• Food Science of Animal Resources
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• v.24 no.4
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• pp.355-360
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• 2004

In Korean beef market, one of the major problems is mislabeling or fraudulent distribution of Holstein dairy meat or imported beef as domestic Hanwoo meat. Therefore, there has been a great need for a development of technology to identify beef breeds in meat and meat products. This study was carried out to develop the accurate and reliable method for the identification of beef breed using PCR-RFLP marker of MC1R, MGF and TYRPl genes affecting coat colors in cattle. A single base substitution (G\longrightarrowT transition) at the codon for amino acid position 104 of MC1R gene was identified between Hanwoo and Holstein and Angus breeds. The change at this position creates Msp I restriction site in Holstein and Angus, but not in Hanwoo. When the DNA amplified products (537 bp) was digested with Msp I, Hanwoo meat showed a single band of 537bp, while two fragments of 329bp and 208 bp were observed in Holstein meat and Angus breed, respectively. Thus, breed-specific RFLP marker in the MC1R gene can be used to distinguish between Hanwoo meat and Holstein and Angus meats. In the RFLP genotype of MGF gene, the frequency of r/r type was 75％ in Manwoo, whereas the frequency of R/R was 80％ in Hereford breed. Holstein and Angus breeds showed 100％ for R/r type. Therefore, Hanwoo meat showed significant difference in the MGF genotype frequencies compared with those of Holstein meat and imported beef cattle breeds. However, TYRP1 gene showed the same genotype in all breeds examined. Thus, this TYRP1 gene can not be used as a molecular marker for breed identification. As a consequence, we suggest that RFLP markers of the MC1R and MGF coat color genes could be used as DNA marker for identification of Hanwoo meat from Holstein and imported meats.

• Journal of Aquaculture
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• v.13 no.3
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• pp.193-196
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• 2000

Rhynchocypris oxycephalus and R. steindachneri show very similar karyotypes: 2n=50(EN=90), consisting of 12 metacentics, 28 submetacentrics and 10 acrocentrics with a gradual decrease in chromosome size, but with significant differences in nuclear DNA content of 2.64 and 2.52 pg/nucleus, respectively (P<0.05). Although the erythrocyte measurement and parameters of two species were similar, R. oxycephalus erythrocyte number was lower than that of R. steindachneri. Mode in karyological evolution within the genus Rhychocypris shows an increase of nuclear DNA without apparent changes in karyotype and erhthrocyte size.

• Journal of Life Science
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• v.19 no.4
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• pp.467-471
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• 2009

The entire D-loop region of the porcine mitochondrial DNA (mtDNA) was amplified from six pig breeds (Landrace, Duroc, Large White, Korean native pig, Berkshire, and Hampshire) using a primer set designed on the basis of reported porcine mtDNA sequences. From analyses through cloning, DNA sequencing and multiple sequence alignment, an 11-bp (TAAAACACTTA) duplication was observed after known tandem repetition in the D-loop region, which promoted hetroplasmy in mtDNA. Although the existence of the 11-bp duplication has been previously reported in Duroc and Japanese native pigs, there have not been any attempts to know the characteristics of this duplication in other breeds so far. A 150 bp fragment containing the 11-duplication was amplified and typed by polyacrylamide gel electrophoresis (PAGE). All Large Whites had two duplication units and Duroc showed heteromorphic patterns, 11.2% (9/80) of the animals had the 11-bp duplication in total. On the other hand, Landrace, Berkshire, Hampshire and Korean native pigs were non-duplicated. This result showed that the 11-bp duplication could be used as a breed-specific DNA marker for distinguishing pure Landrace and Large White breeds.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.879-883
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• 2005

This study was differentiated between Korea and China arkshells using PCR-aided RFLP method which could identify the variation for inter-and intra-species of arkshell (Scapharca broughtonii Schrenck) at the level of DNA. The DNA fragment patterns were compared after digesting gene of mitochondrial 16S rDNA with 8 kinds of restriction enzymes. A 720 bp DNA fragment corresponding to 16S rDNA gene was amplified by PCR with primers ArkF-3 and ArkR-3. PCR products were cut by restriction enzymes (Pvull, BamHI, Hinfl, HaeIII, EcoRI, RsaI, Ksp221, and BstX21), and RFLP pattern was studied. A unique 275 bp DNA band was observed in the samples from Dukyang, Gamak, Namhae, Jinhae, and Taean in Korea when treated by Hinfl, but Chinese arkshell did not show. Treatment of HaeIII could discriminate the sample of Namhae and Jinhae from Dukyang/Gamak/Taean, as well as Korean and Chinese arkshell based on a 700 bp. However, PuvII, BamHI, EcoRI, RsaI, Ksp221, and BstX21 showed the same of 700 bp band in Korean and Chinese arkshell. The phylogenetic tree inferred from PCR-RFLP pattern comparsion in Korean arkshell was different that the distance between Dukyang/Gamak/Taean and Namhae/Jinhae was approximately 7. In particular, the distance between Korean and Chinese arkshell was 25. Consequently, HinfI and HaeIII played an important role in a reliable molecular tool for rapid discriminating Korean and Chinese arkshell, as well as a intra-species in Korea.

• BMB Reports
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• v.30 no.3
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• pp.216-221
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• 1997

Changes in pathogenicity of old and successively-cultured isolates of Fusarium oxysporum f. sp. niveum have been observed and the concept that such cultures will become attenuated is generally accepted. However, the genetic basis for this phenomenon has not been studied. In an effort to identify a DNA marker closely linked to variations, DNA methylation was investigated both before and after the successive transfers of F. o. f. sp. niveum isolates on artificial media. A sector of mycelium in F. o. f. sp. niveum race 2 isolate (TXXID) which showed variation in pigmentation and colonial morphology occurred after 18 successive weekly transfers on potato dextrose agar (PDA). The sector characteristics were stable and did not change after more successive transfers. It was shown that DNA methylation preexists in ribosomal RNA gene (rDNA) of F. o. f. sp. niveum and that additional changes in DNA methylation occurred during successive culturing.

• The Korean Journal of Zoology
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• v.37 no.4
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• pp.437-477
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• 1994

The DNA replication of human Iyrnphocvtes was studied using Bromodeo3fyuridine incorporation. The characteristic patterns of dvnamlc banding were analysed. Human chromosomal ONA was synthesized in a segmental but highly coordinated fashion. Each chromosome replicates according to its innate pattern of chromosome structure (bandinsl. R-positive bands are demonstrated as the initiation sites of DNA synthesis, and G-bnads initiate replication after it has been completed in the autosomal R-bands. Many researchers demonstrated that developmental or induced methvlation of DNA can inactivate the associated gene loci. Such DNA methylation can be reversed and specific genes reactivated by treatment with 5-azacvtidine. We treated the hvpomethvlating agent 5-azacvtidine and tested for changes of DNA replication pattern. Treatment with 5-azacytidine causes an advance in the time of replication. These observed changes in timing of replication suggest that DNA methvlation may modify regional groups of genes in concert.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.280-288
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• 2018

In this study, an approach for the analysis of the five cephalopod species (octopus, long-arm octopus, squid, wet-foot octopus, beka squid) consumed in the Republic of Korea is developed. The samples were collected from the Southeast Asian countries Thailand, Indonesia, Vietnam, and China. The SYBR-green-based real-time qPCR method, based on the mitochondrial DNA genome of the five cephalopods was developed and validated. The intergroup variations in the mitochondrial DNA are evident in the bioinformatic analysis of the mitochondrial genomic DNA sequences of the five groups. Some of the highly-conserved and slightly-variated regions are identified in the mitochondrial cytochrome-c-oxidase subunit I (COI) gene, 16s ribosomal RNA (16s rRNA) gene, and 12s ribosomal RNA (12s rRNA) gene of these groups. To specify each five cephalopod groups, specific primer sets were designed from the COI, 16s rRNA and 12s rRNA regions. The specific primer sets amplified the DNA using the SYBR-green-based real-time PCR system and 11 commercially secured animal tissues: Octopus vulgaris, Octopus minor, Todarodes pacificus, Dosidicus gigas, Sepia esculenta, Amphioctopus fangsiao, Amphioctopus aegina, Amphioctopus marginatus, Loliolus beka, Loligo edulis, and Loligo chinensis. The results confirmed by a conveient way to calculate relative amplification levels between different samples in that it directly uses the threshold cycles (Ct)-value range generated by the qPCR system from these samples. This genomic DNA-based molecular technique provides a quick, accurate, and reliable method for the taxonomic classification of the animal tissues using the real-time qPCR.

• Current Research on Agriculture and Life Sciences
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• v.12
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• pp.69-82
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• 1994

This study was conducted to investigate the physiological characteristics and to isolate plasmid DNA of R. japonicum strains. The results obtained were as follows; Strains S117, S118, 005, 011 and DY-1 were slow-growers and showed alkaline reaction, whereas strains S110, S111, S114, S116, S120 and 010 were fast-growers and produced acid reaction in YEM broth. All the fast- and slow-growing R. japonicum showed gram negative and formed mucous white colony on agar plate. After 7 days, the colonies of the fast-growers were between 2.0 and 4.0mm in diameter, whereas those of slow-growers were approximately between 0.5 and 1.5mm. The fast-growers were uniformly sensitive to the pH of 4.5 and tolerant of the pH of 9.5, whereas the reverse was found for the slow-growers. All the fast-growers were able to grow in the presence of 2% NaCl however the slow-growers were not grown. All the microorganisms grew rapidly in simple mineral salt medium containing as the sole source of carbon. Starch was rarely utilized. All the fast-growers utilized sucrose. The slow-growing R. japonicum strains examined usually contained 1 to 3 plasmid DNA ranging between 15Kb and 250 Kb, whereas the fast-growing R. japonicum strains contained 1 to 3 plasmid DNA ranging from 20 Kb to 250Kb.

• Journal of Microbiology
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• v.41 no.2
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• pp.157-160
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• 2003

To estimate genetic relationships within the genus Rhizopus, genetic variations in 20 strains were investigated by DGGE and PCR-RFLP of rDNA ITS region (ITSI, ITS2,5.8S). The size of the amplified products showed the interspecific polymorphisms, 650 bp,700 bp, and 900 bp. The DGGE approach allowed the separation of PCR amplicons of the same length according to their sequence variations. When the rDNA ITS region was digested with six restriction enzymes, 20 strains were classified into five RFLP haplotypes. The range of similarity between the 20 strains by PCR-RFLP was 42.3-100%. Based on the results of DGGE aud PCR-RFLP, the 20 strains were divided into four groups, R. oryzae, R. stolonifer, R. microsporus and R. homothallicus. Further study of R. homothallicus is required.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.15 no.3
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• pp.161-175
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• 2011

An n-string tangle is a three dimensional ball with n strings properly embedded in it. A tangle model of a DNA-protein complex is first introduced by C. Ernst and D. Sumners in 1980's. They assumed the protein bound DNA as strings and the protein as a three dimensional ball. By using a tangle analysis, one can predict the topology of DNA within the complex. S.Kim and I. Darcy developed the biologically reasonable 4-string tangle equations and decided a solution tangle, called R-standard tangle. The author discussed more about the simple solution tangles of the equations and found a generalized R-standard tangle solution.