• BMB Reports
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• 제32권1호
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• pp.28-32
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• 1999

Annexin I (also called lipocortin 1), a 37-kDa member of the annexin family of proteins, has been implicated in the mitogenic signal transduction by epidermal growth factor (EGF). Annexin I is phosphorylated by the EGF signal, however, the role of annexin I in the EGF signal transduction is still unknown. To transduce extracellular signals into the intracellular targets, selective translocation of the signaling molecules to their targets would be necessary. In this study, we examined the subcellular locations of annexin I during EGF signal transduction. Treatment of A549 cells with EGF resulted in the translocation of cytoplasmic annexin I to the nucleus and perinuclear region as determined by Western blot and immunofluorescent staining. The nuclear translocation of annexin I was inhibited by tyrphostin AG 1478 and genistein, the inhibitors of EGF receptor kinase and downstream tyrosine kineses, respectively. Pretreatment of cells with cyclohexamide did not inhibit the nuclear translocation. The results suggest that nuclear translocation of annexin I is controlled by a series of kinase dependent events in the EGF receptor signaling pathway and may be important in tranducing the signals by EGF.

• 한국균학회지
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• 제16권3호
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• pp.157-161
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• 1988

Fusarium oxysporum은 하나의 종내에서 다양한 변이를 하여 100 이상의 formae specials과 races가 있는 것으로 알려진 종이다. 그중에서 10 strains에 대하여 균사내의 영양핵의 분열상을 찾아 Giemsa staining sol.으로 염색하여 관찰하였고, 그들의 염색체수를 확인하였다. 결과는 10 strains중에서 F. oxysporuml S Hongchun D2와 F. oxysporum S Jinyang 4의 2strains은 n=4개 를, F. oxysporum f. sp. lini KFCC 32585, F. oxysporum f. sp. melongenae KFCC 34743, F. oxysporum f. sp. raphani의 3 strains은 n= 5, F. oxysporum f. sp. vasinfectum과 F. oxysporum f. sp. mori KFCC 34742의 2 strain은 n=6개를, 그리고 F. oxysporum f. sp. cucumerium, F. oxysporum f. sp. niveum과 F. oxysporum f. sp. pisi등의 3 strains은 n=7개로 관찰되 었다.

• Mycobiology
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• 제39권2호
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• pp.79-84
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• 2011

Nuclear distribution within the extra-radical fungal structures and during spore production in the arbuscular mycorrhizae fungus Glomus intraradices was examined using an in vitro monoxenic culture system. A di-compartmental monoxenic culture system was modified using a nitrocellulose membrane and a coverglass slip for detailed observations. Nuclear distribution was observed using the fluorescent DNA binding probes SYBR Green I and DAPI. Both septate and non-septate mycelial regions were observed, but cytoplasmic contents were only found within non-septate mycelia. Nuclear fluorescent staining revealed that the non-septate hyphal region contained nuclei only with cytoplasm, and that nuclear distribution was limited by septa. Swollen hyphal bodies were often associated with septate and empty-looking hyphae. Cytoplasmic contents filled the swollen hyphal body from the non-septate hyphal region following removal of the septa. As a consequence, the swollen body developed into a new spore. These observations provide understanding about the distribution of AM fungal nuclei within extra-radical mycelia and during spore formation. The results suggest a mechanism by which the development of a cytoplasm-containing mycelium is controlled by the formation or removal of septa to efficiently maintain and proliferate essential contents. This mechanism may provide a survival strategy to the fungus.

• 미생물학회지
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• 제29권1호
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• pp.8-15
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• 1991

Interspecific hybrids between the ASpergillus spp., A. awamori, A. usamii and A. oryzae, were obtained by nuclear transfer technique. Nuclei isolated from an auxotrophic mutant strain were transferred into the protoplasts of a recipient strain of different species. The frequency of interspecific hybrid formation by nuclear transfer was $2*10^{-5}$ $-7*10^{-4}$ In contrast, no interspecific hybrid was isolated by protoplast fusion. Among the hybrids tested, 10 strains showed increased activity of some or all components of cellulases, xylanases and amylase up to more than two times. Isozyme pattern of the hybrids were analyzed by polyacrylamide gel electrophoresis and isoelectric focusing followed by activity staining, which showed that some of the hybrids have isozyme patterns unidentical to either of the two parents. By measuring the DNA contents and the sizes ofthe conidia, the karyotypes of the hybrids were estimated to be aneuploid near to haploid, diploid or triploid. It was concluded that the unclear transfer technique is much more efficient in the formation of interspecific hybrids than protoplast fusion and is very useful for the improvement of Aspergillus strains.

• Biomolecules & Therapeutics
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• 제25권3호
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• pp.315-320
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• 2017

We investigated the role of autophagy in SNUC5/5-FUR, 5-fluorouracil (5-FU) resistant SNUC5 colon cancer cells. SNUC5/5-FUR cells exhibited low level of autophagy, as determined by light microscopy, confocal microscopy, and flow cytometry following acridine orange staining, and the decreased level of GFP-LC3 puncta. In addition, expression of critical autophagic proteins such as Atg5, Beclin-1 and LC3-II and autophagic flux was diminished in SNUC5/5-FUR cells. Whereas production of reactive oxygen species (ROS) was significantly elevated in SNUC5/5-FUR cells, treatment with the ROS inhibitor N-acetyl cysteine further reduced the level of autophagy. Taken together, these results indicate that decreased autophagy is linked to 5-FU resistance in SNUC5 colon cancer cells.

• Asian-Australasian Journal of Animal Sciences
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• 제27권2호
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• pp.266-277
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• 2014

Somatic cell nuclear transfer (SCNT) has generally demonstrated that a differentiated cell can convert into a undifferentiated or pluripotent state. In the SCNT experiment, nuclear reprogramming is induced by exposure of introduced donor nuclei to the recipient cytoplasm of matured oocytes. However, because the efficiency of SCNT still remains low, a combination of SCNT technique with the ex-ovo method may improve the normal development of SCNT embryos. Here we hypothesized that treatment of somatic cells with extracts prepared from the germinal vesicle (GV) stage Siberian sturgeon oocytes prior to their use as nuclear donor for SCNT would improve in vitro development. A reversible permeability protocol with $4{\mu}g/mL$ of digitonin for 2 min at $4^{\circ}C$ in order to deliver Siberian sturgeon oocyte extract (SOE) to porcine fetal fibroblasts (PFFs) was carried out. As results, the intensity of H3K9ac staining in PFFs following treatment of SOE for 7 h at $18^{\circ}C$ was significantly increased but the intensity of H3K9me3 staining in PFFs was significantly decreased as compared with the control (p<0.05). Additionally, the level of histone acetylation in SCNT embryos at the zygote stage was significantly increased when reconstructed using SOE-treated cells (p<0.05), similar to that of IVF embryos at the zygote stage. The number of apoptotic cells was significantly decreased and pluripotency markers (Nanog, Oct4 and Sox2) were highly expressed in the blastocyst stage of SCNT embryos reconstructed using SOE-treated cells as nuclear donor (p<0.05). And there was observed a better development to the blastocyst stage in the SOE-treated group (p<0.05). Our results suggested that pre-treatment of cells with SOE could improve epigenetic reprogramming and the quality of porcine SCNT embryos.

• 한국가축번식학회지
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• 제17권4호
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• pp.331-337
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• 1994

처녀발생은 난자의 세포질성숙을 투명대경화나 체외수정에 있어 난자 외적요소의 문제점을 배제하고 측정할 수 있는 지표이다. 본 실험에서는 체외성숙시간에 따른 소 난자의 처녀발생활성을 조사하였다. 도살장 난소로부터 회수한 미성숙난포란을 15% 소 태아혈청이 첨가된 TCM 199에서 6시간 간격으로 24~48시간까지 성숙시킨 후 7% ethanol로 7분간 활성화시켰다. 핵성숙과 세포질성숙은 rapid staining에 의해 핵형태와 전핵의 형성 유무로 판정하였다 핵성숙율은 24~48시간 사이 각각 81, 89, 72, 60 및 60%로 체외성숙 36시간에 성숙율이 최고였으나, 반면 감수분열 중기 II 염색체이상은 36시간부터 증가(0~30%)하였다. 에탄올처리에 의한 전핵형성율은 체외성숙 24~48시간에 각각 67, 68, 73, 84 및 87%였고, 그 중 이배체율은 각각 4, 5, 10, 16 및 20%로 성숙시간이 증가함에 따라 증가하였다. 위 실험의 결과 난자의 체외성숙 연장에 따라 전핵형성과 이배체수가 증가되는 것으로 나타났으며, 정상적인 핵성숙에 비해 세포질성숙은 더 많은 성숙시간이 필요한 것으로 나타났다. 이러한 결과들은 소 초기배 체외생산시와 핵치환용 핵수용란 생산시 적정 성숙시간 결정에 유용하게 이용될 수 있을 것이다.

• 미생물학회지
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• 제26권2호
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• pp.82-87
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• 1988

The genetic analysis and characterization of protoplast fusion hybrids between complementary auxotrophic mutants of Candida pseudotropicalis were carried out. Nuclear fusion appeared to occur in fusion hybrids (e.g., F15 and F33), as strongly suggested by isolation of recombinants after mitotic segregation of parental genetic markers. This was confirmed by KNA content, nuclear staining and comparison of survival rate to UV light. After keeping fusion hybrids for approximately one year, the frequency of spontaneous mitotic segregation was $3.0\times 10^{-4}$ - $8.1\times 10^{-4}$ while that of induced mitotic segregation was $1.4\times 10^{-3}$- $1.7\times 10^{-3}$. These results suggested that they maintained stable karyogamy state. It was also found that the production of $\beta$-D-galactosidase from F15, F33 and F158 was somewhat increased when compared with that from either auxotrophic parents or wild type.

• 한국가축번식학회지
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• 제17권3호
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• pp.249-255
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• 1993

Canine follicular oocytes were used to establish a reliable system for maturation and fertilization in vitro. Ovaries were obtained from either slaughter house or hormone-primed bitches of mixed breeds. The oocytes were recovered by mincing the ovaries in M2＋BSA. Good quality of oocyte-cumulus complexes (OCCs) were selected and cultured in TCM 199 containing 15% fetal calf serum(FCS) for 24~56 h in an atmosphere of 5% CO2 at 39$^{\circ}C$. Maturation rate of follicular oocytes was >87% showing metaphase I. Unlike other domestic animals the cumulus expansion did not occur fully in canine OCCs although minimum expansion was found between the cumulus cells and corona radiata cells, the clear nuclear morphology was presented for the first time by rapid staining. The IVM system used in this study may be useful to obtain fully maturated metaphase I oocyte in dog.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.136-136
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• 2003

Mainly due to deficiencies in nuclear reprogramming, gene expression and DNA fragmentation, which result in early and late embryonic losses, the overall success rate achieved by cloning techniques to date is low. This present study compared the incidences of DNA fragmentation during development of IVF, parthenotes (PT), nuclear transfer (NT) and transgenic (TG) embryos. Terminal deoxynucleotidyl transferase (TdT) nick-end labelling (TUNEL) with propidium iodide counter staining was used for determination of DNA fragmentation and total number, respectively. TG and NT donor cells were fetal fibroblasts with or without transfection with EGFP, and cultured in DMEM+15% FCS until confluent, for 5 days. At 19 h post-maturation (hpm), enucleated oocytes were reconstructed with donor cells and activated at 24 hpm with the combinations of ionomycin (5 M, 5 min) and cyclo-heximide (10 g/ml, 5 h) after electric fusion by a single DC pulse (1.6 KV/cm, 60 sec). Parthenotes were produced by the same activation protocol at 24 hpm. (중략)