• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.31-31
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• 2001

This study was to establish in uitro culture system of mouse preantral follicles and to obtain higher in vitro development rates and production of live young. Preantral follicles were obtained from 12-day-old FI mouse (C57BL $\times$ CBA) by enzymatical methods. Oocyte-granulosa cell complexes (OGCs) of preantral follicles were loaded on Transwell-COL insert and cultured in $\alpha$MEM supplemented with 5% FBS, 100 mIU/$m\ell$ FSH and 100 mIU/$m\ell$ hMG for IVG. IVM was performed in $\alpha$MEM supplemented 1.5 IU/$m\ell$ hCG for 18 hrs and IVF was carried out in Ml6 medium. Embryos were cultured in modified Ml6 medium supplemented 10% FBS for 4 days. The effect of the OGCs size on the nuclear/cytoplasmic maturation was significantly higher in 120-150 ${\mu}{\textrm}{m}$ (MII: 33.0%, $\geq$2-cell: 36.7%, $\geq$morula: 20.9%) than in 70-110 ${\mu}{\textrm}{m}$ (MII: 12.2%, $\geq$2-cell: 10.2%, $\geq$morula: 4.8%) (p<0.001). In period of the IVG days, the rate of $\geq$2-cell was significantly higher in 10 days(38.2%) than in 12 days (20.0%) (p<0.01). In period of IVF time, 9 hrs ($\geq$2-cell: 31.5%, $\geq$ morula: 14.3%) indicated significantly higher cytoplasmic maturation rate than 4 hrs ($\geq$2-cell: 17.5%, This study was to establish in vitro culture system of mouse preantral follicles and to obtain higher in vitro development rates and production of live young. Preantral follicles were obtained from 12-day-old FI mouse (C57BL $\times$ CBA) by enzymatical methods. Oocyte-granulosa cell complexes (OGCs) of preantral follicles were loaded on Transwell-COL insert and cultured in $\alpha$MEM supplemented with 5% FBS, 100 mIU/$m\ell$ FSH and 100 mIU/$m\ell$ hMG for IVG. IVM was performed in $\alpha$MEM supplemented 1.5 IU/$m\ell$ hCG for 18 hrs and IVF was carried out in Ml6 medium. Embryos were cultured in modified Ml6 medium supplemented 10% FBS for 4 days. The effect of the OGCs size on the nuclear/cytoplasmic maturation was significantly higher in 120-150 ${\mu}{\textrm}{m}$ (MII: 33.0%, $\geq$2-cell: 36.7%, $\geq$morula: 20.9%) than in 70-110 ${\mu}{\textrm}{m}$ (MII: 12.2%, $\geq$2-cell: 10.2%, $\geq$morula: 4.8%) (p<0.001). In period of the IVG days, the rate of $\geq$2-cell was significantly higher in 10 days(38.2%) than in 12 days (20.0%) (p<0.01). In period of IVF time, 9 hrs ($\geq$2-cell: 31.5%, $\geq$ morula: 14.3%) indicated significantly higher cytoplasmic maturation rate than 4 hrs ($\geq$2-cell: 17.5%, $\geq$morula: 4.8%) and 7 hrs ($\geq$2-cell: 20.4%, $\geq$morula: 6.1%) (p<0.01). However, there was no difference in cytoplasmic maturation between co-cultured preantral follicle ( $\geq$morula: 17.4%) and preantral follicle cultured in Ml6 ( $\geq$morula: 17.4%). 22 morula and blastocysts produced in above optimal condition were transferred to uterus of 2 pseudopregnant recipients, 1 recipient was pregnant and then born 1 live young. This result demonstrates that in vitro culture system of preantral follicles can be used efficiently as another method to supply mouse oocyte.morula: 4.8%) and 7 hrs (2-cell: 20.4%, $\geq$morula: 6.1%) (p<0.01). However, there was no difference in cytoplasmic maturation between co-cultured preantral follicle ( $\geq$morula: 17.4%) and preantral follicle cultured in Ml6 ( $\geq$morula: 17.4%). 22 morula and blastocysts produced in above optimal condition were transferred to uterus of 2 pseudopregnant recipients, 1 recipient was pregnant and then born 1 live young. This result demonstrates that in vitro culture system of preantral follicles can be used efficiently as another method to supply mouse oocyte.

• 한국수정란이식학회지
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• 제21권2호
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• pp.137-146
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• 2006

본 연구는 공여 세포의 종류, 수핵 난자의 유래 및 수란 산양 발정 동기화 조건이 복제 산양 생산에 미치는 영향을 알아보고자 실시되었다. 공여 세포는 귀 유래 섬유아세포를 분리 배양하여 사용하였으며, 체내 성숙 난자는 성숙한 미경산 재래 산양에 과배란을 유기하여 외과적인 방법으로 난관 관류를 통해 회수하였으며, 배란이 되지 않은 난포란은 난포로부터 흡입 채취한 후, 22시간 동안 체외 성숙을 실시하여 사용하였다. 핵이식은 zona drilling 후, 극체와 세포질 일부분 제거를 통해 제핵을 실시하고, 핵이 제거된 난자의 위란강 내로 공핵 세포를 도입하여 실시하였다. 핵이식란의 융합은 전기 자극 방법으로 실시되었으며, 융합이 완료된 핵이식란의 활성화처리는 핵이식 3시간 후에 Ionomycin과 6-DMAP를 병용 처리하여 실시하였다. 복제 수정란의 체외배양은 0.8% BSA가 첨가된 mSOF 배양액으로 $2{\sim}4$ 세포기까지 체외 배양을 실시한 다음 수란 산양의 난관에 외과적으로 이식하였다. 임신 진단은 초음파 임신 진단기로 이식 후 제 30일과 60일에 실시하였다. 귀세포를 공핵 세포로 사용하였을 때 융합율이(63.8 VS. 26.5%) 태아 세포를 사용했을 때보다 유의적으로 높았다(p<0.05). 총 102개의 복제 수정란을 20두에 이식하였으며, 30일에 4두(20.0%)가 임신하였으며 이중 1두가 1두의 복제 산양을 생산하였다. 수란 산양과 공란 산양간의 발정 동기화 간격(${\pm}0$ 또는 +12시간)별 수태율은 각각 18.2 및 16.7%로서 유의적인 차이가 없었다. 수란 산양의 발정 유기 방법에 따른 수태율에 있어서 CIDR 제거 후 hCG 및 PMSG를 투여하였을 때는 25%가 수태하였으나, hCG만 투여한 수란 산양은 수태가 되지 않아 인위적으로 발정 동기화된 수란 산양을 이용하였을 때는 산자를 생산하지 못했다. 자연 발정 산양의 경우, 발정이 동기화된(${\pm}0$) 수란 산양 1두에 체내 성숙 난자를 수핵란으로 사용하여 생산한 5 개의 복제 수정란을 이식하여 149일만에 국내에서 처음으로 복제 산양(진순이) 생산에 성공하였다. 체외 성숙 난자를 수핵란으로 사용하여 생산된 복제 수정란 5개를 이식하였으나 수태가 이루어지지 않았다. 이상의 결과로 볼 때 재래 산양의 체세포 핵이 식에 의한 복제 산자 생산에서 보다 효율성을 높이고 수태율을 향상시키기 위한 조건은 체내 성숙 난자를 수핵 난자로 이용하여 공란 산양과 발정이 동기화된(${\pm}0$) 자연 발정 수란 산양에 복제 수정란을 이식하는 것이 바람직한 것으로 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제27권2호
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• pp.266-277
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• 2014

Somatic cell nuclear transfer (SCNT) has generally demonstrated that a differentiated cell can convert into a undifferentiated or pluripotent state. In the SCNT experiment, nuclear reprogramming is induced by exposure of introduced donor nuclei to the recipient cytoplasm of matured oocytes. However, because the efficiency of SCNT still remains low, a combination of SCNT technique with the ex-ovo method may improve the normal development of SCNT embryos. Here we hypothesized that treatment of somatic cells with extracts prepared from the germinal vesicle (GV) stage Siberian sturgeon oocytes prior to their use as nuclear donor for SCNT would improve in vitro development. A reversible permeability protocol with $4{\mu}g/mL$ of digitonin for 2 min at $4^{\circ}C$ in order to deliver Siberian sturgeon oocyte extract (SOE) to porcine fetal fibroblasts (PFFs) was carried out. As results, the intensity of H3K9ac staining in PFFs following treatment of SOE for 7 h at $18^{\circ}C$ was significantly increased but the intensity of H3K9me3 staining in PFFs was significantly decreased as compared with the control (p<0.05). Additionally, the level of histone acetylation in SCNT embryos at the zygote stage was significantly increased when reconstructed using SOE-treated cells (p<0.05), similar to that of IVF embryos at the zygote stage. The number of apoptotic cells was significantly decreased and pluripotency markers (Nanog, Oct4 and Sox2) were highly expressed in the blastocyst stage of SCNT embryos reconstructed using SOE-treated cells as nuclear donor (p<0.05). And there was observed a better development to the blastocyst stage in the SOE-treated group (p<0.05). Our results suggested that pre-treatment of cells with SOE could improve epigenetic reprogramming and the quality of porcine SCNT embryos.

• Reproductive and Developmental Biology
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• 제35권3호
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• pp.313-317
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• 2011

This study was conducted to examine the effect of oocyte donor age and micromanipulation medium on the development of mouse cloned embryos receiving cumulus cells. Mouse oocytes were obtained from 6 to 11 week-old mice BDF1 female mice(experiment 1) and cumulus cells were used as donor cells. Micromanipulation procedures for nuclear transfer(NT) were performed in FHM, M2 or Hepes-buffered TCM199(TCM199) medium(experiment 2). After nuclear transfer, the reconstructed oocytes were activated by 10 mM $SrCl_2$ in Ca-free CZB medium in the presence of 5 II ${\mu}$g/ml cytochalasin B for 5 h and cultured in KSOM medium for 4 days. In experiment 1, the survival rate of oocytes after injection of cumulus cells were significantly(p<0.05) lower in oocytes from 6~7 week-old mice(53.3%) than in oocytes from 8~9(80.9%) and 10~11 week-old mice(77.1%). In experiment 2, the survival rate of oocytes after cell injection were significantly(p<0.05) higher in FHM and M2 medium(71.7% and 76.9%) than in TCM199 medium(51.2%). The activation rates of cloned embryos were not different among the micromanipulation media. However, the embryos developed to blastocyst stage were significantly(p<0.05) higher in FHM medium(13.9%) than in M2 and TCM199 medium(0.0% and 0.0%). In conclusion, the present study suggest that oocytes from above 8 week-old mice are superior to oocytes from 6~7 week-old mice as a source of recipient cytoplasm and FHM is superior to M2 and TCM199 as a micromanipulation medium for mouse somatic cell cloning.

• 한국동물위생학회지
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• 제44권4호
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• pp.227-237
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• 2021

Artificial insemination of Korean native cattle (KNC) is the predominant method for breed improvement. However, industrialization of embryo production and transfer is necessary to utilize the genetic potential of KNC. The aim of this study was to examine associations between KNC donor cows and ovum pick-up (OPU) conditions, in-vivo oocyte recovery, and embryo development. Oocyte recovery and blastocyst development rates were higher at 50 and 60 mmHg OPU vacuum pressure than at 40 mmHg, which was, however, not significant. Regarding follicle growth, injection of 500 ㎍ GnRH 36 hours before OPU significantly increased the number of OPU oocytes from an average of 4.6 to 7.6 (P<0.05); no significant difference in embryo development rates was observed. Significant differences were observed in the numbers of OPU oocytes, embryo development rates, and transplantable blastocysts per individual among nine KNC donors (P<0.05). Furthermore, although there was no difference in OPU oocyte recovery intervals in approximately 2~8 weeks, the number of recovered oocytes significantly decreased at the 12-week interval (P<0.05); there was no difference in embryo development rates. The number of oocytes and embryonic development rates only tended to decrease until the seventh OPU session, but decreased significantly until the eighth session (P<0.05). The average pregnancy rate after transfer of OPU-derived in-vitro embryos into recipient cows was 41.8%. To improve the efficiency of OPU egg recovery and in-vitro embryo production, considering KNC donor characteristics, vacuum pressure of 60 mmHg, GnRH pretreatment to induce follicle growth, and effective OPU egg recovery up to seven times at intervals of 2~4 weeks appears to be most suitable. This study may facilitate the industrialization of KNC embryo production and transfer using high-quality cows.

• 한국수정란이식학회지
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• 제10권1호
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• pp.83-90
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• 1995

Production of calves after transfer of nuclear transplant embryos is the latest technology to be applied in commercial livestock breeding. The objective of this study was to establish an efficient procedure to produce offsprings from nuclear transplant embryos. The fusion rates (72.7% vs. 80.8%), cleavage rates (62.5% vs. 71.4%) and rates of development in vitro (12.0% vs. 15.2%) of nuclear transplant embryos were not significantly different between 30 and 40h maturation age of cytoplast. The in vivo and in vitro-derived embryos as nuclei donor were used in this system of bovine nuclear transplantation. Fusion rates of nuclear transplant embryos were not significantly different between in vivo and in vitro-derived embryos (73.0 and 79.2%, respectively). The percentage of embryos reaching the morulae or blastocysts were 21.8% for in vivo-derived embryos and 11.9% for in vitro-derived embryos (p<0.01). Pregnancy rates after embryo transfer of nuclear transplant embryos were not significantly different between in vivo and in vitro-derived embryos (45.9 and 40.5%, respectively). However, calving rates after embryo transfer of nuclear transplant embryos were significantly higher in the in vivo-derived embryos than in vitro (p<0.01). Further research for age of cytoplast and use of in vitro-derived embryos as nuclei donor is required in this system. In conclusion, these results clearly show that the use of in vitro-derived oocytes as recipient cytoplast can improve the nuclear transplant system for genetic progress in cattle.

• 한국가축번식학회지
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• 제20권4호
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• pp.459-465
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• 1997

본 연구는 핵이식의 시기가 융합과 체외발달에 미치는 영향을 조사하고 체외수정 공핵배의 핵과 체외성숙난자간에 전기융합의 최적 통전전압과 통전시간을 결정하기 위하여 시도하였다. 수핵난자는 체외성숙후 25~27시간에 제핵하였고 난자의 추가성숙을 위하여 융합전에 18~20시간 더 배양하였다. 공핵체외수정란은 16~32세포기까지 BOEC와 공배양하였다. 공핵배의 할구 이식시간은 조기핵이식구에서는 체핵후 1~3시간, 자연핵이식구를 체핵후 16~18시간이었다. 융합은 체외성숙후 43~45시간에 행하였다. 융합율은 할구 이식시기에 따라 차이가 없었으나 난할율과 8~16세포기 발달은 자연핵이식구에서 높았다. 융합, 난할 및 상실배 배반포 발달율은 1.0kV/cm보다 0.75kV/cm전압에서 높았으며 0.7kV/cm에서 상실배 배반포율은 17.6%였다. 통전시간에 따라 융합율은 차이가 없었으나 50$\mu$sec와 70$\mu$sec에서 난할율과 상실배-배반포 발달율이 다소 높았다. 본 결과에서 핵이식의 최적시기는 수핵난자의 체외성숙후 42~44시간이었으며 최적 전기융합 조건은 50~70$\mu$sec의 1회 0.75kV/cm임을 알 수 있었다.

• 한국가축번식학회지
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• 제21권1호
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• pp.71-78
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• 1997

본 연구는 체외성숙 직후의 소 미수정란의 활성화 조건을 검토하기 위하여 실시하였다. 체외에서 22~24시간 성숙배양된 소 미수정란을 다양한 활성화 조건으로 처리하였다. 실험 1에서는 성숙직후 난자를 전기자극(1.25kV/cm, 70$\mu$sec$\times$2회), 에탄올(7%, 5분), Ca2+-ionophore(A23187; 10$\mu$M, 5분) 및 cycloheximide(10$\mu\textrm{g}$/ml, 6시간)로 각각 처리하였다. 활성화율은 전기자극, 에탄올 및 A23187 처리시 48.8~54.3%로 비슷하였으나, cycloheximide처리시는 15.9%로 유의적으로(P<0.05) 낮았고, 무처리구인 대조군은 전혀 활성화 되지 않았다. 실험 2에서 체외성숙 미수정란을 전기자극, 에탄올 및 A23187중 2개 또는 3개를 병용처리한 결과, 활성화율은 46.9~63.5%로 나타났다. 실험 3에서는 전기자극, 에탄올 또는 A23187과 cycloheximide를 병용처리한 결과, 대부분의 난자(98.0~100%)가 활성화되었다. 실험 4에서는 실험 3과 같은 조건으로 처리하여 할성화된 난자를 cytochalasin B로 처리하여 2배체배 형성을 유도한 후 체외배양하여 발육율을 검사하였다. 분할율은 79.8~90.4%였으며, 배반포 발육율은 32.1~42.6%로 나타났다. 이러한 결과는 전기자극, 에탄올 또는 A23187과 chcloheximide의 병용처리가 성숙직후 소 미수정란의 활성화에 효과적임을 확증한다.

• 한국수정란이식학회지
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• 제22권1호
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• pp.53-61
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• 2007

본 연구는 PI한 한국흑염소 수정란의 이식 결과를 통해 수란 흑염소의 수태율에 영향을 미칠 것으로 생각되는 여러 가지 요인을 분석함으로써, 높은 수태율을 얻을 수 있는 수란 흑염소의 최적 조건을 찾아낼 목적으로 수행하였다. 분석 결과, 수태율에 유의적인 영향을 주는 요인들은 발정형태, 수술 빈도, 이식 부위, 황체의 발육 단계, 수정란의 발육단계, 이식된 수정란의 수 등이었다. 자연 발정이 관찰되어 이식된 흑염소(59.1%, 13/22)들이 $CIDR^(R)$로 발정이 유도된 후 이식된 흑염소(36.8%, 118/321)에서보다 높은 수태율을 나타내었으며(P<0.05), 두 번째 수술 받은 흑염소의 수태율(56.5%, 13/23)이 처음 이식 받은 흑염소(36.5%, 116/318)에 비해 수태율이 높았다(P<0.05). 이식한 부위에 따른 수태율은 좌측 난관에 이식한 흑염소(49.0%, 50/102)가 오른쪽 난관에 이식한 흑염소(35.9%, 46/128)에 비해 수태율이 더 높게 나타났으며(P<0.05), 황체의 발육 단계에 따른 수태율에서는 $CH_1$단계(47.5%, 57/120) 출혈체를 가진 수란 흑염소에서 $CH_3(17.9%,\;7/39)$의 출혈체를 가진 수란 흑염소보다 높은 수태율을 얻었다(P<0.01). 수정란의 발육단계에 따른 차이는 난관 이식의 경우에 1세포기 배가 이식된 수란 흑염소의 수태율(51.6%, 49/95)이 4세포기배를 이식한 경우(24.5%, 12/49)보다 높았다(P<0.01). 수정란의 수는 2개를 이식했을 때(27.%, 37/137)보다 3개를 이식했을 때(47.6%, 50/105) 더 높은 수태율을 얻었다(P<0.01). 수태율에 유의적인 영향이 없는 요인들은 난관 유착이나 자궁 유착, 난소 유착, 자궁각의 크기, 황체의 수, 대형 난포의 존재 유무, 이식의 난이도 등이었다 그러나, 중간 크기의 자궁을 가진 수란 흑염소(38.9%, 122/314)에서 직경 5mm 이하의 작은 자궁을 가진 수란 흑염소(20%, 1/5)나 20mm 이상의 큰 자궁을 가진 수란 흑염소(18.2%, 2/11)보다 수태율이 높은 경향을 보였고, 배란 황체가 있는 같은 쪽 난소에 대형 난포가 존재할 경우(53.3%, 16/30)에 존재하지 않는 경우(37.1%, 104/280)보다 수태율이 높아지는 경향을 보였으며, 이식이 쉽게 이루어진 경우(39.2%, 125/319)에 이식이 어렵거나(27.8%, 5/18) 곤란한 경우(0%, 0/3)에서보다 높은 수태율을 얻을 수 있었다. 따라서, 자궁각의 크기나 대형 난포의 존재 유무, 이식의 난이도 등도 수정란 이식 후의 수태율에 영향을 줄 수 있을 것으로 생각된다. 이상의 결과로 볼 때 PI한 한국 흑염소 수정란의 이식 시 높은 수태율을 얻기 위해서는 수란 흑염소는 자연 발정 온 개체를 이용하고, 난관에 이식하고자하는 경우에는 난소에 $CH_1$ 단계의 출혈체가 존재하는 쪽 난관에 1세포기의 수정란을, 그리고 자궁에 이식하는 경우에는 난소에 발육 단계가 $CL_3$인 황체가 존재하는 쪽 자궁각에 중기 배반포나 후기 배반포를 이식하는 것이 가장 바람직하다는 결론을 얻었다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권6호
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• pp.856-860
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• 2000

Cloning technology continues to capture widespread attention by the international news media and biomedical and agricultural industries. The future uses of this technology could potentially contribute to major advances in biomedical and agricultural sciences. Cloned transgenic dairy cattle possessing milk promoters directing transgenes will produce pharmaceutical proteins in their milk faster, more efficiently and less expensively than transgenic cattle created using microinjection techniques. Additionally, cloned transgenic fetuses and animals may become a source of cells, tissue and organs for xenotransplantation. Lastly, but maybe most importantly, enhanced production traits and disease resistance may be realized in animal agriculture by utilizing these new technologies. The recent advances in the cattle cloning technology are important but there are still major obstacles preventing widespread commercial use of this technology. The type of donor nucleus, recipient cytoplasm, and cloning procedures used will impact the potential number of clones produced and the uses of the technology. In addition, the new advances in cloning methodology have not improved the relatively low pregnancy rates or reduced the incidence of health problems observed in cloned offspring. These problems may require novel techniques to decipher their cause and new methods of preventing and/or diagnosing them in the preimplantation embryo. The commercial potential is enormous for cloning technology; however, little has been done to improve the efficiencies of the procedure. Improving procedural efficiencies is a critical developmental milestone especially for potential uses of cloning technology in animal agriculture.