• Korean Journal of Animal Reproduction
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• v.17 no.2
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• pp.141-148
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• 1993

This studies were carried out to investigate the effects of co-culture with cumulus cells, oviduct epithelial cells and uterine endometrium cells on the in-vitro fertilization and cleavage rate of bovine follicular oocytes. The ovaries were obtained from slaughtered Korean native cows. The follicular oocytes surrounded with cumulus cells were recovered by aspirating follicular fluids from the visible follicles of diameter 3~5 mm. The follicular oocytes were cultured in TCM-199 medium containing hormones and 10% FCS for 24~48 hrs in a incubator with 5% CO2 in air at 38.5$^{\circ}C$ and then matured oocytes were again cultured for 12~18 hrs with motile capacitated sperm by preincubation. The results obtained in these experiments were summarized as follows: 1. The in vitro maturatin and fertilization rate of bovine oocytes co-cultured with cumulus cells in TCM-199 medium were 64.0~74.1% and 40.0~58.6% respectively. And in-vitro fertilization rate of cumulus-enclosed oocytes(55.4%) were significantly(p<0.05) higher than cumulus-denuded oocytes(23.1%). 2. The in-vitro maturatin and fertilization rate of bovine oocytes co-cultured with 1$\times$104 cells/ml, 1$\times$106 cells/ml, 1$\times$108 cells/ml and 1$\times$1015 cells/ml oviduct epithelial cells in TCM-199 medium were 59.3% and 40.7%, 64.0% and 48.0%, 58.3% and 37.5%, 52.0% and 32.0%, respectively. 3. The in-vitro maturation and fertilization rate of bovine oocytes co-cultured with 1$\times$104 cells/ml, 1$\times$106 cells/ml, 1$\times$108 cells/ml and 1$\times$1015 cells/ml uterine endometrium cells in TCM-199 medium were 56.0% and 36.0%, 60.7% and 42.9%, 59.3% and 37.0%, 52.0% and 36.0%, respectively. 4. When the in-vitro fertilized oocytes were co-cultured with cumulus cells, oviduct epithelial cells and uterine endometrium cells, the development rate to be blastocyst was 12.2%, 15.6% and 11.7%, respectively and rates were higher than that of control, 2.1%(P<0.05).

• Korean Journal of Animal Reproduction
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• v.17 no.2
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• pp.149-157
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• 1993

A new technique was established to maximize the numbers of follicular oocytes recovered from the ovaries obtained at the slaughter house. And their further developmental capacity was demonstrated. There recovery techniques were used; aspiration (ASP, control), slicing (SLC) and slicing combining aspiration (ASP+SLC). Recovered oocytes were cultured in TCM 199+15% FCS+gonadotrophins in an atmosphere of 5% CO$_2$ in air at 39$^{\circ}C$ for 24 h. The nuclear maturation was detemined with chromo-some configuration by rapid staining. And cytoplasmic maturation was examined by the formation of female pronuclei with parthenogenetic activation of the matured oocyte after 18 h of co-culture with granulosa cell monolayer. Total 1,641 bovine follicular oocytes recovered from 245 ovaries. The number of oocytcs per ovary was 1.87 in ASP, 11.05 in SLC and 7.88 in ASP+SLC, respectively. SLC would yield 5.9 folds increase, compared with ASP. The rate of maturation were 92.9% in ASP, 79.1% in SLC and 71.7% in ASP+SLC, respectively. Although the maturation rate in ASP was the highest, metaphase II oocytes per ovary in SLC was 5 times higher than that of ASP. The rates of pronuclei formation upon ethanol activation were 75% in ASP, 67% in SLC and 62.5% in ASP+SLC, respectively. The results demonstrate that it should be possible to maximize the number of the follicular oocyte from the ovary for mass production of bovine embryos. Thus the established technique may provide efficient supply of bovine embryos for biochemical and molecular study of early bovine embryos.

• Journal of Aerospace System Engineering
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• v.14 no.1
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• pp.68-73
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• 2020

This purpose of this paper was to review the development trend of the VTOL MAVs with a ducted propellant that can fly like the VTOL at intermediate and high speeds, hovering, landing, and lifting off vertically over urban areas, warships, bridges, and mountainous terrains. The MAV differs in flight characteristics from helicopters and fixed wings in many respects. In addition to enhancing thrust, the duct protects personnel from accidental contact with the spinning rotor. The purpose of the U.S. Army FCS and DARPA's OAV program is spurring development of a the VTOL ducted MAV. Today's MAVs are equipped with video/infrared cameras to hover-and-stare at enemies hidden behind forests and hills for approximately one hour surveillance and reconnaissance. Class-I is a VTOL ducted MAV developed in size and weight that individual soldiers can store in their backpacks. Class-II is the development of an organic VTOL ducted fan MAV with twice the operating time and a wider range of flight than Class-I. MAVs will need to develop to perch-and-stare technology for lengthy operation on the current hover-and-stare. The near future OAV's concept is to expand its mission capability and efficiency with a joint operation that automatically lifts-off, lands, refuels, and recharges on the vehicle's landing pad while the manned-unmanned ground vehicle is in operation. A ducted MAV needs the development of highly accurate relative position technology using low cost and small GPS for automatic lift-off and landing on the landing pad. There is also a need to develop a common command and control architecture that enables the cooperative operation of organisms between a VTOL ducted MAV and a manned-unmanned ground vehicle.

• Korean Journal of Agricultural Science
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• v.18 no.2
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• pp.114-118
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• 1991

This study was conducted to find out the suitable in vitro media for fertilization and culture on the pig oocytes matured in vivo and in vitro. The results obtained were as follows; A comparison of fertilization media on the oocytes matured in vivo was made between M199 with 10% FCS versus TL Hepes with 1% BSA Fertilization rate was significantly higher in the TL Hepes medium. But polyspermic incidence did not favor in the TL Hepes medium. Embryos were cultured in TL Hepes wash and culture medium for 48h after insemination. A total of 53 embryos were cultured and 39(73.6%) cleaved. Of these 39 embryos, 31(79.5%) cleaved equally to the 2-8 cell stage. Immature oocytes cultured in Waymouth's maturation medium were much more able to induce sperm swelling than immature oocytes cultured in TL Hepes maturation medium, however, most ova were polyspermic and did not develope to the 4 cell stage during 48h culture in TL Hepes wash and culture medium.

• Journal of Embryo Transfer
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• v.10 no.2
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• pp.105-113
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• 1995

This study was conducted to examine the efficiency of enucleation and blastomere isolation from recipient oocytes and donor embryos, respectively and to determine the effect of oocyte age and electric voltage on the fusion rate and in vitro development of the fused oocytes in rabbit nuclear transplantation. Immature oocytes collected from ovarian follicles were matured in vivo for 12 h in TCM-199 containing FCS and hormones and in vivo matured oocytes were collected 17 to 18 h post-HCG. The fresh and frozen donor embryos of 8- to 16-cell stage were collected from the oviduct of superovulated does. The proportion of successfully enucleated oocytes was greatly lower in in vitro matured oocytes (42.3%) than that (62.7%) in in vivo matured oocytes The level of cytochalasin B for in vivo matured oocytes did not affect the efficiency of enuleation, but 7.5 $\mu$g /mL cytochalasin B for in vitro matured oocytes showed a high enucleation rate significantly. The isolation efficiency of a single blastomere nucleus did not differ between 8- and 16-cell stage embryos. The percentage of single blastomeres isolated from 16-cell stage fresh embryos after 0.5% pronase treatment was greatly higher at 16-min treatment (94.4%) than at 8-min(78. 1%) and the blastomeres(61.5%) isolated from frozen-thawed embryos after 16-min pronase were significantly fewer than those of fresh embryos. The age of recipient oocytes affected nuclear fusion rate. The reconstituted oocytes fused at 24-h age showed slightly higher fusion rate (77.8%) than those (65.0%)fused at 18-h age. The fusion rate of in vitro and in vivo matured oocytes inserted with fresh blastomere did not differ among electric voltages, but the cleavage rate and development to morula-blastocysts of in vitro matured oocytes was more higher under 0.6 kV/cm than under 0.8 to 1.2 kV/cm, while the cleavage rate and development of in vivo matured oocytes was higher under 0.8 to 1.0 kV/cm than under 1.2 kV/cm. The fusion and cleavage rate fol1owing insertion with frozen-thawed blastomere was not different between the in vitro and in vivo matured oocytes and was similar to those from fresh blastomere insertion.

• Journal of Embryo Transfer
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• v.10 no.2
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• pp.163-169
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• 1995

In the experiment I for maas production of bovine early embryos, 18~20hpi fertilized eggs (756 eggs) and parthenogenic eggs (618 eggs) which were treated by 10% ethanol were cultured in both TGM and CZB. In the experiment II, suppiment effects each in CZB and CRlaa were tested by matured and fertilized oocytes which were after 18~20hpi. In the case of experiment I after 48hr, the cleavage rates of normally fertilized eggs were 66.6% in TCM treatment and 77.7% in CZB treatment, and after 240h the blastocysts were 7.5% in TCM and 14.1% in CZB. In the parthenogenic eggs, the deavage rates at 48hr were 39.6% in TCM and 57.5% in CZB, and at 240h, the blastocysts were 0.9% in TCM and 4.4% in CZB. These results showed that the effects of CZB on developmental ability to parthenogenic eggs as well as nomally fertilized eggs are relatively high. In experiment W, the effect of exposing the cleaved embryos to CZB for 30h on the blastocyst formation was examined. Similar rates of blastocyst formation were obtained both in TCM and CZB, suggesting that CZB exposure. during ealry development is critical. In experiments III ~ V, the effects of supplements were examined. The cleavage rates of CZB treatments at 48h were 83.8% in control, 78.1% in BSA+A.A+SIT, 75% in 5% FCS+A. A+SIT, 88.6% in BSA+A.A+SIT and not co-cultured BSA+A.A+SIT had 85.7% and in the case of 240h blastocysts showed 22.6, 0.0, fl.1, 6.5 and 0%, respectively. As a result, this study showed that CZB was effective culture system for in vitro development, and that CZB and CR$_1$aa had no significant differences and effects between them. It may be concluded that in the simple media containing supplements could replace the co-culture systems of bovine early embryo development.

• Journal of Embryo Transfer
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• v.22 no.1
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• pp.21-26
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• 2007

본 연구는 mSOF(modified synthetic oviduct fluid medium) 배양액을 이용하여 $100{\mu}1$와 $10{\mu}1$ 배양 소적에서 일본 흑우의 수정란 생산 효율을 개선하기 위하여 수행하였다. 난구세포가 부착된 미성숙 난자는 각각 단독 배양조건($S;\;10{\mu}1$ 소적) 및 그룹 배양 조건 ($G;\;100{\mu}1$ 소적)에서 실시하였고 배양액은 TCM-199의 기본 배지에 10% FCS, 0.02IU/ml FSH와 $1{\mu}g/ml$ $estradiol-17{\beta}$를 첨가하여 사용하였다. 배반포 단계로 발육한 수정란은 1.5M ethylene glycol로 직접 이식법에 의한 동결 방법으로 동결을 실시하였고, 세포수는 융해 후 생존 수정란에 대해 조사하였다. 체외 배양 시간이 $16{\sim}17$시간 배양 조건에서 난자의 성숙율은 그룹 배양 조건$(27.1{\pm}16.8%)$보다는 단독 배양조건$(57.1{\pm}15.0%)$에서 성숙율이 높았다(p<0.05). 그러나 체외 배양 시간이 $18{\sim}19$ 시간과 $20{\sim}21$시간 배양시는 유사한 성숙율을 보였다. 난자의 체외 배양율은 체외 배양 시간의 증가에 의해 성숙도가 $86.3{\pm}9.9%$로 증가하였다. 접합체(zygote)의 분할율은 단독이나 그룹 배양 조건에서도 유사한 결과를 얻었다. 배반포 발달율은 배양 $7{\sim}8$일째에 조사한 결과 단독 배양 방법보다는 그룹 배양 방법에서 발달율이 높았으나, 분할된 접합체를 기준으로 한 경우 배반포 발달율$(S;\; 21.4{\pm}10.6%,\;G;\;39.0{\pm}13.1%)$에서는 유의적인 차이가 없었다. 단독 배양과 그룹 배양에서 $6.5{\pm}8$일 사이에 배반포로 발달된 수정란의 세포수 조사에서는 유사한 결과를 얻었다. 동결 융해 후 24시간 배양 후 배반포 생존율(5; 24.2%, G; 30.2%), 부화율(S: 20.9%, G: 12.7%) 및 생존 수정란수(S; 45.2%, G: 42.8%)에서도 배양 조건에 따른 유의적인 차는 없었다. 결론적으로 mSOF배양액을 이용하는 경우 미성숙 난자의 체외 성숙 유도 배양 시 단독이나 그룹 배양 시 배반포 발달율에서 그룹간에 유의적인 차가 인정되었다(p<0.01).

• Journal of Life Science
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• v.19 no.12
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• pp.1764-1768
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• 2009

This study was carried out to examine a concentration of steroid hormones and in vitro development of mouse embryos in culture supernatant of bovine granulosa cells (GC). To obtain the culture supernatant, granulosa cells were retrieved from mature follicles (6~15 mm diameter) and immature follicles (2~5 mm diameter) of bovine ovary and were cultured, respectively, in media of Ham's F-10 with 15% FCS for 16 days. Mature and immature granulosa cells formed their monolayers easily and showed similar growth patterns in culturing. There was no morphological difference between mature and immature granulosa cells. High levels of both progesterone and estradiol were detected in the culture supernatant of mature granulosa cells and immature granulsa cells, and the endocrine profiles of the two types of cells were similar. Progesterone secretion of granulosa cells was high in the late stage of culturing and estradiol secretion was high in the early stage of culturing. In vitro development rates of mouse embryos to morula, blastocyst and hatched blastocyst were significantly (p<0.05) higher in culture supernatant of mature granulosa cells (92.7%, 78.1% and 34.5%) and in culture supernatant of immature granulosa cells (96.4%, 78.5% and 26.8%) than in Ham's F-10 (86.7%, 41,7% and 13.3%). However, there was no difference between the culture supernatant of mature granulosa cells and the culture supernatant of immature granulosa cells in the development of embryos.

• Journal of Embryo Transfer
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• v.7 no.1
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• pp.1-12
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• 1992

본 연구는 소의 난포란의 체외성숙과 체외수정에 영향을 미치는 요인을 구명하기 위하여 미숙 난포란을 채취하여 형태적 분류를 통해 우수한 란을 공시한 후 난포의 크기, 정액의 형태, 수정능득법, 혈청, 호르몬, 난포액, 난구세포등을 첨가한 TCM-199 배양액에서 배양하면서 체외성숙 및 수정율을 조사하였는 바 그 결과는 다음과 같다. 1. 소 난포란을 채취하여 배양을 통해 형태적 분류를 했을때 A형란은 61.4%, B형란은 12.1%, C형란은 19.2%, D형란은 4.2%였으며 발생중지 또는 퇴화란은 3.0%였다. 또한 A, B, C형란을 배양액에 배양했을때 난포란의 체외성숙율은 각각 89.1%, 78.0%, 52.6%였으며, 수정율은 각각 78.1%, 66.1%, 33.3%였다. 2. 소 난포의 크기를 1-2mm, 3-5mm 및 5mm이상으로 분류하여 채취한 난포란의 수는 각각 67개, 98개, 63개 였으며, 이를 TCM-199 배양액에서 배양했을때의 체외성숙 및 수정율은 각각 56.7%와 44.8%, 82.5%, 72.4%와 46.0%와 28.6%였다. 3. 소 난포란의 체외수정에 있어서 정소상체 미부정자, 희택정액 및 동결정액을 이용하여 매정하였을때 체외수정율과 분할율은 각각 63.3%, 73.3%, 70.0%와 32.7%, 37.8%, 38.3%였다. 4. 소 난포란의 체외수정에 있어서 m-KRB 처리법, HIS처리법, Ca-IA처리법, BFF처리법 및 heparin처리법으로 각각 수정능획득을 유기하였을때 체외성숙 및 분할율은 각각 53.1%, 28.1%, 33.9%와 17.7%, 50.8%와 26.2%, 48.1%와 22.8% 및 58.8%와 32.8%로서 heparin 처리법이 가장 높았다. 5. 소 난포란의 체외성숙과 수정에 있어서 각 농도의 우태아혈청과 FSH, HCG, $\beta$-estradiol을 첨가한 TCM-199배양액에서 배양했을때의 체외성숙 및 수정율은 각각 76.0-82.3%와 26.2-70.0%로서 무첨가에 비해 첨가가 높았다. 6. 발정우혈청 및 우태아혈청 5-20%를 첨가한 배양액에서 배양했을때의 체외성숙율은 각각 71.7-76.9%, 74.0-80.6%였으며 체외수정율은 51.9-58%와 26.2-30.0%로서, 체외수정율의 경우 발정우혈청의 첨가가 우태아혈청의 첨가에 비해 높았다. 7. 난포액20-30%를 첨가한 배양액에서 배양했을때의 난포란의 체외성숙율은 각각 68.0%와 64.6%, 수정율은 각각59.6%와 60.4%로서 난포액10%, 50%를 첨가한 배양액에서 배양시의 체외성숙율과 수정율에 비해 높았다. 8. 1$\times$10 6 /ml의 난구세포를 첨가한 배양액에서 배양했을때의 난포란의 체외성숙율과 수정율은 각각 76.5%와 61.7%로서 FCS 10%와 1$\times$10 4 -10 5/ml 와 1 $\times$10 8/ml난구세포를 첨가한 배양액에서 배양시의 체외성숙율과 수정율에 비해 높았다.

• Korean Journal of Animal Reproduction
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• v.22 no.2
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• pp.187-194
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• 1998

In order to determine suitable conditions for rapid freezing of porcine embryos, the kind and concentration of cryoprotectants, sucrose concentrations, equilibration time and thawing temperature in freezing medium were examined in relation to the survival of frozen-thawed oocyte and embryos. The results obtained are as follows : 1. The suitable concentrations of cryoprotoctant in the freezing medium which consisted of TCM-199+20% FCS were 1.5M for glycerol, 2.0M for DMSO, 2.5M for ethylene glycol, and 2.0M for propanediol. The sucrose concentration of 0.25M in the medium was found to optimal because the survival rate was markedly higher at this concentration when compared to the others. The survival rate was relatively high when the frozen embryos were thawed at 30$^{\circ}C$ in the freezing medium containing 2.5M cryoprotectants. The equilibration periods of 2.0 and 5.0 minutes revealed the higher survival in the media containing 1.5 or 2.1M glycerol when compared to 10 and 15 minutes. 2. The fertilization rates of frozen-thawed follicular oocytes which matured in vitro for 1, 12, 24 and 48 hours were 6.7~26.7% depending on the maturation time, and the rates were relatively high for those matured for a short period of time. The survival rates of frozen-thawed oocytes which matured in vitro for certain periods and fertilized were 10.0~30.0% depending on the maturation time.