Direct injection of genome editing tools such as CRISPR/Cas9 system into developing embryos has been widely used to generate genetically engineered pigs. The approach allows us to produce pigs carrying targeted modifications at high efficiency without having to apply somatic cell nuclear transfer. However, the targeted modifications during embryogenesis often result in mosaicism, which causes issues in phenotyping founder animals and establishing a group of pigs carrying intended modifications. This study was aimed to establish a genomic PCR and sequencing system of a single blastomere in the four-cell embryos to detect potential mosaicism. We performed genomic PCR in four individual blastomeres from four-cell embryos. We successfully amplified target genomic region from single blastomeres of 4-cell stage embryo by PCR. Sanger sequencing of the PCR amplicons obtained from the blastomeres suggested that PCR-based genotyping of single blastomere was a feasible method to determine mutation type generated by genome editing technology such as CRISPR/Cas9 in early stage embryos. In conclusion, we successfully genotyped single blastomeres in a single 4-cell stage embryo to detect potential mosaicism in porcine embryos. Our approach offers a simple platform that can be used to screen the prevalence of mosaicism from designed CRISPR/Cas9 systems.

In the early development of parthenogenetic embryo, cytoplasm and nucleic acid fragmentation may be a cause of lower embryo development. The purpose of this study was to evaluate whether embryonic development and apoptosis factors can be reduced by controlling the in-vitro culture environment by the addition of hormones, pregnancy serum and uterine milk. Our study showed that the activity of Casp-3 increased within the cytoplasm when artificially used hormones to induce the incubation environment, and PCNA's manifestation was low. However, the addition of pregnant serum appeared to lower the Casp-3 activity compared to the other groups. In addition, MMP-9 activity was increased and early embryo development and cytoplasmic fidelity were also increased. Therefore, the results of the present study showed that the use of gestational serum in the development of parthenogenetic embryo inhibit apoptosis and increases cytoplasmic reorganization by natural environmental control in in vitro culture.

Many transcription factors are involved in directing the growth of porcine oocytes. The localization and expression level of a given transcription factor often differ at each stage of early embryonic growth, which spans from fertilization to the formation of the blastocyst. A hallmark of the blastocyst stage is the separation of the endodermal and mesodermal ectoderm. The embryo's medium and its effects are known to be crucial during early development compared to the other developmental stages, and thus require a lot of caution. Therefore, in many experiments, early development is divided into the quality of oocyte and cumulus cells and used in experiments. We thought that we were also heavily influenced by genetic reasons. Here, we examined the expression patterns of five key transcription factors (CDX2, OCT4, SOX2, NANOG, and E-CADHERIN) during porcine oocyte development whose expression patterns are controversial in the pig to the literature. Antibodies against these transcription factors were used to determine the expression and localization of them during the early development of pig embryos. These results indicate that the expressions of key transcription factors are generally similar in mouse and pig early developing embryos, but NANOG and SOX2 expression appears to show species-specific differences between pig and mouse developing embryos. This work helps us better understand how the expression patterns of transcription factors translate into developmental effects and processes, and how the expression and localization of different transcription factors can crucially impact oocyte growth and downstream developmental processes.

This experiment was conducted to analyse the effects of flavone supplementation on the preimplantation development of in-vitro produced porcine embryos. During in-vitro development, immature oocytes and early embryos were exposed to different concentrations of flavone (0, 1μM, 25μM, 50 μM, and 100 μM respectively). Results showed that 100 μM of flavone significantly reduced the intracellular ROS levels of oocytes accompanied with a significant rise in GSH level. In parthenogenesis, no significant change was observed in the cleavage rates whether flavone was supplemented in IVM or IVC media. In IVM supplemented group, the blastocyst development rate was significantly enhanced by 1 μM concentration than other groups (51.5% vs. 41.3%, 44.0%, 36.3%, 31.7%; P<0.05) respectively. However, in IVC group 1 μM concentration significantly improved the blastocysts production than 50 μM and control groups (50.0% vs. 40.5%, 38.0%; P<0.05) respectively. Following nuclear transfer, the cleavage rate of IVM group was significantly more in 1 μM than 50 μM and 100 μM groups (92.9% vs. 89.7%, 87.8%; P<0.05), followed by similar pattern of cloned blastocysts production being significantly higher in 1 μM group than 50 μM, 100 μM and control groups (16.8% vs. 9.0%, 7.1%, 12.8%; P<0.05) respectively. In IVC group, 1 μM concentration resulted in significantly higher cleavage rate than 25 μM and 50 μM groups (91.7% vs. 87.8%, 88.8%; P<0.05) respectively. However, the blastocysts production was significantly higher in 100 μM group than others (26.2% vs. 13.6%, 14.0%, 18.2%; P<0.05) respectively. The optimal concentrations of flavone significantly enhanced the percentages of ICM:TE than control group (43.8% vs. 37.6%; P<0.05) accompanied with significantly higher expression levels of reprogramming related genes. In conclusion, the optimal concentrations of 1 μM during IVM and 100 μM during IVC can significantly improve the production of porcine in-vitro embryos.

Light Mineral Oil is a material generally used as an overlay covering microdrops of culture medium in petri dishes. Although Light Mineral Oil can protect the damage by oxidation in air, it can't completely protect the damage by evaporation and alteration of pH and osmolality in culture medium. To minimize the damage by evaporation and alteration of pH and osmolality, we assumed that Heavy Mineral Oil could be used as an alternative. Heavy Mineral Oil is high purity paraffin oil which has more viscosity and density than Light Mineral Oil, so it can prevent evaporation and maintain stable osmolality and pH in culture medium more than Light Mineral Oil. The objective of this study was to examine whether the effect of Heavy Mineral Oil is superior to the effect of Light Mineral Oil during in vitro cultivation of porcine oocytes. According to the data of repeated six experiments, survival and cleavage rate of porcine oocytes, and cell number of blastocysts were not significantly different between two groups. However, the in vitro development rate of porcine parthenogenetic embryo was significantly higher in Heavy Mineral Oil group than in Light Mineral Oil group (Light, 36.6% ± 3.9%; and Heavy, 52.1% ± 6.4%, p < 0.05). Thus, these results indicated that the treatment of Heavy Mineral Oil can improve the in vitro developmental capacity of porcine parthenogenetic embryos compared to Light Mineral Oil.

Connexin 43 (Cx43) is one of the gap junction proteins which are compounds of transmembrane proteins and transports the small-molecular-weight chemicals up to 2 kDa. Lacking of Cx43 influences the junctional protein, induces autophagy and apoptosis in somatic cells. However, the function of Cx43 in porcine early embryos is still unknown. Aim to find out the molecular mechanism of Cx43 on the developmental competence in early porcine embryos, Cx43 dsRNA (1 ㎍/㎕) was microinjected into the parthenogenetically activated porcine zygotes. Blastocyst rate (treatment, 8.8±1.6% vs. control, 38.6±4.3%) and total cell numbers in the blastocyst (treatment, 20.7±3.5 vs. control, 39.8±4.1) were significantly reduced following Cx43 knocking down. Results from FITC-dextran and Western blot assay show that knock down (KD) of Cx43 significantly increased membrane permeability through down regulation of genes which are component of both adherence and tight junction in the porcine blastocyst. Reactive oxygen species (ROS) was significantly increased in the Cx43 KD group compared to control. In addition, KD of Cx43 activated Caspase 3 and significantly increased ATG8 expression, induced autophagy and apoptosis. Results suggest that KD of Cx43 influences preimplantation porcine embryo development via increasing membrane permeability and ROS generation, and inducing autophagy and apoptosis.

Melatonin (N-aceyl-5-methoxytryptamine) is the major hormone of the pineal gland. Melatonin and its metabolic derivatives possess extensive free-radical scavenging abilities and played critical roles in antioxidative stress, resisting apoptotic cell death. Melatonin also could enhance mitochondrial biogenesis in rats with carbon tetrachloride-induced liver fibrosis. In addition, melatonin attenuates myocardial ischemia/reperfusion injury by reducing oxidative stress damage via activation of SIRT1 signaling in a melatonin receptor 2-dependent manner. Activation or overexpression of SIRT1 could enhance mitochondrial biogenesis and function by inducing PGC-1α expression and deacetylation. The aim of this study was to investigate if melatonin enhances mitochondrial biogenesis and function via activation of melatonin receptor 2/SIRT1/PGC1-α Pathway. The results showed that Melatonin rescued rotenone-induced impairment of porcine embryo development. Treatment with rotenone could increase oxidative stress and apoptosis. Rotenone impaired mitochondrial functions by disrupting mitochondrial membrane potential, reducing mitochondrial DNA copy number and ATP production. Melatonin could improve SIRT1 and PGC-1α expression, inducing mitochondrial biogenesis. Rotenone-induced mitochondrial dysfunction and ATP deficiency was rescued by melatonin treatment, the oxidative stress and apoptosis was significantly decreased. Inhibition of melatonin receptor 2 or Knockdown of SIRT1 abolished the protective effects of melatonin on rotenone-induced impairments. Therefore, melatonin enhanced mitochondrial biogenesis and function, protected against rotenone-induced impairments.

The embryonic genome activation (EGA) is genetically activated states that embryos make the materials such as growth factors for using themselves. EGA is various because they have many materials, different site, different stage, also different species. At this time, transcription factors are expressed. Transcription factors bind to specific DNA region, and regulate the gene expression. Thus, we check the expression of transcription factors, we can know that embryo development is very well or not. The development stages of embryos are basically the stages from fertilization to blastocyst. So, we check the embryos oocyte to blastocyst. In our experiments, we focus the early developmental transcription factors such as Cdx2, Oct4, Sox2, Nanog and E-Cadherin. Above antibody factors showed different expression sites, and there were many differentiated parts from other animal species. In addition, we compared the SCNT and parthenogenetic activation (PA) because these are same methods using electrical activation among the embryo production methods. Our results showed not only similar patterns but also different patterns between pig and mouse. Therefore, we have to investigate that different patterns of transcription factors play a role in pigs, and why occur.

The purpose of this study is to examined the electrofusion and activation conditions for the production of porcine somatic cell nuclear transfer (SCNT) embryos. In this study, immature oocytes were cultured in TCM-199 with and without hormones for 22 hours. Skin fibroblasts cells of porcine were transferred into the perivitelline space of enucleated in vitro matured oocytes. Cell fusion was performed with two different pulses that each one pulse (DC) of 1.1 kV/cm or 1.5 kV/cm for 30 μsec. After fusion subsequent activation were divided into three groups; non-treatment (control) and treatment with 2 mM 6-DMAP or 7.5 μg/ml cytochalasin B for 4 hours. Transferred embryos were cultured in PZM-3 (Porcine Zygote Medium-3) in 5% CO₂ and 95% air at 39℃ for 7 day. Apoptosis-related genes (Caspase-3, BCL-2, mTOR, and MMP-2) were analyzed by immunofluorescence staining. There was no significant difference between two different electrofusion stimuli in the cleavage rate; 64.9±4.8% in 1.1 kV/cm and 62.7±4.0% in 1.5 kV/cm. However, blastocyst formation rate (%) was significantly different among three different activation groups (no treatment, 2 mM 6-DMAP or 7.5 μg/ml cytochalasin B) combined with electrofusion of 1.1 kV/cm. The blastocyst formation rate was 12.6±2.5, 20.0±5.0, and 34.9±4.3% in control, 2 mM 6-DMAP, and 7.5 μg/ml cytochalasin B, respectively. Immunofluorescence data showed that expression levels of caspase-3 in SCNT embryos undeveloped to blastocyst stage were higher than those in the blastocyst stage embryos. Expression levels of Bcl-2 in blastocyst stage embryos were higher than those in the arrested SCNT embryos. These results showed that the combination of an electric pulse (1.1 kV/cm for 30 μsec) and 7.5 μg/ml cytochalasin B treatment was effective for production of the porcine SCNT embryos.

Lysophosphatidic acid (LPA) is an important signaling molecule. Here, the effect and mechanism of LPA on the preimplantation development of porcine embryos during in vitro culture (IVC) was examined. Porcine embryos were cultured in porcine zygote medium (PZM-3) supplemented with 30 μM LPA during different days. There was a significantly higher cleavage rate in Day 1-7 and significantly higher total cell number of blastocysts in Day 1-3 and Day 4-7. It was also found that messenger RNA (mRNA) expression level of PCNA, BCL2 and BAX in blastocysts obtained from D1-7 group were significantly higher and BCL2/BAX mRNA ratio in D1-3 group was significantly lower than control group but Day 4-7 and Day 1-7 groups were comparable with control group. Treatment with 20 μM PLC inhibitor significantly decreased the embryo cleavage rate and blastocyst formation rate. Moreover, LPA as an activator of PLCs, enhanced the 30 μM LPA + 20 μM U73122 group embryo cleavage rate which similar with control group. In conclusion, the results suggest that treatment with LPA during IVC improves the porcine early embryo cleavage by activation of PLC signaling pathway and regulate the mRNA expression that contribute to total cell number of blastocysts during blastocyst formation.

Lysophosphatidic acid (LPA) is an important signaling molecule which mediates many different cellular responses. The purpose of this study was to investigate the effect of in vitro culture (IVC) medium supplemented with LPA on the preimplantation embryonic development of porcine embryos derived from in vitro fertilization (IVF). Embryos derived from IVF were cultured in PZM-3 medium supplemented with 30 μM LPA on Day 1 to Day 7, Day 1 to Day 3 (early stage), or Day 4 to Day 7 (late stage), or without LPA. Moreover, the messenger RNA (mRNA) expression of obtaining blastocysts from each group were analyzed. Data were analyzed by ANOVA followed by Duncan using SPSS (Statistical Package for Social Science) mean ± SEM. There was a significantly higher cleavage rate in Day 1 to Day 7 than control (71.25% and 57.46%, respectively) and significantly higher total cell number of blastocysts in Day 1 to Day 3 and Day 4 to Day 7 than control (56.07,56.53 and 45.19, respectively). The results also showed that the mRNA expression level of PCNA, Bcl-2 and Bax in Day 1 to Day 7 group blastocysts were significantly higher than control and the expression level of Bax in Day 1 to Day 3 was also significantly higher than control. Moreover, it also showed that Bcl-2/Bax mRNA ratio in D1-3 group was significantly lower than control but D4-7 and D1-7 groups were comparable to control group. In conclusion, our results suggest that treatment with 30 μM LPA during IVC improves the porcine early embryo cleavage and the blastocyst total cell number after IVF and regulating the mRNA expression of blastocysts during blastocyst formation.

The nature of molecular mechanisms governing embryo development is largely unknown, but recent reports have demonstrated that proper execution of programmed cell death is crucial for this process. The main objective of this study is to examine the mode of programmed cell death during nuclear transfer embryos development in porcine. In particular, the relative employment of two major pathways in programmed cell death; e.g. apoptosis (type I) and autophagy (type II) was compared. Oocytes use in the study was matured in vitro in the presence of 10% FBS maturation medium. After nuclear transfer embryos were cultured for each programmed cell death control factor [Cysteamine(Cyst : 0.4mM), 3-methyladenine(3MA : 2.5mM) and Rapamycin(RP : 100nM)] in TCM-199 medium supplemented with 0.1% BSA. In this study results of among the blastocysts development in 3MA; PCNA, MAP1LC3A and ATG5 RNA gene expression level increased in the order of IVF<Cyst < 3MA < RP. However Casp-3 and TNF-r RNA gene expression level decreased in the order of IVF < 3MA and RP< Cyst. The expression of mTOR showed a pattern opposite to that of MAP1LC3A. That is, its expression was the lowest in Cyst group. And next experiments analysis of MMP expression patterns. Analysed this MMPs enzyme activation to evaluate the effectiveness of high quality brastocyst culture in porcine. In this results of the enzymatic activity of MMP-2 and MMP-9 was assessed in culture, the level of active MMP-9 was higher expression in the medium of each 3MA and RP treatment group, with the level of another treatment group being relatively higher. These results suggest that the autophagy activation culture medium is more effective for stable and innovative nuclear transfer embryos development.

This study was conducted to investigate the effect of activation method on the endoplasmic reticulum (ER) stress induction, apoptosis and in vitro development of porcine parthenogenetic embryos. Porcine in vitro matured oocytes were activated by four activation methods; 1) electric stimulus (ES) (E), 2) ES+10 μM Ca-ionophore (A23187) treatment (EC), 3) ES+2 mM 6-dimethylaminopurine (6-DMAP) treatment (ED), or 4) ES+A23187 and 6-DMAP treatments (ECD). Parthenogenetic embryos were sampled to analyze x-box binding protein 1 (Xbp1) mRNA, ER stress-associated genes and apoptosis genes at 3 h after ES and the 1-cell and blastocyst stages. In the EC group, the band intensity of spliced Xbp1 (Xbp1s) mRNA was higher than those of the other groups at the 3 h and 1-cell stage, and higher than that of the E group at the blastocyst stage. Four ER stress-associated genes were expressed at the highest level in the EC group and weakly expressed in the ED group at 3 h after activation. However, most of the genes were highly expressed at the 1-cell and blastocyst stages with some variation in the EC and ECD groups. Expression of Bcl-2-associated X protein (Bax) and caspase-3 mRNA was significantly higher in the EC group than in the other groups at all development stages. The developmental rates to the blastocyst stage were higher in the ED and ECD groups than in the E and EC groups. These results suggest that the intracellular ER stress of parthenogenetic porcine embryos is affected by the activation method and subsequently lead to the apoptosis of embryos.

CD26, also known as Dipeptidyl peptidase IV (DPP-4), is a cell surface glycoprotein that belongs to the serine protease family and has wide spread organ distribution throughout the body. CD26 was previously characterized in immune cells but also has important metabolic functions which are not yet fully understood. Thus, we investigated the effect of CD26 in porcine parthenogenetic embryos. We attempted CD26 downregulation of porcine embryos by siRNA, and evaluated CD26 suppression of developmental competencies. Although the porcine embryos injected with CD26 siRNA were able to develop to the early stage, these embryos were decreased to form blastocysts. Our results indicated that CD26 is one of factors for the regulation of development of porcine embryos.

Abnormal epigenetic reprogramming of donor nuclei is supposed to be one of the factors that causes low development efficiency of mammalian somatic cell nuclear transfer (SCNT). Trichostatin A (TSA) is an inhibitor of histone acetylase, and so development of SCNT embryos could be increased by treatment with TSA. In the present study, we examined the effect of TSA on in vitro development of porcine embryos derived from NT (nuclear transfer) by investigating the status of histone acetylation in TSA-treated and control NT embryos and the expression of developmental related genes. In this study, we found that incubating　NT embryos with 40nM TSA for 24h after activation could improved the blastocyst formation rate from 13.7% to 32.5%. Thechange in histone acetylation level as a reslut of TSA treatment were validated using immunofluorescence and confocal microscopy. Immunofluorescence results indicated that the level of aetylation at histone 3 lysine 18 (AcH3K18) was increased at early embryo development stage after TSA treatment. furthermore, we compared the expression patterns of several genes (developmental related genes; Oct4, Sox2, Nanog, Cdx2, the imprinting genes; igf2r). TSA treatment improved the expression of development related genes such as Oct4, Cdx2, Nanog as well as the imprinted genes like igf2r. In conclusion, our results demonstrated that TSA treatment improves the in vitro development of porcine NT embryos, increased the global histone acetylation (AcH3K18) and enhances the expression of some developmentally important genes (Oct4, Cdx2, Nanog) at blastocyst stages.

Lysophosphatidic acid (LPA) is a member of the phospholipid autacoid family and has growth factor and hormone-like activities on various animal cells. In this study, we investigated the effect of LPA on porcine embryo development. Porcine parthenogenetic embryos were treated into various concentrations of 0 (control), 0.1, 1 and 10 μM LPA (0 LPA, 0.1 LPA, 1 LPA and 10 LPA) during in vitro culture for 7 days or cultured in basic culture medium until day 4 and treated LPA from day 4 to day 7. In the LPA treatment for culturing from day 0 to day 7, there was no significant difference on cleavage and blastocyst formation rate. In addition, the blastocyst development proportion which was classified as expanded, hatching, or hatched blastocystshas was no significant difference among all groups. In the LPA treatment for culturing from day 4 to day 7, 0.1 and 1 LPA groups were presented increased blastocyst formation compared to other groups, but cleavage rate and over-expanded blastocyst formation rate were not significantly different among all LPA treated groups. The total cell number was not different but apoptosis was reduced when 1 LPA treated from day 4 to day 7. The relative mRNA expression level of anti-apoptosis gene, BCL2L1 was higher and pro-apoptosis gene, BAK was lower in the 1 LPA treated group than the control. In comparison with the control and the 1 LPA treated group using time-lapse monitoring system, 1 LPA treated embryo was accelerated developmental speed via morula compaction and expanded blastocyst. The 1 LPA treated group significantly increased the relative expression levels of gap junction and tight junction related genes, GJD1, CDH1 and ZO-1 compared to the control. These results indicated that 1 μM LPA supplementation for culturing from day 4 to day 7 post activation is efficient in blastocyst formation and LPA may be helpful for embryo developmental capacity.

This study was conducted to examine the effects of activation methods on the ER stress induction and subsequent apoptosis and in vitro development of porcine parthenogenetic embryos. Porcine in vitro matured oocytes were activated by four activation methods; 1) electric stimulus(ES) with two DC pulses of 1.25 kV/cm, for 30 ㎲ (E), 2) ES + 10 μM Ca-ionophore (A23187) treatment for 5 min (EC), 3) ES + 2 mM 6-dimethylaminopurine treatment for 3 h (ED), or 4) ES + A23187 + 6-DMAP (ECD). After activation, parthenogenetic embryos were in vitro cultured in PZM-3 medium and sampled to analyze the x-box binding protein 1 (Xbp1) mRNA, ER stress-associated genes and apoptotic genes at 3 h post ES and the 1-cell and blastocyst stages. The un-spliced and spliced x-box binding protein 1 (Xbp1) mRNA were confirmed by RT-PCR. Also ER stress-associated genes, such as the C/EBP homologous protein (CHOP), binding protein (BiP), activating transcription factor 4 (ATF4) and glucose-regulated protein 94 (GRP94), and apoptotic genes were analyzed by real-time quantitative RT-PCR (RT-qPCR). The band intensities of spliced Xbp1 (Xbp1s) mRNA was higher in the EC group than other three groups at 3 h and the 1-cell stage, while it was higher in the ED groups compared with E group at the blastocyst stage. Four ER stress-associated genes were showed the highest expression in the EC group and weakly expressed in the ED group at 3 h. However, most of those genes were highly expressed in EC and ECD groups at the 1-cell and blastocyst stages with some variation. The expressions of Bcl-2-associated X protein (Bax) and caspase-3 mRNAs were significantly higher in EC group than other three groups at all stages. The developmental rate to the blastocyst stage was higher (p<0.05) in ED and ECD groups (32.1±3.8 to 34.6±2.2%) than that of E group (26.1±3.9%). These results suggest that the intracellular ER stress of parthenogenetic porcine embryos is affected by activation method and subsequently lead to the apoptosis of embryos.

Somatic cell nuclear transfer (SCNT) technique is a key point of producing transgenic animal disease models. During in vitro production of SCNT embryo, the quality of matured oocytes are one of the important factors that regulate embryo developmental capacity. In preliminary test, we confirmed the effect of fibroblast growth factor 10 (FGF10) on porcine oocyte maturation. In this study, we investigated the developmental potential of SCNT embryos treated with the 10 ng/ml FGF10 (10 F) during in vitro maturation of recipient oocytes. The polar body emission rate was significantly higher in the 10 F treated group than control group. After SCNT, although the rate of fusion was no significant difference, the rate of cleavage and blastocyst formation was significantly increased in the 10 F treated group (p<0.05). In 10 F treated group, the total cell number was increased and the percentage of apoptotic cell was decreased in the blastocyst stage at day 7 (p<0.1). The transcription level of apoptosis relative gene, Casp3 was significantly decreased, while anti-apoptosis gene BCL2l1 was increased in the 10 F treated group compared to control group. The 10 F treated group was highly expressed the reprogramming related genes, Sox2 and POU5f1. Also, the first cleaving time was more faster and the percentage of cell block was significantly lower in 10 F treated group than in control group. In this study, we confirmed that 10 ng/ml FGF10 has effect on enhance the oocyte maturation and developmental capacity. These results demonstrate that FGF10 treatment can be used for in vitro development of porcine SCNT embryos and subsequent production of transgenic animal model.

In vitro production of mammalian embryos has been achieved with the oocytes derived from middle-size follicles (MF, mainly 3-6 mm in diameter) in many species including domestic animals. In the ovaries, however, there are more small-size follicles with less than 3 mm in diameter (SF). If we can develop an efficient system to produce embryos in vitro from the oocytes from SF. In this presentation, I would like to review about embryo production in vitro from the oocytes derived from SF. As well as the diameter of oocytes, the number of cumulus cells surrounding the oocyte derived from SF is significantly smaller those of oocytes from MF. The comparative analysis in electrophoresis about secretions of cumulus-oocyte complexes derived from SF and MF demonstrated a significant difference in the proteins with a molecular weight. Proteins secreted from cumulus cells, vascular endothelial growth factor (VEGF), are 34- to 42-kDa proteins, including seven family members. The molecular weight of VEGF was similar with the secretion we observed. Supplementation of medium for in vitro maturation with VEGF significantly improved the oocytes competence not only to complete the meiosis in vitro but also to develop to the blastocyst stage following parthenogenetical activation. Removing cumulus cells 20 h after the start of culture for in vitro maturation also significantly improved the competence of oocytes derived from SF to achieve the meiosis. A combination of these new techniques may improve more the meiotic and developmental competences.

Even though klotho deficiency in mice exhibits multiple aging-like phenotypes, studies using large animal models such as pigs, which have many similarities to humans, have been limited due to the absence of cell lines or animal models. The objective of this study was to generate homozygous klotho knockout porcine cell lines and cloned embryos. A CRISPR sgRNA specific for the klotho gene was designed and sgRNA (targeting exon 3 of klotho) and Cas9 RNPs were transfected into porcine fibroblasts. The transfected fibroblasts were then used for single cell colony formation and 9 single cell–derived colonies were established. In a T7 endonuclease I mutation assay, 5 colonies (#3, #4, #5, #7 and #9) were confirmed as mutated. These 5 colonies were subsequently analyzed by deep sequencing for determination of homozygous mutated colonies and 4 (#3, #4, #5 and #9) from 5 colonies contained homozygous modifications. Somatic cell nuclear transfer was performed to generate homozygous klotho knockout cloned embryos by using one homozygous mutation colony (#9); the cleavage and blastocyst formation rates were 72.0% and 8.3%, respectively. Two cloned embryos derived from a homozygous klotho knockout cell line (#9) were subjected to deep sequencing and they showed the same mutation pattern as the donor cell line. In conclusion, we produced homozygous klotho knockout porcine embryos cloned from genome-edited porcine fibroblasts.