• Korean Journal of Animal Reproduction
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• v.19 no.4
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• pp.259-264
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• 1996

This study was carried out to investigate on the survival rates and in vitro developmental rates of bisected bovine embryos were by manipulator and micropipette. Bisected embryos were co-cultured in 20% FCS(v/v)＋TCM-199 media containing hormones, oviductal epithelial cells and cumulus cells 0 to 72 hrs after bisection. Survival rate and in vitro fertilization rate were defined as development rate on in vitro culture or FDA-test. The results are summarized as follows ; 1. The in vitro developmental rate of biseciton embryos co-cultured in 20% FCS＋TCM-199 medium containing PMSG, hCG, PMSG＋hCG, hCG＋$\beta$-estradiol 0 to 20 hrs and 20 to 40 hrs were 36.7, 26.7, 33.3, 40.0, and 30.0, and 30.0, 33.3, 30.0, 26.7, and 26.7%, respectively. The survival rate of bisection embryos co-cultured in TCM-199 medium containing hormones was significantly higher than that of non co-culture(25.0%). 2. The in vitro developmental rates of bisection embryos co-cultured in 20% FCS＋TCM-199 medium containing oviductal epithelial cells 4 to 5 hrs and 20 to 24 hrs were 40.0 and 33.3%, respectively. The survival rate of bisection embryos co-cultured in TCM-199 medium containing oviductal epithelial cells was significantly higher than that of non co-culture(25.0%). 3. The in vitro developmental rates of bisection embryos co-cultured in 20% FCS＋TCM-199 medium containing cumulus cells 4 to 5 hrs and 20 to 24 hrs were 43.3 and 36.7%, respectively. The survival rate of bisection embryos co-cultured in TCM-199 medium containing cumulus cells was significantly higher than that of non co-culture (25.0%).

• Journal of Embryo Transfer
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• v.16 no.2
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• pp.139-144
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• 2001

This study was carried out to investigate the effects of the bull, sperm type and sperm pretreatment on the pronuclear formation and in vitro development after injection of spermatozoa into in vitro matured bovine oocytes. 1. Spermatozoa derived room four bulls(A, B, C and D) were used for ICSI. The male pronuclear formation and developmental rates were 73.9∼87.0% and 33.3∼60.9%, respectively. 2. The effects of sperm type were examined. Male pronuclear formation rates by using fresh-and frozen-sperm, tail-cutting and tail-scoring sperm were 82.0%. 78.0%. 42.2% and 51.1% (p<0.05) while development rates were 56.0%. 42.0%, 17.8% and 22.2%, respectively. Fresh sperm achived a high mail pronuclear- and development rates than those of other groups. 3. Cheroical pretreatments were tested and compared. When sperm were pretreated with heparin, BFF(bovine follicula fluid), His, Ca Ionophore(I) and I + caffeine, mate pronuclear formation and developmental rates were 66.7∼82.2% and 33.3∼60.6%. respectively. and these values of treatment of I + caffeine were higher than that of other methods. 4. The male pronuclear formation and developmental rates of oocytes obtained by ICSI treated with or without zona pellucida were 80.0%. 72.0% and 46.0%, 36.0%, respectively.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.113-113
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• 2003

This study was conducted to investigate the effect of vitrification solution(VS) on in vitro developmental competence of immature porcine oocytes. The immature porcine oocytes were exposed to the following vitrification solution, at RT. 1) EFS sol. : 20% ethylene glycol (EG) 3 min, 40% EG + 18%(w/v) Ficoll(MV70, 000) + 0.3 M sucrose 30 sec, 2) GE sol. : 10% glycerol 5 min, 10% G + 20% EG 5 min, 25% G +25% EG 30 sec, 3) EG sol : 1.5M EG 2.5 min, 5.5 M EG + 1.0 M sucrose 30 sec. Oocytes were immediately transferred into 1.0 M, 0.5 M, 0.25 M, 0125 M, 0 M sucrose solution for 2.5 min each at RT. After removal of VS, immature oocytes were matured in vitro and subsequently all oocytes were subjected to IVF followed in vitro culture for 7 days. Maturation rates of oocytes were 38.8%, 44.5%, 22.4% and 57.6%, in EFS, EG, GE and Control, respectively, maturation rates of oocytes in EG and Control was significantly higher than EFS and GE(P<0.01). Fertilization rates of oocytes in Control was significantly higher than other treated groups(P<0.05), but no difference were observed among treated groups. Polyspermic rates were no significant difference among four groups. Cleavage rates of oocytes were 21.9%, 47.1%, 19.0% and 65.9%, in EFS, EG, GE and Control, respectively, cleavage rates of oocytes in EG and Control was significantly higher than EFS and GE(P<0.05), but blastocyst formation rates were no significant difference among four groups. These results suggested that the use of EG solution could be a great challenge for reaching a successful vitrification of immature porcine oocytes.

• Reproductive and Developmental Biology
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• v.37 no.2
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• pp.57-64
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• 2013

Developmental potential of cloned embryos is related closely to epigenetic modification of somatic cell genome. The present study was to investigate the effects of applying histone deacetylation inhibitor, trichostatin A (TSA) to activated porcine embryos on subsequent development of porcine parthenogenetic and nuclear transfer embryos. Electrically activated oocytes were treated with 5 nM TSA for different exposure times (0, 1, 2 and 4 hr) and then the activated embryos were cultured for 7 days. The reconstructed embryos were treated with different concentrations of 0, 5, 10 and 25 nM TSA for 1 hr. Also 5 nM TSA was tested with different exposure times of 0, 0.5, 1, 2 and 4 hr. And fetal fibroblast cells were treated with 50 nM TSA for 1, 2 or 4 hr and with 5 nM TSA for 1 hr. Cumulus-free oocytes were enucleated and reconstructed by TSA-treated donor cells and electrically fused and cultured for 6 days. In parthenogenetic activation experiments, 5 nM TSA treatment for 1 hr significantly improved the percentage of blastocyst developmental rates than the other groups. Total cell number of blastocysts in 1 hr group was significantly higher than other groups or control. Similarly, blastocyst developmental rates of porcine NT embryos following 5 nM TSA treatment for 1 hr were highest. And the reconstructed embryos from donor cells treated by 50 nM TSA for 1 hr improved the percentage of blastocyst developmental rates than the control group. In conclusion, TSA treatment could improve the subsequent blastocyst development of porcine parthenogenetic and nuclear transfer embryos.

• Development and Reproduction
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• v.5 no.1
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• pp.35-38
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• 2001

This study was peformed to find out the optimum larval stage among trochophore, early Dshaped larva, late D-shaped larva, early umbo and late umbo stages for cryopreservation of surf clam, Spisula sachalinensis larvae. Dimethyl sulfoxide (DMSO)and ethylene glycol were used as cryoprotectant, The larvae were immersed to cryoprotectants for 10 minutes and thereafter, cryopreserved in liquid nitrogen. Survival rates of trochophores frozen-thawed in 2.0 M dimethyl sulfoxide and 2.0 M ethylene glycol were the highest as 97.4% and 85.0%, respectively and post-thaw survival rates were decreased with the larval growth.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.103-103
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• 2002

This study was conducted to investigate cryopreservation of pearl oyster, Pinctada fucata martensii larvae. Four cooling rates (-0.25, -0.5, -0.75 and -1.0$^{\circ}C$/min.) were used to examine a proper cooling rate during cryopreservation of trochophores before seeding temperature (-12$^{\circ}C$). Seven developmental stages (early and late trochophores, early and late D-shaped larvae and early, middle and late umbo stage larvae) and different sugars (fructose, glucose and sucrose) were used to investigate optimal larval stage and effective sugar in cryopreservation of larvae. The survival rates of frozen-thawed trochophores increased at cooling rate of -1.0$^{\circ}C$/min. As larval developing, survival rate of frozen-thawed larvae increased, except umbo stage larvae, and especially late D-shaped larvae highly survived as 91%. Addition of sugar revealed positive effect on cryopreservation in this experiment and 0.2 M glucose and sucrose mixed with 2.0 M dimethyl sulfoxide significantly enhanced survival rate of larvae (P<0.05). The results of our study indicate that desirable cooling rate, developmental stages of larvae and effective sugar far cryopreservation of pearl oyster, P. fucata martensii larvae are -1$^{\circ}C$/min, late D-shaped larvae and 0.2 M glucose and sucrose, respectively.

• The Korean Journal of Ecology
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• v.8 no.4
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• pp.179-196
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• 1985

By using temperatures as a key variable, a simulation model was constructed to predict the size and developmental speed for the German cockroach population. The following three research steps were conducted to implement the individual simulation technique to represent the basic life system of the cockroach. First, informations on developmental periods and survival rates in each life stage were obtained through rearing experiments at five different temperatures. Secondly, biological parameters needed for modeling were obtained based on these rearing results. The logistic equation was applied to calculating the developmental speed, while the averages of survival rates were utilized as parameters determining population size. And thirdly, a basic life model was constratued in a stimulative framework in FORTRAN for predicting the populating development on the individual basis. For this purpose the biological characteristics, such as life stage, age in days, developmental speed, fecundity, etc., were assigned as an inherent attribute of the transactiion so that they could accompany each individual automatically all through the simulation. This gave the model flexibility and applicability in representing the isnect life system. The save memory space in computer programing, two files were utilized in translocating the individual informations each other as time proceeded. The developed model could be effectively used as a strategic tool in interpreting and managing the cockroach population. It was also suggested in this study that the individual simulation could efficiently serve as a basis to formulate a fundamental framework on which the advanced and complex life process could be built.

• Journal of Embryo Transfer
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• v.22 no.4
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• pp.265-269
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• 2007

This study was conducted to investigate the efficacy of vitrification procedure for the cryopreservation of porcine oocytes and the utilization of vitrified oocytes as recipient cytoplasts for somatic cell nuclear transfer (NT), and observed that porcine oocytes are evaluated by pronuclear formation, and parthenogenetic development. Single fetal donor cells were deposited into the perivitelline space of vitrified enucleation oocytes, followed by electrical fusion and activation. NT embryos were cultured in NCSU-23 medium supplemented with 5% FBS, at $38.5^{\circ}C$ in 5% $CO_2$ and air. 1. When the developmental rates of the oocytes after being culture for $0{\sim}10$ hours vitrified with EDS and ETS were 42.0%, 38.0%, respectively. This results were lower than the control group(62.2%). 2. When the developmental rates of the oocytes after being culture for $0{\sim}10$ hours vitrified-thawed with sucrose and glucose, 5% PVP, NCSU-23 supplemented with 10% FBS were 33.3%, 25.9%, respectively. This results were lower than the control group(55.6%). 3. The fusion and development to the blastocyst stage between the NT embryos constructed with the vitrified and non-vitrified oocytes were significant differences. Developmental rate of oocytes and NT embryos constructed with the vitrified or non-vitrified oocytes were $13.0{\pm}2.4%\;and\;23.2{\pm}2.4%$, respectively.

• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.639-645
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• 1997

The objectives of the present study were improvements in the efficiency of developmental rates to morula and blastocyst stages to produce a large number of genetically identical nuclear transplanted embryos. The oocytes collected from slaughterhouse ovaries were matured 24h in TCM199+10% FBS and exposed to $39^{\circ}C$ or room temperature to allow cytoplasmic maturation and gain activation competence. Donor embryos were treated for 12h with $10{\mu}g/ml$ nocodazole or $0.05{\mu}g/ml$ demicolcine to synchronize the cell cycle stage at 26h after the onset of culture. The blastomeres and recipient oocytes were fused by electrofusion. The cloned embryos were then cultured in various conditions to allow further development. In the treatment of oocyte activation and cell cycle regulation of donor nuclei, the room temperature exposure and nocodazole treatment group had significant effect on the developmental rates to morula/blastocyst(21.7% vs 12.1~16.7%), but had no significant effect on the fusion rates between donor blastomeres and recipient oocytes. The developmental rates of bovine nuclear transplanted embryos appeared to be higher significantly in mTALP medium under 5% $O_2$ condition and in TCM199 with bovine oviduct epithelial cell under 20% $O_2$ condition(22.2%) than other groups. In embryo transfer of nuclear transplanted embryos, there were no significant differences in calving rates between the use of excellent and good grade donor embryos.

• Journal of Embryo Transfer
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• v.11 no.2
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• pp.151-158
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• 1996

This study was carried out to investigate the effect of equilibration time, sucrose concentration and age of embryo on survival and developmental rates of bovine IVF expanding blastocysts frozen-thawed by direct transfer method. The bovine oocytes were collected from 2~5mm follicles, matured for 20~24hrs in 5% $CO_2$incubator and then fertilized with frozen-thawed semen. Expanding blastocysts at day 7, 8, 9, 10 and 11 after IVF were frozen in 1.8M ethylene glycol(EG). Survival and hatching rates of frozen-thawed IVF embryos were examined. The results were as follow ; Survival and hatching rate of TVF expanding blastocysts after 10, 20, 3Omin exposure in 1.8M EG were 100,0,90.9, 47.1, 85.0, 75.0 and 62.5% respectively. Survival rates of IVF expanding blastocysts frozen with 1.8M EG and various concentration(0, 0.25, 0.5, 1M) of sucrose were 73.3, 25. 0, 16.7, 9.1% respectively. Survival and hatching rates of IVF expanding blastocysts frozen-thawed according to age of embryo(Day 7, 8, 9,10, 11) were 86.1, 84.8, 79.3, 61.4, 51.3, 74.2, 76.9, 71.7, 63.0 and 65.0% respectively. In conclusion, the age of the embryo(Day 7, 8) is very important for the successful freezing of IVF bovine embryos and 1.8M ethylene glycol not containing sucrose may be effective cryoprotectant for direct transfer method.