• Korean Journal of Plant Taxonomy
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• v.51 no.1
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• pp.100-102
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• 2021

The chromosome number of myoga ginger (Zingiber mioga (Thunb.) Roscoe: Zingiberaceae) has been reported as 2n = 22 for Chinese plants and 2n = 55 for Japanese plants. We checked the chromosome number of Z. mioga in plants collected in Jeollabuk-do and Jeollanam-do, Korea, and counted 2n = 44, the first report of this number for the species. As the basic chromosome number of Z. mioga is thought to be x = 11, Z. mioga plants in China, Korea, and Japan appear to be diploids, tetraploids, and pentaploids, respectively. In finding the tetraploid race of Z. mioga in Korea, we can hypothesize that the pentaploid race in Japan is derived through the fertilization of reduced gametes of the diploid race and unreduced gametes of the tetraploid race.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.96-96
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• 2003

Nek2 (NIMA-related protein) is a mammalian cell cycle-regulated kinase that involves in chromosome condensation and centrosome regulation and NuMA (nuclear mitotic apparatus protein) is involved in spindle assembly during a cell cycle. The cellular distribution and organization of the centrosomal components is completely unknown during fertilization and embryonic development. We examined distribution of two well-known centrosomal proteins, Nek2 and NuMA in mouse gametes and embryos to get an insight in the reorganization of centrosomal proteins during germ cell development and early fertilization. Spermatogenic cells, gametes, and embryos were analyzed with anti-Nek2 or -NuMA antibodies by immunological assay, RT-PCR, and overexpression through gene transfection. Mitotically or meiotically active spermatogenic cells were intensively stained with these antibodies in both centrosomes and cytoplasm, whereas the oocytes showed different staining patterns depending on the meiotic stages. During maturation, GV, GVBD, and MI stage were clearly stained with NuMA antibody in the nucleus or cytoplasm at MII. Also, Nek2 was detectable in cytoplasm as scattered spots or chromosome associated at MII. In early developmental embryo, NuMA was detected in nucleus of each blastomere, while Nek2 was detected in cytoplasm. In contrast to previously reported results, Nek2 and NuMA were detected in both decondensing head, and the centriole of demembranated and decondensed sperm or whole body of trypsin-treated sperm for Nek2. During meiotic progress in oocytes, transcripts levels were the highest in MI stage and then downregulated in MII. Also, it shows dramatically change in early developmental embryos, firstly, it was increased until 4 cell stage and reduced in 8 cell stage, and finally, transcript levels were upregulated until blastoscyst. This finding suggests that cnetrosomal component may play an important role in reorganizing of functional centrosome during fertilization process and subsequent development.

• Journal of Embryo Transfer
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• v.1 no.1
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• pp.16-27
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• 1986

Based on the current importing and exporing regulations for disease control of embryo transfer, some important microorganisms and their control possibilities are reviewed. The results reviewed were sumrnarized as follows: 1. Regulations regarding to the import of embryos vary between importing and exporting countries, but exporting countries examine the donor and embryos for the heaith certification by the requirements of importing countries. 2. Organisms that infect the gametes are 5 kinds of viruses and the diseases caused by them could not be controlled or eradicated using embryo transfer. 3. Organisms that do not infect the gametes are 4 kinds of viruses and the causal organisms are potential candidates for control or eradication by embryo transfer. 4. Organisms that penetrate the zona pellucida and infect the embryo are 6 kinds of viruses including bovine viral diarrhea virus. 5. Organisms that cannot penetrate the zona pellucida or do not infect the embryo are 15 kinds of viruses and the removal from their contaminations are recommended by proper washing procedure and antisera treatment. Bovine and porcine parvovirus, porcine pseudorabies virus and vesicular stomatitis virus are included in these organisms. 6. Bovine embryos that artificially exposed to various pathogenic organisms such as bovine herpes virus, IBR virus, bluetongue virus, bovine viral diarrhea virus and Brucella abortus in vitro are discussed about their infection by several treatments.

• The Transactions of the Korea Information Processing Society
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• v.7 no.6
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• pp.1844-1851
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• 2000

In this paper, a metamorphosed genetic algorithm based on the meiosis for human's chromosome is presented. In the algorithm, chromosomes in an individual are divided in half and in the other are divided into other rate. By our definition, they are composed of gametes with X-type chromosomes or Y-type chromosomes or especially M(mutation)-type chromosomes. When tow gametes among them are randomly selected and recombined, the new individual is correspondingly generated. Without reducing the searching space significantly, the global solution can be readily searched by new generated individual. The performance of he presented algorithm is examined and evaluated through proper simulation using test functions.

• Clinical and Experimental Reproductive Medicine
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• v.50 no.1
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• pp.1-11
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• 2023

In reproduction, mitochondria produce bioenergy, help to synthesize biomolecules, and support the ovaries, oogenesis, and preimplantation embryos, thereby facilitating healthy live births. However, the regulatory mechanism of mitochondria in oocytes and embryos during oogenesis and embryo development has not been clearly elucidated. The functional activity of mitochondria is crucial for determining the quality of oocytes and embryos; therefore, the underlying mechanism must be better understood. In this review, we summarize the specific role of mitochondria in reproduction in oocytes and embryos. We also briefly discuss the recovery of mitochondrial function in gametes and zygotes. First, we introduce the general characteristics of mitochondria in cells, including their roles in adenosine triphosphate and reactive oxygen species production, calcium homeostasis, and programmed cell death. Second, we present the unique characteristics of mitochondria in female reproduction, covering the bottleneck theory, mitochondrial shape, and mitochondrial metabolic pathways during oogenesis and preimplantation embryo development. Mitochondrial dysfunction is associated with ovarian aging, a diminished ovarian reserve, a poor ovarian response, and several reproduction problems in gametes and zygotes, such as aneuploidy and genetic disorders. Finally, we briefly describe which factors are involved in mitochondrial dysfunction and how mitochondrial function can be recovered in reproduction. We hope to provide a new viewpoint regarding factors that can overcome mitochondrial dysfunction in the field of reproductive medicine.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.2
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• pp.47-53
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• 2023

Despite numerous advances in in-vitro embryo production (IVP), many documented factors have been shown to influence the development of mammalian preimplantation embryos and the success of IVP. In this sense, elevated levels of reactive oxygen species (ROS) correlate with poor outcomes in assisted reproductive technologies (ART) due to oxidative stress (OS), which results from an imbalance between ROS production and neutralization. Indeed, excessive production of ROS compromises the structural and functional integrity of gametes and embryos both in vivo and in vitro. In particular, OS damages proteins, lipids, and DNA and accelerates cell apoptosis. Several in-vivo and in-vitro studies report an improvement in qualityrelevant parameters after the use of various antioxidants. In this review, we focus on OS and the source of free radicals and their effects on oocytes, sperm, and the embryo during IVP. In addition, antioxidants and their important role in IVP, supplementation during oocyte in vitro maturation (IVM), in vitro culture (IVC), and semen extenders were discussed. Nevertheless, various methods for determining the level of ROS in germ cells have been briefly described. Still, it is crucial to develop standardized antioxidant supplement systems to improve overall IVP success. Further studies should explore the safety, efficacy, mechanism of action, and combination of different antioxidants to improve IVP outcomes.

• Journal of Embryo Transfer
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• v.5 no.2
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• pp.45-55
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• 1990

The in-vitro fertilization in human clinic and animal reproduction is a very important technique but the rate of success is still low. When the in-vitro fertilization and culture of gametes or embryos were done under the condition which Hema hydrogel chamber were implanted into the peritoneal cavity of mouse, the in-vitro fertilization and development of embryos could be significantly improved and the cell-block under in-vitro culture could be overcome. Also, the Rema hydrogel chamber was very useful for the protection of isolated blastomeres. It is concluded that the polymerized Hema (pHema) hydrogel chamber may be effectively used in the fields of embryo transfer and in vitro fertilization.

• Reproductive and Developmental Biology
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• v.32 no.2
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• pp.97-104
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• 2008

Plasminogen activators (PAs) are serine protease that cleave plasminogen to form the active protease plasmin. PA/plasmin system playa role in mammalian fertilization and motility and acrosome reaction of sperm. The present study was undertaken to identify PAs in porcine gametes and investigate a possible role of plasminogen in in vitro fertilization in the pig. When boar spermatozoa were preincubated in a fertilization medium (mTBM) for 0, 2, 4 or 6 h, the activity of tPA-PAI ($110{\sim}117\;kDa$), tPA ($62{\sim}70\;kDa$), and uPA ($34{\sim}38\;kDa$) was observed in the sperm incubation medium and sperm sample. PA activities in the sperm incubation medium significantly (p<0.05) increased according to increasing incubation times, while PA activities in sperm significantly (p<0.05) decreased at the same times. In addition, the rate of acrosome reaction in spermatozoa increased by increasing culture times. When oocytes were separated from porcine cumulus-oocytes complexes at 0, 22 or 44 h of maturation culture, no PA activities were observed in cumulus free-oocyte just after aspiration from follicles. However, the activity of tPA-PAI ($108{\sim}113\;kDa$) and tPA ($75{\sim}83\;kDa$) was observed at 22 h of in vitro culture and significantly (p<0.05) increased as the duration of the culture increased. On the other hand, when porcine oocytes were activated by sperm penetration or calcium ionophore, plasminogen significantly (p<0.05) increased ZP dissolution time (sec) in activated oocytes by sperm penetration. These results suggest that supplementation of plasminogen to fertilization medium may playa positive role in the improvement of in vitro fertilization ability in the pig.

• Korean Journal of Veterinary Research
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• v.35 no.2
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• pp.317-326
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• 1995

The purpose of this study was to establish a method for in vitro culture of C parvum isolated in Korea by determination of suitable cell model to complete development of this parasite. The result obtained were summerized as follows: 1. To determine the most suitable cell line, six types of cell line were examined by microscopy. All cell lines were infected with C parvum and showed the highest infection score in HmLu cells. 2. The staining methods including DMSO-modified acid-fast(A-F) stain, hematoxylin-eosin(H & E) stain and immunofluorescence antibody(IFA) stain were applied to examine the infection of C parvum in cell culture. These staining methods were possible to examine the infection of C parvum in cell culture. The most sensitive one was IFA staining technique. 3. Developmental stages of C parvum in HmLu cell were observed. After the initial 8 hour incubation period, some trophozoites were observed. The meronts and gametes were appeared at 24-48 hour post inoculation(PI), and oocysts were observed firstly at 48-72 hour PI. 4. In H & E stain, the parasite appeared as basophilic within parasitophorous vacuole membrane(PVM) and lying in cytoplasm at near the nucleus of the host cells. It was able to distinguish the type I, type II meronts and gametes. 5. In DMSO-modified acid-fast stain, specific stained parasites were appeared firstly after 48 hour PI. The parasites were showed with different degrees of staining bright red color within PVM. 6. The endogenous stages of parasites in HmLu cell recovered at 48, 96, 120 and 144 hour after inoculation were reacted with rabbit immunized serum in immunofluorescence antibody and avidin-biotin complex peroxidase staining technique.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.2
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• pp.70-76
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• 2023

Background: Despite considerable technological advancements, polyspermy remains a significant challenge in in vitro fertilization (IVF) procedures in pigs, disrupting normal embryonic development. Here, we aimed to determine whether optimal fertilization conditions reduce the polyspermy incidence in pigs. Methods: In vitro-matured oocytes were co-incubated with sperm according to a modified two-step culture system. Results: In the first experiment, oocytes were briefly co-incubated with sperm, washed in IVF medium, and then moved to fresh IVF medium for 5 or 6 h. Although the 6 h sperm-free cultured group had a higher penetration rate than the 5 h cultured group, the polyspermy rate significantly increased in the 6 h sperm-free cultured group. The gamete co-incubation period was either 20 or 40 min. The 40 min cultured group had a higher rate of blastocyst formation and number of total cells in blastocysts than the 20 min cultured group. In experiment 2, oocytes were inseminated with sperm separated by Pecroll treatment. Percoll treatment increased the rate of oocyte penetration and blastocyst formation compared to the control. In experiment 3, fertilized oocytes were cultured in 25 µL microdroplets (10 gametes/drop) or 500 µL (100 gametes/well) of culture medium in 4-well plates. The large volume of medium significantly reduced the number of dead oocytes and increased the rate of blastocyst formation compared to the small volume. Conclusions: Collectively, these results demonstrate that various fertilization conditions, including modified co-culture period, active sperm separation, and culture medium volume, enhance fertilization efficiency and subsequent embryonic development by decreasing polyspermy occurrence.