• Journal of Microbiology and Biotechnology
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• v.10 no.1
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• pp.115-118
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• 2000

Recombinant plasmids harboring a heterologous gene coding for the enhanced green fluorescent protein (EGFP) were transfected and expressed in Drosophila melanogaster S2 cells. A stable transformation of polyclonal cell populations expressing EGFP were isolated after 4 weeks of selection with hygromycin B. The recombinant EFGP expressed in transformed S2 cells consisted of a molecular weight of 27 kDa. EGFP expression was also confirmed by fluorometric measurement. The maximum EGFP concentration was about 9.3 mg/I. The present findings demonstrate not only the successful stable expression of EGFP in Drosophuila was about 9.3 mgI. The present findings demonstrate not only the successful stable expression of EGFP in Drosophila S2 cells, but also the use of EGFP as a reporter to analyze gene expression, with its potential of a Drosophila cell expression system for recombinant protein production being an alternative to a baculovirus-insect cell expression system.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.10a
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• pp.149-150
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• 2003

The purpose of this experiment is to optimize the yield of the recombinant Cox2 from the stably transformed Drosophila melanogaster S2 cells, using dimethylsulfoxide and sodium butyrale. Materials and Methods : Materials - Cell line : Drosophila melanogaster Schneider 2 (S2) cells - vector pMT/BiP/V5-His and pCoHygro (Invitrogen) (omitted)

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.10a
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• pp.147-148
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• 2003

The purpose of this experiment is to confirm whether the recombinant tumstatin revealed from the stably transformed Drosophila melanogaster S2 cells has in vitro capacity. Materials and Methods : Materials - Cell line : Drosophila melanogaster Schneider 2 (S2) cells - vector pMT/BiP/V5-His and pCoHygro (Invitrogen) (omitted)

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.563-568
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• 2002

Stably transformed Drosophila melanogaster 52 cells producing recombinant VP7 were obtained, and recombinant VP7 expression was confirmed by Western blot analysis. The molecular weight of recombinant VP7 expressed in 52 cells was approximately 35.5 kDa, and 75% of the total VP7 produced was present in the medium. Recombinant VP7 contained N-linked glycosylated oligosaccharides. Aprotinin, leupeptin, and polyvinylpyrrolidone did not have any noticeable effect on recombinant VP7 production; however, DMSO and sodium butyrate increased its production by 120% and 60%, respectively.

• Molecules and Cells
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• v.27 no.5
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• pp.583-589
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• 2009

GTP cyclohydrolase I (GTPCH) is a key enzyme in the de novo synthesis of tetrahydrobiopterin. Previously, the Drosophila melanogaster GTPCH gene has been shown to be expressed from two different promoters (P1 and P2). In our study, the 5'-flanking DNA regions required for P1 and P2 promoter activities were characterized using transient expression assay. The DNA regions between -98 and +31, and between -73 and +35 are required for efficient P1 and P2 promoter activities, respectively. The regions between -98 and -56 and between -73 and -41 may contain critical elements required for the expression of GTPCH in Drosophila. By aligning the nucleotide sequences in the P1 and P2 promoter regions of the Drosophila melanogaster and Drosophila virilrs GTPCH genes, several conserved elements including palindromic sequences in the regions critical for P1 and P2 promoter activities were identified. Western blot analysis of transgenic flies transformed using P1 or P2 promoter-lacZ fusion plasmids further revealed that P1 promoter expression is restricted to the late pupae and adult developmental stages but that the P2 promoter driven expression of GTPCH is constitutive throughout fly development. In addition, X-gal staining of the embryos and imaginal discs of transgenic flies suggests that the P2 promoter is active from stage 13 of embryo and is generally active in most regions of the imaginal discs at the larval stages.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.04a
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• pp.40-40
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• 2003

Recombinant plasmids harboring heterologous genes coding enhanced green fluorescent protein (EGFP) and erythropoietin (EPO) were transfected and expressed in Drosophila melanogaster S2 cells. Stably transformed cell populations expressing EGFP or monkey EPO were isolated after 4 weeks of selection with hygromycin B. (omitted)

• Animal cells and systems
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• v.2 no.1
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• pp.113-116
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• 1998

A cDNA clone coding for ribosomal protein 46 (rp46) which is a component of 60S ribosomal large subunit has been identified from Drosophila melanogaster. A cDNA clone encoding S. cerevisiae rp46 was used as a probe to screen a Drosophila larvae cDNA library. The DNA sequence analysis revealed that the cDNA coding for Drosophils rp46 contains a complete reading frame of 153 nucleotides coding for 51 amino acids. The deduced amino acid sequence showed 71-75% homology with those of other eukaryotic organisms. Northern blot analysis showed that about 1-kb rp46 transcripts are abundant throughout fly development. Whole mount embryonic mRNA in situ hybridization also showed no preferential distribution of the transcripts to any specific region. The chromosomal in situ hybridization revealed that the identified gene is localized at position 60C on the right arm of the second polytene chromosome with a possibility of single copy.

• KSBB Journal
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• v.27 no.5
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• pp.313-318
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• 2012

Dimethyl sulfoxide (DMSO) increased the intracellular calcium ion concentration in stably transfected Drosophila melanogaster S2 cells expressing recombinant cyclooxygenase 1 (COX-1). DMSO did not increase the Drosophila NOS (dNOS) transcript level in calcium chelator-treated cells. Expression of recombinant COX-1 due to DMSO was diminished in cells treated with calcium chelators or channel blockers. Our results indicate that an increased intracellular calcium ion concentration due to DMSO is associated with up-regulation of the dNOS gene, leading to enhanced expression of COX-1.

• Korean Chemical Engineering Research
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• v.44 no.1
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• pp.40-45
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• 2006

The baculovirus-insect Drosophila melanogaster S2 cell system combines advantages of conventional baculovirus system and non-lytic S2 cell system because baculoviruses can infect non-permissive cells such as mammalian and Drosophila S2 cells but cannot replicate themselves inside the cells. In the present work, we investigated effects of infection conditions on production of green fluorescent protein (GFP) as a target protein using this baculovirus-S2 cell system. Even though higher MOI and longer baculovirus contact time showed better GFP expression yield during the shorter period, overall protein yield could be lower during the longer period due to the relatively higher cell detachment and lysis (lower cell viability). In addition, maintaining high MOI will be not practical for large-scale cell culture. Therefore, instead of maintaining high MOI, we found that high initial cell number and concentrated (10X) baculovirus volume can confer comparable protein expression even under the moderate MOI condition. Also, we found that the post-infection time that is connected to state of cells after infection was an important factor for production yield.

• Molecules and Cells
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• v.38 no.10
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• pp.911-917
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• 2015

Citronellal, a well-known plant-derived mosquito repellent, was previously reported to repel Drosophila melanogaster via olfactory pathways involving but not directly activating Transient Receptor Potential Ankyrin 1 (TRPA1). Here, we show that citronellal is a direct agonist for Drosophila and human TRPA1s (dTRPA1 and hTRPA1) as well as Anopheles gambiae TRPA1 (agTRPA1). Citronellal-induced activity is isoform-dependent for Drosophila and Anopheles gambiae TRPA1s. The recently identified dTRPA1(A) and ag-TRPA1(A) isoforms showed citronellal-provoked currents with EC50s of $1.0{\pm}0.2$ and $0.1{\pm}0.03mM$, respectively, in Xenopus oocytes, while the sensitivities of TRPA1(B)s were much inferior to those of TRPA1(A)s. Citronellal dramatically enhanced the feeding-inhibitory effect of the TRPA1 agonist N-methylmaleimide (NMM) in Drosophila at an NMM concentration that barely repels flies. Thus, citronellal can promote feeding deterrence of fruit flies through direct action on gustatory dTRPA1, revealing the first isoform-specific function for TRPA1(A).