• The Korean Journal of Mycology
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• v.35 no.2
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• pp.121-127
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• 2007

308 isolates of Ampelomyces sp. were isolated from powdery mildew fungi of 73 plant species in Korea for selection of biocontrol agents. An isolate 94013 isolated from powdery mildew fungus of red bean was selected as an effective biological control agent against cucumber powdery mildew in greenhouse. The morphological characteristics of the isolate is as follows. Pycnidia were sub-globose or elongated to pyriform, pale to dart brown, $52.5{\sim}82.5\;{\times}\;35.0{\sim}47.5\;(ave.\;62.5{\times}40.5){\mu}m$, and conidia were guttulate, straight cylindrical to fusiform, pale brown, $5.0{\sim}8.0\;{\times}\;2.5{\sim}4.3\;(ave.\;6.0{\times}3.0){\mu}m$. The isolate 94013 was identified as Ampelomyces quisqualis by morphological characteristics and rDNA ITS sequencing. The isolate A. quisqualis 94013 was different from that of the commercial product $AQ10^R$ in the rDNA ITS sequence.

• Parasites, Hosts and Diseases
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• v.55 no.1
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• pp.39-45
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• 2017

The present study was performed to reveal the morphological characteristics and molecular phylogenetic position of Platynosomum fastosum Kossack, 1910. A total 167 specimens of P. fastosum were collected in 8 (4.9%) out of 163 sets of gall-bladders and bile ducts of cats. The number of worms was 1-105 per infected cat. This species was characterized by having a long and slender body, slightly larger ventral sucker than the oral sucker, indistinct prepharynx, small pharynx, short esophagus, bifurcation midway between 2 suckers, and ceca extending to the posterior end of the body. The length of the partial sequences of ITS1 and 5.8S rDNA of P. fastosum were 990 bp, GC-rich. AT/GC ratio was 0.9, there were 9 polymorphic sites, and intraspecific variations ranged from 0.1% to 0.9%. Phylogenetic analyses by neighbor-joining phylogram inferred from ITS1 rDNA sequences revealed that the genetic distance between P. fastosum specimens ranged from 0.3 to 1.5% while the smallest interspecific distance among dicrocoeliid species was 20.9 %. The redescription and genetic characters of P. fastosum are taxonomically important to recognize future different species of the genus Platynosomum showing high intraspecific and morphological variability.

• Mycobiology
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• v.42 no.2
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• pp.174-180
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• 2014

We analyzed the genetic diversity of Cylindrocarpon destructans isolates obtained from Korean ginseng (i.e., Panax ginseng) roots by performing virulence tests and nuclear ribosomal gene internal transcribed spacer (ITS) and mitochondrial small subunit (mt SSU) rDNA sequence analysis. The phylogenetic relationship analysis performed using ITS DNA sequences and isolates from other hosts helped confirm that all the Korean C. destructans isolates belonged to Nectria/Neonectria radicicola complex. The results of in vivo and ex vivo virulence tests showed that the C. destructans isolates could be divided into two groups according to their distinctive difference in virulence and the genetic diversity. The highly virulent Korean isolates in pathogenicity group II (PG II), together with foreign isolates from P. ginseng and P. quinquefolius, formed a single group. The weakly virulent isolates in pathogenicity group I, together with the foreign isolates from other host plants, formed another group and exhibited a greater genetic diversity than the isolates of PG II, as confirmed by the mt SSU rDNA sequence analysis. In addition, as the weakly virulent Korean isolates were genetically very similar to the foreign isolates from other hosts, they were likely to originate from hosts other than the ginseng plants.

• Korean Journal of Agricultural Science
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• v.37 no.3
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• pp.341-350
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• 2010

Blue mold is the most important postharvest disease of apples in Korea. Apple fruits with blue mold symptoms were collected from storages in different locations in Korea and were investigated for their association with Penicillium species. A total of sixty five isolates of Penicillium were sampled from the collected apples. Based on DNA sequence analysis of ${\beta}$-tublin gene and ITS and lsu rDNA (ID region) and morphological characteristics, they were identified as P. crustosum, P. expansum, P. italicum, P. solitum and P. sp.. P. sp. which is closely related to P. hirsutum is a new species, not reported before. P. expansum (35%) was predominant species followed by P. crustosum. The phylogenetic tree inferred from combined ${\beta}$-tublin and ID region sequence showed good correlation with species that are defined by morphological characteristics. In pathogenicity test, apples were wound-inoculated with conidial suspension and incubated at $20-22^{\circ}C$. The most severe and destructive species was P. expansum. The species caused a decayed area 42-50mm in diameter after 8-10days. Decayed area caused by P. crustosum and P. sp. was 26-32mm and 20-26mm, respectively. This is the first record of P. crustosum, P. italicum and P. sp. from apple in Korea.

• Genomics & Informatics
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• v.1 no.1
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• pp.50-54
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• 2003

Genome of an extreme thermophile, Thermus caldophilus GK24 has been analyzed to construct the genomic map. The genomic DNAs encapsulated in agarose gel were digested with SspI, EcoRI, SpeI, and HpaI restriction endonucleases, and then the resulting genomic DNA fragments were analyzed by pulsed-field gel electrophoresis. Its restriction map has been constructed by analyzing sizes of the restriction fragments obtained from both complete and partial digestions. The circular form of its genome was composed of about 1.98 Mbp and a megaplasmid. The genomic loci for the genes of xylose isomerase, thioredoxin, tRNA-16S rRNA, 23S rRNA, L5 ribosomal protein, ADP-glucose pyrophosphorylase, DNA-ligase, and Tca DNA polymerase were determined by both Southern hybridization and PCR.

• Parasites, Hosts and Diseases
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• v.52 no.3
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• pp.263-271
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• 2014

PCR detection of intestinal protozoa is often restrained by a poor DNA recovery or by inhibitors present in feces. The need for an extraction protocol that can overcome these obstacles is therefore clear. $QIAamp^{(R)}$ DNA Stool Mini Kit (Qiagen) was evaluated for its ability to recover DNA from oocysts/cysts directly from feces. Twenty-five Giardia-positive, 15 Cryptosporidium-positive, 15 Entamoeba histolytica-positive, and 45 protozoa-free samples were processed as control by microscopy and immunoassay tests. DNA extracts were amplified using 3 sets of published primers. Following the manufacturer's protocol, the kit showed sensitivity and specificity of 100% towards Giardia and Entamoeba. However, for Cryptosporidium, the sensitivity and specificity were 60% (9/15) and 100%, respectively. A series of optimization experiments involving various steps of the kit's protocol were conducted using Cryptosporidium-positive samples. The best DNA recoveries were gained by raising the lysis temperature to the boiling point for 10 min and the incubation time of the InhibitEX tablet to 5 min. Also, using a pre-cooled ethanol for nucleic acid precipitation and small elution volume ($50-100{\mu}l$) were valuable. The sensitivity of the amended protocol to Cryptosporidium was raised to 100%. Cryptosporidium DNA was successfully amplified by either the first or the second primer set. When applied on parasite-free feces spiked with variable oocysts/cysts counts, ${\approx}2$ oocysts/cysts were theoretically enough for detection by PCR. To conclude, the Qiagen kit with the amended protocol was proved to be suitable for protozoan DNA extraction directly from feces and support PCR diagnosis.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.15-20
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• 2010

A Gram negative, aerobic, nonspore-forming, straight or curved rod-shaped bacterium, designated Gsoil $317^T$, was isolated from soil of a ginseng field in Pocheon Province (South Korea) and was characterized using a polyphasic approach. Cells were dimorphic, with stalk (or prostheca) and nonmotile or nonstalked and motile, by means of a single polar flagellum. Comparative analysis of 16S rRNA gene sequences revealed that strain Gsoil $317^T$ was most closely related to Caulobacter mirabilis LMG $24261^T$ (97.2%), Caulobacter fusiformis ATCC $15257^T$ (97.1 %), Caulobacter segnis LMG $17158^T$ (97.0%), Caulobacter vibrioides DSM $9893^T$ (96.8%), and Caulobacter henricii ATCC $15253^T$ (96.7%). The sequence similarities to any other recognized species within Alphaproteobacteria were less than 96.0%. The detection of Q-10 as the major respiratory quinone and a fatty acid profile with summed feature 7 ($C_{18:1}\;{\omega}7c$ and/or $C_{18:1}\;{\omega}9t$ and/or $C_{18:1}\;{\omega}12t;$ 56.6%) and $C_{16:0}$ (15.9%) as the major fatty acids supported the affiliation of strain Gsoil $317^T$ to the genus Caulobacter. The G+C content of the genomic DNA was 65.5 mol%. DNA-DNA hybridization experiments showed that the DNA-DNA relatedness values between strain Gsoil $317^T$ and its closest phylogenetic neighbors were below 11%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil $317^T$ should be classified as representing a novel species in the genus Caulobacter, for which the name Caulobacter ginsengisoli sp. novo is proposed. The type strain is Gsoil $317^T$ (=KCTC $12788^T=DSM\;18695^T$).

• Molecules and Cells
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• v.39 no.7
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• pp.543-549
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• 2016

MicroRNAs (miRNAs) have been reported to be involved in many neurodegenerative diseases. The present study focused on the role of hsa-miR-144-3p in one of the neuro-degenerative diseases, Parkinson's disease (PD). Our study showed a remarkable down-regulation of miR-144-3p expression in 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-treated SH-SY5Y cells. MiR-144-3p was then overexpressed and silenced in human SH-SY5Y cells by miRNA-mimics and miRNA-inhibitor transfections, respectively. Furthermore, ${\beta}$-amyloid precursor protein (APP) was identified as a target gene of miR-144-3p via a luciferase reporter assay. We found that miR-144-3p overexpression significantly inhibited the protein expression of APP. Since mitochondrial dysfunction has been shown to be one of the major pathological events in PD, we also focused on the role of miR-144-3p and APP in regulating mitochondrial functions. Our study demonstrated that up-regulation of miR-144-3p increased expression of the key genes involved in maintaining mitochondrial function, including peroxisome proliferator-activated receptor ${\gamma}$ coactivator-$1{\alpha}$(PGC-$1{\alpha}$), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM). Moreover, there was also a significant increase in cellular ATP, cell viability and the relative copy number of mtDNA in the presence of miR-144-3p overexpression. In contrast, miR-144-3p silencing showed opposite effects. We also found that APP overexpression significantly decreased ATP level, cell viability, the relative copy number of mtDNA and the expression of these three genes, which reversed the effects of miR-144-3p overexpression. Taken together, these results show that miR-144-3p plays an important role in maintaining mitochondrial function, and its target gene APP is also involved in this process.

• Mycobiology
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• v.41 no.4
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• pp.191-201
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• 2013

Distinguishing individual Russula species has been difficult due to extensive phenotypic plasticity and obscure morphological and anatomical discontinuities. Due to highly similar macroscopic features, such as the presence of a red-cap, species identification within the Russula subgenus Amoenula is particularly difficult. Three species of the subgenus Amoneula have been reported in Korea. We used a combination of morphology and three molecular markers, the internal transcribed spacer (ITS), 28S nuclear ribosomal large subunit (LSU), and RNA polymerase II gene (RPB2), for identification and study of the genetic diversity of Russula subgenus Amoenula in Korea. We identified only two species in Korea (R. mariae and R. violeipes); these two species were indistinguishable according to morphology and LSU, but were found to be reciprocally monophyletic species using ITS and RPB2. The markers, ITS, LSU, and RPB2, have been tested in the past for use as DNA barcoding markers, and findings of our study suggest that ITS and RPB2 had the best performance for the Russula subgenus Amoneula.

• Journal of Life Science
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• v.12 no.1
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• pp.67-76
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• 2002

The effect of transgene inactivation in T2, T3 and F2 generations was analyzed in progeny seedlings which had been generated by Agrobacterium (LBA4404/pBI121)-mediated transformation in Arabidopsis thaliana. In a system which investigated in the expression of $\beta$-glucuronidase(GUS)gene in kanamycin-resistant (ke $n^{R}$)seedlings, GUS inactivated seedlings were observed in 5 of 12 tested lines of T2 generation and the frequency of GUS inactivation was approximately 2.3%. Lines with multi-copies of T-DNA exhibited severe GUS gene inactivation with the frequency of 5.8% in T2 generation. In T3 generation lines exhibited GUS gene inactivation with the frequency of 1.3%. In contrast, inactivation increased dramatically up to 12.6% in multi-copy T-DNA line. A similar phenomenon was also found in F2 progeny from a transgenic line which had been crossed with wild-type Arabidopsis plant, WS-O (GUS gene inactivation frequency 9.9%). These results indicate that the foreign gene introduced into the plant was inactivated progressively in its transmission during subsequent generations and the transgenic line with multi-copies of T-DNA tended to show more increased inactivation.