• Korean Journal of Ecology and Environment
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• v.54 no.3
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• pp.156-169
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• 2021

Traditional morphological identification difficulties, such as phenotypic plasticity, misidentification of cryptic species, and larval stage species, can be compensated for by using DNA analysis techniques, such as DNA barcoding, in surveying zooplankton populations, including species identification. Recently, the rapid development of DNA sequencing techniques has allowed DNA-based community analysis not only for zooplankton assemblages in various aquatic ecosystems but also for the gut contents of zooplankton that are limited by conventional methods such as visual and microscopic identification. Therefore, the application of DNA sequencing can help understand biological interactions through the analysis of zooplankton food sources. The present paper introduces the major DNA-based approaches in zooplankton research topics, including taxonomic approaches by DNA barcoding, community-level approaches by metabarcoding, and gut content analyses, summarizes the analysis methods, and finally suggests the methodological topics that need to be considered for future applications.

• Korean Journal of Poultry Science
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• v.22 no.2
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• pp.97-104
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• 1995

Recently, DNA fingerprinting has been utilized as the most powerful tool for genetic analysis and improvement of poultry. This technique enables us to solve several problems of poultry breeding ; traits of low heritability, difficulty in keeping the performance records, measuring in late of life, and sex limited traits. Application of DNA fingerprinting is chiefly focused to individual and population identification, evolution force, quantitative trait marker, introgression of new gene, and prediction of heterosis. Thus, research work on DNA fingerprinting will he accelerated to analyze genetic components exactly and improve the performance of poultry.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.2
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• pp.92-97
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• 2002

One of the important roles of a DNA chip is the capability of detecting genetic diseases and mutations by analyzing DNA sequence. For a successful electrochemical genotyping, several aspects should be considered including the chemical treatment of electrode surface, DNA immobilization on electrode, hybridization, choice of an intercalator to be selectively bound to double standee DNA, and an equipment for detecting and analyzing the output signal. Au was used as the electrode material, 2-mercaptoethanol was used for linking DNA to Au electrode, and methylene blue was used as an indicator that can be bound to a double stranded DNA selectively. From the analysis of reductive current of this indicator that was bound to a double stranded DNA on an electrode, a normal double stranded DNA was able to be distinguished from a single stranded DNA in just a few seconds. Also, it was found that the peak reduction current of indicator is proportional to the concentration of target DNA to be hybridized with probe DNA. Therefore, it is possible to realize a sim71e and cheats DNA sensor using the electrochemical measurement for genotyping.

• Development and Reproduction
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• v.21 no.3
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• pp.237-247
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• 2017

Mammalian spermatogenesis occurs in a precise and coordinated manner in the seminiferous tubules. One of the attempts to understand the detailed biological process during mammalian spermatogenesis at the molecular level has been to identify the testis specific genes followed by study of the testicular expression pattern of the genes. From the subtracted cDNA library of rat testis prepared using representational difference analysis (RDA) method, a complimentary DNA clone encoding type III member of a DnaJ family protein, DnaJC18, was cloned (GenBank Accession No. DQ158861). The full-length DnaJC18 cDNA has the longest open reading frame of 357 amino acids. Tissue and developmental Northern blot analysis revealed that the DnaJC18 gene was expressed specifically in testis and began to express from postnatal week 4 testis, respectively. In situ hybridization studies showed that DnaJC18 mRNA was expressed only during the maturation stages of late pachytene, round and elongated spermatids of adult rat testis. Western blot analysis with DnaJC18 antibody revealed that 41.2 kDa DnaJC18 protein was detected only in adult testis. Immunohistochemistry study further confirmed that DnaJC18 protein, was expressed in developing germ cells and the result was in concert with the in situ hybridization result. Confocal microscopy with GFP tagged DnaJC18 protein revealed that it was localized in the cytoplasm of cells. Taken together, these results suggested that testis specific DnaJC18, a member of the type III DnaJ protein family, might play a role during germ cell maturation in adult rat testis.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6619-6623
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• 2013

Background:The aim of the research was to explore a cost effective, fast, easy to perform, and sensitive method for epidermal growth factor receptor (EGFR) mutation testing. Methods: High resolution melting analysis (HRM) was introduced to evaluate the efficacy of the analysis for dectecting EGFR mutations in exons 18 to 21 using formalin-fixed paraffin-embedded (FFPE) tissues and plasma free DNA from 120 patients. Results: The total EGFR mutation rate was 37.5% (45/120) detected by direct sequencing. There were 48 mutations in 120 FFPE tissues assessed by HRM. For plasma free DNA, the EGFR mutation rate was 25.8% (31/120). The sensitivity of HRM assays in FFPE samples was 100% by HRM. There was a low false-positive mutation rate but a high false-negative rate in plasma free DNA detected by HRM. Conclusions: Our results show that HRM analysis has the advantage of small tumor sample need. HRM applied with plasma free DNA showed a high false-negative rate but a low false-positive rate. Further research into appropriate methods and analysis needs to be performed before HRM for plasma free DNA could be accepted as an option in diagnostic or screening settings.

• Journal of Marine Life Science
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• v.8 no.2
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• pp.93-103
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• 2023

eDNA, an abbreviation for environmental DNA, means DNA derived from organisms inhabiting in a specific environment. The utilization of eDNA extracted from environmental samples allows for efficient and accurate monitoring of organisms inhabiting the respective environment. Specifically, eDNA obtained from seawater samples can be used to analyze marine biodiversity. After collecting seawater samples and extracting eDNA, metagenome analysis enables the taxonomic and diversity analysis among marine organisms inhabiting the sampled area. This review proposed an overall process of marine biodiversity analysis by utilizing eDNA from seawater. Currently, the application of eDNA for analyzing marine biodiversity in domestic setting is not yet widespread. This review can contribute to establishment of marine eDNA research methods in Korea, providing valuable assistance in standardizing the use of eDNA in marine biodiversity studies.

• Toxicological Research
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• v.17 no.4
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• pp.249-253
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• 2001

Fumonisin B1, a mycotoxin, is thought to induce esophageal cancer in humans and apoptosis in animal cells by inhibiting ceramide synthase. Dumonisin Bl may also generate reactive oxygen species directly or indirectly, leading to DNA damage and lipid peroxidation. In this study, a DNA fragmentation assay, dichlorofluorescein (DCF) analysis, and single cell gel electrophoresis (SCGE) were used to investigate the involvement of cellular free radicals, specifically hydrogen peroxide, in the DNA damaging activity of fumonisin B1. From an in vitro DNA fragmentation assay, E. coli DNA, damage by fumonisin Bl was increased by the addition of superxide dismutase (SOD) and decreased by catalase. SCGE and DCF analysis in vivo showed that the nuclear DNA damage and intracellular free radicals in cultured rat hepatocytes treated with fumonisin B1 were increased with the concentration of fumonisin Bl . DNA damage and free radical generation were inhibited by the addition of catalase. Fumonisin Bl , in the presence of SOD, produces hydrogen peroxide causing oxidative DNA damage and protein malfunction, leading to genotoxicity and cytotoxicity of the toxin.

• Analytical Science and Technology
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• v.18 no.3
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• pp.257-262
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• 2005

Mitochondrial DNA (mt DNA) sequence analysis has been a useful tool for species identification of animals and human individuals. Two hypervariable regions (HV1 and HV2) in control region of mitochondrial genome were analyzed for human individual identification. In case of animal species identification, several genes on mt DNA such as cytochrome b (cytb), RNAs, cytochrome oxidases (CO) were used. In this study, co-amplification of HV1 and cytb was carried out in order to check the contamination of animal DNA and to verify the human DNA. The primer sets used in PCR were H15997/L16236 for HV1 and H14724/L15149 for cytb. PCR products for HV1 and cytb were 239 bp and 425 bp, respectively. The appearance of two bands on agarose gel implied the DNA came from human, however the single band of cytb gene represented the non-human animal DNA.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.97-100
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• 2004

The identification of the DNA structure as a double-stranded helix consting of two nucleotide chain molecules was a milestone in modern molecular biology. The DNA chip technology is based on reverse hybridization that follows the principle of complementary binding of double-stranded DNA. DNA chip can be described as the deposition of defined nucleic acid sequences, probes, on a solid substrate to form a regular array of elements that are available for hybridization to complementary nucleic acids, targets. DNA chips based on cDNA clons, oligonucleotides and genomic clons have been developed for gene expression studies, genetic variation analysis and genomic changes associated with disease including cancers and genetic diseases. DNA chips for gene expression profiling can be used for functional analysis in human eel Is and animal models, disease-related gene studies, assessment of gene therapy, assessment of genetically modified food, and research for drug discovery. DNA chips for genetic variation detection can be used for the detection of mutations or chromosomal abnormalities in cnacers, drug resistances in cancer cells or pathogenic microbes, histocompatibility analysis for transplantation, individual identification for forensic medicine, and detection and discrimination of pathogenic microbes. The DNA chip will be generalized as a useful tool in clinical diagnostics in near future. Lab-on-a chip and informatics will facilitate the development of a variety of DNA chips for diagnostic purpose.

• The Korean Journal of Cytopathology
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• v.8 no.1
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• pp.20-26
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• 1997

The specificity of cytologic examination in effusions is high but the sensitivity is low. Therefore, various ancillary methods for the detection of malignant cells in effusions have been proposed. The presence of an aneuploid cell population is generally considered diagnostic of malignancy. The purpose of this study is to determine whether the routine use of flow cytometry adds to standard cytologic evaluation in effusions. We did flow cytometric DNA analysis in 76 effusions(28 malignant and 48 benign fluids). All the 48 benign effusions were diploid. There were 12(42.9%) aneuploid and 16(67.1%) diploid malignant effusions. Based on these results flow cytometric DNA analysis had a sensitivity of 42.9% and a specificity of 100%. These results suggest that flow cytometric DNA analysis may be a useful adjunct to conventional cytology, but its principal limitation is us relatively low sensitivity.