• Asian-Australasian Journal of Animal Sciences
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• v.6 no.4
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• pp.483-489
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• 1993

Bovine fibroblasts were cultured in Dulbecco's Modified Eagle's Medium and then treated with control, insulin (I, $1{\mu}g/ml$), cholera toxin (CT, 0.1-100 ng/ml) or CT (0.1-100 ng/ml) + I ($1{\mu}g/ml$). Cholera toxin, an activator of adenylate cyclase, significantly decreased insulin induced DNA synthesis (p<0.05). The modulation of DNA synthesis apparently involves events occurring in early stage of cell growth, at least between the first 4 and 8 hour of CT treatment. Insulin induced collagen as well as noncollagen synthesis in cell layer, however, these syntheses were reduced by addition of cholera toxin (p<0.05) but were not completely reduced. It is not clear whether the reduction of insulin-induced cell layer collagen or noncollagen proteins by CT is involved in the inhibitory effect on insulin-induced DNA synthesis. However, we could rule out the hypothesis that insulin-induced DNA synthesis is reduced by CT-induced cellular differentiation.

• BMB Reports
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• v.38 no.1
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• pp.97-103
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• 2005

Under the condition of expression of $\lambda$ P protein at lethal level, the oriC DNA-binding activity is significantly affected in wild-type E. coli but not in the rpl mutant. In purified system, the $\lambda$ P protein inhibits the binding of both oriC DNA and ATP to the wild-type DnaA protein but not to the rpl DnaA protein. We conclude that the $\lambda$ P protein inhibits the binding of oriC DNA and ATP to the wild-type DnaA protein, which causes the inhibition of host DNA synthesis initiation that ultimately leads to bacterial death. A possible beneficial effect of this interaction of $\lambda$ P protein with E. coli DNA initiator protein DnaA for phage DNA replication has been proposed.

• BMB Reports
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• v.43 no.11
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• pp.732-737
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• 2010

RNA interference is a post-transcriptional silencing mechanism triggered by the bioavailability and/or exogenous introduction of double-stranded RNA (dsRNA) into cells. Here we describe a novel method for the synthesis of siRNA in a single vessel. The method employs in vitro transcription and a single-stranded DNA (ssDNA) template and design, which incorporates upon self-annealing, two promoters, two templates, and three loop regions. Using this method of synthesis we generated efficacious siRNAs designed to silence both exogenous and endogenous genes in mammalian cells. Due to its unique design the single-stranded template is easily amenable to adaptation for attachment to surface platforms for synthesis of siRNAs. A siRNA synthesis platform was generated using a 3' end-biotinylated ssDNA template tethered to a streptavidin coated surface that generates stable siRNAs under multiple cycles of production. Together these data demonstrate a unique and robust method for scalable siRNA synthesis with potential application in RNAi-based array systems.

• The Korean Journal of Zoology
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• v.23 no.4
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• pp.203-218
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• 1980

Unscheduled DNA synthesis, chromosome aberrations, sister chromatid exchanges and DNA replication inhibition induced by the combined treatments with ara-C and UV-light or MMS in $HF_1$, CHO and $HelaS_3$ cells were studied, and the results obtained were as follows: (1) Ara-C was found to inhibit UV-or MMS-induced unscheduled DNA synthesis and the inhibitory effect of ara-C was more remarkable in its post-treatment. (2) Ara-C enhanced the rate of chromosome aberrations induced by MMS or UV-light. Post-treatment with ara-C exhibited the synergistic effect on MMS-induced chromosome aberrations mainly by increases of chromatid deletions. (3) Contrarily, ara-C did not increase the rate of sister chromatid exchanges, particularly in the pre-treatment with MMS, although it was found to induce sister chromatid exchanges. (4) The rate of DNA synthesis was declined immediately after are-C treatment and then recovered. The combined treatments with ara-C and UV-light or MMS showed that the initial response on replication inhibition was similar to that of ara-C, but later responses were similar to that of UV-light or MMS treated group.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.147-158
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• 1992

This study was aimed to compare the relative cytotoxicity of the five common orthodontic bonding materials (Concise. Mon-lok, Ortho-One, Super C, Transbond) using cell culture technique. DNA synthesis of the fibroblasts was assessed by $^3H$-thymidine uptake to evaluate the effect of the bonding materials on the growth of the cells. The human gingival fibroblasts were explanted from the buccal gingiva of 10 year-old girl and cultured in $\alpha$-MEM/10% FBS/1% antibiotics medium, $37^{\circ}C$, 5% $CO_2$ incuvator. The gingival fibroblasts were tested with the medium into which the bonding materials had been soaked for 1 week. Or the bonding materials were placed on the cells immediately or 2 weeks after polymerization. After 22 hours, $^3H$-thymidine was added into the microtest wells and after 24 hours, the uptake of $^3H$-thymidine was determined by liquid scintilation counter. The results of this study were as follows. 1. DNA synthesis was significantly decreased with Super C and Transbond than Ortho-One, when treated with medium into which the bonding materials had been soaked for 1 week. 2. DNA synthesis was significantly decreased with Concise, Super C and Transbond than control, when treated immediately after polymerization. 3. DNA syntehsis was significantly decreased with Concise, Super C and Transbond than Ortho-One, when immediately after polymerization. 4. There was no significant difference in DNA synthesis between the bonding materials, when treated 2 weeks after polymerization.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.535-540
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• 1990

Bacitlus sphaericus ts-Dl290 was characterized comparatively with the wild type strain 1593 by themeasurements of the biosynthesis of total DNA, RNA and protein on the temperature-shift culturesat permissive temperature of $30^{\circ}C$ and at nonpermissive temperature of $42^{\circ}C$. The growth patterns of the wild type strain and ts-Dl290 were similar at $30^{\circ}C$, but at 4Z C the mutant almost did not grow (temperature-sensitivity). When the growth temperatures of both stains were shifted-up from $30^{\circ}C$ to $42^{\circ}C$ after a 4 hour culture, their growths were normal, but when shifted-down from $42^{\circ}C$ to $30^{\circ}C$ after a 4 h culture, the mutant did not grow. When shifted up from $30^{\circ}C$ to $42^{\circ}C$ after a 4 hculture, the DNA syntheses of the two strains were at a normal rate for 1 h, but after 1 h the biosynthesesdecreased. The rate of DNA synthesis of the wild type strain at the nonpermissive temperature was about 93%, and that of the mutant was about 50% of the ratio of the wild type strain, and the RNA synthesis of the wild type strain was maintained for 3 h, and that of the mutant for 2 h. Thereafter the RNA synthesis decreased, and the synthesis of proteins in the both strains were similarlykept high for 8 h. The reversibility of the DNA synthesis of the mutant at $42^{\circ}C$ was lessened whenthe culture times were increased.re times were increased.

• Toxicological Research
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• v.7 no.1
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• pp.13-20
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• 1991

To investigate the cytotoxicity and genotoxicity of the DNA alkylating agnet, mitomycin C and the antimetabolite, 5-Fluorouracil (5-FU) in cultured rat fibroblasts, the colorimetric assay of netural red (NR) for cytotoxicity and for genotoxicity, sister chromatid exchange (SCE) assay and the measurement of the rate of DNA synthesis were performed in cells cultured in media containing various concentrations of mitomycin C and 5-FU. The uptake ability of neutral red decreased does-dependently. NR90 and NR50 values of mitomycin C were 1.49 nM and 6.87mM and 5-FU were 38.4mM AND 284.4Mm respectively.

• Archives of Pharmacal Research
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• v.12 no.3
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• pp.207-213
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• 1989

This study was performed to investigate the mechanism of in vitro cytotosic actions of polyacetylenes which are panaxydol, panaxynol and panaxytriol isolated from Panax ginseng C. A. Meyer. DNA synthesis of L1210 cells was significantly inhibited with dose dependent pattern when L1210 cells were treated for 1 hour with over 5 .mu.g/ml of polyacetylenes. Panaxydol which had the most potent cytotoxicity among three polyacetylenes showed also the strongest inhibitory effect on DNA synthesis. Intracellular cyclic AMP levels of L1210 cells treated with 2.5 $\mu$g/ml of panaxydol or panaxytriol were significantly elevated on the incubation duration. The elevation of cyclic AMP levels by panaxytriol was higher than that by panaxydol, but no significant increase in cyclic AMP by panaxynol was observed. All three polyacetylenes had no effect on glycolysis of L1210 cells. Electron microscopic observations revealed that polyacetylenes caused damage to plasma membranes of L1210 cells in proportion to their cytotoxicities at each $ED_{50}$ value (panaxydol > panaxynol> panaxytriol). These results suggest that cytotoxicities of polyacetylenes against L1210 cells might be mediated by elevated cyclic AMP level, even though the relationship among their cytotoxicities, inhibitory effect on DNA synthesis and ability to elevation of cyclic AMP level are not fully agreed, and might be also related to membrane damage.

• The Plant Pathology Journal
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• v.31 no.2
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• pp.108-114
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• 2015

Curvularia lunata is an important maize foliar fungal pathogen that distributes widely in maize growing area in China, and several key pathogenic factors have been isolated. An yeast two-hybrid (Y2H) library is a very useful platform to further unravel novel pathogenic factors in C. lunata. To construct a high-quality full length-expression cDNA library from the C. lunata for application to pathogenesis-related protein-protein interaction screening, total RNA was extracted. The SMART (Switching Mechanism At 5' end of the RNA Transcript) technique was used for cDNA synthesis. Double-stranded cDNA was ligated into the pGADT7-Rec vector with Herring Testes Carrier DNA using homologous recombination method. The ligation mixture was transformed into competent yeast AH109 cells to construct the primary cDNA library. Eventually, a high qualitative library was successfully established according to an evaluation on quality. The transformation efficiency was about $6.39{\times}10^5$ transformants/$3{\mu}g$ pGADT7-Rec. The titer of the primary cDNA library was $2.5{\times}10^8cfu/mL$. The numbers for the cDNA library was $2.46{\times}10^5$. Randomly picked clones show that the recombination rate was 88.24%. Gel electrophoresis results indicated that the fragments ranged from 0.4 kb to 3.0 kb. Melanin synthesis protein Brn1 (1,3,8-hydroxynaphthalene reductase) was used as a "bait" to test the sufficiency of the Y2H library. As a result, a cDNA clone encoding VelB protein that was known to be involved in the regulation of diverse cellular processes, including control of secondary metabolism containing melanin and toxin production in many filamentous fungi was identified. Further study on the exact role of the VelB gene is underway.

• Journal of Life Science
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• v.10 no.2
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• pp.188-195
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• 2000

In order to understand molecular events during silk synthesis and provide genetic resources for molecular breeding, we had analyzed the cDNA library constructed from the posterior silkgland of Antheraea yamamai and partially sequenced 276 randomly selected genes from the cDNA library. Database comparisons of the expressed sequence tags (ESTs) revealed that 26 non-redundant clones showed a high similarity with previously identified genes. Among them, 17 clones exhibited a homology with previously identified insect genes and 9 clones were identical to genes that were previously identified from other organisms. A functional categorization showed that silk synthesis-defense- or stress-related genes, as well as genes involved in the metabolic pathways and in the transcriptional or translational apparatus are represented. In this report, the clone (AY479) which had high similarity with fibroin from A. pernyi was particularly analyzed in detail. The AY479 clone was carboxyl terminal region of fibroin. The 472 bp cDNA has 123 amino acids that shared 85% homology with the fibroin from A. pernyi and its deduced peptide had unique feature, that is, sites of alanine rich residues.