALA was supplemented during in vitro maturation (IVM), the methaphase-II rate and gluthathione level was increased. The objective of this study was to evaluate the effects of alpha-linolenic acid (ALA) supplementation during IVM and subsequent of IVF in pigs. The cumulus-oocyte complexes (COCs) were submitted to IVM medium containing 0, 25, 50, and 100 μM ALA for 44 h. After 44 h of IVM, denuded oocytes were co-cultured with spermatozoa during 18 h. After 18 h of in vitro fertilization, oocyte were using aceto-orcein method, to evaluated penetration rate, monospermy (number of monospermy oocytes/total oocytes), and the IVF efficiency (number of monospermy/total penetrated oocytes). In results, 25 and 50 μM ALA groups were significantly increased on penetration rate compared with 100 μM ALA group (p<0.05). Similarly, monospermy rate were significantly increased 25 and 50 μM ALA groups than control group (p<0.05). IVF efficiency was no significant difference between control and ALA treatment groups. Our findings suggested that treatment of ALA supplementation during in vitro maturation (IVM) and subsequent of in vitro fertilization in pigs, ALA can increase IVF efficiency by effectively blocking polyspermy and increasing monospermy some mechanism in porcine oocytes. However, the study of mechanism by which ALA blocks polyspermy are needed, and this study suggests that ALA has a positive effect on in vitro production of porcine oocytes by decreasing polyspermy. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Education) (2016R1D1A1B03931746).

Growth differentiation factor8 (GDF8) is a member of the transforming growth factor-β that has been identified as a strong physiological regulator. Overall of the current studies, the GDF8 is detected in oviduct fluid and uterus which led us to suggest that the GDF8 may effect on preimplantation embryonic development and act paracrine role to correlate with successful late-blastocyst implantation in in vivo. The purpose of this study is the effects of GDF8 on porcine parthenogenesis (PA) embryo development during in vitro culture (IVC). We were investigated the effect of GDF8 supplement during PA embryo IVC by cleavage and blastocyst formation rate and patterning analysis. Data were analyzed by on way ANOVA, followed by Tukey’s range test. Respectively 0.2, 2 and 20 ng/mL of GDF8 were added during IVC followed experiment design as control, 0.2, 2, and 20 GDF8 supplement groups. After 48h of embryo culture time, no significant difference was observed on cleavage rate from the different concentration (0, 0.2, 2, and 20 ng/ml) of GDF8 supplement groups (65.7%, 66.0%, 66.3%, and 65.8%, respectively). After 120h of embryo culture time, the 0.2 and 2 group showed significantly (p<0.05) higher blastocyst formation rate than control (40.4% and 36.4% VS 40.4%, respectively). In embryo developmental pattern analysis, the 0.2 ng/ml GDF8 supplement groups showed significantly higher (p<0.05) 2-3 cell cleavage- and early blastocyst pattern compared with control (12.0% and 10.4% VS 6.6% and 6.2%, respectively). However there are no significantly different pattern was observed in other groups. In conclusion, the 0.2 ng/ml of GDF8 supplementation during porcine PA embryo IVC significantly changed embryonic developmental patterns. However there are further studies are required such as analysis of blastocyst total number, specific gene transcription pattern, and ICM/TE rate to make clarify and support the conclusion.

It is still challenging to establish pESCs due to differences in the genetic backgrounds of mouse, human, and pig. So it is required to find pig specific pluripotency markers and cellular signaling. In this experiments, doxycycline-inducible vectors carrying OCT4, SOX2, NANOG, KLF4 and MYC known as reprogramming factors, were infected into pig stem cells for analyzing gene expression pattern. When cultured without doxycycline, pig stem cells were stably maintained in bFGF supplemented media. However, when treated with doxycycline, pig stem cells lost alkaline phosphatase activity and were differentiated within two weeks. And then, we investigated the expression of genes related to pluripotency in doxycycline-treated pig stem cells by using qRT-PCR. The qRT-PCR data revealed that expression of OCT4, CDH1 and FUT4 were significantly increased by OCT4 overexpression and OCT4 and FUT4 were also upregulated in SOX2-infected group. When infected with combination of two factors including OCT4 or SOX2, some groups could stably maintain at LIF supplemented media, having alkaline phosphatase activity. Given these data, although ectopic gene expression induced differentiation in pig stem cells, ectopic expression of OCT4 and SOX2 could upregulate pluripotent genes and overexpreession of two factors help pig stem cells adapt LIF-contained media. This study could improve understanding of pluripotent networks as well as aid in establishing bona fide pluripotent stem cells in pig.

Mitochondria are well known to regulate the mammalian embryo development. Recent studies showed that the mitochondrial dynamics responses are mainly generated through mitochondrial membrane potential (MMP) and cellular ATP production, which is dependent on mitochondrial reactive oxygen species (ROS). However, these mechanisms are unclear on development process of preimplantation porcine embryos. The aim of this study was to evaluate that difference of the mitochondrial dynamics-derived various functions on the embryo development according to lipid composition of zygote. First, zygote was classify two groups (high lipid, grade 1: G1 and low lipid, grade 2: G2) by lipid composition of cytoplasm. And, we performed the in vitro culture (IVC) using zygote of divided groups. The nuclei numbers and developmental rates of blastocysts were lower in G2 than those of G1 embryos. Next, we investigated the intracellular ROS and mitochondrial derived superoxide production in porcine embryos by using DCF-DA and Mito-SOX staining. As expected, both intracellular ROS and mitochondrial derived superoxide were significantly increased (p<0.05) in the preimplantation stage embryos of G2 group compared with G1 group. In addition, to observe difference of the mitochondrial functions, we investigated the mitochondrial membrane potential (MMP, ΔΨ) and contents of ATP in the preimplantation stage embryos by using JC-1 kit and ATP determination kit. These functions of mitochondria were dramatically reduced in cleavage stage embryos or blastocysts of G2 group. Finally, to verify the difference of the mitochondrial dynamics-derived various functions, we investigated the expressions of mitochondrial fission (Drp1, pDrp1-616) and fusion (Mfn1, Mfn2) factors by Western blotting analysis. Interestingly, the protein levels of pDrp1-616 in embryos of G1 group were continuously increased until blastocyst stage. Whereas, the expression patterns of Mfn1/2 in embryos of G2 group were significantly reduced during IVC progression. The expression patterns of mitochondria dynamic between the two groups were shown opposite. These results demonstrated that the lipid contents of zygote were related the positive-correlation with mitochondrial dynamics-derived functions in porcine embryos. Moreover, we suggest that lipid of zygote is play a important role on mitochondrial functions and dynamics during preimplantation embryos development in pigs.

In order to achieve successful in vitro production of embryo, it is necessary to establish intrauterine environment during in vitro culture. Thus, this study was investigated to establish embryo culture system using co-incubated collagen matrix gel (CM) with endometrial epithelial cells (EC). Endometrial epithelial cells were isolated from porcine endometrium at follicular phase, the cells seeded in insert dish for co-incubation with CM-coated culture dish. Then, culture media treated with/without 2.0 IU/ml hCG or 10 ng/ml IL-1β. After incubation for 24 h, the co-incubated insert dishes were removed from CM-coated culture dish before embryo culture. Embryos at 48 h after in vitro fertilization (IVF) were cultured on the dish for 120 h with porcine zygote medium. We determined PTGS-2 expression in the ECs, VEGF protein in co-incubated CM with EC and observed cleavage rate and blastocyst development of embryos at 168 h after IVF. In result, expression of PTGS-2 was higher at co-incubated EC with hCG and IL-1β groups than EC without hCG and IL-1β. The VEGF protein was detected at co-incubated CM with EC, EC treated with hCG and IL-1β groups higher than CM group. Also, cleavage rate was no significantly difference among all group, however, blastocyst development was significantly higher in co-incubated CM with EC treated with hCG group than un-treated groups (p<0.05). Therefore, we suggest that novel embryo culture system using co-incubated collagen matrix gel with endometrial epithelial cells treated with IL-1β is beneficial and useful for enhancing the production of porcine blastocysts in vitro.

Three-dimensional (3D) culture system is useful technique for study of in vivo environment and it was used various experiments. This study was investigated to establish of embryo co-culture system and changes of PAs activity in 3D cultured endometrial cells of pigs. In results, growth of stromal cells into gel matrix were detected only with endometrial and myometrial cells. The most rapid growth of stromal cells were confirmed in 2.5x105cells/ml and gel matrix containing 15% FBS. Expression of urokinase-PA (uPA) after treatment of hCG (0.5, 1.0, 1.5 and 2.0 IU/ml) were higher than without hCG, but, there are not significant difference among the treatment. On the other hand, expression of uPA after treatment of IL-1β (0.1, 1, 10 and 100 ng/ml) were higher than without IL-1β, but, there are not significant difference. Expression of uPA after treatment of estrogen (0.2, 2, 20 and 200 ng/ml) were not difference, but PA activity was significantly decreased (p＜0.05). Blastocyst was producing in PZM-3 medium containing FBS and endometrial cells were grown in PZM-3 medium. When embryos development with cultured endometrial cells, cleavage rates were not significant difference and blastocyst were not produced in co-culture with stromal cells and 3D culture system. 3D culture system had similar activity to in vivo tissue and these features are very useful for study of in vivo physiology. Nevertheless 3D culture system was not proper in embryo co-culture system. Therefore, we suggest that 3D culture system with embryo co-culture need continuous research.

The present study assessed the effect of FSH and LH on oocyte meiotic, cytoplasmic maturation and on the expression level and polyadenylation status of several maternal genes. Cumulus-oocyte complexes were cultured in the presence of FSH, LH, or the combination of FSH and LH. Significant cumulus expansion and nuclear maturation was observed upon exposure to FSH alone and to the combination of FSH and LH. The combination of FSH and LH during entire IVM increased the mRNA level of four maternal genes, C-mos, Cyclin B1, Gdf9 and Bmp15, at 28 h. Supplemented with FSH or LH significantly enhanced the polyadenylation of Gdf9 and Bmp15; and altered the expression level of Gdf9 and Bmp15. Following parthenogenesis, the exposure of oocytes to combination of FSH and LH during IVM significantly increased cleavage rate, blastocyst formation rate and total cell number, and decreased apoptosis. In addition, FSH and LH down-regulated the autophagy gene Atg6 and upregulated the apoptosis gene Bcl-xL at the mRNA level in blastocysts. These data suggest that the FSH and LH enhance meiotic and cytoplasmic maturation, possibly through the regulation of maternal gene expression and polyadenylation. Overall, we show here that FSH and LH inhibit apoptosis and autophagy and improve parthenogenetic embryo competence and development.

Pyracantha is a genus of thorny evergreen large shrubs in the family of Rosaceae, with common names Firethorn or Pyracantha. It's extract has also been used in cosmetics as a skin-whitening agent and functioning through tyrosinase inhibition. Recent studies have shown that pyracantha extract possesses antioxidant activities and may significantly improve lipoprotein metabolism in rats. Although the mode of action of Pyracantha extract is not fully understood, a strong relationship was observed between antioxidant and apoptosis in some types of cells. Thus, the aim of this study was to evaluated the effect of pyracantha extract on blastocysts formation and their quality of the porcine parthenogenetic embryos. After parthenogenetic activation by chemicals, presumptive porcine parthenogenetic embryos were cultured in PZM-3 medium supplemented with extracts of pyracantha leaf, stalk and root for 6 day (1, 5 and 10 μg/ml, respectively). In our results, the frequency of blastocyst formation in pyracantha root extract (5 μg/ml) treated group had increased that of other groups. Furthermore, blastocysts derived from pyracantha root extract (5 μg/ml) treated group had increased the total cell numbers and reduced apoptotic index. Blastocyst development was significantly improved in the pyracantha root extract (5 μg/ml) treated group when compared with the H2O2 treated group (p<0.05). Subsequent evaluation of the intracellular levels of ROS in pyracantha root extract (5 μg/ml) treated groups under H2O2 induced oxidative stress were decreased (p<0.05). In conclusion, our results indicate that treatment of pyracantha root extract may improve in vitro development of porcine parthenogenetic embryos through its antioxidative and antiapoptotic effects.

The objective of this study was to investigate the effects of NEAA and leptin supplemented to in vitro culture medium on the developmental competence of porcine embryos after intracytoplasmic sperm injection (ICSI), and to modify the culture condition to improve the quality and the development of ICSI-derived porcine embryos in vitro. After ICSI, the putative zygotes were then cultured in PZM-3 medium with/without NEAA or leptin. The proportion of embryos that developed to the blastocyst stage significantly increased when 1% NEAA (24.62%) was added to the medium compared with 2% NEAA and no NEAA group (17.24% and 20.24%, respectively, p<0.05). The effect of different concentration of leptin (0, 10, 100, 500 ng/ml) was evaluated on the development of porcine ICSI embryos cultured in vitro. In case of blastocyst formation, 100 ng/ml group (27.05%) showed significantly higher rate than 10, 500 ng/ml, and control group (23.45%, 17.99%, and 19.68%, respectively, p<0.05). We also evaluated the effects of different NEAA and leptin treatment time on the development of porcine embryos after ICSI. Among groups of embryos cultured in the presence of NEAA or leptin for whole 7 days (D 1-7), first 4 days (D 1-4), the subsequent 3 days (D 5-7), both NEAA (27.13%, 21.17 %, and 17.56%, respectively, p<0.05) and leptin (25.60%, 20.61%, and 16.53%, respectively, p<0.05) showed that supplementation for whole 7 days significantly increased the blastocyst formation rate compared with the other groups of D1-4 and D5-7. We further evaluated the combination effect of 1% NEAA and 100 ng/ml leptin compared with the effect of each supplementation with 1% NEAA or 100 ng/ml leptin or no supplementation on development of embryos. For blastocyst formation, combination group of NEAA and leptin (24.78%) showed significantly higher rate than other three groups (18.37%, 20.44 %, and 13.27%, respectively, p<0.05). We further evaluated the expression of proapoptosis genes such as BAX and BAK and anti-apoptosis genes, BCL-XL and BCL-2 in blastocysts cultured in the presence of 100 ng/ml leptin. RT-PCR analysis revealed that leptin supplementation significantly decreased the expression of pro-apoptosis genes as well as increased the expression of anti-apoptosis genes. These results of present study demonstrate that NEAA and leptin could improve the in vitro development of ICSI- derived porcine embryos with optimal concentration of each reagent. Furthermore, the optimal culture condition could increase the quality of ICSI-derived embryos in vitro.

An understanding of oocyte gene expression is a necessary for the study of early female gamete development. Recently, oocyte has been used in many techniques such as somatic cell nuclear transfer, intracytoplasmic sperm injection and embryonic stem cell derivation. The purpose of this study was to investigate in the proteomes of pig oocytes and identification of differential proteins between using DIGE technique. In this experiment to overcome of limitation of 2D gel method like a low reproducibility and low sensitivity for proteome analysis of very small quantities, 2D fluorescence difference gel electrophoresis (DIGE), which enables co-detection of up to three samples on the same 2DE gels with CyDyes was used for analysis of oocyte proteins. Proteins within an isoelectric point (pI) range of 3 to 10 and a molecular weight (Mw) range of 20～100 kDa were primarily analyzed in DIGE with 2 replications of each sample. Approximately 1000 spots were detected in 2-D gel. Then, image analysis of DeCyder was performed to detect variations in protein spots between mature oocyte and parthenogenesis embryo. In the comparison of mature oocyte and parthenogenesis embryo, 11 spots were identified to be up-regulated proteins and 2 spots to be down-regulated proteins in parthenogenesis embryo, among which proteins were zona pellucida glycoprotein 4, transferrin receptor, apolipoprotein B, L-3-Hydroxyacyl Coa Dehydrogenase Revisited, cytochrome P450 2C33, similar to Monocarboxylate transporter 2, 2'-5' oligoadenylate synthetase 3, interferon alpha/ beta receptor-1, Chloride channel protein 6, pyruvate carboxylase as well as2'-5' oligoadenylate synthetase 3 using MALDI-TOF-MS. These results suggested that differential proteins were present between mature oocyte and parthenogenesis embryo.

Embryo transfer (ET) is the final procedure for getting pregnancy through assisted reproductive technology such as IVF (in vitro fertilization), SCNT (somatic cell nuclear transfer). In our laboratory, the porcine cloned embryos loaded in ET medium are carried for 3 hours by portable incubator because of the great distance from the laboratory to the experimental farm. Thus, before transferring into recipient, porcine cloned embryos are exposed in vitro condition for long time. Medium which is used in this process is the TALP (Tyrode’s medium supplemented with 10 mM HEPES), but it includes little nutrients for embryo. Thus, the aim of this study is to determine whether ET media containing nutrients affect the in vitro development of embryos compared to TALP. For the experiment, porcine zygote medium (PZM)-5 which has amino acids for developing embryo was chosen as ET medium containing nutrients, added 10 mM Hepes as PZM-5 does not contain buffering system. For experiment, we carried out parthenogenesis through a chemical method using Thi/DTT. Parthenogenetic embryos were cultured in PZM-5 for 2 days, and then they were randomly divided into two group; loaded in a straw with TALP or PZM-5-Hepes, respectively. They were stored in a portable incubator for 3 hours to simulate the time consumed in ET, thereafter embryos in both TALP and PZM-5-Hepes groups were respectively cultured in PZM-5 for additional 5 days. All experiments were repeated 5 times. In result, blastocyst formation rate were 22.46%±1.47 and 23.17%± 2.13, respectively and total cell number were 32.9±2.22 and 37.09±2.18, respectively. There is no significant difference between TALP and PZM-5-Hepes groups. * Further study will investigate effect of PZM-5-Hepes on in vivo development of porcine cloned embryo. This study was supported by IPET (#311011-05-1-SB010), RNL Bio (#550-20120006), Institute for Veterinary Science, the BK21 program and TS Corporation.

The purpose of this thesis is to examine the effect of hormone treatment in blastocyst development of in vitro cultured porcine oocyte. Oocytes used in the study was matured in vitro in the presence of 10% FBS or 10% pFF, and treated with FSH, LH or FSH+ LH, and the rate of blastocyst development was assessed based on the expression of autophagic genes. There was no significant differences in blastocyst development between oocytes maturaed in 10% FBS or 10% pFF. In vitro matured oocytes treated with FSH+LH showed blastocyst development rate as high as that of untreated oocytes, while groups treated with LH only showed a decrease in blastocyst development. About the expression of cell death assosiated factors, mRNA levels of autophagy and apoptosis genes were increased in oocytes matured in 10% FBS and treated with LH. Oocytes that did not receive hormone treatment showed low expression of most cell death genes except ATG5. When oocytes were matured in 10% pFF, ATG5 expression was the highest in FSH treated group, while LC3 showed strong expression in all hormone treated groups. On the other hand, the expression level of mTOR and caspase-3 did not show significant differences between groups. We also examined the protein level of apoptotic genes in the blastocyst. The amount of caspase-3 protein was similar between groups matured in 10% FBS and 10% pFF, but was the highest when treated with LH. Blastocysts treated with FSH and FSH+LH showed similar level of caspase-3 protein, while the level was the lowest when hormone treatment was not given. Within the blastocyst, caspase-3 was mostly expressed in trophoblast cells when matured in 10% FBS, while maturation in 10% pFF caused expression of this protein in the inner cell mass (ICM). Expression of MAP1LC3A was higher in groups matured in 10% pFF than groups matured in 10% FBS in all types of hormone treatment. Among the blastocysts matured in 10% pFF, MAP1LC3A level increased in the order of untreated < FSH < FSH+ LH. Expression of MAP1LC3A within the FBS-matured blastocyst was concentrated to the trophoblast, while pFF-matured blastocyst showed expression in both trophoblast and ICM. The expression of mTOR showed a pattern opposite to that of MAP1LC3A. That is, its expression was the lowest in 10% FBS group without hormone treatment. In both FBS and pFF group, and in all three combinations of hormone treatment, mTOR expression was ovserved mostly in ICM. Together, these results indicated that hormone treatments tend to induce expression of genes associated with programmed cell death. We suggest that proper induction of programmed cell death by FSH and LH treatment would increase the rate of blastocyst development. * This work was supported by BioGreen 21 Program (No. PJ008029). Rural Development Administation, Republic of Korea.

Acteoside acts as an anti-oxidative activity and anti-apoptosis in the cells. But, it has been not studied on maturation and development of porcine oocytes. The aims of the present study were to examine the effects of acteoside on the morphological progress of meiosis, developmental competence, and ROS in porcine oocytes. Oocytes were matured in tissue culture medium-199, supplemented with acteoside at various concentrations: 0 (control), 10, 30 and 50 μM. The oocytes maturation rates of groups supplemented with acteoside were no significantly different (81.13, 85.96, 82.95 and 83.68%, respectively). Level of ROS was significantly decreased in acteoside treated group. Furthermore, the parthenogenetic blastocyst rate was significantly improved in 10 μM acteoside treated group compared with control group (44.83 vs. 27.75%). And we investigated effect of acteoside on the oocytes condition represented by cytoplasmic maturation by homogeneous distribution and formation of cytoplasmic organelles and regulation of apoptosis-related genes. In the results. during IVM, 10 μM acteoside treated oocytes showed that the mitochondria and lipid droplet were smaller and homogeneous distribution in cytoplasm compare with control oocytes. And reverse transcription polymerase chain reaction (RTPCR) of parthenogenetic blstocysts revealed that acteoside increased the anti-apoptotic genes (Mcl-1, Bcl-2 and Bcl-xL), whereas reduced the expression of pro-apoptotic genes (Bax and Bak). In conclusion, based on the results, the effect of acteoside on IVM was not attractive. However, in acteoside treated group, cytoplasmic maturation seemed to be improved with morphologically uniform distribution of cytoplasmic organelles. Furthermore, embryonic development in acteoside treated group was significantly highly increased than that of non-treated group. Our results represents that addition of acteoside to the IVM medium has a beneficial effect in physiology of porcine oocytes, providing a improved method for porcine oocytes in vitro. * This work was supported by a grant (Code# PJ008148) from BioGreen21 Program, Rural Development Administration, Republic of Korea.

In the present study, we identified differentially methylated region (DMR) upstream of Dnmt1o and Dnmt1s gene in early porcine embryos. Porcine Dnmt1o had at least one DMR which was located between —530 bp to —30 bp upstream from transcription start site of the Dnmt1o gene. DNA methylation analyses of Dnmt1o revealed the DMR to be hypomethylated in oocytes, whereas it was highly methylated in sperm. Moreover, the DMR upstream of Dnmt1o was gradually hypermethylated from oocytes to two cells and dramatically changed in the methylation pattern from four cells to BL stages in an in vivo. In an IVF, the methylation status in the DMR upstream of Dnmt1o was hypermethylated from one cell to eight cells, but demethylated at the Morula and BL stages, indicating that the DNA methylation pattern in the Dnmt1o upstream ultimately changed from stage to stage before the implantation. Next, to elucidate whether DNA methylation status of Dnmt1s upstream is stage-by-stage changed in during porcine early development, we analyzed the dynamics of the DNA methylation status of the Dnmt1s locus in germ cell, or one cell to BL cells. The Dnmt1s upstream was highly methylated in one and eight cells, while less methylated in two, four, morula, and BL cells. Taken together, our data demonstrated that DNA methylation and demethylation events in upstream of Dnmt1o/Dnmt1s during early porcine embryos dramatically occurred, and this change may contribute to the maintenance of genomewide DNA methylation in early embryonic development.