• 한국잠사곤충학회지
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• 제37권1호
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• pp.52-56
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• 1995

Baculovirus 발현계에서 BmNPV의 증식효율을 향상시키기 위하여, 누에 유충 체액의 BmN-4 세포주에서 BmNPV 증식에 미치는 영향을 조사하였다. 5령 3일째의 누에 유충으로 부터 체액을 추출하여 BmN-4 배양액에 첨가한 결과, 열처리하지 않은 누에 체액의 첨가는 세포의 응집과 소형화 현상으로 인해 세포의 증식을 저해한 반면, $65^{\circ}C$에서 30분간 열처리한 체액 10%와 FBS 3%를 세포배양액에 첨가한 것이 바이러스 감염에 의해 방출된 다각체의 수가 가장 많은 것으로 나타나 바이러스 증식에 가장 효과적이었다. 또한 plaque assay 결과, 체액의 첨가에 의한 바이러스 증식효율의 증가는 세포의 증식에 의한 것이라기보다 바이러스 감염성의 증가에 기인하는 것으로 보여진다.

• 한국잠사곤충학회지
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• 제37권2호
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• pp.181-185
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• 1995

국내 분리주의 BmNPV를 이용한 전이벡터 pBm-KSK1에 외래 유전자로서 E. coli $\beta$-galactosidase 유전자를 클로닝하여 제작한 재조합 바이러스 BmK1-lacZ의 발현 증대를 위해 재조합 바이러스 감염세포주에 누에 체액의 첨가에 따른 발현효율을 조사하였다. 재조합 바이러스의 배양세포주에서 외래 유전자 발현에 대한 누에 체액의 첨가 효과는 FBS가 2% 또는 5% 일때 누에 체액 2%의 소량 첨가만으로도 누에체액이 첨가되지 않았을 때에 비해 약 2배 이상 높은 발현량을 확인하였으며, 그 보다 FBS가 전혀 첨가되지 않고 단지 누에 체액 2% 첨가만으로도 FBS 첨가시와 마찬가지의 높은 발현량을 보여 누에 체액에 의한 FBS의 대체 효과를 나타내었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제7권2호
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• pp.197-201
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• 2003

The recombinant plasmids harboring a heterologous gene coding mouse endostatin were transfected and expressed stably in Trichoplusia ni Tn 5B1-4 cells and Bombyx mori BmN cells, respectively. Recombinant endostatin expressed in the stably transformed Tn 5B1-4 and BmN cells was secreted into the medium. BmN cells are relatively lower in maximum cell growth and recombinant endostatin production than Tn 5B 1-4 cells. Recombinant endostatin was also purified to homogeneity using a simple one-step ${Ni^2+}$ affinity fractionation method. Purified recombinant endostatin inhibited endothelial cell proliferation in a dose-dependent manner. The concentration at half-maximum inhibition $({ED_50})$ for recombinant endostatin was approximately 0.35 ${\mu}g$/ml.

• 한국잠사곤충학회지
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• 제33권1호
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• pp.21-26
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• 1991

Bm 배양세포주(BmN4)에서 BmNPV의 다각체 단백질 합성과 DNA복제에 대한 실험결과는 다음과 같다. 1. BmNPV는 insect Grace's medium에서 배양되고 있는 BmN4 세포에서 NOV나 DNA로 감염시킨 경우 모두 잘 증식되었으며, 도립현미경 관찰 결과 접종 후 48시간이 경과하면서 다각체가 형성되기 시작하였다. 2. 또한 전자현미경으로 핵내 형성된 다각체와 협성중인 nucleocapsid 다발을 관찰하였으며, 바이러스 입자는 SNPV로 존재하였다. 3. Western blot분속에 의한 다각체 단백질의 합성은 접종 후 18시간부터 관찰되었으며, 다각체 단백질의 분자량은 30kd이었다. 4. Wild type BmNPV DNA와 Bm 세포(BmN4)에서 NOV 및 DNA 감염에 의해 형성된 바이러스 DNA간의 제한효소 패턴은 차이가 없었다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권11호
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• pp.1837-1847
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• 2020

Objective: To evaluate the pancreatic differentiation potential of α-1,3-galactosyltransferase knockout (GalTKO) pig-derived bone marrow-derived mesenchymal stem cells (BM-MSCs) using epigenetic modifiers with different pancreatic induction media. Methods: The BM-MSCs have been differentiated into pancreatic β-like cells by inducing the overexpression of key transcription regulatory factors or by exposure to specific soluble inducers/small molecules. In this study, we evaluated the pancreatic differentiation of GalTKO pig-derived BM-MSCs using epigenetic modifiers, 5-azacytidine (5-Aza) and valproic acid (VPA), and two types of pancreatic induction media - advanced Dulbecco's modified Eagle's medium (ADMEM)-based and N2B27-based media. GalTKO BM-MSCs were treated with pancreatic induction media and the expression of pancreas-islets-specific markers was evaluated by real-time quantitative polymerase chain reaction, Western blotting, and immunofluorescence. Morphological changes and changes in the 5'-C-phosphate-G-3' (CpG) island methylation patterns were also evaluated. Results: The expression of the pluripotent marker (POU class 5 homeobox 1 [OCT4]) was upregulated upon exposure to 5-Aza and/or VPA. GalTKO BM-MSCs showed increased expression of neurogenic differentiation 1 in the ADMEM-based (5-Aza) media, while the expression of NK6 homeobox 1 was elevated in cells induced with the N2B27-based (5-Aza) media. Moreover, the morphological transition and formation of islets-like cellular clusters were also prominent in the cells induced with the N2B27-based media with 5-Aza. The higher insulin expression revealed the augmented trans-differentiation ability of GalTKO BM-MSCs into pancreatic β-like cells in the N2B27-based media than in the ADMEM-based media. Conclusion: 5-Aza treated GalTKO BM-MSCs showed an enhanced demethylation pattern in the second CpG island of the OCT4 promoter region compared to that in the GalTKO BM-MSCs. The exposure of GalTKO pig-derived BM-MSCs to the N2B27-based microenvironment can significantly enhance their trans-differentiation ability into pancreatic β-like cells.

• 한국잠사곤충학회지
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• 제38권1호
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• pp.53-56
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• 1996

곤충세포주로 널리 이용되고 있는 Sf 세포주와 Bm 세포주의 분자생물학적 표식자를 탐색하기 위하여, 총 세포 단백질의 SDS-PAGE와 genomic DNA를 RAPD(Random Amplification of Polymorphic DNA) 방법으로 분석하였다. 그 결과, 총 세포 단백질 및 genomic DNA, 패턴에서 두 세포주를 뚜렷하게 구별할 수 있는 밴드를 탐색하였으며, 이들은 유용한 분자 생물학적 표식자로 이용될 수 있을 것이다.

• International Journal of Industrial Entomology and Biomaterials
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• 제4권1호
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• pp.51-56
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• 2002

A recombinant transfer vector pBacSCF was constructed by inserting huamn stem cell factor (hSCF) cDNA into plasmid pBacPAK8. BmN cells were co-transfected with modified Bombyx mori, nuclear polyhedrosis virus (BmBacPAK) DNA and the recmbinant transfer vector to construct a recombinant baculovirus containing hSCE gene. DNA dot blotting and RNA dot blotting demonstrated that the hSCE gene was contained in the recombinant virus and transcribed. The recombinant baculovirus was infectious to BmN cells and to silkworm. SDS-PAGE analysis showed a specific band of expressed product in the extract of infected cells and in the heamolymph of infected larvae. Bioactivity of the recombinant hSCE was determined with W-1 cell line and MTT colorimetric method in synergy with interlukin-3 (IL-3). These results revealed that the hSCF gene was over-expressed in cultured cells and lavae of silkworm.

• 한국잠사곤충학회지
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• 제39권1호
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• pp.36-43
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• 1997

In order to express the FLP recombinase in B. mori cultured cell line, BmN-4, transient expression system using a heat shock protein gene (hsp70) promoter of Dorosophilla melnogaster was constructed. This vector was designated as pHsSV. Activity strength of the hsp70 promoter was compared with that of immediate early gene (IE-1) and polyhedrin gene of BmNPV employing the E. coli $\beta$-galactosidase gene as a reporter gene. The result showed that the pHs $\beta$-gal plasmid vector expressed the $\beta$-galactosidase at 2nd and 3rd day after the transfer of plasmid DNA into BmN-4 cells, which was similar to that of pIE1 $\beta$-gal vector, but different from that of a recombinant virus, vBm $\beta$-gal. For the construction of FLP recombinase transient expression vector, the FLP recombinase gene was cloned by polymerase chain reaction technique. To express the FLP recombinase, this gene was inserted into pHsSV plasmid vector, under the control of the hsp70 promotor, and tranfected in BmN-4 cells. The expressed FLP recombinase was estimated at 44kDa on a 12.5% SDS-PAGE.

• International Journal of Industrial Entomology and Biomaterials
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• 제15권1호
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• pp.35-38
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• 2007

In this study, ORF 46 of Bombyx mod nucleopolyhedrovirus(Bm46) fused with EGFP was expressed in Bombyx mod cell lines, larvae and pupae by BmNPV Bacmid system. Bm46 and EGFP were cloned into donor plasmid pFastBacHTb, which was transformed to competent DH10B cells containing helper and BmNPV bacmid by site-specific transposition. Recombinant bacmid was used to transfected BmN-4 cells to produce the recombinant baculovirus vBm-Bm46-EGFP. Recombination virus was injected into silkworm larvae and pupae. The expression of the fusion protein was monitored by examining green fluorescence using a fluorescent microscope. Intense fluorescence in cells and silkworm was observed at 4 days post-infection, indicating the Bm46-EGFP fusion gene was expressed successfully.

• 한국미생물·생명공학회지
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• 제24권1호
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• pp.72-76
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• 1996

To investigate the expression efficiency of new transfer vector of Bombyx mori nuclear polyhedrosis virus (BmNPV), Escherichia coli lacZ gene was inserted into new transfer vector pBmKSK1, under the control of polyhedrin promoter and expressed in BmN-4 cells and larvae of silkworm, Bombyx mori. The recombinant virus containing lacZ gene was isolated from BmN-4 cells coinfected with transfer vectro pBmKSK1-LacZ and wild type BmNPV genome, and analysed by Southern blotting. The expression of ${\beta}$-galactosidase was characterized by SDS-PAGE, Western blotting and ${\beta}$-galactosidase activity assay. The results showed that the level of expression in silkworm larvae was higher than that of BmN-4 cells.