• Fisheries and Aquatic Sciences
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• 제17권3호
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• pp.377-380
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• 2014

RNA interference (RNAi)-mediated transcriptional knock-down of Crassostrea gigas big defensin 1 and 2 genes (Cg-BigDef1 and Cg-BigDef2) was investigated. The cDNA sequences of Cg-BigDef1 and Cg-BigDef2 were identical, excluding an additional fragment of 20 nucleotides in Cg-BigDef1; thus, a long double-stranded RNA (dsRNA) targeting the mRNA of Cg-BigDef2 effectively downregulated both Cg-BigDef2 and Cg-BigDef1. In addition, long dsRNA targeting green fluorescent protein (GFP) did not affect transcription of the two big defensin genes. These results suggest that the transcriptional downregulation of Cg-BigDef1 and Cg-BigDef2 was mediated by sequence-specific RNA interference (RNAi). Despite injection of long dsRNA targeting Cg-BigDef2 into only the adductor muscle, knock-down of Cg-BigDef1 and Cg-BigDef2 was observed in the adductor muscle, hemocytes, mantle, and gills, suggestive of systemic spread of RNAi in C. gigas. Furthermore, the inhibitory effect of dsRNA persisted until 72 h post-injection, indicative of a long-lasting RNAi-mediated knock-down of target genes.

• 분석과학
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• 제21권2호
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• pp.129-134
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• 2008

순환전압전류법과 벗김전압 전류법을 사용한 폭발물(hexahydro-1,3,5-trinitro-1,3,5-triazine, RDX)의 흔적량 분석을 위하여 double-stranded ds calf thymus (DNA)와 카본 나노튜브 혼합 전극을 사용하였으며. 최적 분석 조건을 시험한 결과 0.2 V vs. Ag/AgCl 전위에서 봉우리 전류를 발견하였다, 이 전위를 사용하여 선형분석 농도 범위: 50-75 ug/의 순환전압전류법과, 5-80 ng/L의 벗김 전압 전류법에 도달하였으며, 10 ug/L의 농도에서15번 반복 측정한 상대 표준편차는 0.086% 이었다. 또한 300초의 벗김 분석 조건에서 0.65 ng/L ($2.92{\times}10^{-12}M$) (S/N=3)의 검출 한계에 도달 하였으며, 이 조건에서 폭약에 오염된 토양중의 RDX 흔적량을 분석 응용하였다.

• 한국식물병리학회지
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• 제13권2호
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• pp.113-117
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• 1997

Low moleuclar weight (LMW) RNAs were isolated form Korean peonies which expressed symptoms of stunt and epinasty. The LMW plant RNAs were purified by Qiagen column chromatography which could separate viroid specific nucleic acid at differential salt concentration. After the inoculation of the purified RNAs from the peonies, the inoculated tomatoes (cv. Rutgers) expressed the symptoms of stunt and epinasty. Also the same molecular weight RNAs with viroid-like RNAs were isolated from the inoculated tomatoes. Double-stranded cDNA were synthesized by the methods of reverse transcription (RT) and polymerase chain reaction (PCR) with the purified RNA and primers. The same cDNAs associated with viroid-like RNAs wre cloned from the inoculated tomatoes. The cDNA has been sequenced and its 375-nucleotides were arranged into secondary structure. The cloned cDNA showed 47~54% homology compared with other viroids. The sequence homology of the cloned cDNA were partially high with plant genomic RNAs.

• Journal of Plant Biology
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• 제32권1호
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• pp.33-40
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• 1989

Polysomal polyadenylated mRNAs which were purified from pea leaves were fractionated by sucrose grandient sedimentation. Fractions corresponding to the peak at 11.5S were found to contain mostly mRNA encoding the precursor polypeptide to the small subunit of ribulose bisphosphate carboxylase (rbcS) by in vitro translation in wheat germ extract. Double-stranded cDNA which was synthesized from the 11.5S mRNA was cloned into Hind III site of plasmid pBR 325. A cDNA clone, H24, was identified to code for rbcS. In vitro translation product of the hybridization-selected mRNA was molecular weight 20,000, presumably the precursor of rbcS. The nucleotide sequences of the H24 showed almost complete homology with the sequences encoding the transit peptide of the rbcS-3A gene which was reported by Fluhr et al.(1986).

• 한국연초학회지
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• 제15권2호
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• pp.161-166
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• 1993

A double - stranded cDNA fragment (436bp) encoding coat protein of tobacco mosaic virus(TMV) was derived from the total 480nucleotides gene after reverse transcription of TMV RNA, and subclorled into a plant expression vector pBl 121, resulting in pBL 430. The plasmid DNA containing this chimeric gene was moved from E. cofi to Agrobacterium tumefaciens strain A28l, and was introduced in시 the tobacco plant by the Agrobocterium Ti - mediated transformtion system. The transformants were selected on a selection media containing kanamycin. The shoots add roots could be differentiated from the explants and whole plants were obtained. From Southern blot hybridization analysis, DNA extracted from transformants, it could be conformed that the chimeric gene fragment was inserted into the genomic DNA of tobacco plant.

• Journal of Microbiology and Biotechnology
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• 제10권2호
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• pp.272-274
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• 2000

Temperate bacteriophage P2 has a nonessential gene called old(overcoming lysoginization defection). In the presence of old, the growth of the host (Escherichia coli) with recBC- genotype is ingibited, and another bacteriophage, lambda, cannot superinfect. The Old protein has been shown to possess an exonuclease actibity. Three mutant P2s(old 1, old 17, old 49) which did gene was coned into expression vectors to produce hexahistidine-tagged proteins. The proteins were affinity-purified and shown to lose its exonuclease activity on both double-stranded and single-stranded DNA substrates. Thus, it was concluded that the lambda exclusion was related to Old's exonuclease activity.

• Journal of Microbiology and Biotechnology
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• 제23권6호
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• pp.837-842
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• 2013

A cryptic plasmid, pMBLR00, from Leuconostoc mesenteroides subsp. mesenteroides KCTC 3733 was isolated, characterized, and used for the construction of a cloning vector to engineer Leuconostoc species. pMBLR00 is a rolling circle replication plasmid, containing 3,370 base pairs. Sequence analysis revealed that pMBLR00 has 3 open reading frames: Cop (copy number control protein), Rep (replication protein), and Mob (mobilization protein). pMBLR00 replicates by rolling circle replication, which was confirmed by the presence of a conserved double-stranded origin and single-stranded DNA intermediates. An Escherichia coli-Leuconostoc shuttle vector, pMBLR02, was constructed and was able to replicate in Leuconostoc citreum 95. pMBLR02 could be a useful genetic tool for metabolic engineering and the genetic study of Leuconostoc species.

• Journal of Life Science
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• 제11권2호
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• pp.111-115
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• 2001

This study was designed to clone the SNF2/SW12 helicase-related genes from the fission yeast Schizosaccha-romyces pombe and thereafter to elucidate the common functions of the proteins in this family. The $hrp^{2+}$gene was cloned by polymerase chain reaction amplification using degenerative primers from conserved SNF2 motifs within the ERCC6 gene, which encodes a protein involved in DNA excision repair. Like other SNF2/SW12 family proteins, the deduced amino acid sequence of Hrp2 contains DNA-dependent ATPase/7 helicase domains as well as the chromodomain and the DNA binding domain. This configuration is similar to that of mCHD1 (mouse chromo-ATPase/helicase-DNA-dinding protein 1), suggesting that Hrp2 is a S. pombe homolog of mCHD1, which is thought to function in altering the chromatin structure to control the gene expression. To characterize the function of Hrp2, 4 Uracil-Hrp2 fusion protein, it was purified near homogeneity by affinity chromatography on $Ni^{2+}$-NTA agarose, DEAE-Sepharose ion exchange arid Sephacryl S-200 gel filtration chromatographies. The purified fusion protein exhibited DNA-dependent ATPase activity, which was stimulated by both double-stranded and single-stranded DNA. To determine the steady-state level of $hrp^{2+}$ transcripts during growth, cells were cultured in medium and collected at every 2hr to prepare total RNAs. The northern blot analysis showed that the level of $hrp^{2+}$ transcripts reached its maximum before the cells entered the exponential growth phase and then decreased gradually, This result implies that Hrp2 may be required at early stages of cell growth.h.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1987년도 식물생명공학 심포지움 논문집 Proceedings of Symposia on Plant Biotechnology
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• pp.51-62
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• 1987

Higher plant transformation vector systems are mainly developed based on the natural biosystems which infecting higher plants. Two major groups attracting much of the research are Cauliflower mosaic virus and Agrobacterium tumefaciens. Cauliflower mosaic virus has a double stranded genome, and a portion of the genome can be substituted for a foreign DNA segment without loosing the ability of infection. A. tumefaciens carries a large plasmid. Ti plasmid whose portion can be substitute and trasferred into the plant chromosome.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1285-1288
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• 2008

The purpose of this study was to characterize and investigate the immune activity of CpG oligodeoxynucleotides (ODNs) from Bifidobacterium longum. Bacterial CpG motifs have attracted considerable interests because of their immunomodulatory activities. Genomic DNA from B. longum was prepared and amplified for 4 different 180-188-mer double-stranded ODNs (BLODN1-BLODN4). When immune cells (RAW 264.7 murine macrophages and JAWS II dendritic cells) with these ODNs were treated, BLODN4 induced the highest immune activity. To assess the effectiveness of the CpG sequences within BLODN4, single-stranded 40-mer ODNs containing CpG sequences (sBLODN4-1, sBLODN4-2) were synthesized. sBLODN4-1 induced higher level of cytokines such as interleukin (IL)-12p40 and tumor necrosis factor (TNF)-$\alpha$ by macrophage and IL-6 and TNF-$\alpha$ by dendritic cells than did sBLODN4-2. The results suggest that CpG ODNs-enriched components of B. longum might be useful as an immunomodulatory functional food ingredient.