• Clinical and Experimental Reproductive Medicine
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• v.22 no.2
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• pp.163-170
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• 1995

Growth factors (GFs) produced by the embryo or by the maternal reproductive tract have been reported to regulate the embryonic development and differentiation. Among GFs, EGF as a mitogen plays a role in mitosis and functional differentiation of trophectoderm cells in mouse. The present study was carried out to investigate the effect of EGF on development of mouse embryos and to localize EGF in the mouse oocytes and embryos, which has been reported to be detected in the reproductive tract in mammals. To investigate the effect of EGF on the development of the embryo, mouse 2-cell embryos were cultured to blastocysts stage in Ham's F10 medium, treated with EGF(10-50 ng/ml) for 72 hrs. Immunocytochemistry was performed from oocyte to blastocyst stage with anti-EGF and anti-Mouse IgG, in order to determine the stage which EGF would be expressed in mouse. Exogenous EGF (more than 10 ng/ml) in the culture medium improved the developmental and hatching rates in the mouse embryos. As a result of immunocytochemistry, the embryonic EGF was expressed after the late 4-cell stage. EGF is thought to enhance preimplantation embryonic development and hatching. Exogenous EGF in the culture medium is thought to activate EGF receptor in the late 4-cell embryos and to enhance blastulation and hatching in mouse embryos. It is concluded that EGF enhances the developmental and hatching rates in the mouse embryos.

• Journal of Embryo Transfer
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• v.22 no.4
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• pp.213-218
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• 2007

This study was performed to investigate the effect of VEGF on in vitro maturation of porcine oocytes. The base medium for IVM, TCM-199 was supplemented with 0.6 mM cysteine, 0.91 mM pyruvate, 10 ng/ml epidermal growth factor, $75{\mu}g/ml$ kenamycin, $1{\mu}g/ml$ insulin and 10% (V/V) porcine follicular fluid (pFF) as a Group A; Group B was consists of Group A plus 5 ng/ml VEGF; Group C was consists of replacement of pFF by 10% PVA and Group D: was consists of Group C plus 5 ng/ml VEGF. 1. The maturation rate was significantly higher (p<0.05) in control and VEGF+pFF group than other two groups ($76.1{\pm}9.6,\;78.9{\pm}6.0\;vs\;60.4{\pm}14.2\;and\;58.3{\pm}14.3$, respectively). 2. Addition of VEGF without pFF showed a negative effect on oocytes maturation and about 58.26% oocytes were reached to M-II stage. 3. In the parthenogenetic development, the cleavage rate was significantly higher (p<0.05) in control and VEGF+pFF group ($73.2{\pm}1.8\;and\;64.6{\pm}1.1$, respectively) than other groups ($47.9{\pm}1.8\;and\;48.3{\pm}1.7$, respectively). 4. The blastocyst formation rate was significantly higher (p<0.05) in VEGF+pFF group ($32.6{\pm}2.4$) compared to control and other groups. 5. There was no significant difference in cell numbers (inner cell mass or trophectoderm) among these groups.

• Journal of Embryo Transfer
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• v.31 no.1
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• pp.27-32
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• 2016

This study was conducted to evaluate the effects of different volume ($100{\mu}l$ vs. 2 ml) of microdrop culture on B6D2F1 mice oogenesis. In the present study, B6D2F1/CrljOri $F_1$ mice were utilized in order to maximize oogenesis. Also we used TCM-199, Dulbecco's medified Eagle's medium (DMEM), embryo culture medium (Fertilization medium, Cleavage medium, Blastocyst medium), G series medium and One step medium. Blastulation rate was not different between groups ($58.4{\pm}2.9%$ vs. $61.2{\pm}4.8%$). Zona hatched rate ($38{\pm}15.4%$ vs. $27{\pm}3.4%$) and attached rate ($55{\pm}13.9%$ vs. $46{\pm}3.9%$) did not differ by the volume of culture media. Total cell numbers ($59.8{\pm}9.7$ vs. $70.3{\pm}8.7$), ICM cell numbers ($15.8{\pm}0.6$ vs. $16.8{\pm}1.5$), TE cell numbers ($44.0{\pm}9.7$ vs. $53.6{\pm}7.3$), % ICM ($26.4{\pm}2.9%$ vs. $23.8{\pm}3.3%$) and ICM:TE ratio ($1:2.8{\pm}0.4$ vs. $1:3.2{\pm}0.6$) were not different between groups (i.e., $100{\mu}l$ vs. 2 ml). These results show that the capacity of the culture medium did not effect the cell numbers of B6D2F1 mice blastocysts. In summary, these results can provide fundamental data to maximize culture condition for in vitro fertilization on B6D2F1 mice.

• Development and Reproduction
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• v.14 no.3
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• pp.155-162
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• 2010

The trophectoderm is one of the earliest cell types to differentiate in the forming placenta. It is an important for the initial implantation and placentation during pregnancy. Trophoblast stem cells (TBSCs) develop from the blastocyst and are maintained by signals emanating from the inner cell mass. However, several limitations including rarity and difficulty in isolation of trophoblast stem cells derived from blastocyst still exist. To establish a model for trophoblast differentiation, we isolated TBSCs from human term placenta ($\geq$38 weeks) and characterized. Cell cycle was analyzed by measuring DNA content by FACS analysis and phenotype of TBSCs was characterized by RT-PCR and FACS analysis. TBSCs have expressed various markers such as self-renewal markers (Nanog, Sox2), three germ layer markers (hNF68, alpha-cardiac actin, hAFP), trophoblast specific markers (CDX-2, CK7, HLA-G), and TERT gene. In FACS analysis, TBSCs isolated from term placenta showed that the majority of cells expressed CD13, CD44, CD90, CD95, CD105, HLA-ABC, cytokeratin 7, and HLA-G. Testing for CD31, CD34, CD45, CD71, vimentin and HLA-DR were negative. TBSCs were shown to decrease the growth rate when cultured in conditioned medium without FGF4/heparin as well as the morphology was changed to a characteristic giant cell with a large cytoplasm and nucleus. In invasion assay, TBSCs isolated from term placenta showed invasion activities in in vivo using nude mice and in vitro Matrigel system. Taken together, these results support that an isolation potential of TBSCs from term placenta as well as a good source for understanding of the infertility mechanism.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.3
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• pp.119-125
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• 2017

Objective: In vitro culture of preimplantation embryos is improved by grouping embryos together in a drop of media. Individually cultured embryos are deprived of paracrine factors; with this in mind, we investigated whether the addition of a single embryo-secreted factor, interleukin-6 (IL-6), could improve the development of individually cultured embryos. Methods: Mouse embryos were cultured individually in $2{\mu}L$ of G1/G2 media in 5% oxygen and supplemented with a range of doses of recombinant mouse or human IL-6. Results: Mouse IL-6 increased hatching at doses of 0.01 and 10 ng/mL compared to the control (93% and 93% vs. 78%, p< 0.05) and increased the total number of cells at a dose of 0.1 ng/mL compared to the control ($101.95{\pm}3.36$ vs. $91.31{\pm}3.33$, p< 0.05). In contrast, the highest dose of 100 ng/mL reduced the total number of cells ($79.86{\pm}3.29$, p< 0.05). Supplementation with human IL-6 had a different effect, with no change in hatching or total cell numbers, but an increase in the percentage of inner cell mass per embryo at doses of 0.1, 1, and 100 ng/mL compared to the control ($22.9%{\pm}1.1%$, $23.3%{\pm}1.1%$, and $23.1%{\pm}1.1%$ vs. $19.5%{\pm}1.0%$, p< 0.05). Conclusion: These data show that IL-6 improved mouse embryo development when cultured individually in complex media; however, an excess of IL-6 may be detrimental. Additionally, these data indicate that there is some cross-species benefit of human IL-6 for mouse embryos, but possibly through a different mechanism than for mouse IL-6.

• Clinical and Experimental Reproductive Medicine
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• v.47 no.4
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• pp.293-299
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• 2020

Objective: The goal of the present study was to investigate the rate of chromosomal aneuploidies in surplus embryos after sex determination at the cleavage stage. Then, the same chromosomal aneuploidies were evaluated in blastocysts after extended culture. Methods: Sixty-eight surplus embryos were biopsied at the cleavage stage and incubated for an additional 3 days to allow them to reach the blastocyst stage. The embryos were reanalyzed via fluorescence in situ hybridization (FISH) to examine eight chromosomes (13, 15, 16, 18, 21, 22, X, and Y) in both cleavage-stage embryos and blastocysts. Results: Although the total abnormality rate was lower in blastocysts (32.35%) than in cleavage-stage embryos (45.58%), the difference was not significant (p=0.113). However, when we restricted the analysis to autosomal abnormalities, we observed a significant difference in the abnormality rate between the cleavage-stage embryos (44.11%) and the blastocysts (17.64%, p=0.008). A higher rate of sex chromosomal abnormalities was also observed in cleavage-stage embryos (29.4%) than in blastocysts (14.70%, p=0.038). Conclusion: The data indicated that embryo biopsy should be conducted at the blastocyst stage rather than the cleavage stage. The results also emphasized that examination of common chromosomal aneuploidies apart from sex selection cycles can be conducted in the blastocyst stage with the FISH method.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.1
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• pp.26-32
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• 2022

Objective: We investigated the effect of supplementing fertilization medium and/or culture medium with astaxanthin (AST) on the two phases of in vitro fertilization: gamete fertilization and embryo development. Methods: Mouse cumulus-oocyte complexes were divided into four groups with 5 µM AST added to the fertilization medium (group 3, n=300), culture medium (group 2, n=300), or both media (group 4, n=290). No AST was added to the control group (group 1, n=300). Results: The fertilization rate was significantly higher (p<0.001) in the groups using AST supplemented fertilization medium (group 3, 79.0%; group 4, 81.4%) than those without AST (group 1, 56.3%; group 2, 52.3%). The blastocyst rate calculated from the two-cell stage was significantly lower (p<0.001) in the groups using AST-supplemented embryo culture medium (group 2, 58.0%; group 4, 62.3%) than in those without AST (group 1, 82.8%; group 3, 79.8%). The blastocyst rate calculated from the number of inseminated oocytes was highest in group 3 (189/300, 63.0%) and lowest in group 2 (91/300, 30.3%) with statistical significance compared to other groups (p<0.001). There were significantly higher numbers of cells in the inner cell mass and trophectoderm, as well as significantly higher total blastocyst cell counts, in group 3 than in the control group. Conclusion: An increased blastocyst formation rate and high-quality blastocysts were found only in the fertilization medium that had been supplemented with AST. In contrast, AST supplementation of the embryo culture medium was found to impair embryo development.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.20-20
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• 2001

It has been reported that cloning cattle is inefficient. One of the problems was placental abnormality, finally resulting in fetal mortality after transfer of nuclear transfer (NT) bovine embryos. This study was focused on the allocations of embryonic cells to the inner cell mass (ICM) or to the trophectoderm(TE) in NT bovine blastocysts. Somatic cells were derived from a Day 45 fetus of gestation, individually transferred into enucleated oocytes and developed to the blastocyst stage in vitro. Differential staining was used to assess the qualify of blastocysts derived from NT, IVF and in vivo. Development rate of NT embryos to blastocysts (25.0%, 41/164) was similar to that of IVF embryos (28.7%, 49/171). The total cell number of NT blastocysts (101.3$\pm$45.9) was not different compared with that of IVF embryos (107.9$\pm$34.2, P>0.05), but was lower than in vivo embryos (122.5$\pm$21.6, P<0.05). Ratio of ICM/total cells was higher in NT embryos (51.6$\pm$ 18.6%) than in IVF and in vivo embryos (42.3$\pm$ 15.3% and 34.9$\pm$8.9%, respectively) (P<0.05). Most IVF (56.8%, 25/44) and in vivo blastocysts(80.8%, 21/26) was distributed in the proportion of ICM/total cells ranging from 20 to 40% group. However, most NT blastocysts was biased in the 40-60%(34.1%, 15/44) and >60% (31.8%, 14/44) groups. Our findings suggest that placental abnormalities or early fetal losses in the present cloning system may be due to aberrant allocation of NT embryos to the ICM cells.

• Korean Journal of Animal Reproduction
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• v.20 no.1
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• pp.27-34
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• 1996

The objective of this study was to examine the cell number of Total, ICM and TE cells of bovine blastocysts according to development progression cultured in CR1 medium, which was reported as successfully supporting medium for preimplantaion bovine embryo development to the blastocyst stage, by differential labelling of the nuclei with immunosurgery and polynucleot-ide-specific fluorochromes. Blastocysts were obtained at day 8 after in vitro fertilization and classified to early, middle, expanded stage according to the developmental morphology; blastocoel expansion and zona thickness. Also, bias tocysts in the same category were divided into two parts to check the Total cell number by using bisbenzimide only and ICM, TE and Total cell number by using immunosurgery and two polynucleotide-specific fluorochromes. 1) The development rate of blastocysts at day 8 after in vitro fertilization was 29.3% and classified bIas tocysts to early, middle, expanded and hatching stage were 8.7, 9.9, 7.6 and 3.1%, respectively. 2) The numbers of total blastomere using bisbenzimide in the classified blastocysts to early, middie and expanded were 46.9${\pm}$8.6, 66.2${\pm}$12.5 and 122.8 ${\pm}$ 14.4, respectively. This indicated that CR1 is a appropriate culture medium for bovine embryo development. 3) The count of ICM and TE cell number by using differential labelling with immunosurgery and polynucleotide-specific fluorochromes in the classified blastocysts to early, middle and expanded; ICM cell numbers of were 12.8${\pm}$5.9, 26.3${\pm}$8.4 and 35.5${\pm}$15.0, respectively and TE cell numbers were 30.5${\pm}$5.0, 4 41.3${\pm}$8.2 and 81.1${\pm}$13.4, respectively. These results presented that the increase of ICM and TE cell numbers averaged two and three doublings between early and expanded blastocyst stage and also total cell number counted from ICM nuclei and TE nuclei by using differential label-ling showed the increase pattern with development advance level and the results were similar to total cell number obtained from bisbenzimide treatment only. Therefore, the differential labelling of ICM and TE nuclei in situ is a very useful technique to evaluate embryo qualities and can be used as an indicator on study of preim-plantation embryo development.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.1
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• pp.49-60
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• 2008

Objective: This study was carried out to investigate the effects of 3-dimensional co-culture of human endometrial cells decidualized with progesterone and TGF-${\beta}1$ on the development of 2-cell mouse embryos. Methods: Stromal and epithelial cells isolated from human endometrial tissue were immunostained for cytokeratin and vimentin. Expression of TGF-${\beta}1$, its receptor-1, -2, integrin-${\beta}3$ and prolactin in mono or co-culture according to three different hormone conditions was investigated by RT-PCR. Differential staining was used to investigate the number of ICM and trophectoderm of hatched mouse blastocysts in different three conditions. Results: The immunohistochemical study was positive for cytokeratin or vimentin and confirmed that epithelial and stromal cells were isolated from endometrial tissue successfully. In co-culture, TGF-${\beta}1$, its receptor-1, integrin-${\beta}3$ and prolactin except TGF-${\beta}1$-r2 were expressed in progesterone dominant condition. The hatching and attaching rate were higher in the co-culture with decidualized cells (p<0.05). However, we observed that lots of the incomplete hatched blactocysts attached on non-decidualized cells. The ICM number of hatched mouse blastocysts was higher in co-culture with decidualized and non decidualized cells than media only culture (p<0.05). The trophectoderm number of hatched blastocyst was higher in the co-culture with decidualized cells than non-decidualized cells or media only culture (p<0.05). Conclusion: The administration of progesterone, estrogen and TGF-$\beta$ could induce decidualization of stromal and epithelial cells isolated from human endometrial tissue using 3-dimensional co-culture, and the decidualization of human endometrial cells could increase the hatching and attaching rate of 2-cell mouse embryos.