• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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• pp.6-6
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• 2002

This study was conducted to investigate the effect of recipient activation time on the nuclear remodeling, chromatin structure, pronuclear formation and in vitro development of bovine nuclear transfer embryos derived from adult ear skin cells. Somatic cells were transferred to enucleated oocytes after quiescent treatments by serum starvation or culture to confluency. Nuclear transfer embryos were activated with a combination of Ca/sup 2+/-ionophore and cycloheximide at 1, 1.5, 2, 2.5, 3, and 5 h after electrofusion. (omitted)

• 한국수정란이식학회지
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• 제23권1호
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• pp.31-36
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• 2008

We attempted to control the maturation promoting factors (MPF) activity and nuclear remodeling of somatic cell nuclear transfer (NT) bovine embryos. Bovine ear skin fibroblasts were fused to enucleated oocytes treated with either 5 mM caffeine for 2.5 h or 0.5 mM vanadate for 0.5 h and activated. The nuclear remodeling type of the reconstituted embryos was evaluated 1.5 h after activation. MPF activity was assessed in enucleated and chemical treated oocytes before the injection of a donor cell. Effect of chemicals on the embryonic development was evaluated with parthenogenetic embryos. MPF activity increased significantly by caffeine treatment, but decreased by vanadate treatment (p<0.05). Caffeine or vanadate had no deleterious effect on the parthenogenetic embryo development. In caffeine treated group, premature chromosome condensation (PCC) was occurred in 72.2% of NT embryos (p<0.05). In contrast, vanadate induced the formation of a pronucleus-like structure (PN) in a high frequency (68.9%, p<0.05) without PCC (NPCC). Blastocyst development of NT embryos increased by treating with caffeine (30.3%), whereas decreased by treating with vanadate (11.4%) compared to control (22.1%, p<0.05). The results indicate that caffeine or vanadate can control of MPF activity and remodeling type of NT embryos, resulting in the increased or decreased in vitro development.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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• pp.51-51
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• 2002

Despite of importance of integrated events of nucleus and microtubule remodeling in nuclear transferred embryos with somatic cells, little information is available on this subject. In this study we compared chromatin, r-tubulin and microtubule organization in porcine oocytes following somatic cell nuclear transfer and parthenogenetically activation in order to clarify nuclear remodeling process and to demonstrate centrosome inheritance during nuclear transfer. (omitted)

• Reproductive and Developmental Biology
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• 제28권4호
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• pp.241-245
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• 2004

This study was conducted to investigate nuclear remodeling and developmental rate following nuclear transfer of fetal fibroblast cells, ear skin cells and oviduct epithelial cells into porcine recipient oocytes. To test par-thenogenetic activation, oocytes were treated with a 6-dimethylaminopurine (6-DMAP), a single DC-pulse (DC), calcium ionomycin (ionomycin), DC+6-DMAP and ionomycin + 6-DMAP after in vitro maturation. For nuclear transfer, in vitro matured oocytes were enucleated, and donor cells were transferred into oocytes. Cloned embryos were fused and stimulated with 6-DMAP for 4 h and cultured in vitro for 6 days. Among treatments for parthenogenesis, the activation rate of DC +6-DMAP treatment was significantly higher than that of single treatment roups (p<0.01), except for DC treatment group. However, the difference was not significant in activation rate compared to other complex treatment groups. Nuclear swelling of the cloned embryos was initiated at 60 min after stimulation and increased afterwards. Fusion rates were not different among different donor cells. Cleavage rates of DC treatment groups were significantly higher than those of DC+6-DMAP treatment groups (p<0.05) in case that fetal fibroblast and ear cells were used for nuclear donor. The cloned embryos from developed to blastocysts in oviduct epithelial cell nuclear transfer with DC+6-DMAP treatment was significantly higher compared to those with DC only treatment (p<0.05). However, no blastocyst was developed from nuclear transfer of fetal fibroblast and ear cells regardless of activation treatments. Based on these results, a proper activation stimulation may be necessary to increase the activation rate and the development to blastocyst in cloned porcine embryos.

• Reproductive and Developmental Biology
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• 제35권1호
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• pp.105-113
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• 2011

The present study investigated the nuclear remodeling, development potential with telomerase activity and transcription level of X-linked genes (ANT3, HPRT, MeCP2, RPS4X, XIAP, XIST and ZFX) in the bovine somatic cell nuclear transfer (SCNT) embryos using two different fusion and activation methods. Female adult fibroblasts were injected into perivitelline space of in vitro matured oocytes. The oocyte-nucleus complexes were fused and followed by immediately either activated (Group 1), or activated at 1 h post-fusion (hpf) (Group 2), respectively. The incidence of normal premature chromosome condensation (PCC) at 1 hpf was slightly increased in the Group 2, compared to those of Group 1, but there was no significant (p<0.05) difference. The incidence of normal pronucleus (PN) and chromosome spread at 5 and 18 hpf were significantly (p<0.05) higher in the Group 2 than those of Group 1. The cleavage rate to 2-cell stage, developmental rate to blastocyst stage, and the mean number of total and ICM cell numbers were significantly (p<0.05) higher in the Group 2, compared to those of Group 1. Level of telomerase activity was significantly (p<0.05) higher in the SCNT blastocysts of Group 2, compared to those of Group 1. Transcript levels of HPRT, MeCP2 and XIST were not significantly (p<0.05) different between blastocysts of Group 1 and 2. However, transcript level of ANT3, RPS4X, XIAP and ZFX were significantly (p<0.05) up-regulated in the SCNT blastocysts of Group 2, compared to those of Group 1. Taken together, it is concluded that oocyte activation at 1 hpf induces the enhanced developmental potential by efficient nuclear remodeling and subsequent facilitation of the nuclear reprogramming of bovine SCNT embryos.

• 한국가축번식학회지
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• 제23권3호
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• pp.271-278
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• 1999

본 연구는 핵이식 기술에 의한 재구축 배의 작성과정에서 핵의 세포주기단계에 따른 재구축 배의 염색체의 핵상변화를 검토하고, 염색체의 핵상변화와 핵이식란의 체외발육과의 관계를 검토하였다. 공핵란은 nocodazole 처리에 의해 분할구가 분열기에 정지되도록 한 후, 분열개시 1.5 시간 이내, 분열 후 3 시간째 핵 및 무처리 분할구 핵올 활성화 전 (metaphase-II기 : M II기 ), 후 (S 기)의 탈핵 미수정란 세포질에 이식하였다. MII기 수핵란에 핵이식 된 재구축 배의 극체상 방출, 미성숙 염색체응축, 염색질구조 변화 등과 같은 핵형 변화 형태 및 재구축 배의 발육능은 핵의 세포주기 단계에 의해 영향을 받았으며, 극체상 방출 유무에 따라서도 재구축 배의 발육율에 차이가 있었다. S기 수핵란에 핵이식 된 경우에는 이식된 핵의 형태변화가 거의 없었다. 본 연구의 결과는 재구축 배의 핵형 변화가 핵 및 세포질의 세포주기단계에 따라 다양하며, 이것이 핵이식 재구축 배의 발육에 영향을 미칠 수 있음을 확증한다.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.18-18
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• 2001

Despite of importance of integrated events of nucleus and microtubule remodeling in nuclear transferred embryos with somatic cells, little information is available on this subject. In this study we configured chromatin and microtubule organization following somatic cell nuclear transfer in pre- and non-activated bovine oocytes in order to clearify nuclear remodeling process and to demonstrate centrosome inheritance during nuclear transfer. The cumulus-oocyte complexes were collected from slaughterhouse and were matured in vitro for 20 h in TCM 199 supplemented hormone. Matured bovine oocytes were enucleated by aspirating the frist polar body and metaphase chromatin using a beveled pipette. Bovine fibroblast cells were fused into enucleated oocyte by electrical stimulation. Reconstructed oocytes were activated with ionomycine and 6-dimethylaminopurin, and then cultured in CRlaa medium. The organization of nuclear and microtubules were observed using laser-scanning confocal microscopy. At 1 hour after fusion, microtubule aster was seen near the transferred nucleus in most oocytes regardless activation condition. While most of fibroblast nuclei remodeled to premature chromosome condensation (PCC) and to the two masses of chromosome in non-activated oocytes, a few number of fibloblasts went to PCC and multiple pronuclear like structures in activated oocytes. Microtubular spindle was seen around condensed chromosome. Gamma-tubulin was detected in the vicinity of condensed chromosome, suggesting this is a transient spindle. The spindle seperated nucleus into two masses of chromatin which developed to the pronuclear like structures. Two pronuclear like structures were than apposed by microtubular aster and formed one syngamy like nuclear structure at 15 h following nuclear transfer. At 17 to 18 h after fusion, two centrosomes were seen near the nucleus, which nucleates micrtubules for two cell cleavage. While 31% of reconstructed oocytes in non-activated condition developed to morulae and blastocysts, a few reconstructed oocytes in pre-activated condition developed to the blastocyst. These results suggested introduction of foreign centrosome during nuclear transfer, which appeared to give an important role for somatic cell nuclear reprogramming.

• BMB Reports
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• 제57권9호
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• pp.381-387
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• 2024

The nucleus, a highly organized and dynamic organelle, plays a crucial role in regulating cellular processes. During cell differentiation, profound changes occur in gene expression, chromatin organization, and nuclear morphology. This review explores the intricate relationship between nuclear architecture and cellular function, focusing on the roles of the nuclear lamina, nuclear pore complexes (NPCs), sub-nuclear bodies, and the nuclear scaffold. These components collectively maintain nuclear integrity, organize chromatin, and interact with key regulatory factors. The dynamic remodeling of chromatin, its interactions with nuclear structures, and epigenetic modifications work in concert to modulate gene accessibility and ensure precise spatiotemporal control of gene expression. The nuclear lamina stabilizes nuclear shape and is associated with inactive chromatin regions, while NPCs facilitate selective transport. Sub-nuclear bodies contribute to genome organization and gene regulation, often by influencing RNA processing. The nuclear scaffold provides structural support, impacting 3D genome organization, which is crucial for proper gene expression during differentiation. This review underscores the significance of nuclear architecture in regulating gene expression and guiding cell differentiation. Further investigation into nuclear structure and 3D genome organization will deepen our understanding of the mechanisms governing cell fate determination.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제36권2호
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• pp.37-49
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• 2014

Purpose: This study compares the bone formation ability of tricalcium phosphate (TCP) with and without recombinant human bone morphogenetic protein-2 (rhBMP-2) and assesses TCP as a carrier of rhBMP-2. Methods: Bilateral round defects (diameter: 8.0 mm) were formed in the cranium of eight New Zealand white rabbits. The defects were grafted with TCP only (control group) or with rhBMP-2-coated TCP (experimental group). The animals were sacrificed at 1st week, 2nd week, 4th week, and 8th week postoperatively; two rabbits sacrificed each time. The skulls were harvested and subjected to radiographic and histological examination. Results: Radiologic evaluation showed faster bone remodeling in the experimental group than in the control group. Histologic evaluation (H&E, Masson's trichrome stain) showed rapid bone formation, remodeling and calcification in the 1st and 2nd week in the experimental group. Immunohistochemical evaluation showed higher expression rate of osteoprotegerin, receptor activator of nuclear factor ${\kappa}B$ ligand, and receptor activator of nuclear factor ${\kappa}B$ in the experimental group at the 1st and 2nd week than in the control group. Conclusion: rhBMP-2 coated TCP resulted in rapid bone formation, remodeling, and calcification due to rhBMP-2's osteogenic effect. TCP performed properly as a carrier for rhBMP-2. Thus, the use of an rhBMP-2 coating on TCP had a synergic effect on bone healing and, especially, bone remodeling and maturation.

• 한국가축번식학회지
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• 제24권2호
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• pp.217-222
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• 2000

본 연구는 세포의 휴면처리가 소 태아섬유아세포 유래 핵이식란의 핵형변화와 체외발육에 미치는 영향을 검토하였다. 임신 3∼4 개월령 한우 웅성 태아의 피부세포를 채취하여 계대배양 후 동결하였다가 핵이식 전에 혈청기아처리 또는 confluency방법으로 휴면처리를 하여 미수정란의 탈핵세포질에 이식하였다. 전기융합과 활성화처리 후 7∼9 일간 체외배양하여 발육능을 검토하였으며, 일부는 whole-mount 법으로 고정하여 염색질 구조를 관찰하였다. 복제란의 극체방출율은 혈청기아처리구와 confluence 구에서 각각 24.5% 와 20.3% 로 무처리구(36.0%) 에 비해 낮은 경향을 보였다. 활성화 후 1개의 염색질괴를 갖는 복제란은 혈청기아처리구(50.9%)와 confluence구 (49.2%)가 무처리구 (40.0%) 보다 높은 경향을 보였다. 극체방출에 따른 염색질의 구조는 극체 미방출구에서 정상적인 1개의 염색질괴를 갖는 핵이식란이 60.5% 로, 극체 방출구 (4.7%) 에 비하여 유의적으로 높았다 (P＜0.01). 배반포기 발육율은 혈청기아처리구 (21.7%) 와 confluence (20.9%) 가 무처리구 (14.1%) 에 비하여 비교적 높게 나타났다. 본 연구의 결과 혈청기아처리나 confluency 방법에 의한 donor 세포의 휴면처리는 태아섬유아세포 유래 핵이식란의 비정상적인 핵형변화를 감소시켜 체외발육능을 향상시키는 것으로 사료된다.