• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.203-203
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• 2002

The present study was conducted to investigate the potential embryo-fetal toxicity of 2-bromopropane(2-BP) in rats. The test agent was subcutaneously administered to pregnant rats from gestational day 6 to 19 at dose level of 0, 500, 1000, 1500 mg/kg.(omitted)

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.11a
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• pp.203-203
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• 2002

• Toxicological Research
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• v.17 no.4
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• pp.279-286
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• 2001

Recently, there is an increasing nationwide concern in Korea that exposure to electric and magnetic fields in the home environment may not be safe in humans. To identify possible effects of horizontally polarized magnetic fields (MF) exposure on embryo-fetal development, timed-mated female Sprague-Dawley rats (24/group) received continuous exposure to 60 Hz MF at field strengths of 0 Gauss (sham control), 50mG,833 mG, or 5000 mG. Dams received MF of sham exposures for 22hr/day on gestation days 6 through 20. Experimentally generated MF were monitored continuously througout the study. There was no evidence of maternal toxicity of developmental toxicity in any MF-exposed groups. Mean maternal body weight, organ weights, and gross findings in groups exposed to MF did not differ from those in sham control. No significant differences in fetal deaths, fetal body weight, and placental weight were observed between MF-exposed groups and sham control. External, visceral, and skeletal examination of fetuses demonstrated no significant differences in the incidence of fetal malformations between MF-exposed and sham control groups. In conclusion, exposure of pregnant Sprague-Dawley rats to 60 Hz at MF strengths up to 5000 mG during gestation day 6-20 did not produce any biologically significant effect in either dams of fetuses.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.45-45
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• 2003

The present study was conducted to investigate the potential embryo-fetal toxicity of Artesunate, an antimalarial drug, in Sprague-Dawley rats. The test item was orally administered by gavage to pregnant rats (22 females per group) from days 6 through 15 of gestation at dose levels of 0, 2, 4 and 8 mg/kg/ day. (omitted)

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.657-666
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• 2003

The present study was undertaken to evaluate the potential adverse effects of 2-BP on pregnant dams and embryo-fetal development after maternal exposure during the gestational days (GD) 6 through 19 in Sprague-Dawley rats. The test chemical was administered subcutaneously to pregnant rats at dose levels of 0, 375, 750 and 1250 mg/kg/day. During the test period, clinical signs, mortality, body weights and food consumption were examined. All dams were subjected to caesarean section on GD 20 and their fetuses were examined for external, visceral and skeletal abnormalities. At above 750 mg/kg, toxic effects including signs of toxicity, suppressed body weight, decreased gravid uterine weight and reduced food intake were observed in pregnant dams. An increase in the fetal deaths, a decrease in the litter size, a reduction in the fetal body weight and an increase in the incidence of fetal morphological alterations were also found. There were no adverse effects on either pregnant dams or embryo-fetal development at a dose level of 375 mg/kg. These results suggest that a 14-day subcutaneous dose of 2-BP is embryolethal and teratogenic at above 750 mg/kg/day in pregnant rats. In the present experimental condition, the no-observed-adverse-effect level of 2-BP is considered to be 375 mg/kg/day for dams and embryo-fetuses, respectively.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2004.10a
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• pp.26-31
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• 2004

This work was undertaken in order to study the developmental competence of nuclear transfer cat embryo with fetal fibroblast and adult skin fibroblast as donor nuclei. Oocytes wererecovered by mincing the ovaries in Hepes-buffered TCM199 and selected the cumulus oocyte complexes (COCs) with compact cumulus cell mass and dark. Homogenous ooplasm were cultured for maturation in TCM199 + 10% fetal bovine serum (FBS) for 12 hours and used as a source of recipient cytoplast for exogenous somatic nuclei. In Experiment 1, we evaluated the effect donor cell types on the reconstruction and development of cloned embryos. Fusion, first cleavage and blastocyst developmental rate was not different between fetal fibroblast and adult skin cell (71.2 vs. 66.8; 71.0 vs. 57.6; 4.0 vs. 6.1 %, P<0.05). In Experiment 2, cloned embryos were surgically transferred into the oviducts of recipient queens. One of seven recipient queens was delivered naturally 2healthy cloned cats and 1 stillborn from fetal fibroblast cell of male origin after 65 days embryo transfer. One of three recipient queens was delivered naturally 1 healthy cloned cat from adult skin cell of female after 65 days embryo transfer. The cloned cats showed genotypes identical to the donor cell lines, indicating that adult somatic cells can be used for feline cloning.

• Journal of Embryo Transfer
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• v.14 no.2
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• pp.93-97
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• 1999

The development potential of bovine somatic cells was evaluated using nuclear transfer. A single donor cell derived from fetus of HanWoo(Korean Native Cattle) was selected and deposited into perivitelline space of each enucleated oocyte before electrical fusion and activation. Nuclei of donor cells starved for 7 days (37%) tended to support the development of reconstitute embryo the blastocyst stage better than those of donor cells starved 3, 14 and 30 days. The cleavage rate was significantly lower(P<0.05) in reconstitute embryos derived from large size donor cells(51.2%), than those from small medium size donor cells(76.6 and 73.5, respectively). The developmental rate to blastocyst of reconstructed embryos from medium size donor cells was higher than those from small and medium size donor cells. This study demonstrates that an appropriate culture period for induction into quiescent stage and the size of donor cells effect on the efficiency of nuclear transfer using cultured bovine cells.

• Journal of Embryo Transfer
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• v.14 no.2
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• pp.107-111
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• 1999

The present study was performed to evaluate the best electric fusion condition in nuclear transfer, Korean Native Cattle fibroblasts were used as nucleic donors. Oocytes from slaughterhouse were matured in vitro for 22 h and enucleated. Each individual cells were transferred into enucleated ocytes and reconstructed embryo were placed into the fusion chamber. In experiment 1, pulse were performed by altering pulse duration at 1. 75kv/cm, 1 time. When pulse duration is 30$mutextrm{s}$, fusion and development rates is higher than other conditions. In experiment 2, the effect of different pulse number were studied at the pulse duration 30$mutextrm{s}$ and the same pulse intensity. When pulse number was one, fusion rates were higher than other conditions. The fused embryos were moved to culture medium and assessed their development to blastocyst. These results showed that best fusion condition was 30$mutextrm{s}$ and one time. And the fibroblasts derived from Han Woo can be reprogrammed by nuclear transplantation and develop subsequently in vitro.

• Toxicological Research
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• v.25 no.4
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• pp.209-216
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• 2009

We have recently reported that the continuous exposure of rats to a concrete building environment under cool temperatures had adverse effects on general health parameters and embryo-fetal development. This study examined to compare the potential effects of concrete and wood building environments on pregnant dams and embryo-fetal development in rats. Groups of 10 mated females were exposed to polycarbonate (control), concrete, or wood cages from gestational days (GD) 0 to 20 under cool temperatures $(11.9\sim12.3^{\circ}C)$. All the females underwent a caesarean section on GD 20, and their fetuses were examined for any morphological abnormalities. The temperatures in the cages were similar in all groups but the relative humidity in the concrete and wood groups were higher than in the control group. The concentration of volatile organic compounds in the wood group was higher than in the control group. In the concrete group, maternal effects manifested as an increase in the incidence of clinical signs, a lower body weight, and a decrease in the thymus and ovary weights. Developmental effects included increased post-implantation loss and decreased litter size. Infrared thermal analysis showed that the skin temperature of the rats in the concrete group was lower than that in the control group. In contrast, there were no exposure-related adverse effects on the maternal and developmental parameters in the wood group. Overall, the exposure of pregnant rats to a concrete building environment under cool temperatures has adverse effects on the clinical signs, body weight, skin temperature, organ weight, and embryo-fetal development. On the other hand, exposure to a wood building environment does not have any adverse effects in rats.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.6
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• pp.693-699
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• 2010

Imprinted genes are essential for fetal development, growth regulation, and postnatal behavior. However, little is known about imprinted genes in livestock. We hypothesized that certain putatively imprinted genes affected normal peri-implantation development such as embryo elongation, initial placental development, and preparation of implantation. The objective of the present study was to investigate the mRNA expression patterns of several putatively imprinted genes during the porcine peri-implantation stages from day 6 to day 21 of gestation. Imprinted genes were selected both maternally (Dlk1, IGF2, Ndn, and Sgce) and paternally (IGF2r, H19, Gnas and Xist). Here, we report that the maternally imprinted gene IGF2 was expressed from day 6 (Blastocyst stage), but Dlk1, Ndn, and Sgce were not expressed in this stage. These genes were first expressed between days 12 and day 14. All the maternally imprinted genes studied showed significantly high expression patterns from day 18 of embryo development. In contrast, paternally imprinted genes IGF2r, H19, Gnas, and Xist were first expressed from day 6 of embryo development (BL). Our data demonstrated that the expression of H19 and Gnas genes was significantly increased from day 14 of the embryo developmental stage, while IGF2r and Xist only showed high expression after day 21. This study is the first to show that the putatively imprinted genes were stage-specific during porcine embryonic development. These results demonstrate that the genes studied may exert important effects on embryo implantation and fetal development.