• Fisheries and Aquatic Sciences
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• v.19 no.7
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• pp.31.1-31.6
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• 2016

Background: The objective of this study was to develop an efficient selectable marker for transgenic Dunaliella salina. Results: Tests of the sensitivity of D. salina to the antibiotic chloramphenicol and the herbicide Basta$^{(R)}$ showed that cells ($1.0{\times}10^6cells/ml$) treated with 1000 or $1500{\mu}g/ml$ chloramphenicol died in 8 or 6 days, respectively, whereas D. salina cells ($1.0{\times}10^6cells/ml$) treated with 5, 10, 20, or $40{\mu}g/ml$ Basta$^{(R)}$ died in 2 days. Therefore, D. salina is more sensitive to Basta$^{(R)}$ than to chloramphenicol. To examine the possibility of using the phosphinothricin N-acetyltransferase (pat) gene as a selectable marker gene, we introduced the pat genes into D. salina with particle bombardment system under the condition of helium pressure of 900 psi from a distance of 3 cm. PCR analysis confirmed that the gene was stably inserted into the cells and that the cells survived in $5{\mu}g/ml$ Basta$^{(R)}$, the medium used to select the transformed cells. Conclusions: The findings of this study suggest that the pat gene can be used as an efficient selectable marker when producing transgenic D. salina.

• Archives of Pharmacal Research
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• v.16 no.2
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• pp.155-157
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• 1993

DNA transfection conditions were investigated by calcium phosphate-DNA co-precipitation in SK-N-BE(2)C human neuroblastoma cells. The DNA plasmid of TH2400CAT was used in which rat tyrosine hydroxylase gene was inserted into chloramphenicol acetyltransferase reporter gent. The transfection efficiency was 25-30% and the method was simple and reproducible. So, the method will be a good tool for transient transfection analysis.

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.600-605
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• 1989

For the purpose of isolation of the Zymomonas mobilis DNA fragments showing promoter activity in Escherichia coli, a promoter screening vector, PCMT215 was constructed by transferring a promoterless chloramphenicol acetyltransferase (CAT) gene of pYEJ001 into pMT21 which contains $\beta$-lactamase gene and multiple cloning sites. A library of Z, mobilis Sau3AI DNA fragments was constructed in E. coli using the newly constructed pCMT215. Fourteen clones showing resistance to chloramphenicol ranging in concentration from 30 to 750 $\mu$g/$m\ell$ were selected. From five clones of them, the Z. mobilis DNA fragments expressing CAT gene of the recombinant plasmids were sequenced and then sites of transcriptional initiation were identified. The nucleotide sequences of the cloned DNA shared AT rich regions, poly A's or T's stretches and palindromic regions. The positions of transcriptional initiation for CAT gene occurred at more than one site spaced over by 4 to 190 base pairs on the cloned fragments in E. coli.

• Archives of Pharmacal Research
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• v.20 no.5
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• pp.404-409
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• 1997

Trout CYP1A-CAT expression construct was generated by cloning -3.5 Kb $5^I$ flanking DNA of trout liver CYP1A gene in front of CAT gene at pCAT-basic vector. Hepa 1 cells, which are known to contain a functional arylhydrbcarbon $receptor^I$ were transfected with trout CYP1A-CAT using lipofectin. 3-Methylcholanthrene (1 nM) was added into hepa 1 cells in culture in order to examine if $5^I$ flanking DNA of trout CYP1A gene could interact with mouse transactivating factors to bring about transcription of the chloramphenicol acetyltransferase(CAT) reporter gene. The level of CAT protein was measured by CAT ELISA and the level of CAT mRNA was determined by RTPCR. The treatment of 1 nM 3-methylcholanthrene resulted in two fold increases in CAT protein as well as CAT mRNA compared to untreated control hepa 1 cells. These data indicate that arylhydrocarbon receptors of mouse hepa 1 cells are functional to activate exogenously transfected trout CYP1A-CAT construct in terms of both transcription and translation of CAT. We also examined the effect of 3-methylcholanthrene on endogenous cyplal activity in hepa 1 cell. 3-Methylcholanthrene (1 nM) treatment to hepa 1 cells trahsfected with trout CYP1A-CAT construct stimulated the level of cyp1a1 mRNA by two folds and the activity of ethoxyresorufin-O-deethylase by two fold compared to that of control cells. In this study we reported that trout CYP1A-CAT reporter gene expression construct could be expressed by 3-methylcholanthrene treatment in mouse hepa 1 cells. Thus trout CYP1A-CAT could serve as a good model to study the mechanism of regulation of CYP1A1 gene expression.

• Archives of Pharmacal Research
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• v.27 no.9
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• pp.906-911
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• 2004

In order to evaluate estrogenic compounds in natural products, an in vitro detection system was established. For this system, the human breast cancer cell line MCF7 was stably trans-fected using an estrogen responsive chloramphenicol acetyltransferase (CAT) reporter plas-mid yielding MCF7/pDsCAT-ERE119-Ad2MLP cells. To test the estrogenic responsiveness of this in vitro assay system, MCF7/pDsCAT-ERE119-Ad2MLP cells were treated with various concentrations of 17f3-estradiol. Treatments of 10$^{-8}$ to 10$^{-12}$ M 17$\beta$-estradiol revealed significant concentration dependent estrogenic activities compared with ethanol. We used in vitro assay system to detect estrogenic effects in Puerariae radix and Ginseng radix Rubra extracts. Treat-ment of 500 and 50 $\mu\textrm{g}$/ml of Puerariae radix extracts increased the transcriptional activity approximately 4- and 1.5-fold, respectively, compared with the ethanol treatment. Treatment of 500, 50, and 5 $\mu\textrm{g}$/ml of Ginseng radix Rubra extracts increased the transcriptional activity approximately 3.2-,2.7, and 1.4-fold, respectively, compared with the ethanol treatment. These observations suggest that Puerariae radix and Ginseng radix Rubra extracts have effective estrogenic actions and that they could be developed as estrogenic supplements.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.789-795
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• 2004

A promoter-probe shuttle vector pSK1Cat was constructed for the isolation of transcriptional signal sequences from Corynebacterium glutamicum. Besides conferring resistance to kanamycin in Escherichia coli and C. glutamicum, the vector carried a promoterless cat gene to confer resistance to chloramphenicol upon insertion of the appropriate transcriptional signals in the multiple cloning site. By utilizing the vector, a series of transcriptionally active fragments were isolated from the genome of C. glutamicum. The clones, ranging from 200 bp to 1 kb in size, were grouped into 3 classes of strong, medium, and weak, based on the chloramphenicol acetyltransferase (CAT) activity and sensitivity to the chloramphenicol of the clone-carrying C. glutamicum cells. C. glutamicum cells carrying the $P_{19}$ clone, a representative in the strong class, were able to grow on minimal agar plates containing over $40 mg/mell$ chloramphenicol, and showed CAT activity of 10 m㏖/mgㆍmin, performing slightly better than the cells carrying $P_{tac}$ , a strong E. coli promoter. Subcloning analysis of the $P_{19}$ clone identified a 180 bp intergenic fragment ($P_{180}$), which was located upstream of a gene encoding a hypothetical membrane protein. The expression conferred by $P_{180}$ was not affected by either the kinds of carbon sources or changes in temperature. These properties make the $P_{180}$ clone useful for the deregulated expression of biosynthetic genes in C. glutamicum during amino acid fermentation.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.438-441
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• 2008

A novel lactobacilli replicon from plasmids of Lactobacillus reuteri KCTC 3678 was isolated. Eight L. reuteri strains from Korean Collection for Type Cultures (KCTC) and Korea Food Research Institute (KFRI) were screened for cryptic plasmids and most strains harbored 1 or 2 plasm ids. Particularly, L. reuteri KCTC 3678 contained 6 plasm ids which all were used for screening of lactobacilli replicon. EcoRI digests of the plasmid DNA prep from L. reuteri KCTC 3678 were ligated with pUC19 and the recombinant DNAs were serially named from pLR1 to pLR7. A cat (chloramphenicol acetyltransferase; $Cm^r$) gene originated from pC194 was introduced into pLR1-7, resulting in pLR1cat-pLR7cat, respectively. The recombinant plasmids were introduced into L. reuteri KCTC 3679, and only transformants harboring pLR5cat were obtained, indicating that the insert in pLR5 functioned as a lactobacilli replicon.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.277-277
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• 1994

Human immunodeficiency virus type (HIV-1 )은 복사에 필수적인 전사촉진단질유전자인 tat를 가지고 있다. 우리는 유전자 재조합기법을 사용하여 tat 유전자와 nef 유전자가 결핍된 HIV-1을 제조하였다. nef, tat-결핍 HIV-1 은 C $D_4$$^{+T}$ 세포에서 전혀 복제를 하지 못하였다. 반면, tat 단백질을 발현하도록 만들어진 재조합 Jurkat-tat세포에서는 복제능력을 다시 회복함을 알 수 있었다. 이러한 nef, tat-결핍 바이러스를 Jurkat-tat 세포에서 두달이상 계대배양했을 때, revertant가 전혀 생기지 않았다. 또한, nef, tat- 결핍 HIV-1 에 chloramphenicol acetyltransferase 유전자를 삽입시키고, 이의 발현정도를 측정함으로써 원형바이러스와 마찬가지로 민감하면서도 안전하고 편리하게 바이러스의 복제를 측정할 수 있었다. nef, tat- 결핍 바이러스는 항 HIV-1 제의 활성도를 측정하고자할 때 원형 바이러스의 대용으로 안전하게 사용될 수 있을것이다.다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.80-80
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• 1993

(목적) 본 연구에서 사용된 바이러스는 HIV-1 nef유전자가 일부 삭제되고 대신 Chloramphenicol acetyltransferase(CAT)가 pSVCAT recombinant 바이러스다. 이러한 recombinant 바이러스를 사용하는 이유는 첫째, CAT activity가 매우 민감하므로 바이러스의 복제억제 정도를 정확하게 측정 할 수 있고 둘째, simian immunodeficiency virus(SIV)의 경우 nef 유전가 in vivo에서는 바이러스의 복제에 필수적이므로 HIV가 SIV와 유사한 것으로 미루어 본 연구에서 사용되는 recombinant SVCAT 바이러스가 안전한 것으로 고려되기 때문이다. (방법) 특히 화합물이 HIV-1의 복제에 얼마나 영향이 있는가는 1) 어느정 도의 virus inoculm을 넣었는지 2) 사용하는 cell line 3) 사용한 cell line의 infection kinetics 4) 실험의 지속기간 5) 테스트하는 assay의 sensitivity에 의존한다. 따라서 $10^{5}$ cell의 H9과 sup T1을 24 well plate에 넣고 sup T1 cell line의 경우 3일 후 항 화합물에 의한 syncytia 형성 및 CAT activity의 억제정도를 현재 AIDS drug으로 쓰이고 있는 Zidovudine을 control로 비교 관찰하였다. H9 cell line의 경우 3일 간격으로 media의 3/4을 fresh media로 바꾸어 주고 9일 후 CAT assay를 하였다. 이러한 assay에서 activity를 보이는 화합물을 reverse transcriptase와 P24 ELISA assay를 재확인하였다.다.

• ALGAE
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• v.33 no.4
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• pp.351-358
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• 2018

The ability to transform the chloroplast of Cyanidioschyzon merolae was limited by lack of confirmed and reliable promoter sequences (among other reasons), capable of delivering stable or modulated DNA transcription followed by protein synthesis. Our research has confirmed the applicability of three selected chloroplast promoters in C. merolae chloroplast overexpression of the exogenous protein (i.e., chloramphenicol acetyltransferase) and genetic transformation. These results might facilitate further research on genetically modified strains of C. merolae to envisage yet unknown aspect of cellular and plastic physiology as well as C. merolae potential applications as bio-factories or sources of useful chemicals.