• Clinical and Experimental Reproductive Medicine
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• 제27권4호
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• pp.345-351
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• 2000

Objective: Hatching of the blastocyst from the zona pellucida (ZP) is a key event in mammalian implantation. In vivo, two factors have been identified as possible mediators of hatching: lysis of the ZP by substances elaborated either from the embryo or female reproductive tract and pressure exerted on the zona by expansion of the blastocyst. Two methods of zona manipulation were already in use to enhance the ability of embryos to hatch: mechanical PZD and chemical ZD by acidic Tyrode's solution. But several controversies of each method have been reported. The purpose of this study was to investigate the effect of pronase for mouse embryo hatching. Methods: Mouse embryos were obtained following ovulation induction of $F_1$ animals. Fresh and cryo-thawed morula embryos were exposed to 0.5, 1.0, 2.0, 5.0 ${\mu}g/ml$ pronase in Ham's F10 for 72 hrs. Main outcome measures were the rates of partial hatching and completely hatched blastocysts, and cell number of it. Results: In fresh and cryo-thawed group, the rates of completely hatched blastocyst were significantly higher in 5 ${\mu}g/ml$ pronase treatment group than control group. There was no difference in completely hatched blastocyst total cell number between pronase treatment group and control group. This suggest that pronase treatment did not harmful in mouse embryo development. In pronase treatment group, zona pellucida were thinner than control group. Conclusion: The addition of pronase to culture media may accelerate the hatching of embryo. So, enzymatic treatment of the zona may provide a valuable and effective assisted hatching technique for human in-vitro fertilization-embryo transfer.

• Clinical and Experimental Reproductive Medicine
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• 제19권2호
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• pp.133-141
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• 1992

We examined effects of co-culture with human oviduct epithelial cells (HOEC) on the development of mouse and human embryos from early embryonic· stage to late morula or blastocyst stage (LM or B). In human, embryos were transferred and pregnancy rate was investigated. The HOEC, collected from surgically removed fallopian tube, were cultured in medium-199 supplemented with 20 % fetal cord serum (FCS). The HOEC were characterized by using immunocytochemical staining with anticytokeratin antibody and then used for cultures of mouse and human embryos. Results obtained from co-culture system were as follows. Development rate of mouse embryos was improved by co-culture system at late developmental stage (p<0.025). Human supernumerary embryos remained after transfer, unsuitable for freezing because of their poor quality, were co-cultured for 72hrs. Co-culture (78.79%) or conditioned medium (78.26%) system improved the developmemt rate, significantly, in comparision with control (11.11%)(p<0.00l). Co-cultured (85.71%) human zygotes for 24hrs showed the better development rate in comparision with control (50.00%) (p<0.01). When we transferred embryos cultured with the HOEC to patients, we obtained one pregnancy. Co-cultured human zygotes for 24hrs showed the better quality and viability for the replacement in comparision with control (p<0.01). In addition, improved pregnancy rate was obtained. Our results suggest that the co-culture system can rescue early degenerating embryos by improving early development and yield a resonable number of blastocyst for the appropriate replacement. The effect provided by cultured HOEC is not species specific for the development of embryos and it can be used to overcome in vitro blocks for the development. And also the co-culture system offers the possibility to freeze embryos at blastocyst stage which is more sucessful stage for the freezing. The HOEC monolayer may provide some stimulus via specific factor, which is unknown, to the development of embryos. Our results showed that the co-culture system with HOEC can be an alternative to conventional culture system.

• Clinical and Experimental Reproductive Medicine
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• 제29권3호
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• pp.201-207
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• 2002

Objective: To observe the capability of fertilization and embryo development including blastocyst formation of the oocytes in simple media after thawing of the cryopreserved cumulus-free mouse oocytes by vitrification method. Methods: Oocytes were collected from 5 to 6 weeks old ICR female mice, and were denuded from the cumulus cells by 0.1% hyaluronidase. Recovered mature oocytes in study group were cryopreserved by vitrification method using EM grid for $5{\sim}7$ days. In brief, oocytes were exposed in dPBS containing 1.5 M EG and 5.5 M EG+1 M sucrose for 2.5 minutes and 20 seconds each, and then executed vitrification by plunging in LN2 after loading on EM grid. Thawing treated by exposure of 1, 0.5, 0.25 and 0.125 M sucrose solution for 2.5 minutes each in order and used for experiments. Spermatozoa aspirated form the epididymis of 12 weeks old ICR male mice were used for insemination after capacitation. T6 media containing 0.4% BSA were used for fertilization and development. Results: Survival and fertilization rates after thawing were 76.9% and 79.6% respectively. Fertilization rate was lower (p<0.005) than that of control group (92.9%). There was no difference in embryo developmental rates from 2-cell to morula, however, the blastocyst formation rate and mean cell numbers of blastocysts in study group (63.3%, $58.9{\pm}9.2$) were lower compared with those of control group (76.1%, $63.5{\pm}8.9$). Conclusion: Vitrification is an effective method for mouse mature oocyte cryopreservation with high survival and fertilization rate after thawing. And in simple media, fertilization rates and embryo development of frozen-thawed mouse oocytes are satisfactory.

• Clinical and Experimental Reproductive Medicine
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• 제28권1호
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• pp.41-46
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• 2001

Objective: To determine the effects of leukemia inhibitory factor (LIF) on embryonal development in in vitro culture. Methods: This is designed in vitro model using eggs from mouse. The eggs from mouse were assigned 29 for control group, 53 for 20 ng/ml of LIF, 88 for 40 ng/ml of LIF, 68 for 80 ng/ml of LIF respectively for in vitro fertilization. And 26 fertilized eggs at 2 cell stage from mouse also were assigned. The mouse embryos of all groups were cultured in medium supplemented with LIF in different concentrations, whereas the eggs in control group was cultured in medium without supplement of LIF. Results: At 72 hours culture of eggs from in vitro fertilization, there was a slight increas in rate of embryonal development to morula in both LIF-20 and LIF-40 as results of 64.15% and 75% respectively, while 42.65% in inferior rate of LIF-80, compare with 51.72% in control group. But the difference between these each groups were not significant in statistically ($p{\le}0.05$). And after 96 hours culture of eggs, the rates blastocyst formation was significantly higher in both LIF-20 and LIF-40 as 56.6% and 63.63% than those in control and LIF-80 as 44.83% and 35.29% respectively. On culturing eggs from in vivo fertilization, the rates of blastocyst formation was significantly not only higher as 85% and 81.81% respectively in medium supplemented with LIF-40 and LIF-80 than 42.3% in LIF-20 but also embryonal cell viability were remakedly improved at 96 hours after culture. Conclusion: The LIF in low dose is embryotrophic, but LIF in high dose is embryotoxic on eggs from in vitro fertilization. Whereas on culturing eggs from in vivo fertilization, LIF is more beneficial with dose dependent in high concentration.

• 생명과학회지
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• 제19권12호
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• pp.1764-1768
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• 2009

본 연구는 소의 과립막세포 배양상층액에서 스테로이드 호르몬의 농도와 생쥐 배의 체외 발달에 미치는 효과를 검토하기 위하여 수행되었다. 소의 성숙난포(직경 6~15 mm)와 미성숙 난포(직경 2~5 mm)로부터 과립막세포를 각각 분리하여 15% FCS가 첨가된 Ham's F-10 배양약에서 16일간 배양하였다. 과립막세포들은 쉽게 단층배엽을 형성 하였으며, 배양과정 중 비슷한 성장패턴을 나타내었다. 또한 성숙 과립막세포와 미성숙 과립막세포 간에 형태적인 차이가 없었다. 과립막세포 배양 중 progesterone과 estradiol 생산이 활발하게 이루어졌으며, progesterone은 배양후기에, estradiol은 배양초기에 분비량이 높았다. 성숙 과립막세포와 미성숙 과립막세포에서 내분비 양상은 비슷하였다. 생쥐배가 상실배, 배반포 및 부화배반포 단계로 체외발달된 비율은 Ham'F-10배양액(86.7%, 41.7%, 13.3%)에 비하여 성숙 과립막세포 배양상층액(92.7%, 78.1%, 34.5%)과 미성숙 과립막세포 배양상층액(96.4%, 78.5%, 26.8%)에서 유의적으로 높았다(p<0.05). 그러나 배의 발달에 대하여 성숙 과립막세포배양상층액과 미성숙 과립막세포 배양상층액 간에는 차이가 없었다.

• Reproductive and Developmental Biology
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• 제31권3호
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• pp.193-198
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• 2007

본 연구는 소의 초기 난할 단계인 2 또는 4세포기 수정란의 특정 분할구가 배반포 단계의 내부 세포괴(Inner Cell Mass)와 영양막 세포(Trophectoderm cells)로의 발달 운명이 미리 정해지는 지를 확인하기 위해 실시되었다. 먼저 생쥐의 체내수정란과 소의 체외 수정란에서 배반포의 영양막 세포에서만 특이적으로 발현하는 cdx2단백질의 발현 양상을 조사하였다. 또한, 소의 경우 2세포기와 4세포기가 내부 세포괴와 영양막 세포로 나눠지는 시점인지를 조사하기 위해 2 또는 4세포기의 특정 분할구에 Dextran의 주입 실험과 분할구 제거 실험을 통해 ICM과 TE 형성을 확인하였다. cdx2의 발현 경향은 생쥐와 소의 2세포기일 때 대칭과 비대칭적으로 발현되는 것을 확인하였다. 생쥐의 4, 8세포기 및 상실배기에서는 분할구 전체에서 발현되었으나, 소 수정란의 분할구에서는 전체 또는 부분적으로 발현되었다. 또한, 생쥐와 소의 배반포기에서는 영양막 세포에서만 발현이 되는 것을 확인하였다. 소 수정란의 2세포기와 4세포기 단계에서 특정 분할구에 주입된 De xtran은 배반포의 내부 세포괴와 영양막 세포의 양쪽에 분포된 것을 관찰할 수 있었다. 2세포기 단계에서 하나의 분할구가 제거된 수정란 역시 ICM 및 TE 세포를 지닌 정상 배반포로 발달함을 확인하였다. 따라서 본 연구 결과는 영양막 세포에서만 특이적으로 발현하는 cdx2의 발현이 2 또는 4세포기 단계 소 수정란에서는 특별한 차이를 보이지 않으며, 궁극적으로 난할 초기에는 ICM과 TE 세포로의 운명이 결정되지 않는다는 것을 보여준다.

• 한국발생생물학회지:발생과생식
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• 제2권2호
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• pp.179-187
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• 1998

부화 및 착상에서 prostaglandins의 역할에 대한 연구는 많으나 배아단계에 따라 포배의 팽창과 부화에 미치는 영향에 대한 연구는 미미하다. 따라서 본 실험에서는 다양한 농도의 prostaglandins를 발생단계에 따라 처리하거나, indomethacin과 prostaglandins의 양 변화를 통해 팽창과 부화에 미치는 영향을 알아보고, 배아 단계별 PG $E_2$와 PG $F_2$$_{\alpha}$의 생합성양 변화양상을 알아보았다. 100$\mu$M이 상 농도의 PG $E_2$처리시 거의 모든 상실배가 퇴화하는 유해성을 보이나 PG $F_2$$_{\alpha}$에 있어서는 관찰되지 않았다. PG $E_2$나 PG $F_2$$_{\alpha}$ 모두에서 배아의 부화를 억제하지만 팽창포배로의 발생은 대조군과 유사하였다. hCG 주사 후 84시간과 96시간 단계 배아에 처리한 경우 부화율이 전반적으로 감소하는 경향을 보였으나 팽창포배로의 발생은 대조군과 유사하였고 PG $E_2$에 의한 세포독성은 발생단계가 높을수록 감소되었다. 한편 배아 단계와 관련없이 PG $F_2$$_{\alpha}$의 농도가 높아짐에 따라 부화가 억제되었다. Indomethacin과 PG $E_2$나 PG $F_2$$_{\alpha}$를 함유한 배양액에서 각 단계의 배아를 배양할 경우 prostaglandins를 단독으로 처리한 경우보다 부화율이 증가하였다. 한편 PG $E_2$의 경우 낮은 농도에서 부화율이 대조군 수준으로 증가하였다. 한편 PG $E_2$ 합성은 발생단계에 따라 급격히 증가한 반면 PG $F_2$$_{\alpha}$는 점진적인 증가를 보였다. 이상의 결과에서 PG $E_2$에 의한 세포독성은 배아 단계가 높아질수록 감소하고, 고농도의 PG $F_2$$_{\alpha}$는 배아의 부화를 억제하였으며, 발생 단계에 따라 prostaglandins의 요구 양이 다름을 알 수 있다. 또한 상실기 이후 배아에서 합성되며, 발생시기에 따라 그 영향이 다르고 팽창과 부화에 관여하는 것으로 사료된다.생 단계에 따라 prostaglandins의 요구 양이 다름을 알 수 있다. 또한 상실기 이후 배아에서 합성되며, 발생시기에 따라 그 영향이 다르고 팽창과 부화에 관여하는 것으로 사료된다.

• Clinical and Experimental Reproductive Medicine
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• 제16권2호
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• pp.139-146
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• 1989

The purpose of this study was to examine the qualitative variation of human fetal-cord sera (HCS) and to accept the sera in human lVF-ET program. One hundred and sixteenth RCS were tested with 1772 2-cell embryos of F1 (C57BL x CBA) virgin mice, Ten to sixteenth embryos were cultured in m-KRB medium with a aliquot of each serum (10%, v/v) or with bovine serum albumin(O.4%, w/v) as a control medium. Embryonic development were recorded at every 24hr for 4 days by such events as cellular compaction, cavitation, and hatching. In the control groups of eight assays, 98.1%(106/ 108) of 2-ce1l embryos developed above expanded blastocyst and the embryonic development was unified through the tests. But the developmental pattern in medium with each serum was various. Namely, the sera that supported development of 100% 2-cell embryos to above morula, early blastocyst, expanded blastocyst and hatching blastocyst was 45,7%(53/116) , 35.3%(41/116), 15.5%08/116.) and 6.9-%(8/116), respectively. And the sera that supported development of above 80% 2-cell embryos to the each embryonic stage was 92.2% (107/116), 83.6%(97/116), 63.8%(74/116) and 36.2%(42/116), respectively. Meanwhile two kinds of toxic pattern to the embryonic development were observed in some sera. The first pattern is that some sera arrested development of most embryos in pre- or post-stage of morula or blastocyst. The second pattern is that some sera promoted or arrested a part of embryos in the same dish. The ability of serum was depended on the batch of serum. Finally we could accept 69%(80/116) of the tested sera for human IVF-ET program. The base line for acceptance was the ability that supported above 80% 2-ce1l embryos to blastocyst. But some deterious sera were contained in this range. We cut off about 10% of the sera (83.6% , 97/116) that passed the baseline. This final percent of sera was similar to that of grade N of this study.

• Reproductive and Developmental Biology
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• 제29권1호
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• pp.19-24
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• 2005

저밀도 리포단백질 수용체 관련 단백질 5(LRP5)는 간과 췌장을 포함하여 많은 조직에서 발현하며 아포리포단백질 E와 결합한다. 이와 같은 LRP5 유전자의 체내 기능을 규명하기 위하여 LRP5 유전자가 결손된 생쥐를 개발하였다. 먼지 LRP5 genomic DNA는 TT2 ES 세포로부터 분리하였으며 LRP5 유전자의 엑손 18에 neo 유전자를 삽입한 vector를 구축하고 TT2 ES 세포에 도입하였다. 178개의 G418 내성을 보인 세포 중 상동유전자 재조합에 의하여 targeting vector가 LRP5 유전자 위치에 삽입된 clone은 3개였다. 키메라 생쥐는 상실배기 수정을 ES 세포와 응집시켜 생산하였으며 생산된 키메라 생쥐는 C57BL/6 생쥐와 교미를 유도하여 heterozygous를 얻었다. 또한 이들 heterozygous간의 교배에 의하여 LRP5 유전자 결손 생쥐를 생산하였다. 이러한 생쥐는 LRP5 유전자의 체내 기능연구에 있어서 모델로 이용될 것으로 생각된다.

• 한국가축번식학회지
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• 제25권2호
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• pp.131-138
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• 2001

생쥐 초기배의 배반포 발달율이 BSA첨가 배양액에 Barodon-FX(equation omitted) 첨가로 증가되지 않았으나 PVP 첨가 배양액에 0.25% 첨가에서는 부화배반포 발달율이 54.7%로 대조구(32.5%)보다 크게 향상 되었다(P ＜0.05). 1∼2% Barodon 첨가는 배발달을 월등히 저하시켰다. Barodon 첨가에 따른 체세포 증식율은 BOEC와 GC의 경우 0.25∼0.5%에서 대조구보다 각각 24∼40%와 17∼22%더 크게 증가되었다(P＜0.05). 그러나 GC와 CC에서는 1%이상 첨가시 세포증식이 크게 억제되었다(P ＜0.05). Barodon의 효과는 체세포간에 큰 차이가 있었다. 소 초기배에서 상실배이상의 배발달율은 BOEC와 GC 공배양조건에서 Barodon 0.5% 첨가에서 대조구보다 크게 향상되었다(P＜0.05). 그러나 다른 처리 수준에서는 배 발달율이 대조구와 차이가 없었다. 결론적으로 Barodon의 세포증식효과는 세포종류에 따라 차이가 많았으며 0.5% 수준의 첨가는 소 초기배의 배반포발달율을 향상시킬 수 있었다.