• The Korean Journal of Zoology
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• v.31 no.4
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• pp.265-272
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• 1988

세포융합방법을 사용하여 성장증인 포유동물의 난자에 들어있는 성숙억제요인(maturation inhibiting activity, 1연Al에 대해 조사하였다. 성장중인 생쥐난자와 성장한 미성숙난자를 1:1로 융합하여 배양했을 서 (14-17시간)에는 거의 모두 핵붕괴를 일으키었으나(90oyo), 2:1로 융합했을 때는 대부분(약 64%) 3개의 핵을 모두 간직하고 있었다. 돼지난자의 경우는 성장중인 것깎 성장한 것을 1:1로 융합하여 배양했을 때에도 융합체들은 모두 핵을 간직하고 있었으며 돼지의 성장중인 난자와 생쥐의 성장한 난자를 융합했을 때에도 모두 핵을 보존하고 있었다. 이에 반하여 돼지와 생쥐 모두에서 성장한 난자끼리 융합했을 때에는 예외없이 핵붕괴가 일어났다. 이러한 결과는 성장중인 생쥐나 돼지의 난자에 각IA가 존재한다는 열과 이종간에도 효과가 있다는 것을 보여주고 있다. 또한 이는 MIA와 성숙촉진요인(maturation promoting factor, MPH의 상대적인 양의 변화가 난자의 성숙조절에 증요한 9f할을 한다는 것을 시사해주고 있다.In an attempt to elucidate the nature of maturation inhibiting activity (MIA) in growing mamma-lian oocvtes, growing mouse and pig oocytes incompetent to resume meiosis were fused with fully grown immature oocvtes in various combinations and cultured for 14-17 hours. In slant cells composed of two mouse growing ooh임es and one large immature oocyte (2:기, their GVs remained well conserved (about 64%) after culture, but not in the ceils composed of one by one pairs. In giant cells of pig composed of one growing and onto large immature oocytes, both GVs remained conserved. In the cells composed of one pig growing and one mouse large oocytes, both GVs were also conserved. In contrast to this, pairs of large mouse oocvtes or those of large pig oocvtes had no CVs after culture. Thus, we could acertain the existEnce of MIA and none-pecificty of it in the mouse and pig growing oocvtes. The results also suggest that the relative amount of substances showlns MfA or MPF activity may be important in the regulation of oocyte amount of substances showing MIA or MPF activity may be important in the regulation of oocyte maturation.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.2
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• pp.191-200
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• 1994

The influence of hypoxanthine and ovarian steroids on the meiotic maturation process of mouse oocytes was investigated for the qualified application of culture medium in in vitro fertilization(IVF). Mouse oocytes were cultured in hypoxanthine and various ovarian steroids(progesterone, estradiol-17${\beta}$ and testosterone) and their effects on the oocyte maturation had been observed. When mouse oocytes were cultured in the various concentration(1-4mM) of hypoxanthine, meiotic maturation of cumulus cell-enclosed oocytes was inhibited by presence itself, which was a dose-dependent effect in meiotic arrest of mouse oocytes. The presence of progesterone, estradiol-17${\beta}$ and testosterone have made the mouse oocyte mature properly. Meanwhile maturation of cumulus cell-enclosed oocyte was severely inhibited by 3 hoursculture in the media of progesterone supplemented with hypoxanthine. However the continuous presence lasting 24 hours of progesterone even supplemented with hypoxanthine had got rid of the inhibition of oocytes maturation. Not only estradiol-17${\beta}$ supplemented with hypoxanthine but also testosterone supplemented with hypoxanthine exert the severe inhibition of the maturation of cumulus cell-enclosed oocytes for 3-hours culture. However the continuous presence lasting 24 hours of estradiol-17${\beta}$ and testosterone even supplemented with· hypoxanthine had relieved the inhibition of oocytes maturation. These results make us suggest that hypoxanthine inhibits the mouse oocyte maturation, particularly markedly in conjunction with ovarian steroids for short period, which indicated some sort of the synergistic inhibitory retationship between the ovarian steroids and hypoxanthine.

• The Korean Journal of Zoology
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• v.31 no.2
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• pp.81-86
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• 1988

The relationship between cumulus cell expansion, cocyte maturation and metabolic cooperativitiy was investigated by using mouse and pig cocyte-cumulus complexes in vitro. Cocyte germinal vesicle breakdown (GVBD) and cumulus expansion were manipulated with hormones or reagents which increase intracellular cAMP leveL Metabolic cooperativity between oocyte and cumulus cells was assessed by determination of the fraction of radiolabelled uridine marker that was transferred from the cumulus mass to the oocyte. Uptake of uddine marker by mouse and pig cumulus mass was increased by about fourfold of basal level with the stimulation of hormones (human choriononic gonadotrophin, HCG; follicle stimulating hormone, FSH) or cyclic AMP sttmulators (3-isobutyl-1-methylxanthine, IBMX; forskolin) during culture. However, the fraction of uridine that was transferred from the cumulus mass to the cocyte (transfer ratio) was gradually decreased during culture, irrespective with the presence of hormones or stimulators. The decrease of the transfer ratio was not correlated with the state of occyte whether they have GV or not, or with the degree of cumulus expansion. In mouse complexes, HCG induced more significant reducton of transfer ratio than other treatments. These results do not support the idea that modulations of metabolic cooperativity between cumulus cells and oocytes are important for the regulation of meiotic resumption in mammals.

• Proceedings of the Korean Society of Life Science Conference
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• 2002.03a
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• pp.78-78
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• 2002

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.161-170
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• 2015

These studies were conducted to establish the practical Hanwoo (Korean native cattle) improvement system through the combining of embryo transfer technology and confirming individual Hanwoo oocyte culture system and to investigate that correlation of Hanwoo carcass classification (intramuscular marbling) and oocyte donor for blastocyst production in vitro. In case of Hanwoo, the carcass meat quality grades were divided to grade $1^{{+}{+}}$, $1^{+}$, 1, 2, and 3 depends on fat distribution of longest muscle cross-sectional surface. As results, the numbers of follicular oocytes collected from individual fundamentally-registered Hanwoo yielded $1^{{+}{+}}$, $1^{+}$, 1, 2 and 3 meat quality were 9.5, 9.4, 8.5, 8.8 and 8.8 per ovary, respectively. The numbers of retrieval oocyte from follicles were significantly higher in the cattle yield $1^{{+}{+}}$, $1^{+}$ meat quality than in the cattle yield 1, 2 and 3 meat quality (p<0.05). The rates of blastocyst formation were 18.2, 21.3, 29.4, 30.9, and 31.5% in the cattle yield $1^{{+}{+}}$, $1^{+}$, 1, 2 and 3 meat quality of after in vitro maturation, respectively. It was significantly lower in the cattle yield $^{{+}{+}}$ and $1^{+}$ meat quality than in the cattle yield 1, 2 and 3 meat quality (p<0.05). In order to evaluate embryos quality, TUNNEL assay was conducted for each meat quality grade using blastocyst stage embryo on day 8. The results showed that apoptosis cell number was higher tendency in the cattle yield $1^{{+}{+}}$and $1^{+}$ meat quality (81 and 79, respectively) than in the cattle yield 1, 2 and 3 meat quality (51, 48 and 50, respectively) but there was no statistical significance in each group. After embryo transfer, the conception rate of recipient was 53.5 (23 out of 43), 52.1 (38 out of 73) and 58.0% (58 out of 100) in the meat quality of 1, $1^{+}$ and $1^{{+}{+}}$, respectively. These results showed that the conception rate was significantly higher in the cattle yield 1 meat quality than in the cattle yield $1^{{+}{+}}$, $1^{+}$, 2, and 3 meat quality (p<0.05). In summary, these results indicate that the application of confirming Hanwoo individual oocyte culture system and embryo transfer technology can make good use of the genetic resources conservation and improvement of Hanwoo. Relevance of the meat quality grade and reproductive ability of carcasses of Hanwoo will be considered to be one of the effective means for the associated research with obesity and reproduction.

• Korean Journal of Agricultural Science
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• v.44 no.3
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• pp.309-317
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• 2017

Melatonin (N-acetyl-5-methoxytryptamine) is an indole synthesized from tryptophan by the pineal gland in animal. The major function of melatonin is to modulate circadian and circannual rhythms in photoperiodic mammals. Importantly, however, melatonin is also a free radical scavenger, anti-oxidant, and anti-apoptotic agent. Recently, the beneficial effects of melatonin on oocyte maturation and embryonic development in vitro have been reported in many species such as pig, cattle, sheep, mouse, and human. In this review, we will discuss recent studies about the role of melatonin in the production of porcine and bovine oocytes and embryos in vitro in order to provide useful information of melatonin in oocyte maturation and embryo culture in vitro.

• Journal of Embryo Transfer
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• v.15 no.3
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• pp.287-293
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• 2000

This study was undertaken to access the effects of collection method, room temperature at oocyte recovery and culture media on the oocyte quality, fertilization and cleavage rates of in vitro matured and fertilized oocytes of Korean native goats. Ovaries obtained from a slaughterhouse were transported to the laboratory and were divided into 2 groups. One group of ovaries was maintained at 30 to 35$^{\circ}C$ of the room temperature and another group was remained at 20 to $25^{\circ}C$ during oocyte recovery. The oocytes were recovered by follicle aspiration, slicing and aspiration+slicing methods from 3 groups of follicles according to size; <2 mm, 2 to 6 mm and >6 mm. The matured oocytes were inseminated with buck epididymal spermatozoa at a concentration of 3~3.5$\times$10$^{6}$ m1 and fertilization was identified when 2 pronuclei were present in the cytoplasm. Although the recovery rate per ovary obtained by the combination of follicle aspiration + slicing(19.6$\pm$2.2) method was higher than aspiration(11.7$\pm$1.1) and slicing(14.8$\pm$1.8) collection, optimal recovery according to oocyte grades resulted form ovarian slicing compared to aspiration or combined methods(P<0.05). However, no significant differences were found in the mean number(2.5$\pm$1.8; 3.3$\pm$3.3; 2.9$\pm$2.4) and the proportion of favorable oocytes(Grades I, II and III) recovered(31.6%, 36.0%, 36.4%,) according to follicle size(<2 mm; 2 to 6 mm; >6 mm). Fertilization rate was 60.0%, 67.7%, 70.6% and 56.4% and the proportion of embryos/zygotes was 11.1%, 7.1%, 5.0% and 2.8% in 20~$25^{\circ}C$/BO, 30~35$^{\circ}C$/BO, 20~$25^{\circ}C$/TALP and 30~35$^{\circ}C$ /groups, respectively.

• Korean Journal of Animal Reproduction
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• v.22 no.2
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• pp.119-126
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• 1998

This study was conducted to find out the recovery rate of oocyte according to the different size of follicles from porcine ovaries, and the effect of in vitro maturation of porcine immature oocyte at the different transportation temperature of ovaries from slaughter house. The results obtained were summarized as follows : 1. The number of follicles per ovary was 22.5. The number of A-and B-typed oocytes(type A: cumulus-enclosed oocyte, type-B : corona-enclosed oocyte) per ovary was 2.4. The proportion of A-and B-typed oocytes was 29.6% of the total recovery oocytes. 2. When the immature oocytes were cultured for 36, 40, 44 and 48 h at 5$^{\circ}C$ transportation temperature of ovary, the germinal vesicle breakdown(GVBD) rates of porcine oocytes were 32.5, 28.2, 22.6 and 25.9% respectively. There were no significant differences between all the culture time for GVBD. Especially, most of oocytes were observed to arrest the development beyond germinal vesicle(GV) stage. 3. When the immature oocytes were cultured for 36, 40, 44 and 48 h at $25^{\circ}C$ transportation temperature of ovary, the GVBD rates were 81.0, 90.0, 91.7 and 92.9%, and the maturation (Met-II) rates were 51.2, 78.8, 76.2 and 78.6%, respectively. 4. When the immature oocytes were cultured for 36, 40, 44 and 48 h at 38$^{\circ}C$ transportation temperature of ovary, the GVBD rates were 93.9, 96.5, 96.5 and 95.3%, and the maturation rates were 62.2, 88.4, 84.7 and 86.0%, respectively. 5. The above results showed that the maturation rates of immature oocytes between $25^{\circ}C$ and 38$^{\circ}C$ transportation temperature of ovary did not differ significantly.

• Journal of Embryo Transfer
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• v.12 no.1
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• pp.1-10
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• 1997

The present study was conducted to investigate the influence of embryo cell stage at 18h post-fusion and oocyte preactivation on sebsequent in vitro developmental potential in the nuclear transplant rabbit embryos. The embryos of 16-cell stage were collected and synchronized to G$_1$ phase of 32-cell stage. The recipient cytoplasms were obtained by removing the first polar body and chromosome rnass from the oocytes collected by non-dis-ruptive microsurgery procedure. The separated G$_1$ phase blastomeres of 32-cell stage were injected into non-preactivated recipient cytoplasms. Otherwise, the enucleated recipient cytoplasms were preactivated by electrical stimulation at 18h post-hCG injection and the separated G$_1$ phase blastomeres of 32-cell stage were injected. Mter culture until 20h post-hOG injection, the nuclear transplant oocytes were electrofused by electrical stimulation. The fused nuclear transplant embryos were classified into 3~4-cell, 2-cell and 1-cell stage at 18 hrs post-fusion and cultured until the embryos reached blastocyst stage. The developmental rate to blastocyst stage was significantly (P <0.05) higher in all the reconstituted embryos of 3~4-cell stage(58.0%) than in 2 and icell stage. The developmental rate to blastocyst stage in the embryos of 3~4-cell stage at 18 hrs post-fusion was significantly (P<0.05) higher in the reconstituted without oocyte preactivation(77.8%) than in the oocyte-preactivated embryos (33.3%). These results indicated that the higher rate of in the in vitro development to blastocyst stage might be obtained form the embryos which were reconstituted with nuclear donor of G$_1$ phase and non-preactivated oocyte, and developed more rapidly for 18 hrs post-fusion.

• Animal Bioscience
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• v.37 no.6
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• pp.1007-1020
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• 2024

Objective: We increased the nuclear maturation rate of antral follicle derived oocytes by using a pre-in vitro maturation (IVM) culture system and improved the developmental potential of these porcine pathenotes by supplementing with melatonin. Furthermore, we investigated the expression patterns of genes involved in cumulus expansion (HAS2, PTGS2, TNFAIP6, and PTX3) derived from small and medium antral follicles before and after oocyte maturation. Methods: Only the cumulus oocyte-complexes (COCs) derived from small antral follicles were induced with [Pre-SF(+)hCG] or without [Pre-SF(-)hCG] the addition of human chorionic gonadotropin (hCG) during the last 7 h of the pre-IVM period before undergoing the regular culture system. The mature oocytes were investigated on embryonic development after parthenogenetic activation (PA). Melatonin (10^-7 M) was supplemented during in vitro culture (IVC) to improve the developmental potential of these porcine pathenotes. Results: A pre-IVM culture system with hCG added during the last 7 h of the pre-IVM period [Pre-SF(+)hCG] effectively supported small antral follicle-derived oocytes and increased their nuclear maturation rate. The oocytes derived from medium antral follicles exhibited the highest nuclear maturation rate in a regular culture system. Compared with oocytes cultured in a regular culture system, those cultured in the pre-IVM culture system exhibited considerable overexpression of HAS2, PTGS2, and TNFAIP6. Porcine embryos treated with melatonin during IVC exhibited markedly improved quality and developmental competence after PA. Notably, melatonin supplementation during the IVM period can reduce and increase the levels of intracellular reactive oxygen species (ROS) and glutathione (GSH), respectively. Conclusion: Our findings indicate that the Pre-SF(+)hCG culture system increases the nuclear maturation rate of small antral follicle-derived oocytes and the expression of genes involved in cumulus expansion. Melatonin supplementation during IVC may improve the quality and increase the blastocyst formation rate of porcine embryos. In addition, it can reduce and increase the levels of ROS and GSH, respectively, in mature oocytes, thus affecting subsequent embryos.