• Reproductive and Developmental Biology
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• 제32권4호
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• pp.249-253
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• 2008

Interspecies somatic cell nuclear transfer (iSCNT) is a valuable tool for studying the interactions between an oocyte and somatic nucleus. The object of this study was to investigate the developmental competence of in vitro-matured porcine oocytes after transfer of the somatic cell nuclei of 2 different species (goat and rabbit). Porcine cumulus oocytes were obtained from the follicles of ovaries and matured in TCM-199. The reconstructed embryos were electrically fused with 2 DC pulses of 1.1kV/cm for $30{\mu}s$ 0.3M mannitol medium. The activated cloned embryos were cultured in porcine zygote medium-3 (PZM-3), mSOF or RDH medium for 7 days. The blastocyst formation rate of the embryos reconstructed from goat or rabbit fetal fibroblasts was significantly lower than that of the embryos reconstructed from porcine fetal fibroblast cells. However, a significantly higher number of embryos reconstructed from goat or rabbit fetal fibroblasts cultured in mSOF or RDH, respectively, developed to the morular stage than those cultured in PZM-3. These results suggest that goat and bovine fetal fibroblasts were less efficacious than porcine-porcine cloned embryos and that culture condition could be an important factor in iSCNT. The lower developmental potential of goat-porcine and porcine-bovine cloned embryos may be due to incompatibility between the porcine oocyte cytoplasm and goat and bovine somatic nuclei.

• 한국가축번식학회지
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• 제19권1호
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• pp.35-41
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• 1995

본 연구는 형질전화우의 생산성 제고를 위한 일환으로서 새로운 기법인 retrovirus vector system의 이용성을 검토하고자 실시하였다. Retrovirus-producing cell은 미세주입법을 이용하여 체외생산된 1.5일(1~4-세포기) 수정란의 위란강에 주입(5~10 cells/embryo) 되었으며, 이때 사용된 retrovirus-producing cell line은 Gibbon ape leukemia virus (GaLV) envelope protein에 encapsidation되어 replication-defective retrovirus를 분비하도록 제작되었다. 주입된 유전자의 표지유전자로서 E. coli LacZ 유전자를 사용하였으며, X-gal 염색법은 발달이 유도된 상실배와 배반포 단계에 실시하여 LacZ 유전자의 발현 유무를 확인하였다. 이 실험의 결과를 요약하면 다음과 같다. 1. Virus의 infectivity를 높이기 위해 사용된 polybrene의 최저농도는 5$\mu\textrm{g}$/ml이었다. 2. Retrovirus-producing cell이 주입된 1.5일 수정란의 상실배기와 배반포기로의 발달율은 29%였다. 3. 이 때의 LacZ+ 발현율은 21%였다. 4. 본 실험에 사용된 retrovirus-producing cell은 replication-competent retroviruses를 생산해 내지않는다는 것을 확인할 수 있었다.

• 한국가축번식학회지
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• 제21권2호
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• pp.85-93
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• 1997

These experiments were carried out to examine the development capacity of sexed and then bisected embryo from 8-cell to morula stage. Antisera to histocompatibility-Y(H-Y) antigen were prepared in inbred SD female rat by repeated immunization of spleen cell or testis supernatant from males of same strain. Male and female embryos were separated by delaying development of embryos against H-Y antibody. After sexing, rabbit embryos were bisected and aggregated. The results obtained from the these experiments were summuerized as follows: 1. When mouse and rabbit 8-, 16-cell and morular embryos were culature in H-Y antiserum, the ratio of embryo which has developed to hatching blastocyst was 53.4, 46.3 and 57.4% in mouse embryos, and 49.0, 52.0 and 61.0% in rabbit embryo, respectively. The ratio of mouse and rabbit embryos developed to hatching blastocyst showed nearly natural sex rate(50%), except rabbit mourla showed a little higher ratio(61.0%) as compared to natural sex ratio. 2. When rabbit demi-embryos from 8-, 16-cell embryo and morula were cultured, the percentage of demi-embryos was 70, 68 and 58% without zona pellucida removed, and 62, 69 and 51% with zona pellucida. The rate of aggregation was higher in 8- and 16-cell demi-embryos than in morula demi-embryo. 4. When sexed-demi-embryo was aggregated with another demi-embryo with demi-embryo with same sex, the rate of embryo developed to blastocyst was 60, 50 and 25%, respectively. Eight-cell demi-embryo showed highest rate. In conclusion, it showed that H-Y antiserum which was made by rat spleen cell enabled sexing rabbit embryos. And when rabbit sexed 8-, 16-cell and morula demi-embryo were aggregated, they were developed to eu-blastocyst which suggested the potential of sexed embryo manipulation.

• Clinical and Experimental Reproductive Medicine
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• 제21권1호
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• pp.77-81
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• 1994

To improve in vitro embryonic cell development, this study was desigend to culture in vitro fertilized early embryos of mouse in two different systems; conditioned medium alone and ampullary cells co-culture. Thirty two of 83 embryos(38.6%) were blocked in the 2 cell stage by co-culture, as compared to forty of 42 embryos(95.2%) in control group for 24hours culture. And all the embryonic cells cultured for conditioned medium alone were blocked for 48 hours culture. Twenty seven of 46 embryos (58.7 %) which overcome culture block in 2 cell stage by cocultured were developed morular and expanded blastocyst, and ninteen of 46 embryos(26.1 %) underwent hatching for 96 hours culture. The cellular fragmented rates for embryo were 26.2% in medium alone; 10 fragmented blastomere were graded mild status and 1 fragmented blastomere in severe status. On the other hand, the fragmented rate for 48 hours co-cultured were 15.7%03/83); 8 fragmented embryos were graded mild status, moderate status in 3 fragmented embryos and severe in 2 fragmented embryos respectively. In conclusion, the co-culture of embryos with ampullary cells is good to improve quality of embryos and overcome of culture block as well as development of cell cleavage.

• 한국가축번식학회지
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• 제18권4호
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• pp.275-284
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• 1995

포유동물 초기 수정란의 성판별에 있어서 biopsied 수정란의 생존성과 성판별의 정확도는 동시에 중요하다. 본 연구자들은 이미 생쥐 수정란에 있어서 biopsy와 PCR을 이용한 성판별의 효율적인 방법을 개발할 바 있다. 본 연구에서는 생쥐 수정란에서 개발된 biopsy방법 (압착방법)을 이용하여 과배란 시킨 상실배기 소 수정란으로부터 몇 개의 할구세포를 분리할 수 있었다. 할구세포가 분리된 13개의 수정란은 biopsy 후 모두 생존하였으며, 이 중 10개의 수정란은 24시간 체외배양에서 정상적인 배반포기로 발달하여 77%의 체외발달율을 나타내었다. 이어서 이렇게 분리된 할구세포에서 PCR 방법으로 수정란의 성을 판별하였는데, 분석된 13개의 수정란 중 수컷은 7개, 암컷은 6개인 것으로 판명되었다. 결론적으로 본 연구에서는 압착방법을 이용하여 상실배기 소 수정란으로부터 적은 수의 할구세포를 쉽게 분리할 수 있었으며, 또한 분리된 할구세포로부터 PCR 방법을 이용하여 소 수정란의 성을 판별할 수 있었다.

• 한국가축번식학회지
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• 제26권2호
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• pp.143-151
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• 2002

본 연구는 돼지의 미성숙 난포란을 체외에서 성숙, 수정시킨 후, 생산된 체외수정란을 NCSU23 체외배양액에 항산화제(NAC, ebselen 및 glutathione)와 성장인자(EGF와 PDGF)의 첨가가 돼지 체외수정란의 체외 발육에 미치는 영향을 검토하였다. NAC을 0, 0.5, 1.0 및 2.0mM 첨가하여 체외배양한 결과, 상실배기 이상 발육된 체외발육성적은 1.0mM과 2.0mM 첨가구가 여타구보다 높은 체외발육성적을 나타냈다. 한편, ebselen을 0, 5, 10 및 25$\mu$M을 첨가하여 배양한 경우 상실배 이상 발육된 체외발육 성적은 각각 17.9, 22.5, 36.9 및 10.8%로서 ebselen 10$\mu$M 첨가구가 여타구에 비해 다소 높은 체외발육성적을 얻었으나 통계적 유의차는 인정되지 않았다(P＞0.05). 또한 glutathione을 0, 50, 100 및 200$\mu$M 첨가시 상실배기 이상 발육된 체외발육성적은 각각 21.8, 17.4, 28.3 및 15.8%로서 100$\mu$M 처리구가 여타구보다 다소 높은 체외발육성적을 얻었으나 통계적 유의차는 인정되지 않았다(P＞0.05). 돼지 체외수정란의 체외배양시 체외배양액에 growth factor의 첨가배양이 돼지수정란의 체외발육에 미치는 영향을 검토한 결과, NCSU 23배양액에 EGF를 0, 10, 50 및 100ng/$m\ell$ 첨가시 상실배기이상 발육된 체외 발육 성적은 각각 19.7, 29.0, 26.6 및 40.4%로서 EGF 100ng1m1 처리구가 여타구보다 통계적으로 유의하게 높은 체외발육 성적을 나타냈으며(P＜0.05), PDGF를 0, 1, 5 및 10ng/$m\ell$ 첨가하여 배양한 경우 상실배기 이상 발육된 체외발육성적은 각각 22.0, 21.6, 33.9 및 15.9%로서 PDGF 5ng/$m\ell$ 처리구가 여타구에 비해 높은 체외발육성적을 얻었다. 본 실험에서 체외수정후 생산된 배반포기 수정란의 세포수는 처리구간 커다란 차이는 인정되지 않았다.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
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• pp.67-67
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• 2003

Early development of porcine oocytes fertilized in vitro was examined in different culture conditions. Porcine ovaries were collected from local slaughter-house. Cumulus-oocytes complexes were aspirated from 2 to 6 mm follicles. The collected oocytes were cultured for in vitro maturation in NCSU-23 medium with 5 mM hypotaurine, 0.57 mM cystein, 10% porcine follicle fluid, 10 IU/ml PMSG and 10 IU/ml hCG for 42~44 hrs. The frozen-thawed spermatozoa were washed by centrifigation 2 times at 1, 500 rpm in D-PBS with 5.56 mM glucose, 0.33 mM Na-pyruvate, 100 IU/ml penicillin, 1$\mu\textrm{g}$/ml streptomycin and 1ng/ml BSA. The fertilization medium used mTBM with 2 mM caffeine and 2 mg/ml BSA and adjusted to a pH of 7.2 to 7.4. The final concentration of spermatozoa was adjusted to 2.5$\times$10$^{6}$ cells/ml motile sperm during fertilization in vitro. At 8hrs h after insemination, the oocytes were transferred into NCSU-23 medium with 5.0 mM hypotaurine and 4 mg/ml BSA and cultured for 7 days. In first experiment, the mean numbers of oocytes collected from 20 ovaries were 674.4 oocytes, and 4.1(27.6), 12.5(84.0), 25.4(171.6) and 57.9%(390.8) for A, B, C and D grade in morphological classification. In the second experiment, when culture medium was supplemented with various concentrations of EGF, the proportions of oocytes cleaved were 56.9, 55.7, 61.9 and 54.7% for 0, 5, 10 and 20ng/ml EGF. The higher proportions(15.1%) of oocytes developed to morular stage were obtained at concentration of 10ng/ml than 0 and 5ng/ml EGF (P<0.05). However, the proportions of embryos developed to blastocyst stage were not significantly different among concentrations of EGF. In another experiment, when the medium supplemented with catalase was used, the proportions of oocytes cleaved were higher in the concentration of 0 unit (56.5%, 61/108) than 100 and 1, 000 unit/ml of catalase (P<0.05). Although the developmental capacity of embryos was improved by medium with 0 unit/ml compared with 100, 500 and 1, 000 units/ml of catalase in oocytes developed to morula and blastocyst stages, were not significantly different among concentrations of catalase.

• Clinical and Experimental Reproductive Medicine
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• 제28권1호
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• pp.55-63
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• 2001

Objectives: This study was carried out to evaluate the effects of embryonic stage, cryoprotectant, and freezing-thawing method on the rates of survival and development of the cryopreserved mouse early embryo and finally to establish the cryopreservation method of surplus embryos obtained during assisted reproductive technology (ART). Materials and Methods: Two to eight cell embryos were obtained from oviducts of mated $F_1$ hybrid female mice superovulated by pregnant mare's serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). Two-step 1,2-propanediol (PROH), dimethylsulfoxide (DMSO) and 4-step PROH DMSO were used as cryoprotectant and dehydration and rehydration method of embryos, and slow-cooling or rapid-cooling method was used as frozen program. The survival rates of embryos were measured after thawing and rehydration, and the developmental rates of embryos were compared and observed during culturing embryos for 24, 48, 72, 96 hrs. Results: As for the survival and development rates of embryos according to embryonic stage, the survival rate of 2 cell stage in PROH and DMSO was significantly higher than 4-8 cell (64.5% versus 62.1 %,79.7% versus 73.2%) (p<0.01, p<0.01), but the development rates of 4-8 cell embryos in PROH and DMSO were significantly higher than 2 cell embryos for whole culture period (p<0.01) and the development rates of 4-8 cell embryos in PROH were significantly higher than 2 cell embryos in DMSO (p<0.01). As for the survival and development rates of embryos according to cryoprotectant, the survival rate of 2 cell embryo in DMSO was significantly higher than that in PROH (74.4% versus 64.5%) (p<0.01), whereas the development rate of embryos was not differ till 24 hrs. The developmen1 rate from morular to hatching blastocyst, however, was significantly higher in PROH than in DMSO during 48 hr (p<0.01). The survival rate of 4-8 cell embryo was 62.1% in PROH and 73.2% in DMSO. The development rates of embryo in PROH were significantly higher for whole culture periods (p<0.01, 0.05). In respect to the effect of freezing and thawing program on the survival and development rates of embryos, method of slow cooling and rapid thawing was more effective than that of rapid cooling and rapid thawing. Conclusions: The survival rate of embryo in 2 cell stage was higher than in 4-8 cell stage, and PROH appears more effective cryoprotectant than DMSO because PROH showed better development rates of embryos in 2 and 4-8 cell stage. Moreover, slow cooling and rapid thawing method was considered as the best cryopreservation program.

• Clinical and Experimental Reproductive Medicine
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• 제25권1호
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• pp.77-86
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• 1998

The uptake of glucose for metabolism and growth is essential to most animal cells and is mediated by glucose-transporter (GLUT) proteins. The aim of this study was to determine which class of glucose transporter molecules was responsible for uptake of glucose in the mouse early embryo and at which stage the corresponding genes were expressed. In addition, co-culture system with vero cell was used to investigate the effect of the system on GLUT expression. Two-cell stage embryos were collected from the superovulated ICR female and divided into 3 groups. As a control, embryos were cultured in 0.4% BSA-T6 medium which includes glucose. For the experimental groups, embryos were cultured in either co-culture system with vero cells or glucose-free T6 medium supplemented with 0.4% BSA and pyruvate as an energy substrate. 2-cell to blastocyst stage embryos in those groups were respectively collected into microtubes (50 embryos/tube). Total RNA was extracted and RT-PCR was performed. The products were analysed after staining ethidium bromide by 2% agarose gel electrophoresis. Blastocysts were collected from each group at l20hr after hCG injection. They were fixed in 2.5% glutaraldehyde, stained with hoechst, and mounted for observation. In control, GLUT1 was expressed from 4-cell to blastocyst. GLUT2 and GLUT3 were expressed in morula and blastocyst. GLUT4 was expressed in all stages. When embryos were cultured in glucose-free medium, no significant difference was shown in the expression of GLUT1, 2 and 3, compared to control. However GLUT4 was not expressed until morular stage. When embryos were co-cultured with vero cell, there was no significant difference in the expression of GLUT1, 2, 3 and 4 compared to control. To determine cell growth of embryos, the average cell number of blastocyst was counted. The cell number of co-culture ($93.8{\pm}3.1$, n=35) is significantly higher than that of control and glucose-free group ($76.6{\pm}3.8$, n=35 and $68.2{\pm}4.3$, n=30). This study shows that the GLUT genes are expressed differently according to embryo stage. GLUTs were detectable throughout mouse preimplantation development in control and co-culture groups. However, GLUT4 was not detected from 2- to 8-cell stage but detected from morula stage in glucose-free medium, suggested that GLUT genes are expressed autocrinally in the embryo regardless of the presence of glucose as an energy substrate. In addition, co-culture system can increase the cell count of blastocyst but not improve the expression of GLUT. In conclusion, expression of GLUT is dependent on embryo stage in preimplantation embryo development.

• Clinical and Experimental Reproductive Medicine
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• 제24권3호
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• pp.377-383
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• 1997

The effects of embryo number and incubation volume on the development of mouse embryos were evaluated. The growth rate of two-cell mouse embryos to attached blastocyst stage and the growth rate of blastocysts to early somite stage were assessed after culture in different incubation volumes and embryo densities. Embryos were collected from ICR female mice superovulated with pregnant mare serum gonadotropin and human chorionic gonadotropin and mated by ICR males. In experiment 1, groups of one, five, ten, twenty 2-cell embryos were cultured in 10-, 50-, 500-, 1000-${\mu}l$ drops of BWW media under mineral oil at $37^{\circ}C$ in a humidified atmosphere of 5% $CO_{2}$ and 95% air. As the incubation volume decreased, significantly (p<0.05) higher rates of embryos reached morular and blastocyst stage on day 3 and 4 culture, respectively. In experiment 2, groups of one, five, ten, twenty blastocysts were cultured in 1- and 2-ml volumes of CMRL 1066 media under same condition as in experiment 1. However the reverse was the result. Decreasing the number of embryos incubated per volume from 1 to 20 significantly (p<0.05) increased the number of blastocysts reaching the late egg cylinder (LEC) and early somite (ES) stage on day 6 and 8 culture, respectively, regardless of incubation volume. Blastocysts cultured in 2ml had higher (p<0.05) development rates to LEC and ES stage on day 6 and 8 culture, respectively, than embryos cultured in 1ml. Our results suggest that the effects of embryo number and incubation volume on the development of mouse embryos are stage specific and the shifting point was between hatching and EEC stage.