• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.355-360
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• 1990

Single nuclei from two-, four- and eight-cell mouse embryos were transplanted into enucleated two-cell embryos by micromanipulation and Sendai virus mediated fusion. The developmental potential of these reconstituted embryos in vitro and in vivo was examined. It was found that the single nuclei which were transplanted to enucleated two-cell embryos were not only able to develop to the blastocyst stage in vitro(two-cell nuclei, 76.5%; four-cell nuclei, 68.4%; eight-cell nuclei, 48.3%), but also able to develop to full term in vivo after transfer to recipient mice(two-cell nuclei, 37.1%; four-cell nuclei, 29.6%; eight-cell nuclei, 16.3%). Although the proportion of live young produced after transfer of nucler of nuclear transplant embryos which received eight-cell nuclei was significantly (p<0.05) reduced, it would be suggested that the overall efficiency in producing identical offspring is greater when eight-cell embryos were selected for nuclear donor than two- or four-cell embryos were selected.

• Korean Journal of Animal Reproduction
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• v.15 no.1
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• pp.49-57
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• 1991

This study was carried out to investigate the effect of equilibration time, precooling and straw loading method on the post-thaw survival rates of mouse embryos cryopreserved by vitrification method. The effect of the vitrification procedure on the damage of the embryos was also examined by the straining of nuclei using Hoechst 33342. The results obtained were summarized as follows; 1. The equilibration in Medium-1 for 10 minutes was considered to be the optimum equilibration time. Embryos equilibrated in Medium-1 for 10 minutes(81.0%) showed significantly(P<0.05) higher survival rates than those equilibrated for 5 minutes(40.0%) or 15 minutes(74.1%). 2. The survival rate of embryos cryopreserved using the double Medium-2 column(81.0%) was significantly(P<0.01) higher than that using the single Medium-2 column, whish was considered to be due to the double Medium-2 column method being more reliable for preventing contamination of diluent solution of 1M sucrose. 3. The survival rate of compacted morula stage embryos cryopreserved with the precooled and non-precooled Medium-2 was not significantly(P<0.05) different. 4. The number of blastomeres of embryos at late blastocyst stage after culture of mouse morulae for 24 to 28hours was significantly(P<0.05) decreased by freezing embryos using vitrification(53.3${\pm}$1.6 vs 41.4${\pm}$1.5), which was considered to be due to the damage of embryos during vitrification and the delay of embryo development by handling in vitro. 5. The vitrification procedure is considered to be a very simple and efficient method for cryopreservation of embryos at early developmental stage.

• Molecules and Cells
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• v.24 no.3
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• pp.409-415
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• 2007

The retinoblastoma (Rb) gene is one of the most important genes in cell cycle regulation and tumorigenesis. Homozygosity for a germ-line Rb mutation results in embryonic lethality and evokes developmental defects associated with inappropriate S-phase entry and high levels of apoptosis. Although Rb has been extensively studied, more target genes need to be identified and characterized to unravel the precise mechanism of Rb function. In order to identify Rb-regulated genes, we analyzed the gene expression profile of Rb-deficient mouse embryo fibroblasts (MEFs), and identified an unknown gene, RbEST47, that is transcriptionally upregulated in Rb-deficient MEFs. This gene is conserved from fruitfly to human. It is expressed in brain, lung, kidney, and testis, and is located on mouse chromosome 2. This region is syntenic to human chromosome 9q34.3, which frequently exhibits loss of heterozygosity in neoplastic diseases. RbEST47 was considerably down-regulated in immortalized cells, and showed cell cycle-dependent expression, suggesting important roles in S and/or G2.

• Clinical and Experimental Reproductive Medicine
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• v.19 no.1
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• pp.1-8
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• 1992

A fluorescence microscopy technique using flurescein diacetateCFDA) as a substract has been tested for the evaluation of the viability of early mouse embryos. Embryos were incubated in T6 containing FDA concentrations of 2.5 to $50{\mu}g/ml$ for 1 to 5min. Embryos were then examined by reflected light fluorescence using a KP 490 and 520 barrier filter in a Nicon Diaphot microscopy. The results were as follow. 1. The rate of fluorescein accumulation increased on the concentration on FDA from $2.5{\times}10^{-6}M$ to $20{\times}10^{-6}M$ 2. The rate at which intracellular fluorescein was lost from embryos was depended on the temperature at which are stored. 3. Embryos with 3 min exposure to FDA have the most intensity of fluorescence. 4. Exposure of 2 cell embryos to FDA ($2.5-5{\mu}g/ml$) for 1 min did not alter their ability to delope normally in vitro.

• Korean Journal of Animal Reproduction
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• v.16 no.1
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• pp.47-53
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• 1992

This study was carried out to investage the effect of cryoprotectant concentration and equilibration time on volume change and in vitro development of intact and bisected mouse embryos by rapid freezing. When compacted morulae were rapidly frozen in 3.0 to 4.0 glycerol or DMSO with 0.25M sucrose solution, the superior(P<0.05) post-thaw survival rate was obtained at the glycerol concentration of 4.0M(89.4%) than 3.0M(71.4%) or 5.0M(42.4%), but at the DMSO concentration of 3.0M(84.5%) than 4.0M(51.1%) or 5.0M(0.0%). The optimal equilibraton time for rapid freezing of ZP-free or bisected morulae in 4.0M glycerol with 0.25M sucrose was found tobe 3 minutes. The minimal volume of compacted morulaewhich corresponded with 61 to 62% of pre-equilibrated embryo volume was obtained from equilibration for 3 minutes in both 3.0 and 4.0M glycerol solutions with 0.25M sucrose.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.236-236
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• 2004

Hyaluronic acid (HA) is one of the most abundant glycosaminoglycans (GAGs) in the female reproductive tract such as uterine, oviductal and follicular fluids in mouse, pig, cattle and human. CD44 is the principal cell membrane receptor for HA, expressed from the 1-to 8-cell stage in human embryos, during post-implantation mouse and bovine embryogenesis and on the surface of differentiated embryonic stem cells. (omitted)

• Korean Journal of Animal Reproduction
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• v.8 no.2
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• pp.110-115
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• 1984

These experiments were carried out to obtain the information about the optimal pH osmolality affecting in vitro fertilization of the mouse eggs, to elucidate the 2-cell block to development in vitro and to find out the method of controlling the subsequent embryo development in vitro. pH and osomlality was adjusted by adding NaCl or NaHCO3 to the basic salt solution. In vitro fertilization were carried out by inroducting the cumulus masses to the suspension of epididymal spermatozoa at each pH, osmolality, and 10${\mu}$M-EDTA medium. The results obtained in these experiments were summarized as follows: 1. The fertilization rates in vitro at each medium of 235, 252, 269, 286, 306, 323, 345, 368, 393 mosmol were 15.6, 38.2, 65.7, 75.6, 80.9, 74.3, 58.1, 35.1, 24.3, 11.1%, respectively. 2. The fertilization rates in vitro at each medium of pH 6.1, 6.4, 6.7, 7.0, 7.3, 7.6, 7.9, 8.1 were 11.8, 17.9, 32.4, 61.9, 79.5, 76.7, 53.5, 13.6%, respectively. 3. In case of ICR female x ICR male embryos, the development rate of 2-cell embryos to 4-8 cell embryos was 16.2% at normal medium, but the rate was increased to 49.3% in medium containging 10 ${\mu}$M-DETA; In case of C3H female x ICR male embryos, the development rate was 41.0% at normal medium, but the rate was increased to 71.7% at 10 ${\mu}$M-EDTA-medium.

• Toxicological Research
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• v.18 no.2
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• pp.117-127
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• 2002

Saururus chinensis Baill has been used in Korean folk medicine for the treatment of various diseases such as edema, Jaundice, and furuncle. The components of this plant were extracted into four fraction. Among the four fraction, hexane and ethyl acetate fraction were highly toxic to 3T3 mouse embryo fibroblast and Raw 264.7 mouse macrophage, but n-butanol and residue fraction did not show any toxic effect to those cell lines. n-Butanol and residue fraction exhibited antioxidant effects on hydro-gen peroxide, hydroxyl radical, and superoxide anion directly in vitro and in the 3T3 fibroblasts. All the four fractions inhibited lipid peroxidation measured by thiobarbituric acid reactive substances (TBARS) formation. In addition, n-butanol and residue fraction showed inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide production, and also down-regulated inducible nitric oxide synthase (iNOS) mRNA transcription 6 h after LPS stimulation in Raw 204.7 cells. Only n-butanol fraction, which mainly consists of flavonoids, inhibited NF-kB activation by decreasing IkBa degradation 90 min after LPS stimulation. horn the results, it is suggested that this plant could be a good candidate material for drug development based on its antioxidant and/or anti-inflammatory constituents.

• Korean Journal of Animal Reproduction
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• v.14 no.2
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• pp.133-140
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• 1990

This study was conducted to develop a simple and efficient technique for fusing 2-cell mouse embryos to obtain tertraploid embryos. Various concentration of PEG and exposure times were compared in order to determine the best condition for fusion and subsequent of fused embryos. The results obtained were follows ; 1. The incidence of fusion induction treated with 40% PEG(70.8%) and 45%(62.7%) for 60 sec. exposure were higher than those of 40% and 45% PEG for 30 sec., 90 sec., or 120 sec. exposure group. Also, the highest incidence of fusion induction(76.9%) was achieved with 120 sec. exposure at 50% PEG concentration. 2. Fused embryos after PEG treatment were cleavaged 2-to 4-cell, 8-cell, morula and blastocyst at 20-24 hr., 30-34., 44-52 hr., respectively, and were not different from those obtained fleshly. 3. The high proportions of the embryos developed to blastocysts after blastomere fusion with 40% PEG for 60 sec., 45% PEG for 60 sec. and 50% for 120 sec. were 66.7%(42/63), 69.0%(29/42) and 32.0%(16/50), respectively, this trend indicated that the fusion rate was similar to the incidence of fused embryos forming blastocysts. 4. The cell number of blastocyst developed from fused embryos(18.7 2.6) was samller than that of untreated embryos(48.9 1.69)

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3405-3409
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• 2013

The activation of heat shock factor 1 (HSF1) can be induced by the changes in environmental pH, but the mechanism of HSF1 activation by acidification is not completely understood. This paper reports that a low pH (pH~6.0) can trigger human HSF1 activation. Considering the involvement of the imidazole group of histidine residues under acid pH stress, an in vitro EMSA experiment, Trp-fluorescence spectroscopy, and protein structural analysis showed that the residue, His83, is the essential for pH-dependent human HSF1-activation. To determine the roles of His83 in the HSF1-mediated stress response affecting the cellular acid resistance, mouse embryo fibroblasts with normal wild-type or mutant mouse HSF1 expression were preconditioned by heating or pH stress. The results suggest that His83 is essential for HSF1 activation or the HSF1-mediated transcription of heat shock proteins, in protecting cells from acid pH stress.