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        검색결과 1,074

        861.
        2014.09 서비스 종료(열람 제한)
        Pluripotent cells are categorized as either "naive" or "primed" based upon their pluripotent status. According to previous studies, embryonic stem cells and embryonic germ cells are identified as naive pluripotent stem cells and epiblast stem cells are identified as primed pluripotent stem cells. In a permissive species such as the mouse, naive and primed pluripotent stem cells can be derived from embryos without genetic manipulations. In non-permissive species such as humans and pigs, primed pluripotent cells are only established from embryos. However, previous studies have shown that the embryonic germ cells of non-permissive species share similar morphology and features with naive pluripotent cells. For these reasons porcine embryonic germ cells (pEGCs) may provide a useful cell source for comparative studies on naive pluripotent cells in non-permissive species. In this study, we attempted to establish and characterize porcine embryonic germ cells. Consequently, an embryonic germ cell line was derived from the genital ridges of a porcine dpc 30 fetus in media containing LIF and bFGF. After establishment, this cells were cultured and stabilized in LIF or bFGF contained media. This cell lines displayed a dome-shaped colony morphology in both culture condition. The cell lines were maintained in both condition over an extended time period and were able to differentiate into the three germ layers in vitro. Interestingly, cell lines cultured in LIF or bFGF expressed different pluripotency markers. LIF-dependent pEGCs expressed naive-pluripotency markers such as OCT4, SOX2, NANOG and SSEA1, while bFGF-dependent pEGCs expressed primed-pluripotency markers such as OCT4, SOX2, NANOG and SSEA4. However, as a result of analysis of XCI, two cell lines showed hemi-methylated pattern similarly in XIST promoter regions. In conclusion, we were able to successfully derive embryonic germ cells from genital ridges of a porcine fetus. Pluripotent state of pEGCs were regulated by modulation of culture condition. In LIF supplement, pEGCs showed naive-pluripotency expressing SSEA1, while pEGCs show primed-pluripotency expressing SSEA4 in bFGF condition. This cell line could potentially be used as naive pluripotent cell source for comparative study with porcine embryonic stem cells and other pluripotent cell lines. As porcine pluripotent cells, pEGCs could be useful candidates for preliminary studies of human disease as well as a source for generating transgenic animals.
        862.
        2014.08 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The paper deals with the impact of the product distribution and information technology sectors on energy resource use, carbon emissions and economic growth by examining the long-run equilibrium relationships and Granger causal relationships among these variables in South Korea. The quarterly time series data from the first quarter of 1970 to the third quarter of 2010 (163 observations) are collected and retrieved from the Bank of Korea database. The paper examines the long-run equilibrium relationships using cointegration techniques and Granger causality using vector error correction models. Test results indicate a long-run equilibrium relationship exists among these variables. In testing directional causality, both the product distribution and the information technology sectors show direct effects on economic growth but only marginal effects on carbon emissions.
        863.
        2014.03 KCI 등재 서비스 종료(열람 제한)
        Cell cycle process is regulated by a number of protein kinases and among them, serine/threonine kinases carry phosphate group from ATP to substrates. The most important three kinase families are Cyclin-dependent kinase (Cdk), Polo-like kinase (Plk), and Aurora kinase. Polo-like kinase family consists of 5 members (Plk1-Plk5) and they are involved in multiple functions in eukaryotic cell division. It regulates a variety of aspects such as, centrosome maturation, checkpoint recovery, spindle assembly, cytokinesis, apoptosis and many other features. Recently, it has been reported that Plks are related to tumor development and over-expressed in many kinds of tumor cells. When injected the anti-Plk antibody into human cells, the cells show aneuploidy, and if inhibit Plks, most of the mitotic cell division does not proceed properly. For that reasons, many inhibitors of Plk have been recently emerged as new target for remedy of the cancer therapeutic research. In this paper, we reviewed briefly the characteristics of Plk families and how Plks work in regulating cell cycles and cancer formation, and the possibilities of Plks as target for cancer therapy.
        864.
        2014.03 KCI 등재 서비스 종료(열람 제한)
        The flower buds of Syzygium aromaticum (clove) have been used as traditional medicine for the treatment of male sexual disorders in Asian countries. Recently, there are some reports about the effects of the clove on reproductive activities in mammals. Therefore, its effect on testicular function was examined in male golden hamsters whose reproductive activity is inhibited by photoperiod such as winter climate. The male animals were given by daily oral administrations (56 consecutive days) in three doses (4 mg, 20 mg, and 100 mg/kg BW) of the alcoholic extract of the clove. Generally lower dose (4 mg) of the extract continued to keep the reproductive activities of testes. The both middle and high doses (20 mg and 100 mg) of the extract completely inhibited the testicular activity in some animals. Taken together, these results suggest a possible biphasic action of alcoholic extract of Syzygium aromaticum flower bud on testicular function.
        865.
        2014.03 KCI 등재 서비스 종료(열람 제한)
        This study was investigated spawning behavior, structure of egg masses and egg development in Aplysia kurodai inhabiting the coastal waters of Jeju Island, Korea. The mating and courtship behavior of A. kurodai occurred in the form of unilateral copulating with chain formation. In chain copulation, only the first animal acted as a female; the second and succeeding animals acted as males (sperm donors) to the animals in front and as females to the animals behind. The fertilized eggs were packaged in capsules that are embedded in jelly to form a cylindrical string called an egg masses. The number of capsule per cm of the egg masses was 55 to 60 capsules and each capsule within the egg masses held 15 to 25 eggs. After spawning, the egg masses were bright yellow or orange in color. This egg masses color not changed until embryos developed into trochophore stage. Thereafter, as embryo developed from trochophore stage to veliger stage the egg masses color became brownish. The fertilized eggs were spherical, with a diameter of approximately 80±1 μm at spawning. At 5 to 6 days after spawning, the embryo developed into trochophore stage and began to rotate within the egg capsule. In the trochophore stage, the precursor of the velum, called the prototroch or prevelum, developed. At 10 days after spawning, the prevelum is transformed into the velum, and the trochophore developed into veliger stage. Between 10 to 15 days after spawning, the veligers broke out of the egg capsule, and hatched as free-swimming larvae.
        866.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        Science in the 21st century does not consider participants’ welfare, safety and human rights in clinical studies, but modern science puts economic profits in its priority. This leads to a growing concern about social responsibility and professionalism ethics of companies, sponsors and scientists. Specifically, there is no way to control conflicts of participants’ welfare with economic profits, leading to simply relying on individual ethics, social responsibilities and audit. This paper helps relevant agencies and people involved understand conflict of interest. Also this study presents the guidelines as well as independence, autonomy, ethical imagination and phronesis required for scientists.
        867.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        In mammals, puberty is a process of acquiring reproductive competence, triggering by activation of hypothalamic kisspeptin (KiSS)-gonadotropin releasing hormone (GnRH) neuronal circuit. During peripubertal period, not only the external genitalia but the internal reproductive organs have to be matured in response to the hormonal signals from hypothalamic-pituitary-gonadal (H-P-G) axis. In the present study, we evaluated the maturation of male rat accessory sex organs during the peripubertal period using tissue weight measurement, histological analysis and RT-PCR assay. Male rats were sacrificed at 25, 30, 35, 40, 45, 50, and 70 postnatal days (PND). The rat accessory sex organs exhibited differential growth patterns compared to those of non-reproductive organs. The growth rate of the accessory sex organs were much higher than the those of non-reproductive organs. Also, the growth spurts occurred differentially even among the accessory sex organs; the order of prepubertal organ growth spurts is testis = epididymis > seminal vesicle = prostate. Histological study revealed that the presence of sperms in seminiferous tubules and epididymal ducts at day 50, indicating the puberty onset. The number of duct and the volume of duct in epididymis and prostate were inversely correlated during the experimental period. Our RT-PCR revealed that the levels of hypothalamic GnRH transcript were increased significantly on PND 40, suggesting the activation of hypothalamic GnRH pulse-generator before puberty onset. Studies on the peripubertal male accessory sex organs will provide useful references on the growth regulation mechanism which is differentially regulated during the period in androgen-sensitive organs. The detailed references will render easier development of endocrine disruption assay.
        868.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        Previous studies, including our own, have demonstrated that the intratesticular injection of hypertonic saline (20%) decreased serum testosterone level which was similar to the surgical castration in the rat, showing the state of chemical castration. In the present study, we further verify the efficacy of this less invasive method as an alternative of surgical orchidectomy in the andrological field. Sterilized 20% saline was directly injected into the adult male rats (750 μl per testis). The tested rats were divided into 3 groups including intact group (intact), orchidectomy group (ORX) and saline injection group (SAL) after bilateral orchidectomy was performed at the same day of injection. All rats were sacrificed at 4 weeks after injection. The reproductive organs (testes, epididymis, seminal vesicles and prostates) were collected and used for DNA and protein pattern analyses. Also, patho-histological studies on the testes were performed. In contrast to the intact group, similar DNA damages of testis and seminal vesicle were appeared in ORX group and SAL group. The DNA degradations seemed to be the results of necrosis rather than apoptosis. In the protein pattern analysis, all the testing tissues exerted similar patterns in the ORX group and the SAL group compared to the those of intact group. Patho-histological studies revealed that severe degenerative changes in testicular seminiferous tubules and massive infiltration of immune cells in SAL group. The present study confirmed that direct injection of hypertonic saline into the testis caused the equivalent biochemical changes in the accessory sex organs as shown in the orchidectomized animals. These results suggest that hypertonic saline injection model could be a useful castration model which can substitute for surgical castration when its safety is secured through further study in the future.
        869.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        This study examines the effects on fertilization rate (FR), hatching rate (HR), and normal individual rate after artificial fertilization using frozen thawed sperm according to the cryoprotectant (DMSO) concentration and the period of cryopreserved sperm of longtooth grouper, Epinephelus bruneus. Performing artificial fertilization using frozen-thawed sperm, after freezing the sperm at different DMSO concentration of 5.0%, 7.5%, 10.0% respectively, FR were (DMSO 5.0%: 99.5±0.8%, DMSO 7.5%: 99.5±0.7%, and DMSO 10.0%: 99.6±0.6%). The results are not significantly different from the control fresh sperm (100%). HR also (DMSO 5.0%: 96.2±2.3%, DMSO 7.5%: 95.3±3.6%, 10.0%: 96.6±1.8%) were not significantly different in each group. The normal individual rate after hatching using with control fresh sperm (98.4%±0.5) and DMSO concentration level of 5.0% (97.8±0.1%) were not significantly different. However, with 7.5% (97.2±0.6%) and 10.0% DMSO concentrations (95.9±0.2%) are lower than the normal individual rate after hatching observed in the control and 5.0% DMSO. Performing artificial fertilization using frozen-thawed sperm at different frozen period (2 days, 2 years, and 3 years), 10% DMSO FR and HR of 3 years (FR; 66.8±1.8%, HR: 82.0±12.9%) and 2 years (FR; 78.5±14.8%, HR: 79.3±0.6%) cryopreserved sperm were lower than control (FR; 100%, HR: 91.1±3.6%) and 2 days cryopreserved sperm (FR; 99.6±0.6%, HR: 96.6±1.8%). These results suggest suitable DMSO concentration ranges of cryopreservation sperm for E. bruneus is 5 to 10% and with 2 to 3 years cryopreservation period, cryopreservation sperm can be useful for seed production.
        870.
        2013.11 서비스 종료(열람 제한)
        Korea Ministry of Environment (Korea MOE) enacted the “Greenhouse Gas and Energy Target Management System (GETMS), which requires annual GHG reporting to establish GHG reduction targets for large-scale business places (458) emitting large amount of greenhouse gases (60% of total amount in Korea). The waste sector has higher potential for reduction of greenhouse gases compared to other sectors. Thus, this paper reviewed the methodologies modified based on national guidelines and estimated the greenhouse gas emissions for three categories of the waste sector in Daejeon Metropolitan City (DMC), South Korea. Further analysis for basic unit, i.e., greenhouse gas emissions per ton of solid waste, wastewater, and purified water in the waste sector was conducted to figure out main contributors for GHG emissions. Direct emissions (Scope 1) and indirect emissions (Scope 2) of 11 environmental infrastructures managed by DMC were selected for quantifying and managing of regional GHG emissions. The annual estimation for greenhouse gas emissions in the waste sector in DMC with a population of 1.52 million people was 254,235 tons CO₂ equiv. per year, which includes the main contributor of wastewater treatment 78,063 tons CO2 equiv., waste incineration 76,186 tons CO₂ equiv., and managed waste disposal sites 70,455 tons CO₂ equiv. Basic unit showed that most contributors were waste incineration, followed by the waste disposal site, biological treatment of solid waste, wastewater treatment, and public water supplies. Solid waste treatment/ disposal has best potential role in reducing GHG emissions. In general, therefore, it seems that reduction strategies for the main contributor should be prior to other categories and lead to best practice for managing GHG emissions, especially considering annual budgets.
        871.
        2013.11 서비스 종료(열람 제한)
        This study characterized PM and VOC emissions from cow dung combustion in a controlled experiment. Dung from grass-fed cows was dried and combusted using a dual cone calorimeter. Heat fluxes of 10, 25, and 50 kW/m² were applied. The concentrations of PM and VOCs were determined using a dust spectrometer and gas chromatography/mass spectrometry, respectively. PM and VOC emission factors were much higher for the lower heat flux, implying a fire ignition stage. When the heat flux was 50 kW/m², the CO₂ emission factor was highest and the PM and VOC emission factors were lowest. Particle concentrations were highest in the 0.23-0.3-μm size range at heat fluxes of 25 kW/m² and 50 kW/m². Various toxic VOCs including acetone, methyl ethyl ketone, benzene, and toluene were detected at high concentrations. Although PM and VOC emission factors at 50 kW/m² were lower, they were high enough to cause extremely high indoor air pollution. The characteristics of PM and VOC emissions from cow dung combustion indicated potential health effects of indoor air pollution in developing countries.
        872.
        2013.11 서비스 종료(열람 제한)
        Due to rapid industrialization and population growth uncontrolled release of heavy metals are entered into the waters. Among these heavy metals Pb(II) is one of the major toxic metal and in recent years the production and consumption of lead is increasing worldwide. Pb(II) can be entered to aqueous streams from several industries and can enter into the humans food chain through drinking water and crop irrigation. Lead can causes severe damage to the kidney, nervous system, reproductive system, liver and brain. The permissible level for lead in drinking water is 0.05 mg/l. Thus in recent years a number of methods and materials were developed to removal Pb(II) from aqueous solutions. Among these material bio-chars obtained from plant materials have gained special attention due to their low-cost and abundant nature. In present investigation we have developed magnetic bio-char composite from pine bark. Pine trees are wide spread throughout the South Korea and the bark from pine tree has no commercial use and is available as waste. Thus we have utilized this waste inexpensive material from preparing bio-char composite. The pin bark obtained was initially made into fine powder and washed several times with water and was filtered. To this powder an appropriate amounts of nitrate salts of cobalt and iron dissolved in ethanol solution was added and stirred for 15 minutes. This solution was oven dried at 70℃ and this was further calcined at 900℃ in nitrogen atmosphere. As obtained material was washed several times with water and dried in oven over night. This was used as adsorbent for treating lead contaminated aqueous solutions. As obtained bio-char composite was used to remove Pb(II) from aqueous solutions. Various parameters influencing Pb(II) removal like initial pH, contact time and initial concentration were studied. Effect of pH on Pb(II) removal was studied in the pH range from 2-8 at Pb(II) concentration 10 mg/L using an adsorbent dose of 300 mg. At below pH 3 a lower percent removal was observed whereas above pH 4>90% removal was observed. Further effect of contact time on Pb(II) removal was studied from time range between 10-180 min. Two kinetic models pseudo-first, pseudo-second-order models were used to evaluated the kinetic data and found that the data was better fitted to the pseudo-second-order model. From the overall results it was found that as prepared magnetic bio-char composite prepared from pin bark waste was effective and economic for treating Pb(II) contaminated aqueous solutions.
        873.
        2013.11 서비스 종료(열람 제한)
        In order to raise awareness about environmental protection, people are paying more attention now-a-days in reusing wastepaper. As a result, most countries in the world have already made significant progress related to wastepaper recycling technology. The aim of this study was to investigate the effects of slow-release nitrogen fertilizer (SRNF) on the growth of radish plants. Wastepaper was deinked by alkaline solution and SRNF was produced from fertilizer impregnated wastepaper, which applied to an experimental plot compared with a urea fertilized plot. The plant height and total chlorophyll content of the radishes were higher while they were treated with SRNF than with urea. Some agronomic and chemical components were also observed and significant differences between the two fertilizers were found. When the soil was treated with SRNF, the pH, organic matter and total nitrogen content were higher than in the soil which was treated with urea.
        874.
        2013.11 서비스 종료(열람 제한)
        In this study, we attempted to solubilize protein in slaughter blood (SB) using ultrasonic technology. The application of ultrasonic technology can make enzymatic degradation of SB more effective, which has no comparable alternative for treatment. The SB was homogenized by grinding it for 10 minutes at 10,000 rpm as a pretreatment for preventing its clotting, and then ultrasonic treatment was attempted to solubilize protein in SB. To maximize the efficiency of ultrasonic treatment for SB, the optimum condition of ultrasonic frequency (UF) was determined to be 20 kHz. To optimize the operation conditions of ultrasonification with 20 kHz of frequency, we used response surface methodology (RSM) based on ultrasonic density (UD) and ultrasonification time (UT). The solubilization rate (SR) of protein (%) was calculated to be 101.304 - 19.4205 X1 + 0.0398X2 + 7.9411X12 + 0.0001X22 + 0.0455X1X2. From the results of the RSM study, the optimum conditions of UD and UT were determined at 0.5 W/mL and 22 minutes, respectively, and SB treated under these conditions was estimated to have a 95% SR. Also, experimentally, a 95.53% SR was observed under same conditions, accurately reflecting the theoretical prediction of 95%.
        875.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        Bisphenol A (BPA) is an estrogenic endocrine disrupter. However, depending on a way of treatment, the harmful effects of BPA have not been confirmed. Also, trans-generational effects of BPA on male reproduction are still controversial. Because the reabsorption of testicular fluid in the efferent ductules (ED) and initial segment (IS) is important for sperm maturation, the present study was designed to determine trans-generational effect of BPA administrated orally on expression of water transport-related molecules in the mouse ED and IS. Ethanol-dissolved BPA was diluted in water to be 100 ng (low), 10 ㎍ (medium), and 1 ㎎/㎖ water (high). BPA-containing water was provided for two generations. Expression of ion transporters and water channels in the ED and IS were measured by relative real-time PCR analysis. In the ED, BPA treatment caused expressional increases of carbonic anhydrase II, cystic fibrosis ransmembrane regulator, Na+/K+ ATPase α1 subunit, and aquaporin (AQP) 1. No change of Na+/H+ exchange (NHE) 3 expression was detected. BPA treatment at medium dose resulted in an increase of AQP9 expression. In the IS, the highest expressional levels of all molecules tested were observed in medium-dose BPA treatment. Generally, high-dose BPA treatment resulted in a decrease or no change of gene expression. Fluctuation of NHE3 gene expression by BPA treatment at different concentrations was detected. These findings suggest that trans-generational exposure to BPA, even at low dose, could affect gene expression of water-transport related molecules. However, such effects of BPA would be differentially occurred in the ED and IS.
        876.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        To effects of sex maturation in olive flounder by regulating long photoperiod, gonadal development and GTH mRNA expression in the pituitary were investigated. Photoperiod was treated natural photoperiod and long photoperiod (15L:9D) conditions from September 2011 to March 2012. The results showed that natural photoperiodic group showed a higher gonadosomatic index (GSI) than long photoperiodic group during the spawning season (March 2012). The histological analysis of ovarian tissue showed that natural photoperiod group of ovaries contained vitellogenic oocytes, but long photoperiod group of ovaries mainly contained perinucleolus staged oocyte and oil-drop staged oocytes. The FSH mRNA of olive flounder, under natural photoperiod group, showed a significantly higher expression but no significant difference under long photoperiod group. The LHβ mRNA showed a significantly higher expression only under natural photoperiod group. These results may suggest that long photoperiodic information regulates secretion of pituitary FSH and LH and maintain early growing stage of gonadal development in this species.
        877.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        Olive flounder (Paralichthys olivaceus) is one of the commercial important flatfish species in Korea. The ocular signal transduction pathway is important in newly hatched flounders because it is closely involved in the initial feeding phase thus essential for survival during the juvenile period. However, the study of gene expression during ocular development is incomplete in olive flounder. Therefore we examined the expression analysis of specifically induced genes during the development of the visual system in newly hatched flounders. We searched ocular development-involved gene in the database of expressed sequence tags (ESTs) from olive flounder eye and this gene similar to arrestin with a partial sequence homology. Microscopic observation of retinal formation corresponded with the time of expression of the arrestin gene in the developmental stage. These results suggest that arrestin plays a vital role in the visual signal transduction pathway of the retina during ocular development. The expression of arrestin was strong in the ocular system during the entirety of the development stages. Our findings regarding arrestin have important implications with respect to its biological role and evolution of G-protein coupled receptor (GPCR) signaling in olive flounder. Further studies are required on the GPCR-mediated signaling pathway and to decipher the functional role of arrestin.
        878.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        아스타잔틴을 포함하는 수중유형 형태의 나노에멀젼을 고압균질기를 이용하여 제조하였다. 이에 유화조건, 유화제 종류, 유화제 농도 그리고 아스타잔틴 농도에 따라 최적화를 되었다. 나노에멀젼의 안정성은 제타포텐셜, FF-SEM, 입도분석기, 색차계를 이용하여 측정하였다. 제조된 아스타잔틴 나노에멀젼의 입도는 160 ~190 nm로 균일하였으며 레시친에 의한 나노에멀젼 보다 glyceryl citrate/lactate/linoleate/oleate에 의한 나노에멀젼이 더욱 안정하고 균일한 입도분포를 가졌다. 아스타잔틴의 봉입도는 HPLC, FF-SEM을 이용하여 확인 하였으며, 제형 구성 후 보관조건에서의 안정도 및 제타 포텐셜 값도 -41의 우수한 결과를 나타내었다.
        879.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        Cathepsins are members of the multigene family of lysosomal cysteine proteinases and have regulated function in several life processes. The potential role of cathepsin F cysteine gene was expected as protease in the yolk processing mechanism during early developmental stage, but expression analysis was unknown after fertilization. The alignment analysis showed that amino acid sequence of cathepsin F from olive flounder liver expressed sequence tag (EST) homologous to cathepsin F of other known cathepsin F sequences with 87-98% identity. In this study, we examined the gene expression analysis of cathepsin F in various tissues at variety age flounder. Tissue distribution of the cathepsin F mRNA has been shown to be ubiquitous and constitutive pattern regardless of age in each group, although derived from cDNA library using liver sample. The mRNA level of cathepsin F more increased as developmental proceed during embryogenesis and early developmental stage, especially increased in the blastula, hatching stage and 3 days post hatching (dph). As a result, it may suggest that the proteolysis of yolk proteins (YPs) has been implicated as a mechanism for nutrient supply during early larval stages in olive flounder.
        880.
        2013.08 서비스 종료(열람 제한)
        Pluripotent cells are categorized as either "naive" or "primed" based upon their pluripotent status. According to previous studies, embryonic stem cells and embryonic germ cells are identified as naive pluripotent stem cells and epiblast stem cells are identified as primed pluripotent stem cells. In a permissive species such as the mouse, naive and primed pluripotent stem cells can be derived from embryos without genetic manipulations. In non-permissive species such as humans and pigs, primed pluripotent cells are only established from embryos. However, previous studies have shown that the embryonic germ cells of non-permissive species share similar morphology and features with naive pluripotent cells. For these reasons porcine embryonic germ cells (pEGCs) may provide a useful cell source for comparative studies on naive pluripotent cells in non-permissive species. In this study, we attempted to establish and characterize porcine embryonic germ cells. Consequently, an embryonic germ cell line was derived from the genital ridges of a porcine dpc 30 fetus in media containing bFGF. This cell line displayed a dome-shaped colony morphology. The cell line was maintained in a stable condition over an extended time period and was able to differentiate into the three germ layers in vitro. Pluripotency markers such as OCT4, SOX2, NANOG and SSEA4 were expressed in these pEGCs. Similar with pESCs, Mek/Erk signaling pathway were activated by bFGF in the cultured pEGCs. In conclusion, we were able to successfully derive embryonic germ cells from genital ridges of a porcine fetus. Unlikely naive pluripotent cells such as mESCs, pluripotency of pEGCs were regulated by Mek/Erk signaling pathway activated by bFGF. This cell line could potentially be used as naive pluripotent cell source for comparative study with porcine embryonic stem cells and other pluripotent cell lines. As porcine pluripotent cells, pEGCs could be useful candidates for preliminary studies of human disease as well as a source for generating transgenic animals.