• Clinical and Experimental Reproductive Medicine
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• 제46권4호
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• pp.189-196
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• 2019

Objective: We aimed to evaluate the effects of different oxygen conditions (20% [high O₂], 5% [low O₂] and 5% decreased to 2% [dynamic O₂]) on mouse pre- and peri-implantation development using a novel double-channel gas supply (DCGS) incubator (CNC Biotech Inc.) to alter the oxygen concentration during in vitro culture. Methods: The high-O₂ and low-O₂ groups were cultured from the one-cell to the blastocyst stage under 20% and 5% oxygen concentrations, respectively. In the dynamic-O₂ group, mouse embryos were cultured from the one-cell to the morula stage under 5% O₂ for 3 days, followed by culture under 2% O₂ to the blastocyst stage. To evaluate peri-implantation development, the blastocysts from the three groups were individually transferred to a fibronectin-coated dish and cultured to the outgrowth stage in droplets. Results: The blastocyst formation rate was significantly higher in the low-O₂ and dynamic-O₂ groups than in the high-O₂ group. The total cell number was significantly higher in the dynamic-O₂ group than in the low-O₂ and high-O₂ groups. Additionally, the apoptotic index was significantly lower in the low-O₂ and dynamic-O₂ groups than in the high-O₂ group. The trophoblast outgrowth rate and spread area were significantly higher in the low-O₂ and dynamic-O₂ groups than in the high-O₂ group. Conclusion: Our results showed that a dynamic oxygen concentration (decreasing from 5% to 2%) had beneficial effects on mouse pre- and peri-implantation development. Optimized, dynamic changing of oxygen concentrations using the novel DCGS incubator could improve the developmental competence of in vitro cultured embryos in a human in vitro fertilization and embryo transfer program.

• The Korean Journal of Physiology and Pharmacology
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• 제3권2호
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• pp.157-164
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• 1999

To determine molecular mechanisms of Aquaporin-CD (AQP2) gene regulation, the promoter region of the AQP2 gene was examined by transiently transfecting a promoter-luciferase reporter fusion gene into mouse renal collecting duct cell lines such as mIMCD-3, mIMCD-K2, and M-1 cells, and NIH3T3 mouse embryo fibroblast cells. PCR-Southern analysis reveals that mIMCD-3 and mIMCD-K2 cells express AQP2, but M-1 and NIH3T3 cells do not, and that the treatment with cpt-cAMP $(400\;{\mu}M)$) or forskolin/isobutylmethylxanthine (IBMX) increased the AQP2 expression in IMCD cells. In both IMCD and NIH3T3 cells, the constructs containing the promoter of AQP2 gene showed promoter activities, indicating lack of tissue-specific element in the 1.4 kb 5'-flanking region of the mouse AQP2 gene. Luciferase activity in the IMCD cells transfected with the construct containing 5-flanking region showed responsiveness to cpt-cAMP, indicating that the 1.4 kb 5'-flanking region contains the element necessary for the regulatory mechanism by cAMP. The promoter-luciferase constructs which do not have a cAMP-responsible element (CRE) still showed the cAMP responsiveness in IMCD cells, but not in NIH3T3 cells. Increase in medium osmolarity did not affect AQP2 promoter activity in mIMCD-K2 cells. These results demonstrate that AQP2 gene transcription is increased with cAMP treatment through multiple motifs including CRE in the 5'-flanking region of the gene in vitro, and the regulatory mechanism may be important for in vivo regulation of AQP2 expression.

• 한국가축번식학회지
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• 제16권3호
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• pp.209-215
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• 1992

These studies were carried out to overcome 2-cell block and in vitro development to blastocysts in vitro fertilization of mouse embryos. The unfertilized ova were obtained by superovulation in ICR mice of 4 to 6 weeks old. Tyrode's 280 solution was used as basal media, and the pH range of media examined was designed from 6.5 to 7.5 with 0.2 interval and the range of osmolality from 250 to 370 mOsm with 20 interval, and the period of sperm preincubation examined was 30, 60, 120, and 180 minutes. The ova developed to 2-cell embryos after 26hrs of incubation with preincubated sperm were evaluatated as in vitro fertilized ones. The results obtained were summarized as follows: 1. The optimal ranges of pH and osmolality of culture media and of sperm preincubation time for in vitro development of in vitro fertilized ova to blastocyst were pH 7.1 to 7.3, 250 to 350 mosmol and 60 to 180 min, respectively. 2. With the media of pH 7.1, 310 mOsm and sperm preincubation period of 120min in another experiment of large sample size, the in vitro fertilized ova was found 66.5% and the in vitro development of in vitro fertilized ova to blastocyst was found 35.8%. From the above results it was concluded that the optimal conditions of pH and osmolality of the media for mouse IVF and embryo culture, and the period of sperm preincubation might be 7.1, 310 mOam and 120min, respectively.

• Clinical and Experimental Reproductive Medicine
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• 제24권3호
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• pp.325-333
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• 1997

The use of hormonal stimulation in human in vitro fertilization and embryo transfer (IVF-ET) leads to increased production of embryos for ET. So to avoid high pregnancies and to allow conception in future, unstimulated cycles, cryopreservation of spare embryos is desirable. One of the improvement of cryopreservation methods is vitrification. We cryopreserved mouse day 3 embryos by vitrification using the three different vitrification solution (EFS40, VS11 and VS3a). EFS40 solution is consisted of 40% (v/v) ethylene glycol, Ficol170 30% (w/v) and 0.5M sucrose and VS11 is 6.0M ethylene glycol and 1.8M glycerol. And VS3a is 6.5M glycerol and 6% (w/v) BSA (bovine serum albumin). First we tested the toxicity of three vitrification solution by exposure to these solution during 3 min. After washing by thawing solution, the survival rates of each groups are 95.5%, 90.9% and 84.4% (EFS40, VS11 and VS3a). High percentages of them developed to expanded blastocyst and hatching embryos in culture 48hrs 94.2%, 97.7%, 100% and 97.4% (no treatment group, EFS40, VS11 and VS3a). So there is no significant differences among the each group. Second, after thawing of vitirfied embryos, the survival rates of each groups are 96.8% (slow freeze), 94.1% (EFS40), 85.5% (VS11) and 80.0% (VS3a, P vs. no freeze or EFS40 is 0.01). Vitrified embryos exhibited a high rate of development in vitro after 48hrs culture. The percentages of each group to blastocyst and hatching embryos are 88.7% (no freeze), 91.8% (slow freeze), 93.4% (EFS40), 87.7% (VS11) and 73.0% (VS3a, P vs. other group is 0.01). The results suggest that there is no significant differences in exposure of various vitrification solution and day 3 mouse embryos can be vitrified in solution EFS40 and VS11 by simple procedure.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.109-109
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• 2003

Even though success in birth of live offspring from nuclear transfer(NT) using somatic cells in many species, detailed information on processes or mechanisms of development are not well known. Cytoplasm of bovine oocyte has been known to support the development of nuclear transferred embryos using nuclear donor cells from different species. Therefore, interspecies NT might be used to find answers of some questions in basic aspect of nuclear transfer In this study, we examined the developmental potential of reconstructed embryos when bovine oocyte as a cytoplasm recipient and mouse embryonic fibroblast as a nuclear donor were used. The nuclear transfer units were aliocated in Group 1 (murine block media and normal media) and Group 2. (bovine block media and normal media). NT units were not blocked at 2-cell stage regardless of types of medium. On mouse media, poor development of interspecies NT units was observed compared to bovine media. However, as NT units cultured in bovine normal medium, embryos developed over 8-cell stage. Further studies performed to increase the developmental rate in condition of antioxidant treatment. Despite low development, bovine-murine interspecies nuclear transferred embryos could develop to blastocysts and they showed that blastocyts rate of antioxidant group was superior to those of non-antioxidant group. Next, we investigated gene expression pattern which is carried out for zygotic activation. The Xist gene is expressed in female mouse embryo after zygotic activation of 4-cell stage. But interspecies nuclear transferred embryos do not express Xist gene at 4-cell stage. As a result, it is suggested that the bovine cytoplasm controls the early preimplantation development in interspecies NT However, the development of later stages might require genomic control from transferred donor nucleus. Therefore, even though the involvement of several other factors such as mitochondrial incompatibility, effective development of embryos produced by interspecies NT requires proper genomic activation of donor nucleus after overcoming the cytoplasmic control of recipient oocytes.

• Clinical and Experimental Reproductive Medicine
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• 제27권1호
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• pp.47-57
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• 2000

Objective: The effects of cryopreservation with or without coculture on the in vitro development of blastomere-biopsied 8-cell mouse embryos were investigated. This experimental study was originally designed for the setup of a preclinical mouse model for the preimplantation genetic diagnosis (PGD) in human. Methods: Eight-cell embryos were obtained after in vitro fertilization (IVF) from F1 hybrid mice (C57BL(표현불가)/CBA(표현불가)). Using micromanipulation, one to four blastomeres were aspirated through a hole made in the zona pellucida by zona drilling (ZD) with acid Tyrode's solution (ATS). A slow-freezing and rapid-thawing protocol with 1.5M dimethyl sulfoxide (DMSO) and 0.1M sucrose as cryoprotectant was used for the cryopreservation of blastomere- biopsied 8-cell mouse embryos. After thawing, embryos were cultured for 110 hours in Ham's F-10 supplemented with 0.4% bovine serum albumin (BSA). In the coculture group, embryos were cultured for 110 hours on the monolayer of Vero cells in the same medium. The blastocyst formation was recorded, and the embryos developed beyond blastocyst stage were stained with 10% Giemsa to count the total number of nuclei in each embryo. Results: The survival rate of embryos after cryopreservation was significantly lower in the blastomere-biopsied (7/8, 6/8, 5/8, and 4/8 embryos) groups than in the non-biopsied, zona intact (ZI) group. Without the coculture, the blastocyst formation rate of embryos after cryopreservation was not significantly different among ZI, the zona drilling only (ZD), and the balstomere-biopsied groups, but it was significantly lower than in the non-cryopreserved control group. The mean number of cells in embryos beyond blastocyst stage was significantly higher in the control group ($50.2{\pm}14.0$) than in 6/8 ($26.5{\pm}6.2$), 5/8 ($25.0{\pm}5.5$), and 4/8 ($17.8{\pm}7.8$) groups. With the coculture using Vero cells, the blastocyst formation rate of embryos after cryopreservation was significantly lower in 5/8 and 4/8 groups, compared with the control, 7/8, and 6/8 groups. The mean number of cells in embryos beyond blastocyst stage was also significantly lower in 4/8 group ($25.9{\pm}10.2$), compared with the control ($50.2{\pm}14.0$), 7/8 ($56.0{\pm}22.2$), and 6/8 ($55.3{\pm}25.5$) groups. Conclusion: After cryopreservation, blastomere-biopsied mouse embryos have a significantly impaired developmental competence in vitro, but this detrimental effect might be prevented by the coculture with Vero cells in 8-cell mouse embryos biopsied one or two blastomeres. Biopsy of mouse embryos after ZD with ATS is a safe and highly efficient preclinical model for PGD of human embryos.

• 한국수정란이식학회지
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• 제8권2호
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• pp.83-90
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• 1993

To investigate the effect of extracellular matrix proteins on the in vitro development of ethanol-induced parthenogenetic eggs of ICR strain mice, those were cultured in vitro in fibronectin, gelatin, or collagen precoated culture dishes containing 1.5 ml of NaH-C03$_3$-BMOC-3 medium at 37$^{\circ}C$ for 96 hrs. under the atmosphere of 5% $CO_2$ and 95% air. Fibronectin, gelatin, or collagen significantly(P$\pm$1.4, 45.4i1.4, and 44.8$\pm$O.9, respectively. And the diameter of those eggs ranged 104.6$\pm$1.9, 102.8$\pm$2.3, and 103.4$\pm$O.8 $\mu$m, respectively.

• 한국수정란이식학회지
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• 제6권1호
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• pp.1-11
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• 1991

가축의 일란성 쌍태를 생산하기 위한 기술 개발을 확립하고자 상실배 및 포배기에 있는 BALB/c 계통의 생쥐 수정란을 micromanipulator로 분할 수정란을 작출하고 이를 체외배양을 실시하여 발달성적을 조사하였으며, 외과적 및 비외과적 이식을 실시하여 착상율 및 산자생산 성적을 조사한 결과는 다음과 같다. 1. 상실배 및 포기배에 있는 총 811개의 정상적인 수정란을 분할하여 이중에서 666(82.1%)개가 분할시의 물리적인 손상이 없이 분할되었고, 이때 분할 성공율은 발달단계 간에 유의적(P<0.05)인 차이가 없었다. 2. 분할 수정란중 상실배는 30-36시간, 초기 배반포 및 확장 배반포는 3-6시간 배양을 실시한 결과 분할 수정란중 한쌍이 모두 정상적으로 배양된 것은 각각 70.0%, 80.4% 및 73.1%로써 이들 발달단계 간에 유의적(P<0.05)인 차이가 없었다. 3. 분할된 상실배와 정상적인 수정란의 이식후 수태율은 각각 63.6% 및 61.3%로써 유의적(P<0.05)인 차이가 없었다. 그러나 분할된 상실배에 있어서 배양을 하지 않고 이식한 경우에는 전혀 수태되지 않았다(P<0.05). 4. 분할된 포배기 수정란을 체외 배양후 이식한 수태율(55.5%)과 배양과정을 거치지 않고 이식한 성적(43.8%) 그리고 정상적인 포배기 수정란을 이식한 수태율(55.4%) 간에는 유의적(P<0.05)인 차이가 없었다. 5. 분할 수정란을 외과적 방법으로 이식한 경우는 52.8%의 수태율을 얻었으나, 비외과적 방법으로 이식한 경우 27.5%로써 외과적 방법으로 이식한 경우보다 수태율이 유의적(P<0.05)으로 낮았다.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2001년도 추계학술대회 및 정기총회
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• pp.12-21
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• 2001

To identify genes implicated in the control of pluripotency as well as characteristics of stem cells, we analyzed expression profiles of genes derived from mouse morulas, blastocysts, embryonic stem cells, mesenchymal stem cells, and uterus tissue using cDNA microarray. Comparative analyses of their expression profiles identified putative clones that expressed specifically in specific samples or not in a specific sample. The expression pattern of these condidate clones was analyzed using RT-PCR and non-radioactive in situ hybridization. Functional annotation of these clones on pluripotency and stem cell plasticity is in ongoing. These studies may further our understanding on the nature of the stem cells and molecular mechanisms underlying many facets of mammalian development and differentiation.

• 한국수정란이식학회지
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• 제15권3호
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• pp.237-245
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• 2000

This study was carried out to elucidate whether sperm contain a factor inducing second polar body extrusion and to search for an effective collection method of the sperm factor Thus, sperm extract, dialyzed sperm-extract or liquid chromatographic fractions of sperm extract was microinjected into ovulated oocytes. And the microinjected oocytes were incubated for 24 hours to investigate about the extrusion of second polar body. The results obtained were as follows; 1. Sperm extract significantly increased the second polar body extrusion. 2. Sperm extract showed five major fractions at retention volumes (RVs) 1.25, 1.37, 1.84, 2.10 and 2.67ml after separation with Superose 12 column. These sperm extract fractions did not significantly increase the second polar body extrusion. 3. Dialyzed sperm-extract significantly increased the second polar body extrusion 4. Dialyzed sperm-extract showed three maior fractions at RVs 1.88, 2.14 and 2.77ml after separation with Superose 12 column. Of these fractions, the fraction RV2.14 significantly increased the second polar body extrusion. In conclusion, sperm extract contained a factor inducing the second polar body extrusion and the factor was contained largely in fraction RV2.14 after dialysis and liquid chromatographic fractionation of sperm extract.