Because the pig is a valuable candidate for a preclinical model of human cell therapy as well as an important food source, understanding a physiology of pig myogenic progenitors such as skeletal muscle satellite cells and myoblasts is required for cure of muscular diseases and improvement of meat production. For these reasons, we tried to isolate and culture the pig progenitor cells from skeletal muscle. Pig satellite cells, known as muscle stem cells, were isolated from biceps femoris of neonatal pigs by enzymatic digestion method. Muscle satellite cells are quiescent in uninjured muscle. Upon injury, they are activated into proliferating state, known as myoblasts, by growth factors and, in turn, differentiated forward to myocytes and myotubes. To trigger proliferation in vitro, the isolated satellite cells were cultured with epidermal growth factor (EGF) and dexamethasone (BMP4 inhibitor). As a result, the pig satellite cells were efficiently converted into proliferating myoblasts and stably maintained over an extended period. The myoblasts were confirmed by markers of PAX7, MYF5, and MYOD1. Our finding showed that modulating EGF and BMP4 signaling are essential for maintaining muscle stem cells. This culture method could be applied for a production of cultured meat and further basic research of muscle development.
This work was supported by the Korea Institute of Planning and Evaluation for Technology in food, agriculture, forestry, and fisheries (IPET) through the Development of High Value-Added Food Technology Program funded by the Ministry of Agriculture, Food, and Rural Affairs (MAFRA; 118042-03-1-HD020).
This study was conducted to evaluate the effects of insulin and epidermal growth factor (EGF) in a in vitro growth (IVG) medium on oocyte growth, in vitro maturation (IVM) and embryonic development of pig oocytes derived from small antral follicles (SAF) less than 3 mm in diameter. SAF oocytes were cultured for 2 days to induce IVG in alpha-minimal essential medium supplemented with 1 mM dbcAMP and 15% (v/v) fetal bovine serum. After IVG culture, oocyte maturation was induced by culturing IVG oocytes in IVM medium for 44 h. IVM oocytes that extruded the first polar body were selected and induced for parthenogenesis (PA) by applying electric stimulus. SAF oocytes cultured under the insulin treatment showed a significantly increased (P < 0.05) nuclear maturation (73.8%) compared to those cultured with insulin and EGF (59.8%). After PA, the proportions of blastocysts based on the number of metaphase II oocytes were significantly higher (P < 0.05) in oocytes that were cultured for IVG with insulin, EGF, and insulin + EGF (32.4%, 35.2%, and 34.8%, respectively) than in control (22.9%). IVG oocytes treated with insulin showed an increased oocyte diameter (116.3 μm) compared to those treated with insulin and EGF (114.0 μm) (P < 0.05). Intra-oocyte GSH content significantly increased (1.07 pixels/oocyte) by insulin treatment during IVG compared to that of oocytes treated with insulin + EGF (0.78 pixels/oocyte). These results demonstrate that IVG culture of SAF oocytes under insulin or/and EGF treatment supports oocyte maturation and improves embryonic development to the blastocyst stage after PA in pigs.
In our previous studies, the cardiac xenotransplantation from an alpha-1,3-galactosyltransferase knockout pig (GT-MCP-MCP) to cynomolgus monkeys showed a mean survival of 38 days. The objective of this study is to genetically upgrade the GT-MCP-MCP pig, to further enhance membrane cofactor protein (MCP) expression and to express an endothelial specific thrombomodulin (TBM). MCP is a complement regulatory protein and TBM is a coagulation inhibitor. As the dicistronic cassette for wild-type-based MCP and TBM concurrent expressions does not show any increase of MCP, we optimized the MCP codon usage (mMCP) and substituted mMCP for MCP. When the mMCP-TBM cassette was transfected to HeLa cells, we were able to find an increased expression of MCP and endothelial cell-specific TBM expression. The cassette was then transfected into ear-skin fibroblasts isolated from one-month-old #23-4 of a GT-MCP-MCP pig, and the cell populations expressing MCP were obtained by MACS cell sorting. We performed a single cell culture of the selected cells, and obtained clones over expressing 90% MCP. The cells of a clone were used as a donor for nuclear transfer and generated GT-MCP/-MCP/mMCP/TBM pig. The transgenic pig was confirmed to be carrying the cells expressing MCP and functioning as an inhibitor against the cytotoxic effect of normal monkey serum, comparable with donor cells. Thus, we believe that the GT-MCP/-MCP/mMCP/TBM transgenic pig would be potential for the prolongation of xenograft survival in the recipients.
The porcine zygotic genome activation occurs along with global epigenetic remolding at the 4-cell stage. The histone acetylation, regulating DNA transcription, replication and so on, requires adequate acetyl-CoA. Acetyl-CoA produced by translocated pyruvate dehydrogenase in the nucleus of mammalian cells has been reported, which is commonly considered locating in the mitochondria. To find out whether the nuclear pyruvate dehydrogenase regulating the histone acetylation by controlling generation of acetyl-CoA, a multiple sgRNAs-CRISPR/Cas9 targeting strategy was employed to generate a pyruvate dehydrogenase E1 alpha1 (Pdha1) knockout (KO) parthenogenetic embryo model. Results showed that the targeting efficiency of Pdha1 reached more than 90%. Hence, this model was used in the subsequent experiments. Furthermore, a translocation of Pdha1 during zygotic genome activation was found by immunofluorescent staining and was significantly inhibited by Pdha1 KO. Meanwhile, the 8-cell stage embryo rate significantly decreased after 72 h (24.19% vs 12.53%, control vs Pdha1 KO), indicating a 4-cell arrest. In addition, the nuclear histone acetylation level significantly decreased when Pdha1 was KO. To determine whether the zygotic genome transcription was affected, the qPCR was performed and showed that the mRNA level of Eif1A, Acly, Sqle and Pdha1 all dropped significantly in the Pdha1 KO group compared to the control. In conclusion, the translocated Pdha1 generates acetyl-CoA for histone acetylation inside the nucleus of porcine embryos, which promotes the zygotic genome activation of porcine embryos.
To improve survival rates of vitrified pig oocytes, the treatment of cytoskeletal stabilizer on an appropriate time is one of the possible approaches. However, the exact treatment timing and effect of cytoskeletal stabilizer such as cytochalasin B (CB) is not well known during oocyte vitrification procedures. Thus, the present study was conducted to determine optimal treatment timing of CB during vitrification and warming procedures. In experiment 1, the survival rates of the post-warming pig oocytes were analyzed by fluorescein diacetate (FDA) assay with 4 classifications. In results, post-warming oocytes showed significantly (p<0.05) decreased number of alive oocytes (31.8% vs. 86.4%) compared to fresh control. In detail, the significant difference (p<0.05) was found only in strong fluorescence (18.2% vs. 70.5%) not in intermediate fluorescence groups (13.6% vs. 15.9%). In experiment 2, CB was treated before (CB-Vitri) and after (Vitri-CB) vitrification. In results, group of Vitri-CB showed significantly (p<0.05) higher (91.6%) survival rates compared to group of CB-Vitri (83.7%), significantly (p<0.05) and comparable with group of Vitri Control (88.7%) by morphological inspection. In FDA assay results, group of Vitri-CB showed significantly (p<0.05) higher (44.2%) survival rates compared to groups of CB-Vitri (36.7%) and Vitri Control (35.1%). In conclusion, the increased survival rates of post-warming pig oocyte treated with Vitri-CB method are firstly described here. The main finding of present study is that the CB treatment during recovery could be helpful to refresh the post-warming pig oocyte resulting its improved survival rates.
Cryopreservation is mainly used for preservation of boar sperm. However, this method stresses the sperm by reactive oxygen species (ROS), and the conception rate and the litter size are not more efficient than the liquid preservation of spermatozoa. Therefore, we use chitosan which is a natural product derived antioxidant compound. We used GnHA and GnHG as chitosan complexes to cryopreserve boar sperm for improve sperm metabolism and function.
Sperm parameter (sperm motility, progressive motility, path velocity, straight-line velocity, curvilinear velocity) is measured by computer-assisted sperm analysis (CASA) using frozen sperm with GnHA or GnHG (0, 0.25, 0.5, 1 mg/mL). Also, lipid peroxidation analysis using malondialdehyde (MDA) is performed to confirm the antioxidative effect of chitosan in frozen spermatozoa.
Sperm motility was higher in GnHA 0.25 mg/mL and GnHG 0.5 mg/mL compared to control. In addition, GnHG 0.5 mg/mL was significantly decreased in lipid peroxidation analysis.
The results suggest that GnHA and GnHG are effective for boar sperm cryopreservation by antioxidant effect.
Until now, problems related to shortage of organ for transplantation have been continuing. Pigs are the most suitable animal for xenotransplantation. Although primates are most similar to humans, they are not suitable because they have low productivity. Pigs are more productive than primates, and their organ size and physiological characteristics are similar to humans, with the exception of primates. In this study, we breeding the transgenic minipigs using natural mating to produce transgenic pigs. And, transgenic pigs has transmission rate that follow mendel’s rule. There are 20% hDAF gene, 20% US11 gene and 50% both hDAF and US11 gene in transgenic offsprings. Furthermore, transgenic pigs followed normal litter size, and piglets also has normal sex ratio. To suppress the immune function, experiments were performed using porcine ear fibroblast that transfected with hDAF and US11gene. In Cytotoxicity experiment against human complement, hDAF gene and double transgenic cell with both hDAF and US11 gene showed effect to reduce cytotoxicity rate in all of human complement condition. US11 gene and double transgenic cell were significantly reduce the cytotoxicity ratio in human NK cell. Besides, hDAF gene transgenic cell also reduce immune response in 10:1 concentration of human NK cell. In conclusion, natural mating was efficient method for breeding transgenic pigs. And, hDAF and US11 genes has effect for reduce cytotoxicity against human NK cell and human complement conditions.
The objective of this study was to determine the effect of injection application of pig slurry on ammonia (NH3) and nitrous oxide (N2O) emission from timothy (Phleum pretense L.) sward. The three treatments were applied: 1) only water as a control, 2) pig slurry application by broadcasting, 3) pig slurry application by injection. The pig slurry was applied at a rate of 200 kg N ha-1. Total NH3 and N2O emission, expressed as a cumulative amount throughout the measurement time (40 days), was 2.68 kg NH3-N ha-1 and 6.58 g N2O-N ha-1, respectively, in the control. The injection application of pig slurry decreased total NH3 and N2O emission by 39.8% and 33.3%, respectively, compared to broadcasting application of pig slurry. The present study clearly showed that injection application exhibited positive roles in reducing N losses through NH3 and N2O emission.
Acute vascular rejection has been known as a main barrier occurring in a xenograted tissue of alpha 1,3-galactosyltransferase knock-out (GalT KO) pig into a non-human primate (NHP). Adenosine which is a final metabolite following sequential hydrolysis of nucleotide by ecto-nucleotidases such as CD39 and CD73, act as a regulator of coagulation, and inflammation. Thus xenotransplantation of CD39 and CD73 expressing pig under the GalT KO background could lead to enhanced survival of recipient NHP. We constructed a human CD39 and CD73 expression cassette designed for endothelial cell-specific expression using porcine Icam2 promoter (pIcam2-hCD39/hCD73). We performed isolation of endothelial cells (pAEC) from aorta of 4 week-old GalT KO and membrane cofactor protein expressing pig (GalT-MCP/-MCP). We were able to verify that isolated cells were endothelial-like cells using immunofluorescence staining analysis with von Willebrand factor antibody, which is well known as an endothelial maker, and tubal formation assay. To find optimal condition for efficient transfection into pAEC, we performed transfection with GFP expression vector using four programs of nucleofection, M-003, U-023, W-023 and Y-022. We were able find that the program W-023 was optimal for pAEC with regard to viability and transfection efficiency by flow cytometry and fluorescent microscopy analyses. Finally, we were able to obtain GalT-MCP/-MCP/CD39/CD73 pAEC expressing CD39 and CD73 at levels of 33.3% and 26.8%, respectively. We suggested that pACE isolated from GalT-MCP/-MCP pig might be provided as a basic resource to understand biochemical and molecular mechanisms of the rejections and as an alternative donor cells to generate GalT-MCP/-MCP/CD39/CD73 pig expressing CD39 and CD73 at endothelial cells.
The annoyance potential for odor sources can be evaluated by separation distances. A separation distance between a standard pig farm and a residential area was investigated by the AERMOD model. The studied area comprised four sites in Korea. The study sites were Paju, Yangpyeong, Suwon, and Icheon, respectively. The separation distances criteria of the three reference Odor Impact Criteria (OIC) were used to evaluate the separation distance. Results show that separation distances for the four sites were calculated 20 m from the fence in the existing pig farm criteria case [exceedance probability P (%) = 2.0% and concentration = 6 OU] in Ireland. In the case of the new pig farm criteria [(exceedance probability P (%) = 2.0% and concentration = 3 OU) of Ireland, results show that the separation distances of the four locations were between 120 m and 145 m from the fence. These values were about 3.0~4.5 times larger than those of the existing pig farm criteria case. In the case of a concentration of 1 OU and the exceedance probability P (%) of a 2.0% criteria, the separation distances of the four sites ranged from 250 m to 290 m.
The investigation of the embryonic development of the cerebellum has a long history. The postnatal normal development of the cerebellum in rodents and other animals became a popular topic for morphological investigations nearly a century ago. However, surprisingly, only a few studies are available regarding the prenatal normal development of the rodent cerebellum, especially in guinea pigs. Cell proliferation is essential for the development of the nervous system. The assessment of cell proliferation can be achieved by using various methods. In this study, we investigated the cell proliferation of the cerebellar cortex in guinea pigs at different stages of pregnancy and in postnatal life. Fetuses were obtained by cesarean section at 50 or 60 days of gestation (dg). Immunohistochemistry was performed with proliferating cell nuclear antigen (PCNA) antibody in the cerebellum. Strong PCNA immunoreactivity was observed in the external granular layer (EGL), which is a neurogenic zone in the cerebellum. The proportion of PCNA-IR cells was greater at 1 week than at 60 dg in lobule I, but not lobule VIII. After 50 dg, the width of the EGL continued to decline until 1 week, due to the maturation of the EGL cells. These results demonstrate the pattern of PCNA immunoreactivity in the developing cerebellum of guinea pigs. This serves as a guideline to study abnormal cerebellum development.
The objective of this study was to comparatively analyze the vocalizations of farrowing sows and their piglets in a welfare certified farm and a conventional farm as they are useful parameters for animal welfare assessment. The conventional farm using the gestation stall, farrowing crate and nursery, grower‐finisher pigs were accommodated in small pens. On the other hand, in the welfare certified farm using the group feeding gestation sows, which allows them to turn around in the furrowing pens, unlike in the crates and nursery, grower‐finisher pigs were accommodated in large pens. Vocalization of farrowing sows and their piglets were recoded and acoustic parameters were analyzed. Eight vocalizations―screaming, fighting, playing, suckling competition, suckling, piglet call, frightened, and space competition―were recoded in the farrowing crate and classified; 4 ordinary and 4 non‐ordinary vocalizations were identified. However, frightened and space competition vocalizations were not detected in the farrowing pen. Screaming, fighting, playing, suckling competition, and suckling vocalizations were significantly (p<0.01) different in pitch, intensity and duration between the farrowing pen and the farrowing crate. Piglet call vocalization did not differ between the farrowing facilities. These findings will aid us in using the differences in vocalizations, under different conditions, as parameters of animal welfare assessment.
In the present study, we evaluated the effect of pH modulation on concentrations of odorous compounds and pollutants in pit slurry from pig operation building. A slurry sample was taken from the pit of a pig operation building where 50 finishing pigs [(Landrase × Yorkshire) × Duroc] were kept. Three levels of pH (6, 8 and 10) were measured and adjusted daily during the incubation periods using chemical reagents of 1 N HCl or 3 N NaOH. Concentrations of odorous compounds and pollutants were analyzed from slurry incubated for 7 days. When these material concentrations were compared with the pH 8 slurry which was the pH of pit slurry, levels of short chain fatty acids, indoles and total organic carbon were reduced 7%, 68% and 2%, respectively, in the pH 6 treatment (P<0.05). Ammonium nitrogen, phenols and total nitrogen concentrations were lower by 31%, 18% and 17%, respectively, than with the pH 10 slurry (P<0.05). When the odor contribution in pH treatments was assessed according to the odor activity value, it was found to be 23% lower in the pH 6 treatment compared with pH 8. The pH modulation would affect odor emissions and microbial activity from pit slurry. Although not all odorous compounds showed the reduction effect with the same pH control, this study can be effectively used as base data when using additives for pH control.
Mitochondrial dysfunction is found in oocytes and transmitted to offspring due to maternal obesity. Treatment of obese mothers with endoplasmic reticulum (ER) stress inhibitors such as salubrinal (SAL) can reverse the mitochondrial dysfunction and result in normal embryonic development. Pig oocytes have also shown ER stress mostly in metaphase II stage. ER stress in oocytes may hinder the in vitro production of pig embryos. This study investigated the effect of ER stress inhibition by SAL treatment during in vitro maturation (IVM) of porcine oocytes at 1, 10, 50 and 100 nM concentrations. Firstly, we tested various concentrations of SAL. SAL at 10 nM showed higher (P < 0.05) developmental competence to the blastocyst stage (55.6%) after parthenogenesis (PA) than control (44.2%) while not different from other concentrations (49.2, 51.6, and 50.8% for 1, 50, and 100 nM, respectively). Secondly, we performed time-dependent treatment at 10 nM of SAL for IVM of oocytes. It revealed that treatment with SAL during 22 to 44 h of IVM significantly improved PA embryonic development to the blastocyst stage compared to control (40.5, 46.3, 51.7 and 60.2% for control, 0 to 22 h, 22 to 44 h and 0 to 44 h of IVM, respectively, P < 0.05). Glutathione (GSH) content is an indicator of cytoplasmic maturation of oocytes. Reactive oxygen species (ROS) have a harmful effect on developmental competence of oocytes. For this, we determined the intraoocyte levels of GSH and ROS after 44 h of IVM. It was found that SAL increased intraoocyte GSH level and also decreased ROS level (P < 0.05). Finally, we performed somatic cell nuclear transfer (SCNT) after treating oocytes with 10 nM SAL during IVM. SAL treatment significantly improved blastocyst formation of SCNT embryos compared to control (39.6% vs. 24.7%, P < 0.05). Our results indicate that treatment of pig oocytes with ER stress inhibitor SAL during IVM improves preimplantation development PA and cloned pig embryos by influencing cytoplasmic maturation in terms of increased GSH content and decreased ROS level in IVM pig oocytes.
The current study identified risk factors associated with porcine circovirus type 2 (PCV2) infection on pig farms in the Republic of Korea using a multinomial logistic regression model to evaluate the PCV2 infection status of pigs at different growth stages. Compulsory disinfection of visitors (odds ratio [OR]: 0.019, 95% confidence interval [CI]: <0.001–0.378, p=0.0095), compulsory registration of visitors (OR: 0.002, 95% CI: <0.001–0.184, p=0.0070), regular blood testing (OR: 0.012, 95% CI: <0.001–0.157, p=0.0007), and running on-farm biosecurity learning programs for workers (OR: 0.156, 95% CI: 0.040–0.604, p=0.0072 and OR: 0.201, 95% CI: 0.055–0.737, p=0.0155, respectively) were identified as factors which could reduce the risk of PCV2 infection. However, visitation by a regular veterinarian (OR: 32.733, 95% CI: 3.768–284.327, p=0.0016) was associated with PCV2 infection.
Eighty pigs (40 pigs per farm aged 40 days old) that had been raised on two commercial pig farms A and B were used to evaluate oxidative stress status. The results from each farm were compared to investigate a relationship between pig performance and oxidative stress status. Pig performance on farm A was relatively better than that on farm B for the period of 3 years.
The level of plasma total antioxidant status (TAS) of the pigs in group 1 (farm A) was significantly higher (p=0.045<0.05 ) than that of the pigs in group 2 (farm B). The level of plasma total oxidant status (TOS) and oxidative stress index (OSI) value of the pigs in group 2 were significantly higher (p= 0.045<0.05 and p=0.001<0.05) than those of the pigs in group 1 These results revealed that pig performance was associated inversely with oxidative stress status.