• Reproductive and Developmental Biology
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• v.32 no.4
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• pp.229-235
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• 2008

Silencing of Dicer1 by siRNA did not inhibit development up to the blastocyst stage, but decreased expression of selected transcription factors, including Oct-4, Sox2 and Nanog, suggesting that Dicer1 gene expression is associated with differentiation processes at the blastocyst stage (Cui et al., 2007). In order to get insights into genes which may be linked with microRNA system, we compared gene expression profiles in Gapdh and Dicer1 siRNA-microinjected blastocysts using the Applied Biosystem microarray technology. Our data showed that 397 and 737 out of 16354 genes were up- and down-regulated, respectively, following siRNA microinjection (p<0.05), including 24 up- and 28 down-regulated transcription factors. Identification of genes that are preferentially expressed at particular Dicer1 knock down embryos provides insights into the complex gene regulatory networks that drive differentiation processes in embryos at blastocyst stage.

• Korean Journal of Animal Reproduction
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• v.20 no.4
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• pp.473-477
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• 1997

This research was performed to investigate the developmental ability of mouse oocytes following cold-culture(4$^{\circ}C$) in vitro. When the oocytes were fertilized after 10 hour cold-culture in D-PBS or Ham's F10 with 0.3% BSA, the cleavage rage of the oocytes was not different in the rate of oocytes fertilized in vitro without cold-culture(126/189, 66.2% vs 88/133, 66.7%) and also the rate of embryos developed to blastocyst did not(123/189, 65.1% vs 82/133). But, when the time of the cold-cultre was extended from 10 to 24 hours, the rate of embryos developed to blastocyst was slightly decreased(73.5% vs 52.2%). However, when the oocytes were cultured for 10 and 24hours at 37$^{\circ}C$, the rate of oocytes developed to blastocyst was significantly decreased than that of oocytes following cold-culture. By the results of this study, it'll be possible to utilize effectively the cold-culture of the oocytes when in vitro fertilization is delayed.

• Clinical and Experimental Reproductive Medicine
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• v.29 no.2
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• pp.83-90
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• 2002

Objective : The purpose of the current series of experiments were to assess the effect of GM-CSF, as a medium supplement, on the development of mouse embryos and the expression of LIF and IL-1? mRNA. Materials and Methods: Mouse 2-cell embryos were collected from the oviducts of 6 weeks old ICR mice at 48 hours after hCG injection. Embryos were cultured in P-1 medium supplemented with mouse GM-CSF (0, 1, 5, 10 ng/ml). The embryo development to blastocysts and hatching blastocysts was assessed and the cell number in blastocyst was also examined. Using RT-PCR, the expressions of LIF and IL-1? mRNA in blastocyst were evaluated in the GM-CSF supplemented group and control group. Results: In mouse, the addition of GM-CSF increased the percentage of blastocysts (65.5%, 68.6%, 73.0% and 76.1% for control and 1, 5 and 10 ng/ml, respectively), and increased the proportion of hatching blastocysts (35.2%, 36.4%, 43.2% and 53.0% for control and 1, 5 and 10 ng/ml, respectively). The mean cell numbers in blastocyst were significantly increased in GM-CSF supplemented groups compared to control group. LIF and IL-1? expression in blastocyst were significantly higher in GM-CSF supplemented group than in control group. Conclusion: The results of experiment by mouse embryos showed beneficial effects of GM-CSF as a medium supplement. Furthermore, the addition of GM-CSF significantly increased the expression of LIF and IL-1? in mouse embryos. These results suggest that GM-CSF might be a important molecule in embryo implantation.

• Reproductive and Developmental Biology
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• v.36 no.4
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• pp.255-260
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• 2012

The purpose of this study was to assess follicular viability and competence through in vitro culture of preantral follicles isolated from vitrified mouse whole ovaries. Mouse preantral follicles were enzymatically isolated from vitrified- warmed and fresh ovaries and cultured for 10 days followed by in vitro oocyte maturation. In vitro matured oocytes were fertilized and cultured to the blastocyst stage. Five minutes pre-exposure to vitrification solution of whole ovaries had significantly higher (p<0.05) oocyte survival and maturation rates than between 10 min exposure groups. Oocyte diameter was significantly smaller (p<0.05) in the 5 and 10 min exposure groups ($69.4{\pm}2.8$ and $67.8{\pm}3.1$) when compared to that of control group ($71.7{\pm}2.1$). There was no statistical significant difference in blastocyst development rates between vitrification group (8.6%) and the fresh control group (12.0%). The mean number of cells per blastocyst was significantly lower (p<0.05) in the vitrification group ($41.9{\pm}20.2$) than in the fresh control group ($55.1{\pm}22.5$). The results show that mouse oocytes within preantral follicles isolated from the vitrified whole ovaries can achieve full maturation, normal fertilization and embryo development.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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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.

• Clinical and Experimental Reproductive Medicine
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• v.30 no.1
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• pp.77-84
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• 2003

Objective : The aim of this study was to evaluate the influence of three different media on preimplatation embryo development and the expression of Bcl-2, Mcl-1, Bax, and Bok in mouse. Materials and Methods: Two-cell embryos were retrieved from ICR female mice (4 weeks old) at 48 hr after hCG injection and cultured in Ham's F-10, HTF, and G1.2 media. The developmental rate of 2-cell embryos was evaluated from 24 hr to 72 hr after culture. RT-PCR was performed for the detection of Bcl-2, Mcl-1, Bax, and Bok gene expression. Results: The rates of morula and blastocyst in HTF and G1.2 media (88%, 98.1%) were significantly higher than those in Ham's F-10 media (39.6%) at 48 hr. Likewise, the rates of hatching and hatched blastocyst in HTF and G1.2 media (21.9%, 52.9%) were higher than those in Ham's F-10 media (3.5%) at 72 hr. Bcl-2 and Bax mRNAs were highly detected in embryos cultured in Ham's F-10 when compared in embryos cultured in HTF and G1.2. In contrast, the expression of Mcl-1 and Bok was not significantly different. Conclusion: These results show that HTF and G1.2 culture media increase the rate of blastocyst formation and stimulate Bcl-2 and Bax gene expression in mouse preimplantation embryos.

• Korean Journal of Animal Reproduction
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• v.21 no.2
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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.

• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.126-133
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• 1998

Effects of B(a)P on preimplantation mouse embryos in vitro were studied. Preimplantation mouse embryos were exposed to a concentration of 0.3, 1, 3 and 10 $\mu$M B(a)P for 72 hrs. The toxicological effects of B(a)P were evaluated by morphological observation of embryos up to the blastocyst stage, and by measuring DNA, RNA and protein synthesis by radioactive precursor incorporation. At 1 $\mu$M B(a)P did not affect preimplantation development but interfered with hatching and ICM formation. Suppressing effect of ICM formation was dose dependent. At the eight cell stage, the developmental rate was decreased at above 3 $\mu$M of B(a)P. At the blastocyst stage, attachment and trophoblast outgrowth were diminished at the 10 $\mu$M of B(a)P and ICM formation was decreased at 1 $\mu$M of B(a)P. Inner cell number of blastocyst was decreased dose dependently. So, number of ICM was one of the most sensitive and toxicological end point. The RNA incorporation rate of 0.1 $\mu ^3$H-uridine was dosedependent and the protein incroporation of 0.5 $\mu Ci ^{35}$S-methionine showed a significant decrease after 48 hrs. But the DNA incorporation rate of methyl-$^3$H thymidine was not affected. Our results suggested that B(a)P did not affect the DNA replication but transcription was inhibited by dose dependent manner. There delay of development during the blastocyst stage was mainly due to the inhibition of RNA synthesis followed by protein synthesis.

• Proceedings of the Zoological Society Korea Conference
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• 1997.04a
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• pp.64.2-64
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• 1997

No Abstract, See Full Text

• Clinical and Experimental Reproductive Medicine
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• v.30 no.1
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• pp.5-14
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• 2003

Objective: Present study was aimed to verify the effect of granulocyte macrophage-colony stimulating factor (GM-CSF) in the preimplantation development of mouse embryos and the involvement of the mitogen activated protein kiase (MAPK) in the GM-CSF signaling. Methods: Two-cell embryos were cultured for 96 h in the presence or absence of GM-CSF (0, 0.4, 2, 10 ng/ml) and PD98059, a MEK inhibitor (10 ${\mu}M$). Morphological development, cell number per blastocyst, and apoptotic nuclei, were eamined. MAPK activity of embryonic immunoprecipitate by MAPK (ERK1/2) antibody was measured by in vitro phosphorylation of myelin basic protein. Results: At post hCG 122 h the embryonic development among the experimental groups was significantly different (p=0.018). The rate of blastocyst development and cell number per embryo were the highest in 2 ng/ml GM-CSF treatment group. The percent of apoptotic cells of the GM-CSF-treated embryos was the lowest among the group. In blastocysts, GM-CSF treatment transiently increased MAPK activity. PD098059 attenuated the effect of GM-CSF on the morphological development, increase in cell number per blastocyst, down regulation of apoptosis, and upregulation of MAPK activity, suggesting that activation of MAPK cascade possibly mediated the embryotropic effect of GM-CSF. Conclusion: This result suggested that GM-CSF potentiated the development of preimplantation mouse embryos by activation of MAPK.