• The Korean Journal of Physiology and Pharmacology
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• v.71 no.2
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• pp.223-233
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• 2020

The embryoid body test (EBT) is a developmental toxicity test method that measures the size of embryoid bodies (EBs) and the viability of mouse embryonic stem cells (mESCs) and fibroblasts (3T3 cells). The previous pre-validation study confirmed the high accuracy (above 80%) of EBT using 26 coded test chemicals. This second-phase validation study assessed the inter-laboratory reproducibility (5 chemicals in common) and predictive capacity (10 chemicals in each laboratory) test using the coded test chemicals at three laboratories. For the prediction model, the accuracy is increased when more data is accumulated. Therefore, we updated the prediction model and analyzed the results of the second year with the newly created-prediction model. Statistical analysis of the inter-laboratory reproducibility test results indicated that accuracy, sensitivity, and specificity were 87%, 78%, and 100%, respectively. The results of the statistical analysis of the predictive capacity test showed an accuracy of 80%, sensitivity of 78%, and specificity of 81%. In conclusion, the EBT can accurately classify various embryotoxicants within a short period and with relatively little effort. Therefore, EBT can be used as a good way to test developmental toxicity.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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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.

• Fisheries and Aquatic Sciences
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• v.16 no.1
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• pp.15-23
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• 2013

Normal embryonic development at a constant temperature ($18^{\circ}C$) has been described for the Siberian sturgeon Acipenser baerii (Acipenseriformes). Hormone-induced spawning and artificial insemination were performed to prepare embryonic batches for embryologic examination. After insemination, early cleavages of the Siberian sturgeon embryos continued for 7 h post-fertilization (HPF), showing the typical pattern of uneven holoblastic cleavage. Blastulation and gastrulation began at 9 HPF and 19 HPF, respectively. Epiboly formation (2/3 covered) was observed at 25 HPF during gastrulation. Neurulation was initiated with the formation of a slit-like neural groove from the blastopore at 33 HPF. During neurulation, the primary embryonic kidney (pronephros) and s-shaped heart developed. The embryos underwent progressive differentiation, which is typical of Acipenseriform species. A mass hatching was observed at 130 HPF, and the average total length of the hatched prolarvae was 10.5 mm. The hatched prolarvae possessed a typical pigment plug (yolk plug). The results of this study are valuable not only as a reference guide for the artificial propagation of Siberian sturgeon in hatcheries but also as the basis for the derivation of developmental gene expression assays for this species.

• International Journal of Industrial Entomology and Biomaterials
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• v.18 no.2
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• pp.113-120
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• 2009

Embryonic lethal abnormal visual (elav) is a lethal gene in Drosophila inducing the abnormal development and function of nervous system. We cloned a Bm-elav gene by bioinformatics and biological experiment, based on sequence of ELAV protein and dbEST of Bombyx mori. The full-length of Bm-elav cDNA is 1498 bp, contains a 906 bp open read frame (ORF) encoding a precursor of 301 amino acid residues with a calculated molecular weight of 34 kDa and pI of 8.99. Bm-ELAV protein precursor contains three RNA recognition motifs (RRM) in $24{\sim}91$, $110{\sim}177$ and $222{\sim}295$ bit amino acid residues respectively, and belongs to RNA-binding protein family. Bm-ELAV shared varying positives, ranging from 56% to 60% (Identities from 41% to 45%), with RRM from other species of Xenopus tropicalis, Apis mellifera, Tribolium castaneum, Branchiostoma belcheri and Drosophila. Gene localization indicated that Bm-elav is a single-copy gene, gene mapping within 12-chromosome from 7916.68 knt to 7918.16 knt region of nscaf2993. Spatiotemporal expressions pattern analysis revealed that Bm-elav expressed higher in most tested tissues and developmental stages in whole generation, such as silk gland, fat body, midgut, hemopoietic organ and ovary, but almost no expression in terminated diapause eggs. This suggested that the expression of Bm-elav in early developmental embryonic stages might induce abnormal development like in Drosophila. Cloning of the Bm-elav gene enables us to test its potential role in controlling pests by transferring the gene into field lepidopteran insects in the future.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2000.11a
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• pp.75-77
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• 2000

Retaining migratory activity is a prerequisite for the manipulation and use of PGCs. This study was conducted to examine whether migratory activity is retained in the primordial germ cells(PGCs) from gonads at the later embryonic developmental stage. In the present study, gonads were dissected from 5-, 6- and 10-day-old quail embryos and treated with trypsin-EDTA for the degradation of gonadal tissue. Gonadal PGCs (gPGCs) were purified by Ficoll density gradient centrifugation and labeled with PKH26 fluorescent dye. The PKH26-labeled gPGCs were microinjected into the blood vessels of recipient quail embryo. After further incubation of 3 days, the manipulated recipients were embedded in paraffin and sectioned. The gPGCs were detected by their fluorescence under the fluorescent microscopy and the confocal laser microscopy. As a result, 10-day-old quail gPGCs as well as 5-and 6-day-old gPGCs, could migrate to recipient embryonic gonads and settle down. These results suggest that the 10-day-old gPGCs have the properties of circulating PGCs at early stage. Therefore the PGCs from 10-day old embryonic gonads can be used for the tools of genetic manipulation.

• 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.

• Development and Reproduction
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• v.21 no.4
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• pp.425-434
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• 2017

Polyploidy is occurred by the process of endomitosis or cell fusion and usually represent terminally differentiated stage. Their effects on the developmental process were mainly investigated in the amphibian and fishes, and only observed in some rodents as mammalian model. Recently, we have established tetraploidy somatic cell nuclear transfer-derived human embryonic stem cells (SCNT-hESCs) and examined whether it could be available as a research model for the polyploidy cells existed in the human tissues. Two tetraploid hESC lines were artificially acquired by reintroduction of remained 1st polar body during the establishment of SCNT-hESC using MII oocytes obtained from female donors and dermal fibroblasts (DFB) from a 35-year-old adult male. These tetraploid SCNT-hESC lines (CHA-NT1 and CHA-NT3) were identified by the cytogenetic genotyping (91, XXXY,-6, t[2:6] / 92,XXXY,-12,+20) and have shown of indefinite proliferation, but slow speed when compared to euploid SCNT-hESCs. Using the eight Short Tendem Repeat (STR) markers, it was confirmed that both CHA-NT1 and CHA-NT3 lines contain both nuclear and oocyte donor genotypes. These hESCs expressed pluripotency markers and their embryoid bodies (EB) also expressed markers of the three embryonic germ layers and formed teratoma after transplantation into immune deficient mice. This study showed that tetraploidy does not affect the activities of proliferation and differentiation in SCNT-hESC. Therefore, tetraploid hESC lines established after SCNT procedure could be differentiated into various types of cells and could be an useful model for the study of the polyploidy cells in the tissues.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.10a
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• pp.126-127
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• 2005

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.02a
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• pp.19-19
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• 2003

No Abstract, See Full Text

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2002.02a
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• pp.40-40
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• 2002