• Journal of the Korean Applied Science and Technology
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• v.31 no.3
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• pp.472-477
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• 2014

A voltammetric investigation of Au assay was conducted at a low cost, using Nafion and DNA immobilized on a graphite Pencil working electrode (NDP) with a black lead counter and reference. The following optimal parameters were found: 0.4 V amplitude, 500 Hz frequency, -0.7 V initial potential, and 0.015 V increment potential. These optimal conditions were also applied to sand obtained from the river site. The aforementioned technique is simpler and less costly compared to the common voltammetry and spectrophotometric methods.

• Korean Journal of Plant Taxonomy
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• v.48 no.1
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• pp.1-8
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• 2018

Mankyua chejuense is the only member of the monotypic genus Mankyua (Ophioglossaceae) and is endemic to Jejudo Island, Korea. To determine the precise phylogenetic position of M. chejuense, two cpDNA regions of 42 accessions representing major members of lycophytes are obtained from GenBank and analyzed using three phylogenetic analyses (maximum parsimony, maximum likelihood, and Bayesian inference). In addition, the divergence time is estimated based on a relaxed molecular clock using four fossil calibration points. The phylogenetic position of Mankyua still appears to be uncertain, representing either the earliest diverged lineage within Ophioglossaceae or a sister to the clade containing Ophioglossum and Helminthostachys. The most recent common ancestor of Ophioglossaceae and its sister lineage, Psilotum, was estimated to be 256 Ma, while the earliest divergence of Mankyua was estimated to be 195 Ma in the early Jurassic.

• Animal Bioscience
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• v.35 no.6
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• pp.826-837
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• 2022

Objective: Cambodia is located within the distribution range of the red junglefowl, the common ancestor of domestic chickens. Although a variety of indigenous chickens have been reared in Cambodia since ancient times, their genetic characteristics have yet to be sufficiently defined. Here, we conducted a large-scale population genetic study to investigate the genetic diversity and population genetic structure of Cambodian indigenous chickens and their phylogenetic relationships with other chicken breeds and native chickens worldwide. Methods: A Bayesian phylogenetic tree was constructed based on 625 mitochondrial DNA D-loop sequences, and Bayesian clustering analysis was performed for 666 individuals with 23 microsatellite markers, using samples collected from 28 indigenous chicken populations in 24 provinces and three commercial chicken breeds. Results: A total of 92 haplotypes of mitochondrial D-loop sequences belonging to haplogroups A to F and J were detected in Cambodian chickens; in the indigenous chickens, haplogroup D (44.4%) was the most common, and haplogroups A (21.0%) and B (13.2%) were also dominant. However, haplogroup J, which is rare in domestic chickens but abundant in Thai red junglefowl, was found at a high frequency (14.5%), whereas the frequency of haplogroup E was considerably lower (4.6%). Population genetic structure analysis based on microsatellite markers revealed the presence of three major genetic clusters in Cambodian indigenous chickens. Their genetic diversity was relatively high, which was similar to findings reported for indigenous chickens from other Southeast Asian countries. Conclusion: Cambodian indigenous chickens are characterized by mitochondrial D-loop haplotypes that are common to indigenous chickens throughout Southeast Asia, and may retain many of the haplotypes that originated from wild ancestral populations. These chickens exhibit high population genetic diversity, and the geographical distribution of three major clusters may be attributed to inter-regional trade and poultry transportation routes within Cambodia or international movement between Cambodia and other countries.

• Animal Systematics, Evolution and Diversity
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• v.28 no.1
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• pp.48-53
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• 2012

The tiger population that once inhabited the Korean peninsula was initially considered a unique subspecies (Panthera tigris coreensis), distinct from the Amur tiger of the Russian Far East (P. t. altaica). However, in the following decades, the population of P. t. coreensis was classified as P. t. altaica and hence forth the two populations have been considered the same subspecies. From an ecological point of view, the classification of the Korean tiger population as P. t. altaica is a plausible conclusion. Historically, there were no major dispersal barriers between the Korean peninsula and the habitat of Amur tigers in Far Eastern Russia and northeastern China that might prevent gene flow, especially for a large carnivore with long-distance dispersal abilities. However, there has yet to be a genetic study to confirm the subspecific status of the Korean tiger. Bone samples from four tigers originally caught in the Korean peninsula were collected from two museums in Japan and the United States. Eight mitochondrial gene fragments were sequenced and compared to previously published tiger subspecies' mtDNA sequences to assess the phylogenetic relationship of the Korean tiger. Three individuals shared an identical haplotype with the Amur tigers. One specimen grouped with Malayan tigers, perhaps due to misidentification or mislabeling of the sample. Our results support the conclusion that the Korean tiger should be classified as P. t. altaica, which has important implications for the conservation and reintroduction of Korean tigers.

• BMB Reports
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• v.39 no.5
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• pp.502-510
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• 2006

2C-methyl-D-erythritol 2, 4-cyclodiphosphate synthase (MECPS, EC: 4.6.1.12) is the fifth enzyme of the non-mevalonate terpenoid pathway for isopentenyl diphosphate biosynthesis and is involved in the methylerythritol phosphate (MEP) pathway for ginkgolide biosynthesis. The full-length mecps cDNA sequence (designated as Gbmecps) was cloned and characterized for the first time from gymnosperm plant species, Ginkgo biloba, using RACE (rapid amplification of cDNA ends) technique. The full-length cDNA of Gbmecps was 874 bp containing a 720 bp open reading frame (ORF) encoding a peptide of 239 amino acids with a calculated molecular mass of 26.03 kDa and an isoelectric point of 8.83. Comparative and bioinformatic analyses revealed that GbMECPS showed extensive homology with MECPSs from other species and contained conserved residues owned by the MECPS protein family. Phylogenetic analysis indicated that GbMECPS was more ancient than other plant MECPSs. Tissue expression pattern analysis indicated that GbMECPS expressed the highest in roots, followed by in leaves, and the lowest in seeds. The color complementation assay indicated that GbMECPS could accelerate the accumulation of $\beta$-carotene. The cloning, characterization and functional analysis of GbMECPS will be helpful to understand more about the role of MECPS involved in the ginkgolides biosynthesis at the molecular level.

• Journal of Photoscience
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• v.9 no.2
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• pp.269-271
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• 2002

To investigate the visual and extra-ocular photoreception, we cloned the opsin genes in ayu (Plecoglossus allivelis). Amplified fragments encoding exon-4 (-5) of opsin cDNAs were cloned from the retina and brains of ayu, and sequenced. One clone was identified as rod (AYU-Rh), two as green cone (AYU-GI, -G2), one as red cone (A YU-R), two as ultraviolet cone (AYU-UVl, UV2), one as VA (AYU-VA), and one as extra-ocular rod (AYU-ExoRh) opsins. 335 amino acids sequence deduced from the full-length cDNA of AYU-Rh showed high identity with that of other fish. Southern blotting analysis indicated that ayu possess two 'rhodopsin' genes, one is visual rhodopsin and the other is non-visual extra-ocular rhodopsin. In situ hybridization showed that the mRNA of AYU-Rh was localized only in rod cells in the retina. On the other hands, AYU-ExoRh was expressed only in the pineal. We cloned two isoforms (AYU-VAM and -VAL) of VA opsin from ayu. The deduced amino acid sequences of these variants were identical to each other within the first 342 residues, but they showed divergence in the C-terminal sequence. AYU- VAL corresponded to the long isoform found in other fish, and AYU-VAM was identified as a new type of VA opsin variant. Pal-VAM is a new probably functional non-visual photoreceptive molecule in fish.

• Journal of Pharmacopuncture
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• v.22 no.2
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• pp.55-67
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• 2019

The incidences of cancer are continuously increasing worldwide, affecting life of millions of people. Several factors associated with the internal and external environment are responsible for this deadly disease. The key internal determinants like abnormal hormonal regulation, genetic mutations and external determinants such as lifestyle and occupational factors enhances onset of cancer. From the ancient time, plants were remained as the most trusted source of medicine for the treatment of diverse disease conditions. Extensive studies have been performed for the discovery of effective anticancer agent from the plant and still it is going on. Pentacyclic triterpenoids are biologically active phytochemicals having a different range of activities such as anti-inflammatory, hepatoprotective, anti-hypertensive, antiulcerogenic and anti-tumor. These compounds generally contain ursane, oleanane, lupane and friedelane as a chief skeleton of pentacyclic triterpenoids which are generally present in higher plants. Isoprene unit, phytochemical, with good antitumor/anticancer activity is required for the biosynthesis of pentacyclic triterpenoids. Mechanisms such as cytotoxicity, DNA polymerase inhibition, regulation of apoptosis, change in signal transductions, interfere with angiogenesis and dedifferentiation, antiproliferative activity and metastasis inhibition are might be responsible for their anticancer effect. Present review spotlights diverse targets, mechanisms and pathways of pentacyclic triterpenoids responsible for anticancer effect.

• International Journal of Industrial Entomology and Biomaterials
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• v.23 no.1
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• pp.155-166
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• 2011

The leaf beetle, $Chrysolina$ $aurichalcea$ (Coleoptera: Chysomelidae), is a pest damaging plants of Compositae. In order to understand the genetic diversity and geographic variation we sequenced a portion of mitochondrial COI gene (658 bp) and complete nuclear internal transcribed spacer 2 (ITS2) of the species collected from seven Korean localities. A total of 17 haplotypes (CACOI01~CACOI17), with the maximum sequence divergence of 3.04% (20 bp) were obtained from COI gene sequence, whereas 16 sequence types (ITS2CA01~ITS2CA16), with the maximum sequence divergence of 2.013% (9 bp) were obtained from ITS2, indicating substantially larger sequence divergence in COI gene sequence. Phylogenetically, the COI gene provided two haplotype groups with a high nodal support (${\geq}87%$), whereas ITS2 provided only one sequence type group with a high nodal support (${\geq}92%$). The result of COI gene sequence may suggest the presence of historical biogeographic barriers that bolstered genetic subdivision in the species. Different grouping pattern between COI gene and ITS2 sequences were interpreted in terms of recent dispersal, reflected in the ITS2 sequence. Finding of unique haplotypes and sequence types only from Beakryeng-Islet population was interpreted as an intact remnant of ancient polymorphism. As more samples are analyzed using further hyper-variable marker, further fruitful inference on the geographic contour of the species might be available.

• CELLMED
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• v.5 no.3
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• pp.15.1-15.12
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• 2015

Comparative studies have established that the North-Eastern (NE) region of India which is a part of the Eastern Himalayan region is affluent in both traditional knowledge based phytomedicine and biodiversity. About 1953 ethno-medicinal plants are detailed from the NE region of India out of which 1400 species are employed both as food and ethnopharmacological resources. Nearly 70% of species diversity has been reported from the two Indian biodiversity hotspots-The Western Ghats and the Eastern Himalayas and these hotspots are protected by tribal communities and their ancient traditional knowledge system. Paris polyphylla Smith belongs to the family Melanthiaceae and is a traditional medicinal herb which is known to cure some major ailments such as different types of Cancer, Alzheimer's disease, abnormal uterine bleeding, leishmaniasis etc. The major phytoconstituents are dioscin, polyphyllin D, and balanitin 7. Phylogeny of Paris was inferred from nuclear ITS and plastid psbA-trnH and trnL-trnF DNA sequence data. Results indicated that Paris is monophyletic in all analyses. Rhizoma Paridis, which is the dried rhizome of Paris polyphylla is mainly used in Traditional Chinese Medicine and its mode of action is known for only a few cancer cell lines. The current review determines to sketch an extensive picture of the potency, diversity, distribution and efficacy of Paris polyphylla from the Eastern Himalayan region and the future validation of its phytotherapeutical and molecular attributes by recognizing the Intellectual Property Rights of the Traditional Knowledge holders.

• Journal of Microbiology
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• v.43 no.2
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• pp.172-178
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• 2005

To determine the prevalence and genotypes of $\beta$-lactamases among clones of a metagenomic library from the cold-seep sediments of Edison seamount (10,000 years old), we performed pulse-field gel electrophoresis, antibiotic susceptibility testing, pI determination, and DNA sequencing analysis. Among the 8,823 clones of the library, thirty clones produced $\beta$-lactamases and had high levels of genetic diversity. Consistent with minimum inhibitory concentration patterns, we found that five ($167\%$) of thirty clones produced an extended-spectrum $\beta$-lactamase. 837- and 259-bp fragments specific to bla$_{TEM}$ genes were amplified, as determined by banding patterns of PCR amplification with designed primers. TEM­1 was the most prevalent $\beta$-lactamase and conferred resistance to ampicillin, piperacillin, and cephalothin. TEM-116 had a spectrum that was extended to ceftazidime, cefotaxime, and aztreonam. The resistance levels conferred by the pre-antibiotic era alleles of TEM-type $\beta$-lactamases were essentially the same as the resistance levels conferred by the TEM-type alleles which had been isolated from clinically resistant strains of bacteria of the antibiotic era. Our first report on TEM-type $\beta$-lactamases of the pre-antibiotic era indicates that TEM-type $\beta$-lactamases paint a picture in which most of the diversity of the enzymes may not be the result of recent evolution, but that of ancient evolution.