• Plant Biotechnology Reports
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• v.3 no.2
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• pp.139-145
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• 2009

DNA methylation is known to play an important role in the regulation of gene expression in eukaryotes. In this study, we isolated NtMET1 from Nicotiana tabacum cv. Havana (SR1) and obtain transgenic plants that reduced MET1 expression level with the double-strand RNA (dsRNA) MET1 gene. Transgenic tobacco plants showed dwarf and abnormal flower development when compared with the wild type. Using methylation-sensitive amplified polymorphism (MSAP) analysis, the patterns of cytosine methylation in transformed plants and the wild type were compared. MseI/HpaII selection primers showed an interesting polymorphism, and 153 DNA bands of interest were detected. Among these, 30 selective fragments were sequenced and analyzed with a BLAST search by successful MSAP modifications. The homology search showed that the transposons and tandem repeated sequences were related to the phenotypes. These results suggested that the decreased degree of methylation by dsRNA strategy caused abnormal growth and development in N. tabacum.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.231-236
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• 1989

The larger segment of double stranded RNA genome from a new serotype of Infectious Pancreatic Necrosis Virus (IPNV), DRT, has been partially cloned at Sma I site in pUC19 and compared with the restriction maps of VR-299 and Sp. Restrction sites found in DRT was distinct and hence a new serotype. The cDNA clones of DRT were about 800, 850, and 1, 400 bp long each and do not share any common restiction site. It is not clear yet if there exist any overlapping sequences among them. This partial cloning, however, was sufficient for the comparison of restriction maps with the other serotypes.

• KSBB Journal
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• v.8 no.4
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• pp.405-408
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• 1993

Absidia zychae NRIC 1199 produced two forms of carboxypeptidase(CPZ-1 and CPZ-2) which were distinguished in their isoelectric points but had almost identical properties(1). The amino acid sequences for the N-terminal of both enzymes were the same (Tyr-Thr-Ser-Pro-Lys-Leu-Xaa-Asp-Pro-Asp-Val) and any significant difference was not observed between amino acid compositions of the two enzymes. The ouchterlony double diffusion technique using antibody raised against the CPZ-2 protein demonstrated a good cross-reaction between CPZ-1 and CPZ-2 Genomic Southern analysis showed only one gene encoding CPZ in the genome of Absidia zychae. However, a significant difference between two enzymes was observed on peptide map using Staphylococcus aureus V8 protease, distinguishable only one band, indicating that multiple forms of CPZ are caused by post-translational modification, such as deamidation.

• YAKHAK HOEJI
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• v.39 no.5
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• pp.516-520
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• 1995

The anti-dansyl antibodies were specifically labeled with stable isotope by growing hybridoma cells in serum-free medium. Assignments of the observed carbonyl carbon resonances have been determined by using $^{13}C-{15}N$ double labeling method in order to assign the Leu resonances. However, when the identical dipeptide appears more than twice in the polypeptide sequences, we applied the proteolytic fragments in the fragment-specific method. Carboxypep-tidase B-treated antibody has also been used to assign the Lys-447 in C terminal amino acid. These unambiguously assigned carbonyl carbon resonances in antibodies are thought to be useful in elucidating not only the structure of antibodies but also the structure-function relationship in the antibody by $^{13}C$ neuclear magnetic resonance spectroscopy.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.346.2-346.2
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• 2002

Recently, several branched-nucleosides have been synthesized and evaluated as potent antitumor or antiviral agents. Among them, 4'${\alpha}$--C-ethenyl and 4'${\alpha}$-C-ethynyl nucleosides which having an additional double or triple bond at 4'-position were reported to be as potent antiviral and anlitumor activities. Encouraged by these interesting structures and antiviral activities, it was determined to synthesize novel classes of nucleosides comprising branched carbocyclic nucleosides with an additional aryl group at 4'${\alpha}$-position using versatile reiterative three-step sequences from simple acyclic precursor '2-hydroxyacetophenone. Our efforts toward the synthesis of novel nucleosides analogues are reported herein.

• The Plant Pathology Journal
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• v.26 no.2
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• pp.130-138
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• 2010

Orchid fleck virus (OFV) is an unassigned plant virus in the family Rhabdoviridae. OFV was isolated from Cymbidium sp. showing oval necrotic lesions on their leaves in Korea, and designated as OFV-NHHS1. The complete nucleotide sequence of the RNA1 (6,413 nt) (GenBank accession no. AB516442) and RNA2 (6,001 nt) (GenBank accession no. AB516441) was determined in this study. RNA1 and RNA2 contained five and one ORF respectively. RNA1 encodes nucleocapsid (N) of 49 kDa, ORF2 of 26 kDa, ORF3 of 38 kDa, ORF4 of 20 kDa and glycoprotein (G) of 61 kDa proteins, whereas RNA2 encodes a single polymerase of 212 kDa. OFV-NHHS1 shared extremely high similarity of 98.6-100% and 98.9-99.6% in nucleotidle and amino acid sequences with a Japanese isolate, OFV-so, respectively. However, the N, G and L of OFV-NHHS1 revealed 6.9-19.3%, 7.3-12.0%, and 13.4-26.6% identities to those of 29 Rhabdoviruses, respectively. To survey the infection rate of OFV in commercial orchids in Korea, 51 Cymbidium sp., 10 Phalaenopsis sp., 22 Oncidium sp. and 21 Dendrobium sp. plants that showed typical viral symptoms were collected. RT-PCR with specific primers for detection of Cymbidium mosaic virus (CymMV), ORSV and OFV showed high infection rate by ORSV alone and double infection by ORSV and CymMV. One of the orchids tested was infected with OFV. This is the first report of the complete nucleotide sequences of OFV isolated in Korea.

• Journal of Food Hygiene and Safety
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• v.15 no.1
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• pp.51-54
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• 2000

In the 5'-flanking region of the D-AAT, AspAT and AlaDH gene, I found three or two pairs of sequences(designated as Pl, P2, P3) which show significant similarity to the E.coli consensus sequences of -35 and -10 for promoters. The spacing between -35 and -10 is 16 to 18bp in all the three putative promoters Pl, P2 and P3 which is in good agreement with the preferred spacer length in E.coli and in B.subtilis. Therefore, the putative promoters may also function to increase the efficiency of transcriptional initiation. The most stable, double-helical“Shine-Dalgarno”pairing is formed with a free energy change(ΔG) of -13.0 kcal/mol, -9.6 kcal/mol, -15.8 kcal/mol.

• BMB Reports
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• v.54 no.2
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• pp.98-105
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• 2021

The clustered regularly interspaced short palindromic repeats (CRISPR) system is a family of DNA sequences originally discovered as a type of acquired immunity in prokaryotes such as bacteria and archaea. In many CRISPR systems, the functional ribonucleoproteins (RNPs) are composed of CRISPR protein and guide RNAs. They selectively bind and cleave specific target DNAs or RNAs, based on sequences complementary to the guide RNA. The specific targeted cleavage of the nucleic acids by CRISPR has been broadly utilized in genome editing methods. In the process of genome editing of eukaryotic cells, CRISPR-mediated DNA double-strand breaks (DSB) at specific genomic loci activate the endogenous DNA repair systems and induce mutations at the target sites with high efficiencies. Two of the major endogenous DNA repair machineries are non-homologous end joining (NHEJ) and homology-directed repair (HDR). In case of DSB, the two repair pathways operate in competition, resulting in several possible outcomes including deletions, insertions, and substitutions. Due to the inherent stochasticity of DSB-based genome editing methods, it was difficult to achieve defined single-base changes without unanticipated random mutation patterns. In order to overcome the heterogeneity in DSB-mediated genome editing, novel methods have been developed to incorporate precise single-base level changes without inducing DSB. The approaches utilized catalytically compromised CRISPR in conjunction with base-modifying enzymes and DNA polymerases, to accomplish highly efficient and precise genome editing of single and multiple bases. In this review, we introduce some of the advances in single-base level CRISPR genome editing methods and their applications.

• Parasites, Hosts and Diseases
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• v.31 no.3
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• pp.285-292
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• 1993

C. sinensis total RMh was containing large amount of 185 rRNA but little 285 rRNA. The size of the double-stranded cDNA synthesized from poly $(A)^{+}$ mRNA was 0.4-4.2 kb long with tapering unto 9.5 kb. Degenerated oligonucleotides (as 2 sense and 3 antisense Primers) were designed on the conserved regions of the known tropomyosin amino acid sequences. From one out of the PCR amplifications using total CDNA and matrix of primers, a specific gene product, 580 bp in size, was produced. Upon Southern hybridization of the PCR products with Schistosomn mnnsoni tropomyosin (SMTM) CDNA, only one signal appeared at the band of 580 bp product. This 580 bp product was considered to encode C. sinensis tropomyosin (CSTM) and cloned in pGEM-3Zf(-) for DNA sequencing. CSTM cDNA was 575 bp containing one open reading frame of 191 predicted amino acids, which revealed 86.3% homology with SMTM and 51.1% with rrichostronsylur coeubnlormis tropomyosin. CSTM cDNA obtained will serve as a probe in the studies of molecular cloning of CSTM.

• Journal of Broadcast Engineering
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• v.12 no.2
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• pp.177-184
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• 2007

In this paper, we compared two subjective assessment methods DSCQS(Double Stimulus Continuous Quality Scale method) and ACR(Absolute Category Rating). These methods are widely used in order to evaluate video quality for multimedia application. We performed subjective quality tests using DSCQS and ACR methods. The subjective scores obtained by the DSCQS and ACR methods show that these methods are highly correlated in terms of MOS(Mean Opinion Score) and have slightly lower correlation in terms of DMOS(Difference Mean Opinion Score). The results indicate that ACR method is an effective subjective quality assessment method, which shows compatible performance with DSCQS method and can evaluate a larger number of video sequences.