• Journal of the Korean Institute of Telematics and Electronics
• /
• v.27 no.1
• /
• pp.37-45
• /
• 1990

In this paper, a knowledge base editor is presented as a supporting environment for an expert system building tool, OPS5. The knowledge base editor is especially useful for the fast and easy development of a knowledge base when the OPS5 production language is used. This knowledge base editor has some special facilities such as syntax and type checking, rule browsing and automatic bokkeeping. The syntax and type checking provides the facilities to find syntax and type errors in an edited knowledge base, respectively. The rule browsing facility offers various pattern matching schemes to see the causes and effects of a concerned rule. Automatic bookkeeping keeps the updated date and user name of a rule for the later reference whenever a user adds or changes a rule.

• Korean Journal of Agricultural Science
• /
• v.46 no.4
• /
• pp.885-895
• /
• 2019

Plant biotechnologists have long dreamed of technologies to manipulate genes in plants at will. This dream has come true partly through the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology, which now has been used to edit genes in several important crops. However, there are many restrictions in editing a gene precisely using the CRISPR/Cas9 technology because CRISPR/Cas9 may cause deletions or additions in some regions of the target gene. Several other technologies have been developed for gene targeting and precision editing. Among these, base editors might be the most practically and efficiently used compared to others. Base editors are tools which are able to cause a transition from cytosine into thymine, or from adenine into guanine very precisely on specific sequences. Cytosine base editors basically consist of nCas9, cytosine deaminase, and uracil DNA glycosylase inhibitor (UGI). Adenine base editors consist of nCas9 and adenine deaminase. These were first developed for human cells and have since also been applied successfully to crops. Base editors have been successfully applied for productivity improvement, fortification and herbicide resistance of crops. Thus, base editor technologies start to open a new era for precision gene editing or breeding in crops and might result in revolutionary changes in crop breeding and biotechnology.

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

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.05a
• /
• pp.277-280
• /
• 2003

Established XML at February, 1998 in W3C by solution about document processing and exchange and reusability to be shortcoming that early web happens using nonstructural document. Existing electron transaction is changing in electronic business form between corporation through XML base message exchange using XML. Necessity about solution that can masticate structured electron transaction of XML base that is used in electron transaction between corporation rose. Structured electron transaction of XML base that is used in electron transaction in treatise that see hereupon efficiently study about XML document editing system that integrate XML Schema editor to masticate XML Schema document that define edit and XML instance editor of user central that can write a book and structure of XML document efficiently do.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.3
• /
• pp.513-518
• /
• 2003

Established XML at February, 1998 in W3C by solution about document processing and exchange and reusability to be shortcoming that early web happens using nonstructural document. Existing electron transaction is changing in electronic business form between corporation through XML base message exchange using XML. Necessity about solution that can masticate structured electron transaction of XML base that is used in electron transaction between corporation rose. Structured electron transaction of XML base that is used in electron transaction in treatise that see hereupon efficiently study about XML document editing system that integrate XML Schema editor to masticate XML Schema document that define edit and XML instance editor of user central that can write a book and structure of XML document efficiently do.

• Journal of the Korea Society for Simulation
• /
• v.25 no.1
• /
• pp.29-34
• /
• 2016

Many researchers have used cohort DB (database) to predict the occurrence of disease or to keep track of disease spread. Cohort DB is Big Data which has simply stored disease and health information as separated DB table sets. To measure the relations between health information, It is necessary to reconstruct cohort DB which follows research purpose. In this paper, XML descriptor, editor has been used to construct ontology-based Big Data cohort DB. Also, we have developed ontology based cohort DB search system to check results of relations between health information. XML editor has used 7 layered Ontology development 101 and OWL API to change cohort DB into ontology-based. Ontology-based cohort DB system can measure the relation of disease and health information and can be used effectively when semantic relations are found. We have developed ontology-based cohort DB search system which can measure the relations between disease and health information. And it is very effective when searched results are semantic relations.

• Journal of Industrial Technology
• /
• v.42 no.1
• /
• pp.29-36
• /
• 2022

The CRISPR system has revolutionized gene editing field. Cas9-mediated gene editing such as Indel induction or HDR enable targeted gene disruption or precise correction of mutation. Moreover, CRISPR-based new editing tools have been developed such as base editors. In this review, we focus on gene editing in human pluripotent stem cells, which is principal technique for gene correction therapy and disease modeling. Pluripotent stem cell-specific drug YM155 enabled selection of target gene-edited pluripotent stem cells. Also, we discussed base editing for treatment of congenital retina disease. Adenine base editor delivery as RNP form provide an approach for genetic disease treatment with safe and precise in vivo gene correction.

• BMB Reports
• /
• v.57 no.1
• /
• pp.30-39
• /
• 2024

Directed evolution (DE) of desired locus by targeted random mutagenesis (TRM) tools is a powerful approach for generating genetic variations with novel or improved functions, particularly in complex genomes. TRM-based DE involves developing a mutant library of targeted DNA sequences and screening the variants for the desired properties. However, DE methods have for a long time been confined to bacteria and yeasts. Lately, CRISPR/Cas and DNA deaminase-based tools that circumvent enduring barriers such as longer life cycle, small library sizes, and low mutation rates have been developed to facilitate DE in native genetic environments of multicellular organisms. Notably, deaminase-based base editing-TRM (BE-TRM) tools have greatly expanded the scope and efficiency of DE schemes by enabling base substitutions and randomization of targeted DNA sequences. BE-TRM tools provide a robust platform for the continuous molecular evolution of desired proteins, metabolic pathway engineering, creation of a mutant library of desired locus to evolve novel functions, and other applications, such as predicting mutants conferring antibiotic resistance. This review provides timely updates on the recent advances in BE-TRM tools for DE, their applications in biology, and future directions for further improvements.

• Safety and Health at Work
• /
• v.12 no.2
• /
• pp.282-283
• /
• 2021

• Molecules and Cells
• /
• v.40 no.11
• /
• pp.823-827
• /
• 2017

Genome editing using programmable nucleases such as CRISPR/Cas9 or Cpf1 has emerged as powerful tools for gene knock-out or knock-in in various organisms. While most genetic diseases are caused by point mutations, these genome-editing approaches are inefficient in inducing single-nucleotide substitutions. Recently, Cas9-linked cytidine deaminases, named base editors (BEs), have been shown to convert cytidine to uridine efficiently, leading to targeted single-base pair substitutions in human cells and organisms. Here, we first report on the generation of Xenopus laevis mutants with targeted single-base pair substitutions using this RNA-guided programmable deaminase. Injection of base editor 3 (BE3) ribonucleoprotein targeting the tyrosinase (tyr) gene in early embryos can induce site-specific base conversions with the rates of up to 20.5%, resulting in oculocutaneous albinism phenotypes without off-target mutations. We further test this base-editing system by targeting the tp53 gene with the result that the expected single-base pair substitutions are observed at the target site. Collectively, these data establish that the programmable deaminases are efficient tools for creating targeted point mutations for human disease modeling in Xenopus.