• Journal of Embryo Transfer
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• v.24 no.3
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• pp.145-150
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• 2009

This study was conducted to examine the effects of human follicular fluid and gonadotropin (FSH+HCG+rhEGF) on in vitro maturation, fertilization and development of human immature oocytes. Cumulus-oocyte complexes (COCs) were collected following for in vitro fertilization and embryo transfer (IVF-ET) cycles of the patients. At the time of oocytes collection, oocytes were classified into MII, MI and GV in accordance with their appearance (MII: Fully mature oocyte at metaphase II of meiosis; MI: Nearly mature oocytes at metaphase I of meiosis; GV: Immature oocytes at prophase I of meiosis). After controlled ovarian stimulation using gonadotropin(FSH) and human chorionic gonadotropin (HCG) in 70 ICSI cycles, 158 MI to MII matured oocytes were intracytoplasmic sperm injection (ICSI) ${\sim}4$ h after in vitro culture and 553 MII oocytes were ICSI after denudation. The aspirated MI and GV oocytes were cultured in culture medium containing 10% (v/v) serum protein substitute (SPS), 10% (v/v) human follicular fluid (hFF) and 10% (v/v) serum protein substitute (SPS)+1 IU/ml FSH+10 IU/ml HCG+10 ng/ml recombinant human epidermal growth factor (rhEGF). The maturation rate of immature oocytes was similar among the three group. When maturation medium was supplemented with 10% SPS, 10% hFF or gonadotropins, the fertilization rate of in vitro matured oocytes was higher in 10% SPS (80.0%), but there was no statistical significance (78.2%; hFF, 76.9%; gonadotropin, p>0.05). The development rate of human embryos developed to $6{\sim}8$ cells were not significant difference in the medium containing SPS, hFF and gonadotropins (65.6%, 65.9% and 66.7%). The results of these study suggest that human follicular fluid and gonadotropins supplemented in the culture medium was not effected on the in vitro maturation, fertilization and development of human immature oocytes.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.11
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• pp.1541-1546
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• 2011

This study was carried out to examine the influence of minimum essential medium (MEM) vitamins supplementation to in vitro maturation medium and in vitro culture medium on the development of porcine embryos. Porcine embryo development was investigated following cultivation in both in vitro maturation and culture medium with the supplementation of MEM vitamins (0, 0.1, 0.2 and 0.4%) using immature oocytes collected from the ovary of prepubertal gilts. Embryo development was observed and the total cell number in each blastocyst generated under the culture conditions was quantified following supplementation of the medium. The embryonic development rate of the blastocyst and hatched blastocyst was higher, but not significantly so, when 0.4% MEM vitamins were supplemented to the in vitro maturation medium of the porcine oocyte. Interestingly, the total number of cells in the blastocyst was significantly higher in the in vitro maturation MEM vitamins supplemented group compared to either the untreated group or the group which had MEM vitamins supplemented to both in vitro maturation and in vitro culture medium simultaneously (p<0.05). Therefore, the supplementation of 0.4% MEM vitamins to the in vitro mature medium has a beneficial effect on the embryonic development of in vitro produced blastocysts derived from the immature porcine oocytes.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.58-58
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• 2020

Xanthoceras sorbifolium Bunge (yellowhorn) is a woody tree in the soapberry family, Sapindaceae, native to northern China. This species has been identified as a major woody bioenergy plant for bio-diesel production because of high oil content in seed. But the flowers do not bear fruit well while the many flowers blooming. This study was performed to regenerate in vitro plantlet using adventitious shoot formation. To establish the protocol of plant regeneration, adventitious shoots formation rate in the culture of cotyledon of immature zygotic embryos was 68.6% in 1/2 MS medium with 0.5 mg l-1 BA and 3% sucrose (w/v). In the culture of cotyledons of mature zygotic embryos, induction of adventitious shoots was needed to contain high sucrose in pre-culture medium and the frequency of shoot induction was 64.4%. Multiple shoots were induced in 0.5 mg l-1 TDZ, and rooting of shoot was induced 4.0 mg l-1 IBA. Flow cytometry analysis revealed that all the regenerated plantlets were diploid.

• Proceedings of the Botanical Society of Korea Conference
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• 1999.07a
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• pp.85-89
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• 1999

Somatic embryogendesis is one of good examples of the basic research for plant embryo development as well as an important technique for plant biotechnology. This paper describes the direct somatic embryogenesis from zygotic embryos of Panax ginseng is reversely related to normal axis growth of zygotic embryos by the experiment of various chemical treatments. Under the normal growth condition, the apical tips of embryo axis produced an agar-diffusible substance, which suppressed somatic embryo development from cotyledons. Although the cells of zygotic embryos were released from the restraint of embryo axis, various factors were still involved for somatic embryo development. Electron microscopic observation revealed that the ultrastructure of cells of cotyledon epidermis markedly changed before initiation of embryonic cell division, probably indicating reprogramming events into the cells embryogenically determined state. Polar accumulation of endogenous auxin or cell-cell isolation by plasmolysis pre-treatment is the strong inducer for the somatic embryo development. The cells for the process of somatic embryogenesis might be determined by the physiological conditions fo explants and medium compositions. Direct somatic embryos from cotyledons fo ginseng were originated eithrer from single or multiple cells. The different cellular origin of somatic embryos was originated either from single or multiple cell. The different cellular origin of somatic embryos was depended on various developmental stages of cotyledons. Immature meristematic cotyledons produced multiple cell-derived somatic embryos, which developed into multiple embryos. While fully mature cotyledons produced single cell-derived single embryos with independent state. Plasmolysis pretreatment of cotyledons strongly enhanced single cell-derived somatic embryogenesis. Single embryos were converted into normal plantlets with shoot and roots, while multiple embryos were converted into only multiple shoots. GA3 or a chilling treatment was prerequisite for germination and plant conversion. Low concentration of ammonium ion in medium was necessary for balanced growth of root and shoot of plantlets. Therefore, using above procedures, successful plant regeneration of ginseng was accomplished through direct single embryogenesis, which makes it possible to produce genetically transformed ginseng efficently.

• Journal of Ginseng Research
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• v.23 no.2 s.54
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• pp.74-80
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• 1999

Excised cotyledon segments of ginseng zygotic embryos cultured on MS basal medium without growth regulators produced somatic embryos near the basal excised portion at a high frequency. The frequency of somatic embryo formation on the segments declined along with advancing zygotic embryo maturity. In immature cotyledons, all the cells of the epidermis and subepidermis were smaller and more densely cytoplasmic than those in mature cotyledons, and from which multiple cells participated in embryogenic division to form somatic embryos with multiple cotyledons and fasciated radicles (poly-embryos). But in germinating cotyledons, only the epidermal cells were densely cytoplasmic and singularly competent to develop into somatic embryos resulting in single-embryos with closed radicles. This result means that the origin and development of somatic embryos is determined according to whether the cells participating in embryonic division are in a single state or a massive state relative to cotyledon maturity.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.3
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• pp.111-117
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• 2015

Objective: In order to increase the number of mature oocytes usable for intracytoplasmic sperm injection (ICSI), we aimed to investigate the effect of co-culturing granulosa cells (GCs) on human oocyte maturation in vitro, the fertilization rate, and embryo development. Methods: A total of 133 immature oocytes were retrieved and were randomly divided into two groups; oocytes that were cultured with GCs (group A) and oocytes that were cultured without GCs (group B). After in vitro maturation, only oocytes that displayed metaphase II (MII) underwent the ICSI procedure. The maturation and fertilization rates were analyzed, as well as the frequency of embryo development. Results: The mean age of the patients, their basal levels of follicle-stimulating hormone, and the number of oocytes recovered from the patients were all comparable between the two study groups. The number of oocytes that reached MII (mature oocytes) was 59 out of 70 (84.28%) in group A, compared to 41 out of 63 (65.07%) in group B (p=0.011). No significant difference between fertilization rates was found between the two study groups (p=0.702). The embryo development rate was higher in group A (33/59, 75%) than in group B (12/41, 42.85%; p=0.006). The proportion of highest-quality embryos and the blastocyst formation rate were significantly lower in group B than in group A (p=0.003 and p<0.001, respectively). Conclusion: The findings of the current study demonstrate that culturing immature human oocytes with GCs prior to ICSI improves the maturation rate and the likelihood of embryo development.

• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.375-383
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• 2000

The nuclear maturation and developmental competence of immature, oocytes collected from donors at various morphology of corpus luteum (CL) and fertilized in vitro was investigated by comparing the meiotic activity and the yields of embryos. Ovaries were divided and classified into 4 groups as the following criteria : Group 1 ; ovaries showed evidence of recent ovulation (corpus hemorragicum). Group 2 ; apex of CL was red or brown. Vasculization was limited to periphery of CL. Group 3 ; apex of CL was orange or tan. Vasculization was covered over apex of CL. Group 4 ; CL was light yellow to white and firm in texture and the vascular network on the surface of CL had disappeared. Modified TCM 199 was used for maturation in vitro of immature oocytes and development was induced by using TLP-PVA as a basic medium. When oocytes collected from each group of donors had been matured for 4, 14, and 24 hours in vitro, the proportion of oocytes reaching metaphase I and metaphase II were not different among oocytes from 4 group of ovaries. Mature metaphase II stage of oocytes in each group was first observed at 14 hours, whereas completion of maturation of. oocytes in each group was at 24 hours. Luteal morphology of ovaries had little effect on the proportion of embryos reached 2 cells and 8 cell stage. However, the proportion of embryos cleaved to morula and blastocyst stage was significantly higher in the oocytes obtained from group 1 and 3 than in the oocytes from group 2 and 4 (p＜0.05). This data suggest that reproductive status of the donor significantly influence the yield of in vitro embryos.

• Reproductive and Developmental Biology
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• v.36 no.4
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• pp.237-241
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• 2012

Embryonic genome activation (EGA) is the first major transition that occurs after fertilization, and entails a dramatic reprogramming of gene expression that is essential for continued development. Although it has been suggested that EGA in porcine embryos starts at the four-cell stage, recent evidence indicates that EGA may commence even earlier; however, the molecular details of EGA remain incompletely understood. The RNA polymerase II of eukaryotes transcribes mRNAs and most small nuclear RNAs. The largest subunit of RNA polymerase II can become phosphorylated in the C-terminal domain. The unphosphorylated form of the RNA polymerase II largest subunit C-terminal domain (IIa) plays a role in initiation of transcription, and the phosphorylated form (IIo) is required for transcriptional elongation and mRNA splicing. In the present study, we explored the nuclear translocation, nuclear localization, and phosphorylation dynamics of the RNA polymerase II C-terminal domain in immature pig oocytes, mature oocytes, two-, four-, and eight-cell embryos, and the morula and blastocyst. To this end, we used antibodies specific for the IIa and IIo forms of RNA polymerase II to stain the proteins. Unphosphorylated RNA polymerase II stained strongly in the nuclei of germinal vesicle oocytes, whereas the phosphorylated form of the enzyme was confined to the chromatin of prophase I oocytes. After fertilization, both unphosphorylated and phosphorylated RNA polymerase II began to accumulate in the nuclei of early stage one-cell embryos, and this pattern was maintained through to the blastocyst stage. The results suggest that both porcine oocytes and early embryos are transcriptionally competent, and that transcription of embryonic genes during the first three cell cycles parallels expression of phosphorylated RNA polymerase II.

• Clinical and Experimental Reproductive Medicine
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• v.11 no.2
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• pp.59-67
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• 1984

In vitro fertilization have been performed to know whether the frozen semen has fertilizing ability and can be used clinically. The results of cultured and developed embryos obtained are as follows: 1. The semen was frozen in three media for the good viability. The viability was more than 50% and the motility was also moderate (grade III), 2. As the 33 oocytes were collected from 45 follicles, the oocyte recovery rate was 73.3%. Among them, mature and immature ova were 5% each, and premature ova were 69.7%, When the first polar body was appeared, above ova were inseminated after adequate incubation with activated sperms. 3. The main components of three freezing medium containing egg yolk, glycerol and pyruvate respectively were the best for sperm viability, and Ham's F-10 medium was used for the fertilization and culture of eggs. 4. The results of in vitro fertilization of 33 ova, showed the second polar body developed in 12%, polyspermia in 24%, 1-cell embryo in 21% and 2-cell embryo in 9%. One mature ova developed to blastocyst via 16-cell to 32-cell embryo. The fertilization rate was 66%. 5. Above mentioned results represent that the frozen semen has fertilizing ability and can be used practically in the clinic.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.343-356
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• 2010

Plant micropropagation techniques include bud cultures using apical or axillary buds, organogenesis through callus culture or adventitious bud induction, and somatic embryogenesis. In Korea Forest Research Institute (KFRI), the first tissue culture trial in woody plant was initiated from the bud culture of hybrid poplars (Populus alba x P. glandulosa) in 1978. Since then several mass propagation techniques have developed from conifer and hardwood species, resulting in allowing practical application to Poplars, Birches and some oak species. In addition, useful micropropagation and genetic resources conservation techniques were established in some rare and endangered tree species including Abeliophyllum distichum. Among various in vitro propagation techniques, somatic embryogenesis is known to be the most efficient plant regeneration system. Since the first somatic embryo induction was reported in Tilia amurensis by KFRI in 1986, various protocols for direct or indirect somatic embryogenesis systems have developed in conifer and hardwood species including Larix leptolepis, Pinus rigida x P. taeda F1, Kalopanax septemlobus and Liliodendron tulipifera, etc. However, most of these technologies have been developed using juvenile tissues, i.e. immature zygotic embryos or mature embryos. Therefore it has been difficult to directly application to tree breeding program due to their unproven genetic background. Recently remarkable progresses and new approaches have been achieved in mature tree somatic embryogenesis. In this article we reviewed several micropropagation techniques, which have been mainly developed by KFRI and recent international progresses.