• Journal of Embryo Transfer
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• v.18 no.1
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• pp.35-41
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• 2003

Three experiments were performed to develop an optimal culture system of in-vitro derived porcine embryos. In experiment 1, embryos were cultured in two different basic culture media (NCSU-23 and PZH) supplemented with BSA (4mg/ml), FBS (10%), PVA (3mg/ml). Although no difference on the percentage of embryos developed to blastocysts was found (P>0.05), more 2-cell embryos (59.5% vs. 44.7 to 52.0%) were obtained when embryos were cultured in NCSU-23 added with BSA. In experiment 2, identical treatment was conducted using PZM medium. More (P<0.05) 2-cell embryos (54.4% vs. 40.7 to 44.5%) and blastocysts (12.5% vs. 5.8 to 9.0) were produced when embryos were cultured in PZM added with BSA (4mg/ml). In experiment 3, embryos were cultured in media as follows; 1) NCSU-23 without BSA for 192 hours; 2) NCSU-23 with BSA for 192 hours; 3) NCSU-23 with BSA for 96 h and then subsequently injected with FBS into culture drops. Although no difference on the percentage of embryos developed to blastocysts was found (P>0.05), more 2-cell embryos (63.8 to 69.2% vs. 52.0%) were obtained when embryos were cultured both in NCSU-23 added with BSA throughout culture duration and in FBS supplemented medium. In conclusion, no difference was found when porcine preimplantation embryos were cultured in NCSU-23 added with various macromolecules. However, when PZM medium was used, PZM medium supplemented with BSA showed more potential to support embryo development. Finally, FBS supplemented into culture drop 96h post-insemination did not show any benefits on embryo development.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.9-9
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• 2002

This study was to evaluate the in vitro survival of vitrified-thawed bovine MII enucleated (MIIe) oocytes according to activation timing and minimun volume cooling (MVC) method and their in vitro development after somatic cell nuclear transfer (SONT). Bovine oocytes were recovered from slaughtered bovine ovary and matured in TCM-199 supplemented with 10% FBS. (omitted)

• The Korean Journal of Zoology
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• v.29 no.1
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• pp.13-22
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• 1986

In order to investigate the 'In Vitro 2-Cell Block' phenomenon found in certain mouse strains such as ICR, the present studies have been done. Fertilized eggs (1-cell) and 2-cell embryos recovered from the oviducts of the ICR mouse at the various time intervals after hCG injection to induce ovulation were cultured for 3 or 4 days to examine the capability for further cleavage beyond 2-cell stage. Consequently, it was found that some proportions of the 1-cell or 2-cell embryos recovered at 30 hours post hCG showed their cleaving capability and if the embryos were obtained after 48 hours of hCG injection, they were all at 2-cell stage and most of them developed to the blastocysts in vitro. It was also found that the embryos obtained at 27 hours post hCG showed their stronger capacity of further development in the groups cultured for shorter period than 24 hours in vitro before transferring to the oviduct. Based on the results, it can be inferred that mouse fertilized eggs should be remained inside the oviduct for a certain length of period after fertilization, or they should be cultured for a short period than 12 hours before returning back to the oviduct in order to develop to blastocysts. It was also found that though the embryos under the 2-cell block in culture showed normal feature up to 24 hours under the microscopical observation, they had already lost their capacity for the normal development, and if the culture of the 2-cell embryos was extended to 48 hours, they showed nuclei with heteropyknosis, and the vacuoles were were detected in the cytoplasm of embryonic cell if they were cultured for 72 hours.

• Korean Journal of Animal Reproduction
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• v.27 no.2
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• pp.115-123
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• 2003

The present study was carried out to examine the effect of catalase (CAT) on in vitro maturation (IVM) of porcine follicular oocytes and oxygen concentration with CAT on in vitro development (IVD) of porcine IVM/IVF embryos. The results were summarized as follows - 1 . The rates of nuclear maturation, penetrated oocytes, pronucleus formation rates, polyspermic oocytes and mean numbers of the penetrated sperm were significantly lower in oocytes matured with 100, 500 and 1,000 units/ml CAT than those of central groups (P>0.05). 2. The rates of blastocyst formation and total cell numbers of blastocyst at day 7 after in vitro fertilization were significantly lower in CAT treatment groups than those of the central groups (P>0.05). 3. There were not significant difference in the blastocyst development and total cell numbers of blastocyst on in vitro culture of NCSU-23 media with 0, 100, 500 and 1000 units/ml CAT under the 5% and 20% $O_2$ concentrations. These results suggested that the addition of CAT was not helpful for porcine oocyte maturation and further development, also the rates of blastocyst formation and total cell numbers of blastocyst at day 7 of porcine IVM/IVF embryos were not significantly different in the NCSU-23 culture medium under the 5% and 20% $O_2$ concentrations.

• Reproductive and Developmental Biology
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• v.29 no.1
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• pp.37-41
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• 2005

The aim of this study was to improve efficiency and quality of the production of Korean Native Cow embryos. We examined effects of ovarian morphology and maturation vessel on the development and cell number of blastocysts. The development rates to the 2-cell embryos from oocytes collected from the ovaries of different morphological statues were similar ranging between 70.3 and 84.1%. The development rate to the 8 cell- and blastocyst-stage embryos was the highest in the group without both corpus luteum (CL) and follicle. The inner cell mass (ICM), trophectoderm (TE) and total cell number (TCN) were significantly higher in the groups of follicular cyst and regressive CL than other treatment groups, and the same pattern was observed in the ICM/TCN ratio. The development rate to the 2-cell stage was significantly higher in 0.5-㎖ straw group than 0.25-㎖ straw group. However, the development rates to the blastocyst stage were similar between the dish and the straw group. There were no differences in the number of ICM and TE cells, TCN and ICM/TCN ratio of blastocysts from oocytes matured in the different vessels.

• Korean Journal of Animal Reproduction
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• v.18 no.1
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• pp.31-37
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• 1994

This study carried out to investigate the effects of cryoprotectants in the medium on the survival rate of rapidly frozen porcine bisected demi-embryos. The porcine bisected demi-embryos following dehydration by cryoprotectants containing sucrose were directly plunged into liquid nitrogen and thawed in 3$0^{\circ}C$ water bath. Survival rate was defined as development rate on in vitro culture or FDA-test. The results are summarized as follows : 1. The survival rates of without-zona pellucida embryos and 2 blastomeres porcine embryos were 10.0 and 7.1%, respectively. The rate of unfrozen blastomeres (20.00%) was significantly higher than that of non-frozen oocytes. 2. The survival rates of with and without-zona pellucida of bisected porcine embryos by micromanipulator were 20.0 and 14.3%, respectively. 3. The developmental rates of with and without-zona pellucida of bisected poricine embryos by micromanipulator were 13.3 and 7.1%, respectively.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.1
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• pp.9-20
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• 1999

The genetic defects in human gametes and embryos can cause adverse effects on overall reproductive events. Biopsy of embryos for preimplantation genetic diagnosis (PGD) offers a new possibility of having children free of the genetic disease. In addition, advanced embryo culture method may enhance the effectiveness of embryo biopsy for the practical application of PGD. This experimental study was undertaken to evaluate the effects of coculture on the development in vitro of biopsied mouse embryos as a preclinical model for PGD of human embryos. Embryos were obtained after in vitro fertilization (IVF) from F1 hybrid mice (C57BLfemale/CBAmale). Using micromanipulation, 1, 2, 3 or 4 blastomeres of 8-cell stage embryos were aspirated through a hole made in the zona pellucida by zona drilling (ZD) with acidic Tyrode's solution (ATS). After biopsy of blastomeres, embryos were cultured in vitro for 110 hours in Ham's F-10 supplemented with 0.4% BSA or cocultured on the monolayer of Vero cells in the same medium. The frequence of blastocyst formation were recorded, and the embryos beyond blastocyst stage were stained with 10% Giemsa to count the total number of nuclei in each embryo. There was no significant difference in the blastocyst formation between the zona intact control group and the zona drilling (ZD) only, or biopsied groups. The hatching rate of all the treatment groups except 4/8 group was significantly higher than that of control group. In all the treatment groups, there was a significant reduction in the mean cell number of embryos beyond blastocyst stage ($50.2{\pm}14.0$ in control group vs. $41.2{\pm}7.9$ in ZD, $39.3{\pm}8.8$ in 7/8, $29.7{\pm}6.4$ in 6/8, $25.1{\pm}5.7$ in 5/8, and $22.1{\pm}4.3$ in 4/8 groups, p<0.05). When the same treatments were followed by coculture with Vero cells, a similar pattern was seen in the blastocyst formation and the hatching rate. However, in all the treatment groups, there was a significant increase in the mean cell number of embryos beyond blastocyst stage with coculture, compared with the parallel groups without coculture. In the cleavage rate of biopsied blastomeres cultured for 110 hours after IVF, there was no significant difference between coculture and non-coculture groups (87.2% vs. 78.7%). However, the mean cell number of embryos developed from the biopsied blastomeres was significantly higher in coculture group ($11.5{\pm}4.7\;vs.\;5.9{\pm}1.9$, p<0.05). In conclusion, biopsy of mouse embryos after ZD with ATS is a safe and highly efficient method for PGD, and coculture with Vero cells showed a positive effect on the development in vitro of biopsied mouse embryos and blastomeres as a preclinical model for PGD of human embryos.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.2
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• pp.161-171
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• 1989

The development of 2-cell mouse embryos to the blastocyst stage in vitro has been used as quality control for the culture media and supplements employed for human in vitro fertilization and embryo transfer(IVF-ET). 2-cell mouse embryos were cultured to the blastocyst stage in SECM, Medium 199-Earle's, Ham's F-10 I , Ham's F-10 II , Hoppe & Pitts, MEM and $HT_6$. The protein supplements contained in media were bovine serum albumine, fetal bovine serum and human fetal cord serum. The results were as follows; 1. The successful development was 81.3% in Medium 199-Earle’s, 91.9% in Ham’s F-10 I and 97.1% in $HT_6$. 2. 2-cell mouse embryos developed properly in all supplements but the best development was particularly noted in $HT_6$ media when HFCS was supplied as protein supplement.

• Journal of Veterinary Science
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• v.24 no.1
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• pp.10.1-10.10
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• 2023

Background: The collection of ovaries from slaughterhouses is an important source of oocytes for in vitro embryo production. On the other hand, the physiological stage of slaughtered females varies and influences embryo production. Objectives: The study examined the in vitro efficiency of embryos and demi-embryos from young, non-pregnant adult, and pregnant adult ewes from a local slaughterhouse. Methods: One thousand three hundred ovaries were collected from August to October 2020. The recovered oocytes were matured, fertilized, and cultured at 5% CO2, 38.5℃, and 100% humidity. Embryo bisection was performed in 96 blastocysts (n = 32 per treatment). The demiembryo pairs were incubated for their reconstitution for 12 h. SAS was used for data analysis. Results: The number of oocytes collected from the experimental group of non-pregnant adult ewes was higher (p ≤ 0.007) than those collected from the group of pregnant adult ewes (2.67 ± 0.19 vs. 2.18 ± 0.15 oocytes/group, respectively). The blastocyst rate was higher (p ≤ 0.0001) in the non-pregnant adult group (36.39%) than in the young (17.96%). The ratio of demi-embryos that recovered the blastocoelic cavity was higher (p < 0.05) in the young group (81.25%) than in the pregnant adult group (59.38%). The diameter of the demi-embryos was higher (p < 0.05) in the non-pregnant adult group (186.54 ± 8.70 ㎛) than those in the young and pregnant adult groups. Conclusions: In conclusion, the in vitro embryo production efficiency was highest when using oocytes from non-pregnant adult ewes under the conditions of this study.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.1
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• pp.59-64
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• 1998

This study was designed to evaluate the influence of pronuclear age on the survival and post-thawing development after cryopreservation of mouse embryos. Freezing and thawing were performed in the different pronuclear stages of mouse embryos after IVF. Embryos were obtained from $F_1$ hybrid mice and classified into 4 groups according to the pronuclear stage (6hr, 9hr, 12hr and 15hr after insemination). Pronuclear ova were slowly cooled in a biological freezer using 1.5M 1,2-propanediol and 0.1M sucrose as cryoprotectant. Thawing was done at room temperature and 1,2-propanediol was removed by multi-step dilutions. Both frozen-thawed embryos and control fresh embryos were cultured in vitro in Ham's F-10 medium supplemented with 4mg/ml BSA. In control group, the development rate after 48hr was 99.3%, and the complete hatching rate after 144hr was 61.3%. In experimental groups, the survival rate after thawing was 95.4% in 6hr, 88.7% in 9hr, 75.2% in 12hr and 62.4% in 15hr after insemination, the development rate after 48hr was 61.1, 77.0, 67.0 and 79.6%, respectively, and the complete hatching rate after 144hr was 25.7, 43.7, 42.2 and 60.0%, respectively. The survival rate in 15hr was significantly lower (p<0.05) compared with other groups. In vitro development rates after 48hr were similar in all groups, but complement hatching rate was significantly lower (p<0.05) in 6hr group. In conclusion, cryopreservation of mouse pronuclear ova with 2 distinct pronuclei (9hr and 12hr groups) showed better results after thawing compared with early (6hr group) or late pronuclear ova just prior to cleavage (15hr group).