• Reproductive and Developmental Biology
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• v.35 no.4
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• pp.407-414
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• 2011

The development of embryos reconstructed by somatic cell nuclear transfer (SCNT) is dependent upon numerous factors. Central to development is the quality and developmental competence of the recipient cytoplast and the type of the donor nucleus. Typically metaphase of the second meiotic division (MII) has become the cytoplast of choice. Production of a cytoplast requires removal of the recipient genetic material, however, it may remove proteins which are essential for development or reduce the levels of cytoplasmic proteins to influence subsequent reprogramming of the donor nucleus. In this study, enucleation at MII did not affect the activities of either MPF or MAPK kinases. Immunocytochemical staining showed that both Cyclin B1 (MPF) and Erk1/2 (MAPK) were associated with the meiotic spindle of AI/TI oocytes with little staining in the cytoplasm, however, at MII association of both proteins with the spindle had reduced and a greater degree of cytoplasmic distribution was observed. The analysis of oocyte proteins removed during enucleation is a difficult approach to the identification of factors which may be depleted in the cytoplast. This is primarily due to the large numbers of aspirated karyoplasts which would be required for the analysis.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.3
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• pp.301-305
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• 2000

Globozoospermia is a rare type of teratozoospermia. It occurs in 0.1% of all andrological patient's and used to be considered sterile. Globozoospermic patient has 100% round headed spermatozoa, but the spermiogram is normal. The spermatozoa show oval-shape head, the lack of a nuclear envelope, acrosome, and post acrosomal sheath. Objective: To report that a couple with infertility secondary to globozoospermia received ICSI treatment. Material and Method: Case report Results: In the first trial, fertilization was failed. In the second trial, 40% of oocytes were fertilized and all of these embryos were cleaved, but pregnancy did not achieved. In the third trial, sperm injected oocytes were exposed to 10 ${\mu}M$ calcium ionophore for 15 min. All of the injected oocytes were fertilized and proceeded to develop. Triplet pregnancy was achieved after the transfer of six embryos in their third cycle. One embryo vanished and the remaining twins (female) were delivered at 33 weeks of gestation by Caesarean section. Conclusion: This result shows that assisted activation following ICSI may overcome infertility associated with globozoospermia.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.2
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• pp.67-71
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• 2015

Objective: Elevated serum progesterone (P) levels on triggering day have been known to affect the pregnancy rate of in vitro fertilization (IVF). This study aimed to identify the possible factors influencing serum P levels on triggering day in stimulated IVF cycles. Methods: Three hundred and thirty consecutive fresh IVF cycles were included in the study. All cycles were first attempts and were performed in a single infertility center. The indications for IVF were male factor infertility (n=114), ovulatory infertility (n=84), endometriosis (n=61), tubal infertility (n=59), unexplained infertility (n=41), and uterine factor infertility (n=39). A luteal long protocol of a gonadotropin-releasing hormone (GnRH) agonist (n=184) or a GnRH antagonist protocol (n=146) was used for pituitary suppression. Ovarian sensitivity was defined as the serum estradiol level on triggering day per 500 IU of administered gonadotropins (OS[a]) or the retrieved oocyte number per 500 IU of administered gonadotropins (OS[b]). Results: Univariate analysis revealed that the serum P level on triggering day was associated with the serum estradiol level on triggering day (r=0.379, p<0.001), the number of follicles ${\geq}14mm$ (r=0.247, p<0.001), the number of retrieved oocytes (r=0.384, p<0.001), and ovarian sensitivity (OS[a]: r=0.245, p<0.001; OS[b]: r=0.170, p=0.002). The woman's age, body mass index, antral follicle count, and basal serum follicle stimulating hormone and estradiol levels were not associated with serum P level on triggering day. The serum P level on triggering day did not show significant variation depending on the type or cause of infertility, pituitary suppression protocol, or the type of gonadotropins used. Conclusion: The serum P level on triggering day was closely related to the response to ovarian stimulation.

• Molecules and Cells
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• v.25 no.2
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• pp.265-271
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• 2008

Single nucleotide polymorphisms (SNPs) are the most common form of human genetic variation. Non-synonymous SNPs (nsSNPs) change an amino acid. Organic anion transporters (OATs) play an important role in eliminating or reabsorbing endogenous and exogenous organic anionic compounds. Among OATs, hOAT4 mediates high affinity transport of estrone sulfate and dehydroepiandrosterone sulfate. The rapid bone loss that occurs in post-menopausal women is mainly due to a net decrease of estrogen. In the present study we searched for SNPs within the exon regions of hOAT4 in Korean women osteoporosis patients. Fifty healthy subjects and 50 subjects with osteoporosis were screened for genetic polymorphism in the coding region of SLC22A11 (hOAT4) using GC-clamp PCR and denaturing gradient gel electrophoresis (DGGE). We found three SNPs in the hOAT4 gene. Two were in the osteoporosis group (C483A and G832A) and one in the normal group (C847T). One of the SNPs, G832A, is an nsSNP that changes the $278^{th}$ amino acid from glutamic acid to lysine (E278K). Uptake of [$3^H$] estrone sulfate by oocytes injected with the hOAT4 E278K mutant was reduced compared with wild-type hOAT4. Km values for wild type and E278K were $0.7{\mu}M$ and $1.2{\mu}M$, and Vmax values were 1.8 and 0.47 pmol/oocyte/h, respectively. The present study demonstrates that hOAT4 variants can causing inter-individual variation in anionic drug uptake and, therefore, could be used as markers for certain diseases including osteoporosis.

• Development and Reproduction
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• v.7 no.2
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• pp.119-126
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• 2003

In the previous study, we obtained list of differentially expressed genes between postnatal day 1 and day 5 mouse ovaries using suppression subtractive hybridization(SSH) and found that MT Oansposon-like element, clone MTi7(MTi7) was one of the highly expressed genes in the day 5 mouse ovary(Park et at., 2002). Results of in situ hybridization and RNA interference revealed that the expression of MTi7 is oocyte-specific in the ovary and may be involved in the regulation of oocyte maturation(Park et at., 2003). At present, MTi7 sequence has been known only in the mouse. Therefore, the present study was accomplished 1) to identify MTi7 sequence in the other mammalian species, such as bovine, porcine, rat, and human, and 2) to evaluate the flanking sequence of the mouse MTi7 since it has transposon characteristics. Using ovarian cDNAs derived from low different species, we cloned and identified new MTi7 sequence showing a high degree of sequence homology with the mouse MTi7(87∼98%). By using inverse PCR, we found that the mouse MTi7 may intercalated the beta-carotene 15, 15'-monooxygenase(Bcdo) gene and/or serine protease inhibitor, Kunitz Dpe I(Spint 1) gene. By finding the MTi7 sequences in the other mammalian species and the flanking gene of the MTi7 in mouse, it is expected to reveal the role(s) of MTi7 in the oogenesis as well as folliculogenesis in the near future.

• Applied Microscopy
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• v.41 no.3
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• pp.155-161
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• 2011

Three spot gourami (Trichogaster trichopterus Pallas, 1770) is a teleost belonging to Belontiidae. The oogenesis of three spot gourami was investigated by light microscope. The ovary was of light peach color and ellipsoidal shape with the major axis 2 cm and the minor axis 1 cm. Cytoplasm of oogonia was basophilic and many nucleoli were located at inside of nuclear membrane. In primary oocyte, lipid droplets were distributed only in the marginal area first, than at nuclear envelope near. In secondary oocyte, the egg envelope was formed and yolk vesicles was formed in the marginal area. The basophilic substance of cytoplasm was changed to acidic. In case of matured egg, thickness of egg envelope and size of egg were increased. The yolk vesicles were changed to yolk mass in accordance with development. The fertilized eggs were the colorless, transparent, spherical, adhesive and pelagic type. A large oil droplet was located in vitelline membrane of the fertilized egg. In conclusion, the oogenesis of three spot gourami was characterized by the increase in cell size, the formations of lipid droplets and yolk, the decrease of basophilic substance in the cytoplasm, and formation of one large oil droplets.

• Journal of Embryo Transfer
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• v.12 no.3
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• pp.293-300
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• 1997

Supplementation of maturation medium with additional granulosa cells has beneficial effect on in vitro maturation of bovine follicular oocytes and their subsequent cleavage and development in vitro. However, maturation system using granulosa cells have some disadvantages that collection of granulosa cells is cumbersome and metabolic activity of the cells is variable according to ovarian cycle or follicular size. We hypothesized that bovine immsture oocytes matured without granulosa cell coculture can fertilize and develop normally if the medium volume per oocyte is reduced during in vitro maturation. Immature oocytes were matured for 24 hours in a TCM199 containing 10% fetal calf serum, anterior pitultary hormone (0.02 AU /ml Antrinⓡ) and estradiol with or without granulosa cells in vitro. In Group 1, 35 to 40 oocytes were matured in a well of 4-well plastic dish containing 500 $\mu$l of maturation medium and granulosa cells, and 9 to 10 oocytes were matured in a 50-$\mu$l drop of maturation medium without granulosa cells in Group 2. After maturation, oocytes were coincubated with sperm for 30 hours in a modified Tyrode's medium (IVF). Inseminated oocytes were cultured in a microdrop (30 $\mu$l) of a synthetic oviduct fluld medium (SOFM) containing BSA, Minimum Essential Medium essential and non-essential amino acids for 9 days. As a preliminary experiment, we investigated the beneficial effect of granulosa cells during maturation on subsequent cleavage and development using the same type of culturedishes (4-well dish). Granulosa cells could not increase embryo cleavage after fertilization but significantly improved (p<0.05) embryo development to expanding blastocyst (Table1 and 2). In Group 1, 68 and 80% of inseminated oocytes have cleaved at 30 hours and 2 days after IVF, respectively, which is similar (p>0.05) to the result of Group 2 (69% at 30 hours and 78% at 2 days after IVF). The oocytes in Group 2 showed 21 and 11% of developmental rates to expanding and hatching blastocysts, respectively, which was not significantly different (p>0.05) from those (20 and 10%, respectively) of oocytes in Group 1. In conclusion, it has been clarified that a microdrop culture system without granulosa cells for in vitro maturation can support bovine embryonic development to blastocyst in vitro as readily as a granulosa cell coculture system.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.6
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• pp.856-860
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• 2000

Cloning technology continues to capture widespread attention by the international news media and biomedical and agricultural industries. The future uses of this technology could potentially contribute to major advances in biomedical and agricultural sciences. Cloned transgenic dairy cattle possessing milk promoters directing transgenes will produce pharmaceutical proteins in their milk faster, more efficiently and less expensively than transgenic cattle created using microinjection techniques. Additionally, cloned transgenic fetuses and animals may become a source of cells, tissue and organs for xenotransplantation. Lastly, but maybe most importantly, enhanced production traits and disease resistance may be realized in animal agriculture by utilizing these new technologies. The recent advances in the cattle cloning technology are important but there are still major obstacles preventing widespread commercial use of this technology. The type of donor nucleus, recipient cytoplasm, and cloning procedures used will impact the potential number of clones produced and the uses of the technology. In addition, the new advances in cloning methodology have not improved the relatively low pregnancy rates or reduced the incidence of health problems observed in cloned offspring. These problems may require novel techniques to decipher their cause and new methods of preventing and/or diagnosing them in the preimplantation embryo. The commercial potential is enormous for cloning technology; however, little has been done to improve the efficiencies of the procedure. Improving procedural efficiencies is a critical developmental milestone especially for potential uses of cloning technology in animal agriculture.

• Korean Journal of Agricultural Science
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• v.45 no.3
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• pp.493-498
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• 2018

There has been widespread warming and a general increase in summer temperatures over the Korean peninsula ($0.5^{\circ}C$/10 years from 2001 to 2010). South Korea is transforming into a subtropical region, and the productivity of livestock is affected by the climatic changes. In this study, we investigated whether the summer heat waves affect the developmental competency of Korean native cattle (Hanwoo), a taurine type of cattle with a small portion of indicine varieties. We collected oocytes during the summer (heat stress, HS) and autumn (non-HS condition) and examined the developmental competencies including in vitro maturation and preimplantation embryo development. No significant differences were observed between the HS and non-HS oocytes in nuclear maturation (extrusion of the polar body); however, the cleavage and blastocyst rates were significantly lower in the HS group than those in the non-HS group. The lower developmental competence of the HS oocytes compared to the non-HS is, in part, due to insufficient cytoplasmic maturation because of a higher production of Reactive oxygen species (ROS) levels as well as peri/cortical distributed mitochondria in the HS oocytes after in vitro maturation. Next, we examined the ROS and mitochondria distribution and found a significant increase in the levels of ROS in the HS oocytes and a polarized distribution (pericortical cytoplasm) of mitochondria in the HS oocytes. In summary, impaired cytoplasmic maturation of oocytes from exposure to HS affects the preimplantation embryo development by dysfunction of mitochondria. To improve reproductive performance, embryo transfer using cryopreserved embryos/oocytes is recommended in the hot summer season of South Korea.

• Development and Reproduction
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• v.14 no.2
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• pp.43-50
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• 2010

Recently induced pluripotent stem (iPS) cells are derived from somatic cells by ectopic expression of several transcription factors (reprogramming factors) using technology of somatic cell reprogramming. iPS cells are able to selfrenew and differentiate into all type of cells in the body similarly to embryonic stem cells. Because iPS cells have advantages that can avoid immune rejection after transplantation and ethical issues unlike embryonic stem cells, research on iPS has made significant progress since the first report by Yamanaka in 2006. Nevertheless of many advantages of iPS, safer methods to introduce reprogramming factors into somatic cells must be developed due to safety concerns regarding viral vectors, and safer reprogramming factors to substitute the oncogenes should be evaluated for clinical application of iPS. Here we discuss the recent progress in reprogramming factors in embryonic stem cells, oocytes, and embryos, and discuss further research for finding new, more reliable and safer reprogramming factors.