• The Korean Journal of Mycology
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• v.24 no.2 s.77
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• pp.155-165
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• 1996

This study was carried out to identify the phylogenetic relationship among several isolates of Pleurotus species by comparing ITS II region of ribosomal DNA(rDNA) repeat unit. Two primers from ribosomal DNA sequences were chosen to amplify the specific internal transcribed spacer (ITS) II region of Pleurotus spp. The exact ITS II region with an unique band from six species of Pleurotus genus could be amplified using the two primers taken from at the 3'-end of 5.8S rDNA and 5'-end of 28S rDNA. Six representative species of the Pleurotus genus were easily characterized according to the length differences of ITS II region. Furthermore, within P. ostreatus species, different sizes of ITS II region could be observed in the isolates of ASI 2025 and ASI 2095 although they were classified as P. ostreatus by the conventional observation. The nucleotide sequence analyses of PCR-amplified ITS II region indicated that the isolates ASI 2025 and ASI 2095 were different from other Pleurotus spp. When the nucleotide sequences of six Pleurotus species were compared, three typical ITS II regions were highly variable especially at both ends of this region. The phylogenetic tree obtained by the Neighbor program of Felsenstein PHYLIP package with all the nucleotide sequence of Pleurotus spp. indicated that P. ostreatus, P. florida, P. sajor-caju and P. eryngii were closely related to one phylogenetic branch and P. cystidious was related to other branch with P. cornucopiae. The isolates ASI 2025 and 2038, however, were not closely related to any other Pleurotus spp. and formed their own individual branches.

• Korean Journal of Veterinary Pathology
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• v.6 no.2
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• pp.101-104
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• 2002

닭의 전신장기에 림프종 발생이 특정인 마렉병(Marek's disease; MD)은 림프구성 백혈병(Lymphoid leukosis; LL)과 병리학적 소견이 매우 유사하여 감별이 요구된다. 마렉병 바이러스(Marek's disease virus; MDV)는 질병초기에서 후기에 이르기까지 모낭상피세포에 세포용해성 감염을 지속적으로 일으킨다. 세포용해성 감염이 있는 모낭상피세포는 변성내지 괴사되어 있고 핵내봉입체가 관찰된다. 또한 세포용해성 감염이 있는 모낭상피세포 바로 밑의 진피와 깃털 수질(feather pulp)내의 혈관주위에 림프구 침윤이 관찰된다. 이러한 피부병변은 MD의 특징적인 병변들로서 LL과 감별할 수 있는 결정적인 단서이다. 본 고에서는 MD에 관한 전반적인 것과 특히 MD 진단을 위한 피부병변의 유용성에 대해서 자세히 논하고자 한다. 양계산업에 문제를 야기하고 있는 림프구 증식성 종양은 크게 마렉병(Marek’s disease; MD)과 백혈병(Lymphoid leukosis; LL)이 있다. 이들 질환의 원인체들이 분리되기 전까지는 이들 질병들은 발병부위에 따라 질병명을 붙였다. 즉, 내부장기냐 근육에 발생한 것은 visceral lymphomatosis, 피부에 발생한 것은 skin leukosis, 말초신경의 병변은 poly­n neuritis, neuritis, neurolymphomatosis gallinarum, range paralyis로 불리었다. 또한 눈에 발생한 것은 blindness, gray eye, iritis, uveitis, ocular lymphomatosis라고 불리었다. 1961년에 Biggs는 이러한 림프구 증식성 질병을 마렉병과 백혈병 으로 분류하자는 제안을 하였고, 드디어 1960년대 중반에 림프구 증식성 병변 중의 일부에서 herpesvirus가 분리되어서 Biggs가 제안한 병명인 마렉병을 본격적으로 사용하게 되었다. MD는 마렉병 바이러스(Marek’s disease virus; MDV)가 원 인제로서 닭에 전염성이 강한 염증성에서 종양성의 병변을 내부장기, 피부, 근육, 안구, 중추신경계, 말초신경계 등에 일 으킨다. MDV는 림프종을 유발하기 때문에 처음에는 사람에서 림프종을 유발하는 Epstein-Bar 바이러스와 관련이 있을 것으로 생각되어 gamma-herpesvirus로 분류되었지만, MDV의 게놈 구조와 세포배양에서 빠르게 성장한다는 점 때문에 지금은 alpha-herpesvirus로 재분류 되었다. MDV는 바이러스 중화시험과 한천 겔 침강법에 의해서 3개의 혈청형으로 분류 된다. 혈청형 1은 종양원성 바이러스와 종양원성 바이러스의 계대배양에 의한 약독주가 있다. 혈청형 2는 자연적으로 발 생하는 비종양원성 닭의 MDV이고, 혈정형 3은 바종양원성 칠면조 herpesvirus (HVT)이다. 림프종을 유발하는 MDV 감염은 4개의 과정, 즉 초기 세포용해성 감염, 잠복감염, 후기 세포용해성 감염, 마지막으로 종양화로 나눌 수 있다. 감염의 경로를 보면, 흡입된 MDV는 폐의 대식세포에 감염한 후 전선 장기로 MDV를 전파 시킨다. 특히, 흉선, F냥, 비장 등의 림프구에 초기 세포용해성 감염을 일으키는데, B 림프구가 주로 감염된다. 세포용해성 감염음 방어하기 위해 몰려든 T 림프구가 활성화가 되면, T 세포도 감염되게 된다. 잠복감염은 여러 가지 사이토카인 등 을 포함한 면역반응에 의해서 일어나며, 이 때 잠복감염된 세포는 특히 혈중의 T 세포라고 한다. 혈중 MDV 감염세포 는 피부 모낭상피세포, 선장 등 상피세포 유래의 조직에 MDV를 전파 시켜서 이들 조직에서 후기 세포용해성 감염이 일어나게 한다. 후기 세포용해성 감염을 유발하는 것은 이러한 MDV가 감염된 혈중 림프구라는 증거는 혈중의 세포 외에는 감염성 바이러스가 없기 때문이다. 후기 세포용해성 감염이 있는 후 육안적 혹은 현미경적으로 검출이 가능한 림프종이 여러 장기에서 관찰된다. MDV가 감염되면 병변 발생부위에 따라서 다양한 임상증상이 발생한다. 즉 내부장기에 병변이 있을 경우는 침울, 체중감소, 산란율 저하 등이 발생하며, 신경계는 발생부위별 신경증상이 일어난다. 이러한 장기나 조직에서는 육안적으로 백색에서 회백색의 종양성 병변이 관찰된다. 말초신경에 병변이 발생한 경우에는 특히 좌골신경 및 신경총에서 호발하는데, 이들 조직은 편측성 혹은 양측성으로 종창되어 있다. 안구는 간혹 육안적으로 식별이 가능한 홍채 퇴색 및 증식 병변이 관찰된다. 피부형 MD는 특히 육용계에서 문제가 되고 있으며, 산란계의 내장형 MD가 발생한 경우에도 피부를 자세히 설펴보면 피부형 MD를 간혹 관찰할 수 있다. 피부형 MD는 모낭주위에 원형의 결절형태로 발생하는데, 이들 병변이 커지면 바로 옆의 병변과 융합 되어 큰 결절을 형성하기도 한다. (중략)

• Korean journal of applied entomology
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• v.56 no.4
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• pp.377-385
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• 2017

Estimates of evolutionary sequence divergence and inference of a phylogenetic tree for eight delphacid planthopper species were based on the full-length nucleotide sequence of the internal transcribed spacer 2 (ITS2) region. Size of the ITS2 DNA sequence varied from 550 bp in Sogatella furcifera to 699 bp in Nilaparvata muiri. Nucleotide sequence distance ($d{\pm}S.E.$) was lowest between N. muiri and N. bakeri ($0.001{\pm}0.001$), and highest between Ecdelphax cervina and Stenocranus matsumurai ($0.579{\pm}0.021$). Sequence distance between N. lugens and other planthoppers ranged from $0.056{\pm}0.008$ (N. muiri) to $0.548{\pm}0.021$ (S. matsumurai). In the neighbor-joining phylogenetic tree, all planthoppers were clustered separately into a species group, except N. muiri and N. bakeri. The ITS2 nucleotide sequence of N. lugens was used to design four loop-mediated isothermal amplification (LAMP) primer sets (BPH-38, BPH-38-1, BPH-207, and BPH-92) for N. lugens species-specific detection. After the LAMP reaction of three rice planthoppers, N. lugens, S. furcifera, and Laodelphax striatellus, with the four LAMP primer sets for 60 min at $65^{\circ}C$, LAMP products were observed in the genomic DNA of N. lugens only. In the BPH-92 LAMP primer set, the fluorescence relative to that of the negative control differed according to the amount of DNA (0.1 ng, 10 ng, and 100 ng) and incubation duration (20 min, 30 min, 40 min, and 60 min). At $65^{\circ}C$ incubation, the difference was clearly observed after 40 min with 10 ng and100 ng, but with a 60-min incubation period, the minimum DNA needed was 0.1 ng. However, there was little difference in fluorescence among all DNA amounts tested with 20 or 30 min incubations.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.112-121
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• 2016

Development of genetically-modified (GM) crops enables the introduction of new traits to the plant to confer characteristics such as disease resistance, herbicide resistance and human health-promoting bioactivity. Successful commercialization of newly developed GM crops requires stable inheritance of integrated T-DNA and newly introduced traits through the multiple generations. This study was carried out to confirm the stable inheritance of the integrated T-DNA in $T_1$ and $T_2$ transgenic Chinese cabbage (Brassica rapa ssp. pekinensis) that was genetically modified to increase concentrations of phenylethylisothiocyanate (PEITC), which is a potential anti-carcinogenic phytochemical. For this purpose, the IGA 1-3 ($T_1$ generation) and IGA 1-3-5 ($T_2$ generation) lines were selected by PCR and a IGA 1-3 transgenic plant ($T_1$ generation) was analyzed to confirm the T-DNA insertion site in the Chinese cabbage genome by VA-TAIL PCR. The results of this study showed that the introduced T-DNA in IGA 1 line was stably inherited to the next generations without any variations in terms of the structure of the transgenes, and this line also showed the expected transgene function that resulted in increased concentration of PEITC through the multiple generations. Finally, we confirmed the increased QR activity in IGA 1 $T_1$ and $T_2$ transgenic lines, which indicates an enhanced potential anti-carcinogenic bioactivity and its stable inheritance in IGA1 $T_1$ and $T_2$ transgenic lines.

• Journal of Life Science
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• v.7 no.4
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• pp.392-401
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• 1997

The poliovirus is a small, and non-enveloped virus. The RNA genome of poliovirus is continuous, linear, and has a single open reading frame. This polyprotein precursor is cleaved proteolytically to yield mature products. Most of the cleavages occur by viral protease. The mature proteins derived from the P1 polyprotein precursor are the structural components of the viral capsid. The initial cleavage by 2A protease is indirectly involved in the cleavage of a cellular protein p220, a subunit of the eukaryotic translation initiation factor 4F. This cleavage leads to the shut-off of cap-dependent host cell translation, and allows poliovirus to utilize the host cell machinery exclusively for translation its own RNA, which is initiated by internal ribosome entry via a cap-independent mechanism. The functional role of the 2B, 2C and 2BC proteins are not much known. 2B, 2C, 2BC and 3CD proteins are involved in the replication complex of virus induced vesicles. All newly synthesized viral RNAs are linked with VPg. VPg is a 22 amino acid polypeptide which is derived from 3AB. The 3C and 3CD are protease and process most of the cleavage sites of the polyprotein precursor. The 3C protein is also involved in inhibition of RNA polymerase II and III mediated transcription by converting host transcription factor to an inactive form. The 3D is the RNA dependent RNA polymerase. It is known that poliovirus replication follows the general pattern of positive strand RNA virus. Plus strand RNA is transcribed into complementary minus strand RNA that, in turn, is transcribed for the synthesis of plus strand RNA is transcribed into complementary minus strand RNA that, in turn, is transcribed for the synthesis of plus strand RNA strands. Poliovirus RNA synthesis occurs in a membranous environment but how the template RNA and proteins required for RNA replication assemble in the membrane is not much known. The RNA requirements for the encapsidation of the poliovirus genome (packaging signal) are totally unknown. The poliovirus infection cycle lasts approximately 6 hours.

• Journal of Life Science
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• v.32 no.12
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• pp.947-955
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• 2022

Silkworms, which have recently shown promise as functional health foods, show functional differences between varieties; therefore, the need for variety identification is emerging. In this study, we analyzed the whole silkworm genome to identify 10 unique silkworm varieties (Baekhwang, Baekok, Daebaek, Daebak, Daehwang, Goldensilk, Hansaeng, Joohwang, Kumkang, and Kumok) using single nucleotide polymorphisms (SNP) present in the genome as biomarkers. In addition, nine SNPs were selected to discriminate between varieties by selecting SNPs specific to each variety. We subsequently created a decision tree capable of cross-verifying each variety and classifying the varieties through sequential analysis. Restriction fragment length polymorphism (RFLP) was used for SNP867 and SNP9183 to differentiate between the varieties of Daehwang and Goldensilk and between Kumkang and Daebak, respectively. A tetra-primer amplification refractory (T-ARMS) mutation was used to analyze the remaining SNPs. As a result, we could isolate the same group or select an individual variety using the nine unique SNPs from SNP780 to SNP9183. Furthermore, nucleotide sequence analysis for the region confirmed that the alleles were identical. In conclusion, our results show that combining SNP analysis of the whole silkworm genome with the decision tree is of high value as a discriminative marker for classifying silkworm varieties.

• Journal of Life Science
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• v.33 no.11
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• pp.897-904
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• 2023

This study was done to develope genetic markers with the unique characteristics of genes according to the genomic information of Bacillus velezensis K10. B. velezensis K10 maintained a total of 4,159,835 bps, which was found to encode 5,136 open reading frames (orfs). B. velezensis K10 was found to have much more gene migration due to external factors overall compared to standard strain B. velezensis JS25R. In order to discover genetic selection markers, orfs on the genome to be easily induced to gene mutation were surveyed such as recombinase, integrase, transposase, and phage-related genes. As a result of the investigation, 9 candidate markers were isolated with high possibility as genetic selection markers. Although a part in the various origin's areas showed specificities in comparison with homology, the selected markers were all existed in phage-related areas because they were relatively lower homologies in phage-related genes. PCR analysis was done on B. licheniformis K12, B. velezensis K10, B. subtilis, and B. cereus to establish them as inter-species candidate selection markers. As a result, it was confirmed that B. velezensis K10-specific PCR products were formed in a total of 6 primer sets such as BV3 and BV5 to 9. On the other hand, analysis at the subspecies level observed the formation of B. velezensis K10-specific PCR products in 4 primer sets such as BV3, 5, 8, and 9. Among them, since BV5 and BV8 were detected by very specific results, we suggest that BV5 and 8 can be used as B. velezensis K10 gene selection markers at the species and sub-species level.

• Journal of Life Science
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• v.33 no.10
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• pp.808-819
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• 2023

This study was conducted to develop a selection marker for the identification of the Bacillus licheniformis K12 strain in microbial communities. The strain not only demonstrates good growth at moderate temperatures but also contains enzymes that catalyze the decomposition of various polymer materials, such as proteases, amylases, cellulases, lipases, and xylanases. To identify molecular markers appropriate for use in a microbial community, a search was conducted to identify variable gene regions that show considerable genetic mutations, such as recombinase, integration, and transposase sites, as well as phase-related genes. As a result, five areas were identified that have potential as selection markers. The candidate markers were two recombinase sites (BLK1 and BLK2), two integration sites (BLK3 and BLK4), and one phase-related site (BLK5). A PCR analysis performed with different Bacillus species (e.g., B. licheniformis, Bacillus velezensis, Bacillus subtilis, and Bacillus cereus) confirmed that PCR products appeared at specific locations in B. licheniformis: BLK1 in recombinase, BLK2 in recombinase family protein, and BLK3 and BLK4 as site-specific integrations. In addition, BLK1 and BLK3 were identified as good candidate markers via a PCR analysis performed on subspecies of standard B. licheniformis strains. Therefore, the findings suggest that BLK1 can be used as a selection marker for B. licheniformis species and subspecies in the microbiome.