• Plant Biotechnology Reports
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• v.5 no.4
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• pp.331-344
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• 2011

The well-conserved NBS domain of resistance (R) genes cloned from many plants allows the use of a PCR-based approach to isolate resistance gene analogs (RGAs). In this study, we isolated an RGA (CapRGC) from Capsicum annuum "CM334" using a PCR-based approach. This sequence encodes a protein with very high similarity to Rx genes, the Potato Virus X (PVX) R genes from potato. An evolutionary analysis of the CapRGC gene and its homologs retrieved by an extensive search of a Solanaceae database provided evidence that Rx-like genes (eight ESTs or genes that show very high similarity to Rx) appear to have diverged from R1 [an NBS-LRR R gene against late blight (Phytophthora infestans) from potato]-like genes. Structural comparison of the NBS domains of all the homologs in Solanaceae revealed that one novel motif, 14, is specific to the Rx-like genes, and also indicated that several other novel motifs are characteristic of the R1-like genes. Our results suggest that Rx-like genes are ancient but conserved. Furthermore, the novel conserved motifs can provide a basis for biochemical structural. function analysis and be used for degenerate primer design for the isolation of Rx-like sequences in other plant species. Comparative mapping study revealed that the position of CapRGC is syntenic to the locations of Rx and its homolog genes in the potato and tomato, but cosegregation analysis showed that CapRGC may not be the R gene against PVX in pepper. Our results confirm previous observations that the specificity of R genes is not conserved, while the structure and function of R genes are conserved. It appears that CapRGC may function as a resistance gene to another pathogen, such as the nematode to which the structure of CapRGC is most similar.

• Animal cells and systems
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• v.15 no.2
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• pp.161-168
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• 2011

Siberian chipmunks, Tamias sibiricus, are one of several popular companion animals found in the pet shops of South Korea. At present, however, there have been no studies done in South Korea examining their origin even though they could be potential carriers of zoonotic diseases, and are a species of concern for efficient conservation and management strategies. Sequences of the mitochondrial cytochrome b gene (1140 bp) were determined to investigate the origin of Siberian chipmunks sold in four South Korean pet shops through comparison with sequence data from animals of known locality. Nine Siberian chipmunks were collected from pet shops in South Korea, which resulted in nine haplotypes. One (AR) of these coincided with the haplotype previously described. Phylogenetic and network analyses using 53 haplotypes including 45 haplotypes from GenBank showed three phylogenetic groups in South Korea, almost concordant to locality, designated as northern, central, and southern parts as described in a previous study. Of the nine individuals examined from the pet shops, eight were clustered into the northern phylogroup but one (cgrb9153) was grouped with the southern phylogroup, implying that at least the Siberian chipmunks examined in this study did not originate from other countries. It is likely that most individuals sold in the pet shops of Seoul were caught in the wild in Gyeonggi-do and Gangwon-do, or are maternal descendants of captive-bred individuals originating from the northern part of South Korea. It is recommended that conservation and management units of Korean chipmunks should be examined in further detail.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.379-386
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• 2021

Asian gypsy moth, Lymantria dispar asiatica (Lepidoptera: Erebidae), which is an indigenous pest in Korea, a large outbreak has been reported in Gyeonggi-do, Chungcheong-do, and northern Gyeongsangbuk-do from 2019 in forest and nearby downtown areas, causing emotional damage to forests and city dwellers. During the indoor culture of gypsy moth eggs collected in Yecheon, Gyeongbuk in 2021 we found that 79.65% (321/403 of first instar larvae) were died due to Lymantria dispar multiple nucleopolyhedrovirus (LdMNPV) infection. Sequence analyses of 36 gypsy moths collected from 12 regions in Korea using LdMNPV late expression factor-8 (lef-8) and polyhedrin (polh) genes showed a genetic variation of 0.80% and 0.86%, respectively. Comparison to GenBank data showed that the Korean samples were most similar to LdMNPV in Japan, whereas most different to those of Turkey. These results showed a high infection rate of LdMNPV in Korea and LdMNPV is one of the important population regulators of the gypsy moth.

• Journal of Mushroom
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• v.19 no.3
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• pp.184-190
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• 2021

With the development of sawdust medium cultivation technology, Lentinula edodes (shiitake mushroom) has become the most extensively produced and consumed mushroom globally. In this study, the approximate composition, nutritional components, and bioactive compounds of L. edodes were analyzed and compared for the five sawdust-cultivated shiitake mushrooms cultivars namely Sanjo701ho, Sanjo707ho, Sanjo715ho, Chamaram, and L808. The approximate range of the composition of freeze-dried shiitake mushrooms was 4.06-5.92 g/100 g of ash, 0.75-1.02 g/100 g of crude fat, and 21.24-29.15 g/100 g of crude protein. Sanjo701ho had the highest trehalose content (9.60±0.08 g/100 g), total polyphenol content (3.49±0.04 mg GAE/g), and total flavonoid content (1.33±0.03 mg QE/g) among the other shiitake mushroom cultivars. The total amino acid content was as follows: glutamic acid>aspartic acid>leucine. Glycine, alanine, valine, isoleucine, leucine, and phenylalanine contents were significantly decreased in the following sequence: Sanjo707ho, Sanjo715ho, Sanjo701ho, Chamaram, and L808. Crude protein, trehalose, and six types of amino acids were identified as classification indicators for the five cultivars of sawdust-cultivated shiitake mushrooms.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.3
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• pp.27-33
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• 2021

CO I gene sequence analysis was applied to earthworms that had been used as test animals in toxicity test in Institute of Kyeongbook Agrochemicals and earthworms used as vermicomposting agents in the farm of Youngdong province to identify their species names. In terms of molecular species, the former was identified as Eisenia fetida and the latter was Eisenia andrei. Cocoons produced from Eisenia fetida was more than those from Eisenia andrei. And No. of adults developed from eggs of Eisenia fetida was more or less higher than those developed from eggs of Eisenia andrei. These results were contradictory to previous reports on two Eisenia spp.. When Eisenia fetida was crossed with Eisenia andrei, hybridized eggs were produced and adults were developed from those eggs, but cocoons and adults were much less than those from non-crossed Eisenia fetida or Eisenia andrei. This indicated that two Eisenia spp. were not distinctly different biological species because there was no complete 'reproductive isolation' between Eisenia fetida and Eisenia andrei. However, this also meant that Eisenia fetida and Eisenia andrei had already been on the tract of speciation.

• Journal of Life Science
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• v.30 no.12
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• pp.1063-1069
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• 2020

Two crucian carp species (Carassius auratus and C. cuvieri) inhabit Lake Yedang in South Korea, and C. auratus is known to be native to Korea. Classification of these two freshwater fish species is often confused because of their morphological similarity. To distinguish the two species, we conducted phylogenetic and population genetic analyses of C. auratus and C. cuvieri based on their mitochondrial DNA sequences of the cytochrome b gene (CYTB). We also compared our partial CYTB sequence (<1,056 bp) with 10 Chinese, nine Japanese, and two Russian crucian carp fishes. The results of our phylogenetic analysis showed that C. auratus and C. cuvieri were clearly divided into two phylogroups. The nucleotide diversity (π) of C. auratus from Korea, China, and Japan showed a range of 0.146%~0.421%, while the range of π of C. cuvieri from Korea and Japan was lower than those of C. auratus (0.0%~0.054%). Moreover, the comparison of CYTB divergence among crucian carp fishes in China, Japan, and Korea indicated that Korean Carassius fishes were distantly related to those from China and Japan, with two exceptions: the pairwise Fst value between Korean C. auratus and northern Chinese C. auratus was not significantly different. In addition, no significant genetic divergence between Korean and Japanese C. cuvieri was detected. We conclude that, despite the morphological similarities, C. auratus and C. cuvieri should be considered as separate freshwater fish resources in conservation efforts for genetic diversity.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.2
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• pp.37-47
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• 2011

In the recent years, malicious codes called malware are having shown significant increase due to the code obfuscation to evade detection mechanisms. When the code obfuscation technique is applied to malwares, they can change their instruction sequence and also even their signature. These malwares which have same functionality and different appearance are able to evade signature-based AV products. Thus, AV venders paid large amount of cost to analyze and classify malware for generating the new signature. In this paper, we propose a novel approach for detecting metamorphic malwares. The proposed mechanism first converts malware's API call sequences to call graph through dynamic analysis. After that, the callgraph is converted to semantic signature using 128 abstract nodes. Finally, we extract all subgraphs and analyze how similar two malware's behaviors are through subgraph similarity. To validate proposed mechanism, we use 273 real-world malwares include obfuscated malware and analyze 10,100 comparison results. In the evaluation, all metamorphic malwares are classified correctly, and similar module behaviors among different malwares are also discovered.

• Research in Plant Disease
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• v.27 no.1
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• pp.32-37
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• 2021

In May 2020, necrosis and necrotic ring patterns were observed on leaves of three of 140 Iris domestica plants in a demonstration garden in Wanju, Jeollabuk-do. Three symptomatic plants were found to be infected by tomato spotted wilt virus (TSWV). To analyze the whole genomic sequence of one TSWV isolate, 'Blackberry lily-kr1', L, M, and S genome segments were sequenced and analyzed by comparison of nucleotide sequences of the three segments with corresponding sequences of other TSWV isolates. 'Blackberry lily-kr1' isolate was most closely related to 'JJ' isolate (MF159046) or 'HJ' isolate (LC273305) in the L segment, and to 'JJ' isolate (MF159058 and KY021439) in the M and S segments, respectively. Phylogenetic analysis by Maximum likelihood method using MEGA X program with 'Blackberry lily-kr1' isolate showed high relationship with 'JJ' pepper isolate or 'HJ' Humulus japonicas isolate in the all three segment. Necrosis and double ring patterns on leaves were formed in the glasshouse after inoculation of healthy I. domestica plants with sap of 'Blackberry lily-kr1'-infected Nicotiana rustica plants. This result suggests that I. domestica plants showing necrotic ring patterns in the open field are caused by TSWV infection. This is the first report of TSWV infection of I. domestica in Korea.

• Journal of Korea Water Resources Association
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• v.55 no.5
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• pp.383-392
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• 2022

The restoration of the Nakdong River estuary is one of the most important projects of the Ministry of Environment, Republic of Korea. A real-scale experiment of gate operation was executed from 2019 to 2020, and a pilot operation was performed in 2021. The gate of Nakdong River Estuary Barrier (NEB) is supposed to be continuously opened based on the experiment results. Many critical decisions should be made immediately during the experiment based on the real-time measured data and numerical analysis considering the seawater inflows. The decision-making sequence was made systematically with the accurate estimation of seawater inflow. The estimation of seawater inflow is the main research objective and the equations of seawater inflow were developed, reflecting the structural characteristics of NEB. The inflow equations were developed in two forms, overflow and underflow. ADCP (Acoustic Doppler Current Profiler) was used to measure seawater inflow, check the accuracy of the developed equations, and derive the flow coefficient. The comparison error of the developed equations was about 3% compared to the measured data.

• Journal of Korean Elementary Science Education
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• v.41 no.2
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• pp.307-324
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• 2022

This study examined the content diversity of seven authorized science textbooks by comparing the characteristics of the science concept description and the contents of inquiry activities in the "weight of objects" unit. For each textbook, the flow of concept description content and the uniqueness of the concept description process were analyzed, and the number of nodes and links and words with high connections were determined using language network analysis. In addition, for the inquiry activities described in each textbook, the inquiry subject, inquiry type, science process skill, and uniqueness were investigated. Results showed that the authorized textbooks displayed no more diversity than expected in their scientific concept description method or their inquiry activity composition. The learning elements, inclusion of subconcepts, and central words were similar for each textbook. The comparison of inquiry activities showed similarities in their contents, inquiry types, and scientific process skills. Specifically, these textbooks did not introduce any research topics or experimental methods that were absent in previous textbooks. However, despite the fact that the authorized textbook system was developed based on the same curriculum, some efforts were made to make use of its strengths. Since the sequence of subconcepts to explain the core contents differed across textbooks, this explanation process was divided into several types, and although the contents of inquiry activities were the same, the materials for inquiry activities were shown differently for each textbook to improve and overcome the difficulties in the existing experiments. These findings necessitate the continuation of efforts to utilize the strengths of certified textbooks.