• Development and Reproduction
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• v.4 no.1
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• pp.79-85
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• 2000

This study was made to optimize the conditions needed to produce two types of gynogenetic diploids in the sweet fish, Plecoglossus altivelis. Firstly, ultraviolet (UV) ray doses between 3,000 erg to 14,000 erg/$\textrm{mm}^2$ were tested to inactivate sperm genetically. Based on the appearance of the haploid syndromes in the embryo, a dose of UV ray 6000~7000 erg was required to inactivate sperm genetically. Then, cold shock treatment at 1~2$^{\circ}C$ for 15~30 min were conducted to retain the 2nd polar body in inseminated egg. The best elapsed time before the start of the cold shock was examined between 5~8 min. The experiments in which began 5 min after insemination at 1~2$^{\circ}C$ during 17.5 min gave 21.2％ survival rate and 89.7% normal eyed embryo rate. The gynogenetic diploid produced by suppression of the first cleavage, a considerably high number of heteroploids appeared and high mortality was observed at the metamorphosis stage, so further investigation is needed. The production of gynogenetic diploids were confirmed by GPI isozyme marker. The heterozygous type in Gpi-1 locus was observed in the meiotic-G2N as a result of gene-centromere recombination during meiosis. The heterozygous type was never observed in mitotic-G2N and showed segregation into two homozygous types at Gpi-1 locus.

• Journal of Embryo Transfer
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• v.25 no.3
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• pp.171-177
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• 2010

Plasminogen activators (PAs) are serine proteases that convert plasminogen to plasmin. The PA/plasmin system has been associated with a number of physiological processes such as fibrinolysis, ovulation and fertilization. Although correlations have been reported between reactive oxygen species (ROS) and oocyte maturation, the relationship between PA activity and ROS is unknown. The present study was undertaken to determine the effects of cumulus cells on PA activity in matured porcine oocytes under xanthine (X)-xanthine oxidase (XO) system. When oocytes were matured under the X-XO system, the proportion of oocytes remaining GV stage was higher (p<0.05) in oocytes without cumulus cells. The incidence of degenerated oocytes was higher (p<0.05) in the X+XO ($11.1{\pm}6.1$ and $21.6{\pm}3.4%$) than in the control group ($2.9{\pm}1.8$ and $4.0{\pm}1.6%$). The proportion of TUNEL-positive oocytes and activity of caspase-3 were higher (p<0.05) in cumulus-free oocytes and oocytes exposed to ROS. Tissue-type plasminogen activator-plasminogen activator inhibitor (tPA-PAI) and tissue-type plasminogen activator (tPA) activity were detected in oocytes that were separated from cumulus-oocytes complexs (COCs) at 44 h of maturation culture, and only tPA was produced in oocytes that were denuded before the onset of maturation culture. On the other hand, the activities of PA were increased (p<0.05) when oocytes were cultured under the X-XO system. The higher activity of tPA was observed in denuded oocytes (DOs) underwent apoptotic changes by oxidative stress. In COCs, however, tPA-PAI as well as tPA activity was detected and apoptotic changes such as DNA cleavage or caspase-3 activation were not observed. These results suggest that tP A may be relevant to apoptotic cell death in porcine oocytes by oxidative stress.

• Journal of Embryo Transfer
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• v.33 no.3
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• pp.177-183
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• 2018

The identification of biomarkers of a living tissues is essentially required to understand specific functions of the cells. In previous study, we reported IGFBP 3 as one of the putative biomarkers, by showing specific expression at porcine spermatogonial stem cells (SSCs) of early stage of porcine testis. In this study, we analyzed the expression of seven members of IGFBP family (IGFBPs) in SSCs and histological expression pattern of pregnancy-associated plasma protein-A (PAPP-A), which plays a role on the growth promoting enzyme by cleavage of IGFBPs in testis of 5 days old pig. RT-PCR analysis showed that IGFBP 1, 2, 3, 4, and 6 were expressed at high level specifically in porcine SSCs compared with whole testis. We performed immunohisotochemical staining of testis sections with PAPP-A and protein gene product 9.5 (PGP9.5) which are the known biomarkers for SSCs. We were not able to find co-expression of PAPP-A and PGP9.5; PAPP-A was expressed only in Sertoli cells and PGP9.5 expression was confirmed in spermatogonium. Additionally, we were able to confirm the GATA4 expression in Sertoli and Leydig cells as a regulator of Sertoli cell function was not detected PGP9.5 expressing cells, indicating indirect evidence of that cytolocalization of PAPP-A expression is limited in Sertoli cells. These results suggested that the PAPP-A expressed in Sertoli cells may play role on regulation of development and differentiation of testicular cells through the IGF axis in neonatal porcine testis.

• Journal of Embryo Transfer
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• v.33 no.3
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• pp.119-127
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• 2018

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 $30{\mu}sec$. After fusion subsequent activation were divided into three groups; non-treatment (control) and treatment with 2 mM 6-DMAP or $7.5{\mu}g/ml$ cytochalasin B for 4 hours. Transferred embryos were cultured in PZM-3 (Porcine Zygote Medium-3) in $5%\;CO_2$ and 95% air at $39^{\circ}C$ 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; $64.9{\pm}4.8%$ in 1.1 kV/cm and $62.7{\pm}4.0%$ in 1.5 kV/cm. However, blastocyst formation rate (%) was significantly different among three different activation groups (no treatment, 2 mM 6-DMAP or $7.5{\mu}g/ml$ cytochalasin B) combined with electrofusion of 1.1 kV/cm. The blastocyst formation rate was $12.6{\pm}2.5$, $20.0{\pm}5.0$, and $34.9{\pm}4.3%$ in control, 2 mM 6-DMAP, and $7.5{\mu}g/ml$ 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 $30{\mu}sec$) and $7.5{\mu}g/ml$ cytochalasin B treatment was effective for production of the porcine SCNT embryos.

• Journal of Embryo Transfer
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• v.28 no.2
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• pp.157-162
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• 2013

Methoxychlor (MXC) was developed to be a replacement for the banned pesticide DDT. HPTE [2,2-bis (p-hydroxyphenyl)-1,1,1-trichloroethane], which is an in vivo metabolite of MXC, has strong oestrogenic and anti-androgenic effects. MXC and HPTE are thought to produce potentially adverse effects by acting through oestrogen and androgen receptors. Of the two, HPTE binds to sex-steroid receptors with greater affinity, and it inhibits testosterone biosynthesis in Leydig cells by inhibiting cholesterol side-chain cleavage enzyme activity and cholesterol utilisation. In a previous study, MXC was shown to induce Leydig cell apoptosis by decreasing testosterone concentrations. I focused on the effects of MXC on male mice that resulted from interactions with sex-steroid hormone receptors. Sex-steroid hormones affect other organs including the kidney and liver. Accordingly, I hypothesised that MXC can act through sex-steroid receptors to produce adverse effects on the testis, kidney and liver, and I designed our experiments to confirm the different effects of MXC exposure on the male reproductive system, kidney and liver. In these experiments, I used pre-pubescent ICR mice; the puberty period in ICR mice is from postnatal day (PND) 45 to PND60. I treated the experimental group with 0, 100, 200, 400 mg MXC/kg b.w. delivered by an intra-peritoneal injection with sesame oil used as vehicle for 4 weeks. At the end of the experiment, the mice were sacrificed under anaesthesia. The testes and accessory reproductive organs were collected, weighed and prepared for histological investigation. I performed a chemiluminescence immune assay to observe the serum levels of testosterone, LH and FSH. Blood biochemical determination was also performed to check for other effects. There were no significant differences in our histological observations or relative organ weights. Serum testosterone levels were decreased in a dose-dependent manner; a greater dose resulted in the production of less testosterone. Compared to the control group, testosterone concentrations differed in the 200 and 400 mg/kg dosage groups. In conclusion, I observed markedly negative effects of MXC exposure on testosterone concentrations in pre-pubescent male mice. From our biochemical determinations, I observed some changes that indicate renal and hepatic failure. Together, these data suggest that MXC produces adverse effects on the reproductive system, kidney and liver.

• Journal of Aquaculture
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• v.11 no.3
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• pp.337-344
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• 1998

This paper documented mophological changes of embryonic development and first zoea larvae of snow crab, Chinoecetes opilio. Female crabs were sampled by the Danish seine fishery at the depth about 200m in Sep. 1997 in the eastern coast of Korea. Female with newly berried eggs was reared at the water temperature of 5$^{\circ}C$ till the time of hatching. The results obtained are as follwos. Embryonic development : According to morphogenesis of fertilized eggs, the developemental process of the embryo was classified into the following seven stages : First stage (cleavage and blastula stage, 24 days) Second stage (gastrula stage, 72 days) Third stage (nauplius stage, 22 days) Fourth stage (metanauplius stage, 57days) Fifth stage (stage of a pigmentary deposit in the compound eye, 30 days) sixth stage (chromatophore appearance stage in maxillipede, 56 days) Seventh stage (hatching stage, 36 days) Larvae hatched as prezoeas and they molted to first zoea in about an hour. The first zoea is 4.6 to 5.1mm in length, 3.2~3.6mm in width. The abdomen consists of five segments and a bifurcate telson.

• Journal of Embryo Transfer
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• v.16 no.2
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• pp.99-106
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• 2001

This study was undertaken to compare the efficiency of recovery rate and development rate of follicular oocytes collected either by aspiration or by slicing method. The follicular oocytes collected by the two methods matured in TCM199 supplemented with 10% steer serum at 39$^{\circ}C$ in a humidified atmosphere of 5% $CO_2$in air. After 22 h of culture, the oocytes were inseminated with frozen-thawed semen (2$\times$10$^{6}$ sperm/ml of final concentration) prepared with Percoll-density gradient in IVF-TALP medium for 16 h. Later, sets of 15 presumptive zygotes were transferred into 50 $\mu$L, droplets of CR1aa medium. On day 4 of the culture, embryos were transferred to TCM199 until day 9. The percentages of nuclear maturation to pre-metaphase II in the oocytes collected by aspiration are significantly (P<0.05) higher than that by slicing (83% vs. 62%, respectively). The mean number of oocytes recovered by slicing per ovary is significantly (P<0.05) higher than that by aspiration (15.1 vs. 6.7, respectively). Although the rates of cleavage and development to blastocyst of oocytes collected b)\\\\`aspiration are significantly (P<0.05) higher than that by slicing, the number of transferable embryos obtained by slicing method is significantly (P<0.05) higher than that by aspiration. From the results. we may conclude that slicing method is better than aspiration method for obtaining large number of transferable embryos per ovary.

• Journal of Embryo Transfer
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• v.27 no.1
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• pp.57-62
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• 2012

Efficient oocyte activation is a key step for the success of nuclear transfer in cloning. Ionomycin sequentially combined with 6-DMAP is now widely used to activate normal oocytes for analytical studies of oocyte activation and to activate reconstructed oocytes after nuclear transfer. The present study investigated sources of oocytes, duration of ionomycin and 6-DMAP, laser and electric stimulation in goat oocyte activation in order to optimize the protocols. Goat ovaries were collected in individual abattoirs during the breeding season and were delivered to the laboratory within 6 h in saline with 100 IU/ml streptomycin and 0.05 mg/ml penicillin. The oocytes were denuded from the cumulus cell by pipetting with 0.2% hyaluronidase in PBS at 20~22 hr post maturation. Oocytes with the polar body were selected and assigned to four groups for parthenogenetic activation. To examine the effect of duration of ionomycin treatment, oocytes after 20~22 hr of maturation were treated with 2.5 uM ionomycin for 1 or 5 min times and then cultured in 2 mM 6-DMAP for 2 or 4 hr. The activated oocytes were cultured in mSOF at $38.5^{\circ}C$ in $CO_2$ 5%, $O_2$ 5% and $N_2$ 90% multi incubator. Cleavage and blastocyst development was observed at 48 hr and day 8 of culture $in$ $vitro$, respectively. Activation rates of oocytes exposed to ionomycin for 1 min(86.4%) were significantly higher than those treated for 5 min(74.3%) duration. This indicated that 1 min ionomycin treatment was most suitable for activation of goat oocytes. The duration of 6-DMAP treat duration was in 2 mM 6-DMAP for 2 hr after 1 min exposure to 2.5 uM ionomycin. The activation rate of oocytes incubated in 6-DMAP for 2 hour(82.5%) was significantly higher than those in oocytes treated with 4 hr(75.5%).

• Clinical and Experimental Reproductive Medicine
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• v.25 no.2
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• pp.109-113
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• 1998

Objective: To ananlyze the direct effect of nitric oxide (NO), generated from sodium prusside (SNP) on the embryo developments in reproductive process. Design: Ova from mouse were treated to allow fertilization in in vitro culture. And the samples of fertilized ova were alloted into five alliqutos. Each alliquot was cultured in media treated with either concentration at 0 (n=92), $25{\mu}M$ (n=84), $50{\mu}M$ (n=80), $100{\mu}M$ (n=77), $500{\mu}M$ (n=54) of SNP. Main Outcome Measure: Rates of embryonal cell cleavages, viability and cell morphology were assessed during in vitro fertilization and culture. Results: As analyse the cell cleavage at 24 hours after in vitro culture of fertilised egg in variuos NO concentration, all of egg cells of each alliquot were developed to $2\sim4$ cell stage. But the alliquot of egg cells treated with $50{\mu}M$, which were totally degenerated. And also all embryonal cells of each alliquot were developed to 8 cell stage and morula stage on culture continuosly. And the embryonal cells of each alliquot were analysed at 24 and 48 hours following the in vitro culture. The rates of cell fragmentation and fusion were $4.2{\pm}3.4%$ in control group which is not treated with NO, while experimental groups was high, as rated $23.4{\pm}6.2%$ in $25{\mu}M$, $28.2{\pm}5.7%$ in $50{\mu}M$ and $32.1{\pm}6.4%$ in $100{\mu}M$ concentration of NO. Accordingly the rate of abnormal morphology of embryonal cell in control was lower significantly than that in each alliquot of experimental groups (p<0.05). And the degenerated rates of embryonal cells were 0% in control, $17.8{\pm}6.7%$ in $25{\mu}M$, $23.6{\pm}4.7%$ in $50{\mu}M$ and $26.8{\pm}11.2%$ in $100{\mu}M$ at 8 cells and morula on culture of 48 and 72 hours. On the examination of embryonal cells developed to blastocyst through in vitro culture, the rates of degenerated cells were $16.8{\pm}7.2%$ in control, $37.5{\pm}6.2%$ in $25{\mu}M$, $73.4{\pm}4.6%$ in $50{\mu}M$, 100% in $100{\mu}M$. Conclusion: This results suggeted that the NO in any concentrations is harmful on embryos in view of morphology as well as viability of cell, and the toxicity of NO on embryo is stronger at condition in higher concentration of NO.

• Journal of Embryo Transfer
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• v.12 no.1
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• pp.27-36
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• 1997

The studies were carried out to investigate the effects of co-culture with cumulus cells and oviduct epithelial cells on the in vitro fertilization and cleavage rate of bovine follicular cocytes and to determine the optimum thawing temperature and equilibration time on in vitro developmental rate of frozen bovine embryos. The ovaries were obtained from slaughtered Korean native cows. The follicular oocytes were cultured in TGM-199 medium containing 10 IU /ml의 PM SG, 10 IU /ml의 hCG, ip g/ml의 $\beta$-estradiol and 10% FCS for 24~48 hrs in incubator with 5% $CO_2$ in air at 38.5$^{\circ}C$. The bovine embryos following dehydration by cryoprotective agents and a various concentration of sucrose were directly plunged into liquld nitrogen and thawed in 3$0^{\circ}C$ water. Survival rate was defined as developmental rate on in vitro culture or FDA-test. The results are sunanarized as followes :1. The in vitro fertilization and in vitro developmental rates of bovine oocytes co-cultured with cumulus cells in TCM499 medium were 75.0~76.8% and 17.3~27.6%, respect-ively. And in-vitro fertilization rates of cumulus-enclosed oocytes(55.4%)were significantly(p<0.05) higher than cumulus-denuded oocytes (23.1%). 2. The in vitro fertilization and in vitro developmental rates of bovine oocytes co-cultured with l$\times$ l04cells /ml, 1 x l06cells /ml, lx l08cells /ml and 1 x l015cells /ml oviduct epithelial cells in TCM-199 medium were 74.5~77.8% and 15.7~21.20 respectively.3. The in-vitro fertilization and in vitro developmental rates of bovine oocytes cocultured in '1CM-199 media containing PMSG, hCG, PMSG+hCG. PMSG+$\beta$-estradiol, hCG+$\beta$-estradiol 0 to 40 hrs after insemination were 74.0~77.4% and l8.9~23.l%, re-spectiv ely.4.The survival rates of bovine embryos thawed after rapid freezing in the freezing medium containing a various concentration of sucrose added 1.5M and 2.OM glycerol,DMSO and propanediol were 23.5~31.4% and 20.6~34.l%, respectively. 5. The temperature thawed at 3$0^{\circ}C$ after rapid freezing of bovine embryos resulted in a significantly higher embryos survival rate than did at 2$0^{\circ}C$ and 35$^{\circ}C$.6. The equilibration time on the survival rates of bovine embryos was attained after short period of time(2.5~5 min.) in the freezing medium higher than long period of time (10~20min.). (Key words : bovine embryos, co-culture, freezing, in vitro development)